Now showing items 1-20 of 21

Assessing Peptide Binding to MHC II: An Accurate Semiempirical Quantum Mechanics Based Proposal

Ortiz Mahecha, Carlos A.; Bohórquez, Hugo Javier; Agudelo, William A.; Patarroyo, Manuel A.; Patarroyo, Manuel Elkin; Suárez, Carlos F. (2019)

Estimating peptide-major histocompatibility complex (pMHC) binding using structural computational methods has an impact on understanding overall immune function triggering adaptive immune responses in MHC class II molecules. ...
Comparative genomics identifies potential virulence factors in Clostridium tertium and C. paraputrificum

Muñoz, Marina; Restrepo Montoya, Daniel; Kumar, Nitin; Iraola, Gregorio; Herrera, Giovanny; Ríos Chaparro, Dora I.; Díaz Arévalo, Diana; Patarroyo, Manuel A.; Lawley, Trevor D.; Ramírez, Juan David (2019)

Some well-known Clostridiales species such as Clostridium difficile and C. perfringens are agents of high impact diseases worldwide. Nevertheless, other foreseen Clostridiales species have recently emerged such as Clostridium ...
Critical role of HLA-DRb* binding peptides' peripheralflankingresidues in fully-protective malaria vaccine development

Reyes, César; Rojas-Luna, Rocío; Aza-Conde, Jorge; Tabares, Luisa; Patarroyo, Manuel A.; Patarroyo, Manuel Elkin (2017)

A vaccine candidate component must fit perfectly into the antigen presenting HLA-DRβ* molecule's groove (or canonical nonapeptide) peptide binding region (PBR) during antigen presentation to the T-cell receptor (TCR), ...
Critical role of HLA-DRβ* binding peptides' peripheral flanking residues in fully-protective malaria vaccine development

Reyes, Cesar; Rojas Luna, Rocío; Aza Conde, Jorge; Tabares, Luisa; Patarroyo, Manuel A.; Patarroyo, Manuel Elkin (2017)

A vaccine candidate component must fit perfectly into the antigen presenting HLA-DRβ* molecule's groove (or canonical nonapeptide) peptide binding region (PBR) during antigen presentation to the T-cell receptor (TCR), ...
From a basic to a functional approach for developing a blood stage vaccine against Plasmodium vivax

Patarroyo, Manuel A.; Arevalo Pinzon, Gabriela; Moreno Pérez, Darwin Andrés (2020)

Introduction: Numerous challenges have hampered developing an anti-malarial vaccine against the most widespread malarial parasite worldwide: Plasmodium vivax. Despite the progress achieved in studying proteins in short-term ...
Identifying the HLA DRB1-DQB1 molecules and predicting epitopes associated with high-risk HPV infection clearance and redetection

Del Río Ospina, Luisa; Camargo, Milena; Soto De León, Sara Cecilia; Sánchez, Ricardo; Moreno Pérez, Darwin Andrés; Patarroyo, Manuel Elkin; Patarroyo, Manuel A. (2020)

Several determining factors are involved in HPV infection outcomes; human leukocyte antigen (HLA) polymorphisms have been described as related factors. This study has ascertained the effect of genetic variation on HLA-DRB1 ...
Inferring Plasmodium vivax protein biology by using omics data

Moreno Pérez, Darwin Andrés; Patarroyo, Manuel A. (2020)

Deciphering Plasmodium vivax biology has long been a challenge for groups working on this parasite, mainly due to the complications involved in propagating it in vitro. However, adapting P. vivax strains in non-human ...
Integrated genomic epidemiology and phenotypic profiling of Clostridium difficile across intra-hospital and community populations in Colombia

Muñoz, Marina; Restrepo Montoya, Daniel; Kumar, Nitin; Iraola, Gregorio; Camargo, Milena; Díaz Arévalo, Diana; Roa Molina, Nelly S.; Tellez, Mayra A.; Herrera, Giovanny; Ríos Chaparro, Dora I.; Birchenall, Claudia; Pinilla, Dario; Pardo Oviedo, Juan M.; Rodríguez Leguizamón, Giovanni; Josa, Diego F.; Lawley, Trevor D.; Patarroyo, Manuel A.; Ramírez, Juan David (2019)

Clostridium difficile, the causal agent of antibiotic-associated diarrhea, has a complex epidemiology poorly studied in Latin America. We performed a robust genomic and phenotypic profiling of 53 C. difficile clinical ...
Major Histocompatibility Complex Class II (DRB3) Genetic Diversity in Spanish Morucha and Colombian Normande Cattle Compared to Taurine and Zebu Populations

Bohórquez, Michel David; Ordoñez, Diego; Suárez, Carlos F.; Vicente, Belén; López Abán, Julio; Muro, Antonio; Ordóñez, Iván; Patarroyo, Manuel A. (2020)

Bovine leukocyte antigens (BoLA) have been used as disease markers and immunological traits in cattle due to their primary role in pathogen recognition by the immune system. A higher MHC allele diversity in a population ...
Malaria: Paving the way to developing peptide-based vaccines against invasion in infectious diseases

Reyes, César; Molina Franky, Jessica S.; Aza Conde, Jorge; Suárez, Carlos F.; Pabón, Laura; Moreno Vranich, Armando; Patarroyo, Manuel A.; Patarroyo, Manuel Elkin (2020)

Malaria remains a large-scale public health problem, killing more than 400,000 people and infecting up to 230 million worldwide, every year. Unfortunately, despite numerous efforts and research concerning vaccine development, ...
Micro-epidemiology of mixed-species malaria infections in a rural population living in the Colombian Amazon region

Camargo, Milena; Soto De León, Sara C.; Del Río Ospina, Luisa; Páez, Asrtid C.; González, Zanony; González, Edgardo.; Cubides, Juan R.; Camargo Ayala, Paola A.; Patarroyo, Manuel E.; Patarroyo, Manuel A. (2018)

Malaria outbreaks have been reported in recent years in the Colombian Amazon region, malaria has been re-emerging in areas where it was previously controlled. Information from malaria transmission networks and knowledge ...
Plasmodium vivax in vitro continuous culture: The spoke in the wheel

Bermúdez, Maritza; Moreno Pérez, Darwin Andrés; Arévalo Pinzón, Gabriela; Curtidor, Hernando; Patarroyo, Manuel A. (2018)

Understanding the life cycle of Plasmodium vivax is fundamental for developing strategies aimed at controlling and eliminating this parasitic species. Although advances in omic sciences and high-throughput techniques in ...
Plasmodium vivax Pv12 B-cell epitopes and HLA-DRβ1-dependent T-cell epitopes in vitro antigenicity

Yepes Pérez, Yoelis; López, Carolina; Suárez, Carlos F.; Patarroyo, Manuel A. (2018)

Malaria is an infectious disease caused by parasites from the genus Plasmodium (P. falciparum and P. vivax are responsible for 90% of all clinical cases); it is widely distributed throughout the world’s tropical and ...
Preliminary Evaluation of the Safety and Immunogenicity of an Antimalarial Vaccine Candidate Modified Peptide (IMPIPS) Mixture in a Murine Model

Lambraño, Jennifer; Curtidor, Hernando; Avendaño, Catalina; Díaz Arévalo, Diana; Roa, Leonardo; Vanegas, Magnolia; Patarroyo, Manuel Elkin; Patarroyo, Manuel A. (2019)

Malaria continues being a high-impact disease regarding public health worldwide; the WHO report for malaria in 2018 estimated that 219 million cases occurred in 2017, mostly caused by the parasite Plasmodium falciparum. ...
Semi-empirical quantum evaluation of peptide – MHC class II binding

González, Ronald; Suárez, Carlos F.; Bohórquez, Hugo J.; Patarroyo, Manuel A.; Patarroyo, Manuel E. (2017)

Peptide presentation by the major histocompatibility complex (MHC) is a key process for triggering a specific immune response. Studying peptide-MHC (pMHC) binding from a structural-based approach has potential for reducing ...
Shorter antibacterial peptide having high selectivity for e. Coli membranes and low potential for inducing resistance

Barreto Santamaría, Adriana; Rivera Monroy, Zuly Jenny; García Castañeda, Javier Eduardo; Curtidor, Hernando; Patarroyo, Manuel Elkin; Patarroyo, Manuel A.; Arevalo Pinzon, Gabriela (2020)

Antimicrobial peptides (AMPs) have been recognised as a significant therapeutic option for mitigating resistant microbial infections. It has been found recently that Plasmodium falciparum-derived, 20 residue long, peptide ...
Specific β-turns precede PPIIL structures binding to allele-specific HLA-DRβ1* PBRs in fully-protective malaria vaccine components

Bermudez, Adriana; Alba, Martha p.; Vanegas, Magnolia; Patarroyo, Manuel A.; Patarroyo, Manuel Elkin (2018)

The 3D structural analysis of 62 peptides derived from highly pathogenic Plasmodium falciparum malaria parasite proteins involved in host cell invasion led to finding a striking association between particular β-turn types ...
Strong -LAMP Assay Based on a Strongyloides spp.-Derived Partial Sequence in the 18S rRNA as Potential Biomarker for Strongyloidiasis Diagnosis in Human Urine Samples

Fernández Soto, Pedro; Celis Giraldo, Carmen Teresa; Collar Fernandez, Coralina; Gorgojo, Óscar; Camargo, Milena; Muñoz, José; Salas Coronas, Joaquín; Patarroyo, Manuel A.; Muro, Antonio (2020)

Human strongyloidiasis a soil-transmitted infection caused by Strongyloides stercoralis is one of the most neglected amongst the so-called Neglected Tropical Diseases (NTDs). S. stercoralis is a nematode, which is distributed ...
TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria

Alba, Martha P.; Suarez, Carlos F.; Varela, Yahson; Patarroyo, Manuel A.; Bermudez, Adriana; Patarroyo, Manuel Elkin (2016)

Fully-protective, long-lasting, immunological (FPLLI) memory against Plasmodium falciparum malaria regarding immune protection-inducing protein structures (IMPIPS) vaccinated into monkeys previously challenged and re-challenged ...
The in vitro antigenicity of Plasmodium vivax rhoptry neck protein 2 (PvRON2) B- and T-epitopes selected by HLA-DRB1 binding profile

López, Carolina; Yepes Pérez, Yoelis; Díaz Arévalo, Diana; Patarroyo, Manuel E.; Patarroyo, Manuel A. (2018)

Malaria caused by Plasmodium vivax is a neglected disease which is responsible for the highest morbidity in both Americas and Asia. Despite continuous public health efforts to prevent malarial infection, an effective ...

Envíos recientes

Assessing Peptide Binding to MHC II: An Accurate Semiempirical Quantum Mechanics Based Proposal
...
Ortiz Mahecha, Carlos A. | 2019

Estimating peptide-major histocompatibility complex (pMHC) binding using structural computational methods has an impact on understanding overall immune function triggering adaptive immune responses in MHC class II molecules. We developed a strategy for optimizing pMHC structure interacting with water molecules and for calculating the binding energy of receptor + ligand systems, such as HLA-DR1 + HA, HLA-DR1 + CLIP, HLA-DR2 + MBP, and HLA-DR3 + CLIP, as well as a monosubstitution panel. Taking pMHC's structural properties, we assumed that ΔH ≫ -TΔS would generate a linear model for estimating relative free energy change, using three semiempirical quantum methods (PM6, PM7, and FMO-SCC-DFTB3) along with the implicit solvent models, and considering proteins in neutral and charged states. Likewise, we confirmed our approach's effectiveness in calculating binding energies having high correlation with experimental data and low root-mean-square error (<2 kcal/mol). All in all, our pipeline differentiates weak from strong peptide binders as a reliable method for studying pMHC interactions.

LEER
Comparative genomics identifies potential virulence factors in Clostridium tertium and C. paraputrificum
...
Muñoz, Marina | 2019

Some well-known Clostridiales species such as Clostridium difficile and C. perfringens are agents of high impact diseases worldwide. Nevertheless, other foreseen Clostridiales species have recently emerged such as Clostridium tertium and C. paraputrificum. Three fecal isolates were identified as Clostridium tertium (Gcol.A2 and Gcol.A43) and C. paraputrificum (Gcol.A11) during public health screening for C. difficile infections in Colombia. C. paraputrificum genomes were highly diverse and contained large numbers of accessory genes. Genetic diversity and accessory gene percentage were lower among the C. tertium genomes than in the C. paraputrificum genomes. C. difficile tcdA and tcdB toxins encoding homologous sequences and other potential virulence factors were also identified. EndoA interferase, a toxic component of the type II toxin-antitoxin system, was found among the C. tertium genomes. toxA was the only toxin encoding gene detected in Gcol.A43, the Colombian isolate with an experimentally-determined high cytotoxic effect. Gcol.A2 and Gcol.A43 had higher sporulation efficiencies than Gcol.A11 (84.5%, 83.8% and 57.0%, respectively), as supported by the greater number of proteins associated with sporulation pathways in the C. tertium genomes compared with the C. paraputrificum genomes (33.3 and 28.4 on average, respectively). This work allowed complete genome description of two clostridiales species revealing high levels of intra-taxa diversity, accessory genomes containing virulence-factors encoding genes (especially in C. paraputrificum), with proteins involved in sporulation processes more highly represented in C. tertium. These finding suggest the need to advance in the study of those species with potential importance at public health level.

LEER
Critical role of HLA-DRb* binding peptides' peripheralflankingresidues in fully-protective malaria vaccine development
...
Reyes, César | 2017

A vaccine candidate component must fit perfectly into the antigen presenting HLA-DRβ* molecule's groove (or canonical nonapeptide) peptide binding region (PBR) during antigen presentation to the T-cell receptor (TCR), conforming a specific and stable macromolecular complex and induce an appropriate immune response. Antigen's peripheral flanking residues (PFR, positions (p) -p2 and p10) must thus establish strong interactions with the HLA-DRβ* - TCR complex. These amino acids (aa) have specific physico-chemical characteristics enabling differentiation between non-protective but antibody-inducer (NPAI), short-lived protection inducer (SLPI) and long-lasting protection inducer (LLPI) peptides when used as an antimalarial vaccine component. Their identification (through 1H-NMR and Aotus monkey immunization) and proper modification contributes to a logical and rational methodology for long-lasting and protective immunological memory.

LEER
Critical role of HLA-DRβ* binding peptides' peripheral flanking residues in fully-protective malaria vaccine development
...
Reyes, Cesar | 2017

A vaccine candidate component must fit perfectly into the antigen presenting HLA-DRβ* molecule's groove (or canonical nonapeptide) peptide binding region (PBR) during antigen presentation to the T-cell receptor (TCR), conforming a specific and stable macromolecular complex and induce an appropriate immune response. Antigen's peripheral flanking residues (PFR, positions (p) -p2 and p10) must thus establish strong interactions with the HLA-DRβ* - TCR complex. These amino acids (aa) have specific physico-chemical characteristics enabling differentiation between non-protective but antibody-inducer (NPAI), short-lived protection inducer (SLPI) and long-lasting protection inducer (LLPI) peptides when used as an antimalarial vaccine component. Their identification (through 1H-NMR and Aotus monkey immunization) and proper modification contributes to a logical and rational methodology for long-lasting and protective immunological memory.

LEER
From a basic to a functional approach for developing a blood stage vaccine against Plasmodium vivax
...
Patarroyo, Manuel A. | 2020

Introduction: Numerous challenges have hampered developing an anti-malarial vaccine against the most widespread malarial parasite worldwide: Plasmodium vivax. Despite the progress achieved in studying proteins in short-term in vitro culture or in experimental models, there is still no clear method for defining which antigens or their regions should be prioritized for including them in a vaccine. Areas covered: The methods used by research groups so far which have focused on the functional analysis of P. vivax blood stage antigens have been reviewed here. A logical strategy orientated toward resolving two of the most commonly occurring problems in designing vaccines against this species has thus been proposed (i.e. the search for candidates and evaluating/ascertaining their functional role in the invasion of such molecules). Expert commentary: Advances in knowledge regarding P. vivax biology have been extremely slow. Only two key receptor–ligand interactions concerning merozoite entry to reticulocytes have been reported during the last 20 years: PvDBP1-DARC and PvRBP2b-CD71. Despite increasing knowledge about the parasite’s intimate preference for its host cells, it has yet to be determined which regions of the merozoite molecules characterized to date meet the requirement of inducing protective immune responses effectively blocking heterologous parasite entry to human cells.

LEER
Identifying the HLA DRB1-DQB1 molecules and predicting epitopes associated with high-risk HPV infection clearance and redetection
...
Del Río Ospina, Luisa | 2020

Several determining factors are involved in HPV infection outcomes; human leukocyte antigen (HLA) polymorphisms have been described as related factors. This study has ascertained the effect of genetic variation on HLA-DRB1 and DQB1 genes on HPV-16/-18/-31/-33/-45 and -58 clearance and redetection in Colombian women. PCR and qPCR were used for viral identification and the Illumina MiSeq system was used for HLA-typing of cervical samples (n = 276). Survival models were adjusted for identifying alleles/haplotypes related to HPV clearance/redetection; L1/L2 protein-epitope binding to MHC-II molecules was also predicted. Significant associations suggested effects favouring or hampering clearance/redetection events depending on the viral type involved in infection, e.g. just DRB1*12:01:01G favoured HPV-16 (coeff: 4.8) and HPV-45 clearance (coeff: 12.65) whilst HPV-18 (coeff: 2E-15), HPV-31 (coeff: 8E-17) and HPV-58 hindered elimination (coeff: 1E-14). An effect was only observed for some alelles when configured as haplotypes, e.g. DRB1*04:07:01G (having the greatest frequency in the target population) was associated with DQB1*02:01:1G or *03:02:03. Epitope prediction identified 23 clearance-related peptides and 29 were redetection-related; eight might have been related to HPV-16/-18 and -58 persistence and one to HPV-18 elimination. HLA allele/haplotype relationship with the course of HPV infection (clearance/redetection) depended on the infecting HPV type, in line with the specific viral epitopes displayed.

LEER
Inferring Plasmodium vivax protein biology by using omics data
...
Moreno Pérez, Darwin Andrés | 2020

Deciphering Plasmodium vivax biology has long been a challenge for groups working on this parasite, mainly due to the complications involved in propagating it in vitro. However, adapting P. vivax strains in non-human primates and the arrival of high-performance analysis methods has led to increased knowledge regarding parasite protein composition and the ability of some molecules to trigger an immune response or participate in protein-protein interactions. This review describes the state of the art concerning proteomics-, immunomics- and interatomics-related P. vivax omic studies, discussing their potential use in developing disease control methods.

LEER
Integrated genomic epidemiology and phenotypic profiling of Clostridium difficile across intra-hospital and community populations in Colombia
...
Muñoz, Marina | 2019

Clostridium difficile, the causal agent of antibiotic-associated diarrhea, has a complex epidemiology poorly studied in Latin America. We performed a robust genomic and phenotypic profiling of 53 C. difficile clinical isolates established from diarrheal samples from either intrahospital (IH) or community (CO) populations in central Colombia. In vitro tests were conducted to evaluate the cytopathic effect, the minimum inhibitory concentration of ten antimicrobial agents, the sporulation efficiency and the colony forming ability. Eleven different sequence types (STs) were found, the majority present individually in each sample, however in three samples two different STs were isolated. Interestingly, CO patients were infected with STs associated with hypervirulent strains (ST-1 in Clade-2). Three coexistence events (two STs simultaneously detected in the same sample) were observed always involving ST-8 from Clade-1. A total of 2,502 genes were present in 99% of the isolates with 95% of identity or more, it represents a core genome of 28.6% of the 8,735 total genes identified in the set of genomes. A high cytopathic effect was observed for the isolates positive for the two main toxins but negative for binary toxin (TcdA+/TcdB+/CDT− toxin production type), found only in Clade-1. Molecular markers conferring resistance to fluoroquinolones (cdeA and gyrA) and to sulfonamides (folP) were the most frequent in the analyzed genomes. In addition, 15 other markers were found mostly in Clade-2 isolates. These results highlight the regional differences that C. difficile isolates display, being in this case the CO isolates the ones having a greater number of accessory genes and virulence-associated factors.

LEER
Major Histocompatibility Complex Class II (DRB3) Genetic Diversity in Spanish Morucha and Colombian Normande Cattle Compared to Taurine and Zebu Populations
...
Bohórquez, Michel David | 2020

Bovine leukocyte antigens (BoLA) have been used as disease markers and immunological traits in cattle due to their primary role in pathogen recognition by the immune system. A higher MHC allele diversity in a population will allow presenting a broader peptide repertoire. However, loss of overall diversity due to domestication process can decrease a population’s peptide repertoire. Within the context of zebu and taurine cattle populations, BoLA-DRB3 genetic diversity in Spanish Morucha and Colombian Normande cattle was analyzed and an approach to estimate functional diversity was performed. Sequence-based typing was used for identifying 29, 23, 27, and 28 alleles in Spanish Morucha, Nariño-, Boyacá-, and Cundinamarca-Normande cattle, respectively. These breeds had remarkably low heterozygosity levels and the Hardy-Weinberg principle revealed significant heterozygote deficiency. FST and DA genetic distance showed that Colombian Normande populations had greater variability than other phenotypically homogeneous breeds, such as Holstein. It was also found that Spanish Morucha cattle were strongly differentiated from other cattle breeds. Spanish Morucha had greater divergence in the peptide-binding region regarding other cattle breeds. However, peptide-binding region covariation indicated that the potential peptide repertoire seemed equivalent among cattle breeds. Despite the genetic divergence observed, the extent of the potential peptide repertoire in the cattle populations studied appears to be similar and thus their pathogen recognition potential should be equivalent, suggesting that functional diversity might persist in the face of bottlenecks imposed by domestication and breeding.

LEER
Malaria: Paving the way to developing peptide-based vaccines against invasion in infectious diseases
...
Reyes, César | 2020

Malaria remains a large-scale public health problem, killing more than 400,000 people and infecting up to 230 million worldwide, every year. Unfortunately, despite numerous efforts and research concerning vaccine development, results to date have been low and/or strain-specific. This work describes a strategy involving Plasmodium falciparum Duffy binding-like (DBL) and reticulocyte-binding protein homologue (RH) family-derived minimum functional peptides, netMHCIIpan3.2 parental and modified peptides’ in silico binding prediction and modeling some Aotus major histocompatibility class II (MHCII) molecules based on known human molecules’ structure to understand their differences. These are used to explain peptides’ immunological behaviour when used as vaccine components in the Aotus model. Despite the great similarity between human and Aotus immune system molecules, around 50% of Aotus allele molecules lack a counterpart in the human immune system which could lead to an Aotus-specific vaccine. It was also confirmed that functional Plasmodium falciparum’ conserved proteins are immunologically silent (in both the animal model and in-silico prediction); they must therefore be modified to elicit an appropriate immune response. Some peptides studied here had the desired behaviour and can thus be considered components of a fully-protective antimalarial vaccine.

LEER
Micro-epidemiology of mixed-species malaria infections in a rural population living in the Colombian Amazon region
...
Camargo, Milena | 2018

Malaria outbreaks have been reported in recent years in the Colombian Amazon region, malaria has been re-emerging in areas where it was previously controlled. Information from malaria transmission networks and knowledge about the population characteristics influencing the dispersal of parasite species is limited. This study aimed to determine the distribution patterns of Plasmodium vivax, P. malariae and P. falciparum single and mixed infections, as well as the significant socio-spatial groupings relating to the appearance of such infections. An active search in 57 localities resulted in 2,106 symptomatic patients being enrolled. Parasitaemia levels were assessed by optical microscopy, and parasites were detected by PCR. The association between mixed infections (in 43.2% of the population) and socio-spatial factors was modelled using logistic regression and multiple correspondence analyses. P. vivax occurred most frequently (71.0%), followed by P. malariae (43.2%), in all localities. The results suggest that a parasite density-dependent regulation model (with fever playing a central role) was appropriate for modelling the frequency of mixed species infections in this population. This study highlights the under-reporting of Plasmodium spp. mixed infections in the malaria-endemic area of the Colombian Amazon region and the association between causative and environmental factors in such areas.

LEER
Plasmodium vivax in vitro continuous culture: The spoke in the wheel
...
Bermúdez, Maritza | 2018

Understanding the life cycle of Plasmodium vivax is fundamental for developing strategies aimed at controlling and eliminating this parasitic species. Although advances in omic sciences and high-throughput techniques in recent years have enabled the identification and characterization of proteins which might be participating in P. vivax invasion of target cells, exclusive parasite tropism for invading reticulocytes has become the main obstacle in maintaining a continuous culture for this species. Such advance that would help in defining each parasite protein's function in the complex process of P. vivax invasion, in addition to evaluating new therapeutic agents, is still a dream. Advances related to maintenance, culture medium supplements and the use of different sources of reticulocytes and parasites (strains and isolates) have been made regarding the development of an in vitro culture for P. vivax; however, only some cultures having few replication cycles have been obtained to date, meaning that this parasite's maintenance goes beyond the technical components involved. Although it is still not yet clear which molecular mechanisms P. vivax prefers for invading young CD71+ reticulocytes [early maturation stages (I-II-III)], changes related to membrane proteins remodelling of such cells could form part of the explanation. The most relevant aspects regarding P. vivax in vitro culture and host cell characteristics have been analysed in this review to explain possible reasons why the species' continuous in vitro culture is so difficult to standardize. Some alternatives for P. vivax in vitro culture have also been described.

LEER
Plasmodium vivax Pv12 B-cell epitopes and HLA-DRβ1-dependent T-cell epitopes in vitro antigenicity
...
Yepes Pérez, Yoelis | 2018

Malaria is an infectious disease caused by parasites from the genus Plasmodium (P. falciparum and P. vivax are responsible for 90% of all clinical cases); it is widely distributed throughout the world’s tropical and subtropical regions. The P. vivax Pv12 protein is involved in invasion, is expressed on merozoite surface and has been recognised by antibodies from individuals exposed to the disease. In this study, B- and T-cell epitopes from Pv12 were predicted and characterised to advance in the design of a peptide-based vaccine against malaria. For evaluating the humoral response of individuals exposed to natural P. vivax infection from two endemic areas in Colombia, BepiPred-1.0 software was used for selecting B-cell epitopes. B-cell epitope 39038 displayed the greatest recognition by naturally-acquired antibodies and induced an IgG2/IgG4 response. NetMHCIIpan-3.1 prediction software was used for selecting peptides having high affinity binding for HLA-DRβ1* allele lineages and this was confirmed by in-vitro binding assays. T-epitopes 39113 and 39117 triggered a memory T-cell response (Stimulation Index2) and significant cytokine production. Combining in-silico, in-vitro and functional assays, two Pv12 protein regions (containing peptides 39038, 39040, 39113 and 39117) have thus been characterised as promising vaccine candidates against P. vivax malaria.

LEER
Preliminary Evaluation of the Safety and Immunogenicity of an Antimalarial Vaccine Candidate Modified Peptide (IMPIPS) Mixture in a Murine Model
...
Lambraño, Jennifer | 2019

Malaria continues being a high-impact disease regarding public health worldwide; the WHO report for malaria in 2018 estimated that 219 million cases occurred in 2017, mostly caused by the parasite Plasmodium falciparum. The disease cost the lives of more than 400,000 people, mainly in Africa. In spite of great efforts aimed at developing better prevention (i.e., a highly effective vaccine), diagnosis, and treatment methods for malaria, no efficient solution to this disease has been advanced to date. The Fundación Instituto de Inmunología de Colombia (FIDIC) has been developing studies aimed at furthering the search for vaccine candidates for controlling P. falciparum malaria. However, vaccine development involves safety and immunogenicity studies regarding their formulation in animal models before proceeding to clinical studies. The present work has thus been aimed at evaluating the safety and immunogenicity of a mixture of 23 chemically synthesised, modified peptides (immune protection-inducing protein structure (IMPIPS)) derived from different P. falciparum proteins. Single and repeat dose assays were thus used with male and female BALB/c mice which were immunised with the IMPIPS mixture. It was found that single and repeat dose immunisation with the IMPIPS mixture was safe, both locally and systemically. It was observed that the antibodies so stimulated recognised the parasite's native proteins and inhibited merozoite invasion of red blood cells in vitro when evaluating the humoral immune response induced by the IMPIPS mixture. Such results suggested that the IMPIPS peptide mixture could be a safe candidate to be tested during the next stage involved in developing an antimalarial vaccine, evaluating local safety, immunogenicity, and protection in a nonhuman primate model.

LEER
Semi-empirical quantum evaluation of peptide – MHC class II binding
...
González, Ronald | 2017

Peptide presentation by the major histocompatibility complex (MHC) is a key process for triggering a specific immune response. Studying peptide-MHC (pMHC) binding from a structural-based approach has potential for reducing the costs of investigation into vaccine development. This study involved using two semi-empirical quantum chemistry methods (PM7 and FMO-DFTB) for computing the binding energies of peptides bonded to HLA-DR1 and HLA-DR2. We found that key stabilising water molecules involved in the peptide binding mechanism were required for finding high correlation with IC50 experimental values. Our proposal is computationally non-intensive, and is a reliable alternative for studying pMHC binding interactions.

LEER
Shorter antibacterial peptide having high selectivity for e. Coli membranes and low potential for inducing resistance
...
Barreto Santamaría, Adriana | 2020

Antimicrobial peptides (AMPs) have been recognised as a significant therapeutic option for mitigating resistant microbial infections. It has been found recently that Plasmodium falciparum-derived, 20 residue long, peptide 35409 had antibacterial and haemolytic activity, making it an AMP having reduced selectivity, and suggesting that it should be studied more extensively for obtaining new AMPs having activity solely targeting the bacterial membrane. Peptide 35409 was thus used as template for producing short synthetic peptides (<20 residues long) and evaluating their biological activity and relevant physicochemical characteristics for therapeutic use. Four of the sixteen short peptides evaluated here had activity against E. coli without any associated haemolytic effects. The 35409-1 derivative (17 residues long) had the best therapeutic characteristics as it had high selectivity for bacterial cells, stability in the presence of human sera, activity against E. coli multiresistant clinical isolates and was shorter than the original sequence. It had a powerful membranolytic effect and low potential for inducing resistance in bacteria. This peptide’s characteristics highlighted its potential as an alternative for combating infection caused by E. coli multiresistant bacteria and/or for designing new AMPs.

LEER
Specific β-turns precede PPIIL structures binding to allele-specific HLA-DRβ1* PBRs in fully-protective malaria vaccine components
...
Bermudez, Adriana | 2018

The 3D structural analysis of 62 peptides derived from highly pathogenic Plasmodium falciparum malaria parasite proteins involved in host cell invasion led to finding a striking association between particular β-turn types located in the N-terminal peripheral flanking residue region (preceding the polyproline II left-handed structures fitting into the HLA-DRβ* allele family) and modified immune protection-inducing protein structure induced long-lasting protective immunity. This is the first time association between two different secondary structures associated with a specific immunological function has been described: full, long-lasting protective immunity.

LEER
Strong -LAMP Assay Based on a Strongyloides spp.-Derived Partial Sequence in the 18S rRNA as Potential Biomarker for Strongyloidiasis Diagnosis in Human Urine Samples
...
Fernández Soto, Pedro | 2020

Human strongyloidiasis a soil-transmitted infection caused by Strongyloides stercoralis is one of the most neglected amongst the so-called Neglected Tropical Diseases (NTDs). S. stercoralis is a nematode, which is distributed worldwide; it has been estimated that it could affect millions of people, mainly in tropical and subtropical endemic regions. The difficulties of diagnosis lead to infection rates being underreported. Asymptomatic patients have chronic infections that can lead to severe hyperinfection syndrome or disseminated strongyloidiasis in immunocompromised patients. Strongyloidiasis can easily be misdiagnosed because conventional faecal-based techniques lack of sensitivity for the morphological identification of infective larvae in faeces. None of the currently used molecular methods have used urine samples as an alternative to faecal samples for diagnosing strongyloidiasis. This study was thus aimed at comparing, for the first time, the use of a new loop-mediated isothermal amplification (LAMP) molecular assay (Strong-LAMP) to traditional methods on patients’ urine samples. Twenty-four urine samples were taken from patients included in a study involving two Spanish hospitals for strongyloidiasis screening using parasitological and serological tests. Strongyloides larvae were found in 11 patients’ faecal samples, thereby ascertaining that they had the disease. Other patients had high antibody titres but no larvae were found in their faeces. All urine samples were analysed by PCR and Strong-LAMP assay. No amplification occurred when using PCR. Strong-LAMP led to detecting S. stercoralis DNA in urine samples from patients having previously confirmed strongyloidiasis by parasitological tests and/or a suspicion of being infected by serological ones. The Strong-LAMP assay is a useful molecular tool for research regarding strongyloidiasis in human urine samples. After further validation, the Strong-LAMP assay could also be used for complementary and effective diagnosis of strongyloidiasis in a clinical setting.

LEER
TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria
...
Alba, Martha P. | 2016

Fully-protective, long-lasting, immunological (FPLLI) memory against Plasmodium falciparum malaria regarding immune protection-inducing protein structures (IMPIPS) vaccinated into monkeys previously challenged and re-challenged 60 days later with a lethal Aotus monkey-adapted P. falciparum strain was found to be associated with preferential high binding capacity to HLA-DRβ1* allelic molecules of the major histocompatibility class II (MHC-II), rather than HLA-DRβ3*, β4*, β5* alleles. Complete PPIIL 3D structure, a longer distance (26.5 Å ± 1.5 Å) between residues perfectly fitting into HLA-DRβ1*PBR pockets 1 and 9, a gauche− rotamer orientation in p8 TCR-contacting polar residue and a larger volume of polar p2 residues was also found. This data, in association with previously-described p3 and p7 apolar residues having gauche+ orientation to form a perfect MHC-II-peptide-TCR complex, determines the stereo-electronic and topochemical characteristics associated with FPLLI immunological memory.

LEER
The in vitro antigenicity of Plasmodium vivax rhoptry neck protein 2 (PvRON2) B- and T-epitopes selected by HLA-DRB1 binding profile
...
López, Carolina | 2018

Malaria caused by Plasmodium vivax is a neglected disease which is responsible for the highest morbidity in both Americas and Asia. Despite continuous public health efforts to prevent malarial infection, an effective antimalarial vaccine is still urgently needed. P. vivax vaccine development involves analyzing naturally-infected patients' immune response to the specific proteins involved in red blood cell invasion. The P. vivax rhoptry neck protein 2 (PvRON2) is a highly conserved protein which is expressed in late schizont rhoptries; it interacts directly with AMA-1 and might be involved in moving-junction formation. Bioinformatics approaches were used here to select B- and T-cell epitopes. Eleven high-affinity binding peptides were selected using the NetMHCIIpan-3.0 in silico prediction tool; their in vitro binding to HLA-DRB1*0401, HLA-DRB1*0701, HLA-DRB1*1101 or HLA-DRB1*1302 was experimentally assessed. Four peptides (39152 (HLA-DRB1*04 and 11), 39047 (HLA-DRB1*07), 39154 (HLADRB1*13) and universal peptide 39153) evoked a naturally-acquired T-cell immune response in P. vivax-exposed individuals from two endemic areas in Colombia. All four peptides had an SI greater than 2 in proliferation assays; however, only peptides 39154 and 39153 had significant differences compared to the control group. Peptide 39047 was able to significantly stimulate TNF and IL-10 production while 39154 stimulated TNF production. Allele-specific peptides (but not the universal one) were able to stimulate IL-6 production; however, none induced IFN-γ production. The Bepipred 1.0 tool was used for selecting four B-cell epitopes in silico regarding humoral response. Peptide 39041 was the only one recognized by P. vivax-exposed individuals' sera and had significant differences concerning IgG subclasses; an IgG2 > IgG4 profile was observed for this peptide, agreeing with a protection-inducing role against P. falciparum and P. vivax as previously described for antigens such as RESA and MSP2. The bioinformatics results and in vitro evaluation reported here highlighted two T-cell epitopes (39047 and 39154) being recognized by memory cells and a B-cell epitope (39041) identified by P. vivax-exposed individuals' sera which could be used as potential candidates when designing a subunit-based vaccine.

LEER

‹›

Browsing by Author "Patarroyo, Manuel A."

Assessing Peptide Binding to MHC II: An Accurate Semiempirical Quantum Mechanics Based Proposal ﻿

Comparative genomics identifies potential virulence factors in Clostridium tertium and C. paraputrificum ﻿

Critical role of HLA-DRb* binding peptides' peripheralflankingresidues in fully-protective malaria vaccine development ﻿

Critical role of HLA-DRβ* binding peptides' peripheral flanking residues in fully-protective malaria vaccine development ﻿

From a basic to a functional approach for developing a blood stage vaccine against Plasmodium vivax ﻿

Identifying the HLA DRB1-DQB1 molecules and predicting epitopes associated with high-risk HPV infection clearance and redetection ﻿

Inferring Plasmodium vivax protein biology by using omics data ﻿

Integrated genomic epidemiology and phenotypic profiling of Clostridium difficile across intra-hospital and community populations in Colombia ﻿

Major Histocompatibility Complex Class II (DRB3) Genetic Diversity in Spanish Morucha and Colombian Normande Cattle Compared to Taurine and Zebu Populations ﻿

Malaria: Paving the way to developing peptide-based vaccines against invasion in infectious diseases ﻿

Micro-epidemiology of mixed-species malaria infections in a rural population living in the Colombian Amazon region ﻿

Plasmodium vivax in vitro continuous culture: The spoke in the wheel ﻿

Plasmodium vivax Pv12 B-cell epitopes and HLA-DRβ1-dependent T-cell epitopes in vitro antigenicity ﻿

Preliminary Evaluation of the Safety and Immunogenicity of an Antimalarial Vaccine Candidate Modified Peptide (IMPIPS) Mixture in a Murine Model ﻿

Semi-empirical quantum evaluation of peptide – MHC class II binding ﻿

Shorter antibacterial peptide having high selectivity for e. Coli membranes and low potential for inducing resistance ﻿

Specific β-turns precede PPIIL structures binding to allele-specific HLA-DRβ1* PBRs in fully-protective malaria vaccine components ﻿

Strong -LAMP Assay Based on a Strongyloides spp.-Derived Partial Sequence in the 18S rRNA as Potential Biomarker for Strongyloidiasis Diagnosis in Human Urine Samples ﻿

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria ﻿

The in vitro antigenicity of Plasmodium vivax rhoptry neck protein 2 (PvRON2) B- and T-epitopes selected by HLA-DRB1 binding profile ﻿

Envíos recientes

Assessing Peptide Binding to MHC II: An Accurate Semiempirical Quantum Mechanics Based Proposal

Comparative genomics identifies potential virulence factors in Clostridium tertium and C. paraputrificum

Critical role of HLA-DRb* binding peptides' peripheralflankingresidues in fully-protective malaria vaccine development

Critical role of HLA-DRβ* binding peptides' peripheral flanking residues in fully-protective malaria vaccine development

From a basic to a functional approach for developing a blood stage vaccine against Plasmodium vivax

Identifying the HLA DRB1-DQB1 molecules and predicting epitopes associated with high-risk HPV infection clearance and redetection

Inferring Plasmodium vivax protein biology by using omics data

Integrated genomic epidemiology and phenotypic profiling of Clostridium difficile across intra-hospital and community populations in Colombia

Major Histocompatibility Complex Class II (DRB3) Genetic Diversity in Spanish Morucha and Colombian Normande Cattle Compared to Taurine and Zebu Populations

Malaria: Paving the way to developing peptide-based vaccines against invasion in infectious diseases

Micro-epidemiology of mixed-species malaria infections in a rural population living in the Colombian Amazon region

Plasmodium vivax in vitro continuous culture: The spoke in the wheel

Plasmodium vivax Pv12 B-cell epitopes and HLA-DRβ1-dependent T-cell epitopes in vitro antigenicity

Preliminary Evaluation of the Safety and Immunogenicity of an Antimalarial Vaccine Candidate Modified Peptide (IMPIPS) Mixture in a Murine Model

Semi-empirical quantum evaluation of peptide – MHC class II binding

Shorter antibacterial peptide having high selectivity for e. Coli membranes and low potential for inducing resistance

Specific β-turns precede PPIIL structures binding to allele-specific HLA-DRβ1* PBRs in fully-protective malaria vaccine components

Strong -LAMP Assay Based on a Strongyloides spp.-Derived Partial Sequence in the 18S rRNA as Potential Biomarker for Strongyloidiasis Diagnosis in Human Urine Samples

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria

The in vitro antigenicity of Plasmodium vivax rhoptry neck protein 2 (PvRON2) B- and T-epitopes selected by HLA-DRB1 binding profile

Assessing Peptide Binding to MHC II: An Accurate Semiempirical Quantum Mechanics Based Proposal

Comparative genomics identifies potential virulence factors in Clostridium tertium and C. paraputrificum

Critical role of HLA-DRb* binding peptides' peripheralflankingresidues in fully-protective malaria vaccine development

Critical role of HLA-DRβ* binding peptides' peripheral flanking residues in fully-protective malaria vaccine development

From a basic to a functional approach for developing a blood stage vaccine against Plasmodium vivax

Identifying the HLA DRB1-DQB1 molecules and predicting epitopes associated with high-risk HPV infection clearance and redetection

Inferring Plasmodium vivax protein biology by using omics data

Integrated genomic epidemiology and phenotypic profiling of Clostridium difficile across intra-hospital and community populations in Colombia

Major Histocompatibility Complex Class II (DRB3) Genetic Diversity in Spanish Morucha and Colombian Normande Cattle Compared to Taurine and Zebu Populations

Malaria: Paving the way to developing peptide-based vaccines against invasion in infectious diseases

Micro-epidemiology of mixed-species malaria infections in a rural population living in the Colombian Amazon region

Plasmodium vivax in vitro continuous culture: The spoke in the wheel

Plasmodium vivax Pv12 B-cell epitopes and HLA-DRβ1-dependent T-cell epitopes in vitro antigenicity

Preliminary Evaluation of the Safety and Immunogenicity of an Antimalarial Vaccine Candidate Modified Peptide (IMPIPS) Mixture in a Murine Model

Semi-empirical quantum evaluation of peptide – MHC class II binding

Shorter antibacterial peptide having high selectivity for e. Coli membranes and low potential for inducing resistance

Specific β-turns precede PPIIL structures binding to allele-specific HLA-DRβ1* PBRs in fully-protective malaria vaccine components

Strong -LAMP Assay Based on a Strongyloides spp.-Derived Partial Sequence in the 18S rRNA as Potential Biomarker for Strongyloidiasis Diagnosis in Human Urine Samples

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria

The in vitro antigenicity of Plasmodium vivax rhoptry neck protein 2 (PvRON2) B- and T-epitopes selected by HLA-DRB1 binding profile