Now showing items 1-20 of 22

A comparative analysis of SLA-DRB1 genetic diversity in Colombian (creoles and commercial line) and worldwide swine populations

Celis‑Giraldo, Carmen Teresa; Bohórquez, Michel David; Camargo, Milena; Suárez, Carlos Fernando; Camargo, Anny; Rodríguez‑Obediente, Kewin; Martínez, Alejandra; Lucero, Carlos Edmundo; Hernández, Byron; Manzano‑Román, Raúl; Patarroyo, Manuel Elkin (2021)

Analysing pig class II mayor histocompatibility complex (MHC) molecules is mainly related to antigen presentation. Identifying frequently-occurring alleles in pig populations is an important aspect to be considered when ...
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. ...
Association of HIV status with infection by multiple HPV types

Camargo, Milena; Del Río Ospina, Luisa; Soto-De León, Sara Cecilia; Sánchez, Ricardo Andrea; Pineda Peña, Clemencia; Sussmann, Otto; Patarroyo, Manuel Elkin; Patarroyo, Manuel Alfonso (2018)

Objectives: To identify the clinical and demographic characteristics of HIV-positive and HIV-negative women infected by multiple HPV types. Methods: 1399 women participated in the study (240 HIV-positive and 1159 HIV-negative ...
Behavior and abundance of Anopheles darlingi in communities living in the Colombian Amazon riverside

Prado, César Camilo; Alvarado Cabrera, Luis Antonio; Camargo Ayala, Paola Andrea; Garzón Ospina, Diego; Camargo, Milena; Soto-De León, Sara Cecilia; Cubides, Ricardo; Celis-Giraldo, Carmen Teresa; Patarroyo, Manuel Elkin; Patarroyo, Manuel Alfonso (2019)

In the past few years, relative frequencies of malaria parasite species in communities living in the Colombian Amazon riverside have changed, being Plasmodium vivax (61.4%) and Plasmodium malariae (43.8%) the most frequent. ...
A Comprehensive Review of the Immunological Response against Foot-and-Mouth Disease Virus Infection and Its Evasion Mechanisms

Rodriguez Habibe, Ibett; Celis-Giraldo, Carmen; Patarroyo, Manuel Elkin; Avendaño, Catalina; Patarroyo, Manuel Alfonso (2020)

Foot-and-mouth disease (FMD) is a highly contagious viral disease, which has been reported for over 100 years, and against which the struggle has lasted for the same amount of time. It affects individuals from the order ...
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), ...
Erratum: Publisher Correction: Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements

Bohórquez, Hugo J.; Suárez, Carlos F.; Patarroyo, Manuel Elkin (2018)

Why is an amino acid replacement in a protein accepted during evolution? The answer given by bioinformatics relies on the frequency of change of each amino acid by another one and the propensity of each to remain unchanged. ...
Functionally relevant proteins in Plasmodium falciparum host cell invasion

Patarroyo, Manuel Elkin; Alba, Martha Patricia; Rojas Luna, Rocío; Bermúdez, Adriana; Aza-Conde, Jorge (Bogotá : Universidad de Ciencias Aplicadas y Ambientales, 2017, 2017)

A totally effective, antimalarial vaccine must involve sporozoite and merozoite proteins (or their fragments) to ensure complete parasite blocking during critical invasion stages. This Special Report examines proteins ...
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 ...
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, ...
Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements

Bohórquez, Hugo J.; Suárez, Carlos F.; Patarroyo, Manuel Elkin (2017)

Why is an amino acid replacement in a protein accepted during evolution? The answer given by bioinformatics relies on the frequency of change of each amino acid by another one and the propensity of each to remain unchanged. ...
Multiple high-risk HPV genotypes are grouped by type and are associated with viral load and risk factors

Del Río-Ospina, Luisa; Soto de León, Sara Cecilia; Camargo, Milena; Sánchez, Ricardo; Moreno Pérez, Darwin Andrés; Pérez - Prados, Antonio; Patarroyo, Manuel Elkin; Patarroyo, Manuel (2017)

Investigating whether high-risk human papillomavirus (HR-HPV) types tend to become grouped in a particular way and whether factors are associated with such grouping is important for measuring the real impact of vaccination. ...
p-Methoxyphenol: A potent and effective scavenger for solid-phase peptide synthesis

Samacá, Jhoan; Velandia Bautista, Erika; Tabares, Luisa; Escamilla, Luis; Vanegas, Magnolia; Patarroyo, Manuel Elkin (2020)

During the final step of t-Boc/Bzl, solid-phase peptide synthesis (SPPS)-protecting groups from amino acids (aa) side chains must be removed from the target peptides during cleavage from the solid support. These reaction ...
Plasmodium falciparum pre-erythrocytic stage vaccine development

Molina Franky, Jessica; Cuy Chaparro, Laura; Camargo, Anny; Reyes, César; Gómez, Marcela; Salamanca, David Ricardo; Patarroyo, Manuel Alfonso; Patarroyo, Manuel Elkin (2020)

Worldwide strategies between 2010 and 2017 aimed at controlling malarial parasites (mainly Plasmodium falciparum) led to a reduction of just 18% regarding disease incidence rates. Many biologically-derived anti-malarial ...
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. ...
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 ...
Structural analysis of owl monkey MHC-DR shows that fully-protective malaria vaccine components can be readily used in humans

Suárez, Carlos F.; Pabón, Laura; Barrera, Ana; Aza Conde, Jorge; Patarroyo, Manuel Alfonso; Patarroyo, Manuel Elkin (2017)

More than 50 years ago the owl monkey (genusAotus) was found to be highly susceptible to developinghuman malaria, making it an excellent experimental model for this disease. Microbes and parasites'(especially malaria) ...
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 ...

Envíos recientes

A comparative analysis of SLA-DRB1 genetic diversity in Colombian (creoles and commercial line) and worldwide swine populations
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Celis‑Giraldo, Carmen Teresa | 2021

Analysing pig class II mayor histocompatibility complex (MHC) molecules is mainly related to antigen presentation. Identifying frequently-occurring alleles in pig populations is an important aspect to be considered when developing peptide-based vaccines. Colombian creole pig populations have had to adapt to local conditions since entering Colombia; a recent census has shown low amounts of pigs which is why they are considered protected by the Colombian government. Commercial hybrids are more attractive regarding production. This research has been aimed at describing the allele distribution of Colombian pigs from diverse genetic backgrounds and comparing Colombian SLA-DRB1 locus diversity to that of internationally reported populations. Twenty SLA-DRB1 alleles were identified in the six populations analysed here using sequence-based typing. The amount of alleles ranged from six (Manta and Casco Mula) to nine (San Pedreño). Only one allele (01:02) having > 5% frequency was shared by all three commercial line populations. Allele 02:01:01 was shared by five populations (around > 5% frequency). Global FST indicated that pig populations were clearly structured, as 20.6% of total allele frequency variation was explained by differences between populations (FST = 0.206). This study’s results confirmed that the greatest diversity occurred in wild boars, thereby contrasting with low diversity in domestic pig populations.

LEER
Assessing Peptide Binding to MHC II: An Accurate Semiempirical Quantum Mechanics Based Proposal
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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
Association of HIV status with infection by multiple HPV types
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Camargo, Milena | 2018

Objectives: To identify the clinical and demographic characteristics of HIV-positive and HIV-negative women infected by multiple HPV types. Methods: 1399 women participated in the study (240 HIV-positive and 1159 HIV-negative women). Samples were provided for Pap tests and for HPV detection and typing by PCR. Data were collected on HPV infection, frequency of multiple infection, and HPV type distribution. Odds ratios were reported from logistic regression models. Results: Compared with HIV-negative women, HIV-positive women had higher frequencies of cervical abnormality (30% vs. 20.8%), higher HPV prevalence (68.3% vs. 51.3%) and were more commonly infected with multiple HPV types (78.7% vs. 44.3%). HPV-16 was the most common type detected in the study population, with other types showing variable associations with HIV status. Positive associations were observed between infection by multiple HPV types and HIV status, cervical abnormality and having had more than three pregnancies. The odds of multiple infection by HPV types were higher in HIV-positive women who used an intrauterine device, who had a history of abortions and who had HIV viral loads >100 000 copies/ml, whilst the odds were lower in women with >500 CD4 cells/mm 3 . Conclusions: HIV immunosuppression favours infection by multiple high-risk HPV types, mainly in women affected by low-grade squamous intraepithelial lesions. Antiretroviral therapy had no effect on infection by multiple HPV types. Risk factors related to progressive damage to the cervix were positively associated with infection by multiple HPV types in women living with HIV.

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Behavior and abundance of Anopheles darlingi in communities living in the Colombian Amazon riverside
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Prado, César Camilo | 2019

In the past few years, relative frequencies of malaria parasite species in communities living in the Colombian Amazon riverside have changed, being Plasmodium vivax (61.4%) and Plasmodium malariae (43.8%) the most frequent. Given this epidemiological scenario, it is important to determine the species of anophelines involved in these parasites’ transmission. This study was carried out in June 2016 in two indigenous communities living close to the tributaries of the Amazon River using protected human bait. The results of this study showed a total abundance of 1,085 mosquitos, of which 99.2% corresponded to Anopheles darlingi. Additionally, only two anopheline species were found, showing low diversity in the study areas. Molecular confirmation of some individuals was then followed by evolutionary analysis by using the COI gene. Nested PCR was used for identifying the three Plasmodium species circulating in the study areas. Of the two species collected in this study, 21.0% of the An. darlingi mosquitoes were infected with P. malariae, 21.9% with P. vivax and 10.3% with Plasmodium falciparum. It exhibited exophilic and exophagic behavior in both study areas, having marked differences regarding its abundance in each community (Tipisca first sampling 49.4%, Tipisca second sampling 39.6% and Doce de Octubre 10.9%). Interestingly, An. mattogrossensis infected by P. vivax was found for the first time in Colombia (in 50% of the four females collected). Analysis of An. darlingi COI gene diversity indicated a single population maintaining a high gene flow between the study areas. The An. darlingi behavior pattern found in both communities represents a risk factor for the region’s inhabitants living/working near these sites. This highlights the need for vector control efforts such as the use of personal repellents and insecticides for use on cattle, which must be made available in order to reduce this Anopheline’s abundance.

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A Comprehensive Review of the Immunological Response against Foot-and-Mouth Disease Virus Infection and Its Evasion Mechanisms
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Rodriguez Habibe, Ibett | 2020

Foot-and-mouth disease (FMD) is a highly contagious viral disease, which has been reported for over 100 years, and against which the struggle has lasted for the same amount of time. It affects individuals from the order Artiodactyla, such as cattle, swine, sheep, wild animals from this order, and a few non-cloven hoofed species, such as mice and elephants. FMD causes large-scale economic losses for agricultural production systems; morbidity is almost 100% in an affected population, accompanied by a high mortality rate in young animals due to myocarditis or an inability to suckle if a mother is ill. The aetiological agent is an Aphthovirus from the family Picornaviridae, having seven serotypes: A, O, C, SAT1, SAT2, SAT3, and Asia 1. Serotype variability means that an immune response is serospecific and vaccines are thus designed to protect against each serotype independently. A host’s adaptive immune response is key in defence against pathogens; however, this virus uses successful strategies (along with most microorganisms) enabling it to evade a host’s immune system to rapidly and efficiently establish itself within such host, and thus remain there. This review has been aimed at an in-depth analysis of the immune response in cattle and swine regarding FMD virus, the possible evasion mechanisms used by the virus and describing some immunological differences regarding these species. Such aspects can provide pertinent knowledge for developing new FMD control and prevention strategies

LEER
Critical role of HLA-DRb* binding peptides' peripheralflankingresidues in fully-protective malaria vaccine development
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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
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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
Erratum: Publisher Correction: Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements
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Bohórquez, Hugo J. | 2018

Why is an amino acid replacement in a protein accepted during evolution? The answer given by bioinformatics relies on the frequency of change of each amino acid by another one and the propensity of each to remain unchanged. We propose that these replacement rules are recoverable from the secondary structural trends of amino acids. A distance measure between high-resolution Ramachandran distributions reveals that structurally similar residues coincide with those found in substitution matrices such as BLOSUM: Asn ↔ Asp, Phe ↔ Tyr, Lys ↔ Arg, Gln ↔ Glu, Ile ↔ Val, Met → Leu; with Ala, Cys, His, Gly, Ser, Pro, and Thr, as structurally idiosyncratic residues. We also found a high average correlation (R¯¯¯¯ = 0.85) between thirty amino acid mutability scales and the mutational inertia (I X ), which measures the energetic cost weighted by the number of observations at the most probable amino acid conformation. These results indicate that amino acid substitutions follow two optimally-efficient principles: (a) amino acids interchangeability privileges their secondary structural similarity, and (b) the amino acid mutability depends directly on its biosynthetic energy cost, and inversely with its frequency. These two principles are the underlying rules governing the observed amino acid substitutions.

LEER
Functionally relevant proteins in Plasmodium falciparum host cell invasion
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Patarroyo, Manuel Elkin | 2017

A totally effective, antimalarial vaccine must involve sporozoite and merozoite proteins (or their fragments) to ensure complete parasite blocking during critical invasion stages. This Special Report examines proteins involved in critical biological functions for parasite survival and highlights the conserved amino acid sequences of the most important proteins involved in sporozoite invasion of hepatocytes and merozoite invasion of red blood cells. Conserved high activity binding peptides are located in such proteins' functionally strategic sites, whose functions are related to receptor binding, nutrient and protein transport, enzyme activity and molecule-molecule interactions. They are thus excellent targets for vaccine development as they block proteins binding function involved in invasion and also their biological function.

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Identifying the HLA DRB1-DQB1 molecules and predicting epitopes associated with high-risk HPV infection clearance and redetection
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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
Malaria: Paving the way to developing peptide-based vaccines against invasion in infectious diseases
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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
Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements
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Bohórquez, Hugo J. | 2017

Why is an amino acid replacement in a protein accepted during evolution? The answer given by bioinformatics relies on the frequency of change of each amino acid by another one and the propensity of each to remain unchanged. We propose that these replacement rules are recoverable from the secondary structural trends of amino acids. A distance measure between high-resolution Ramachandran distributions reveals that structurally similar residues coincide with those found in substitution matrices such as BLOSUM: Asn Asp, Phe Tyr, Lys Arg, Gln Glu, Ile Val, Met → Leu; with Ala, Cys, His, Gly, Ser, Pro, and Thr, as structurally idiosyncratic residues. We also found a high average correlation (\overline{R} R = 0.85) between thirty amino acid mutability scales and the mutational inertia (I X ), which measures the energetic cost weighted by the number of observations at the most probable amino acid conformation. These results indicate that amino acid substitutions follow two optimally-efficient principles: (a) amino acids interchangeability privileges their secondary structural similarity, and (b) the amino acid mutability depends directly on its biosynthetic energy cost, and inversely with its frequency. These two principles are the underlying rules governing the observed amino acid substitutions. © 2017 The Author(s).

LEER
Multiple high-risk HPV genotypes are grouped by type and are associated with viral load and risk factors
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Del Río-Ospina, Luisa | 2017

Investigating whether high-risk human papillomavirus (HR-HPV) types tend to become grouped in a particular way and whether factors are associated with such grouping is important for measuring the real impact of vaccination. In total, 219 women proving positive for HPV as detected by real-time PCR were included in the study. Each sample was analysed for detecting and quantifying six viral types and the hydroxymethylbilane synthase gene. Multiple correspondence analysis led to determining grouping patterns for six HR-HPV types and simultaneous association with multiple variables and whether viral load was related to the coexistence of other viral types. Two grouping profiles were identified: the first included HPV-16 and HPV-45 and the second profile was represented by HPV-31, HPV-33 and HPV-58. Variables such as origin, contraceptive method, births and pregnancies, educational level, healthcare affiliation regime, atypical squamous cells of undetermined significance and viral load were associated with these grouping profiles. Different socio-demographic characteristics were found when coinfection occurred by phylogenetically related HPV types and when coinfection was due to non-related types. Biological characteristics, the number of viral copies, temporality regarding acquiring infection and competition between viral types could influence the configuration of grouping patterns. Characteristics related to women and HPV, influence such interactions between coexisting HPV types reflecting the importance of their evaluation

LEER
p-Methoxyphenol: A potent and effective scavenger for solid-phase peptide synthesis
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Samacá, Jhoan | 2020

During the final step of t-Boc/Bzl, solid-phase peptide synthesis (SPPS)-protecting groups from amino acids (aa) side chains must be removed from the target peptides during cleavage from the solid support. These reaction steps involve hydrolysis with hydrogen fluoride (HF) in the presence of a nucleophile (scavenger), whose function is to trap the carbocations produced during SN1-type reactions. Five peptide sequences were synthesised for evaluating p-methoxyphenol effectiveness as a potent scavenger. After the synthesis, the resin–peptide was then separated into two equal parts to be cleaved using two scavengers: conventional reactive p-cresol (reported in the literature as an effective acyl ion eliminator) and p-methoxyphenol (hypothesised as fulfilling the same functions as the routinely used scavenger). Detailed analysis of the electrostatic potential map (EPM) revealed similarities between these two nucleophiles, regarding net atomic charge, electron density distribution, and similar pKa values. Good scavenger efficacy was observed by chromatography and mass spectrometry results for the synthesised molecules, which revealed that p-methoxyphenol can be used as a potent scavenger during SPPS by t-Boc/Bzl strategy, as similar results were obtained using the conventional scavenger.

LEER
Plasmodium falciparum pre-erythrocytic stage vaccine development
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Molina Franky, Jessica | 2020

Worldwide strategies between 2010 and 2017 aimed at controlling malarial parasites (mainly Plasmodium falciparum) led to a reduction of just 18% regarding disease incidence rates. Many biologically-derived anti-malarial vaccine candidates have been developed to date; this has involved using many experimental animals, an immense amount of work and the investment of millions of dollars. This review provides an overview of the current state and the main results of clinical trials for sporozoite-targeting vaccines (i.e. the parasite stage infecting the liver) carried out by research groups in areas having variable malaria transmission rates. However, none has led to promising results regarding the effective control of the disease, thereby making it necessary to complement such efforts at finding/introducing new vaccine candidates by adopting a multi-epitope, multi-stage approach, based on minimal subunits of the main sporozoite proteins involved in the invasion of the liver.

LEER
Preliminary Evaluation of the Safety and Immunogenicity of an Antimalarial Vaccine Candidate Modified Peptide (IMPIPS) Mixture in a Murine Model
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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
Shorter antibacterial peptide having high selectivity for e. Coli membranes and low potential for inducing resistance
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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
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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
Structural analysis of owl monkey MHC-DR shows that fully-protective malaria vaccine components can be readily used in humans
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Suárez, Carlos F. | 2017

More than 50 years ago the owl monkey (genusAotus) was found to be highly susceptible to developinghuman malaria, making it an excellent experimental model for this disease. Microbes and parasites'(especially malaria) tremendous genetic variability became resolved during our malaria vaccine devel-opment, involving conserved peptides having high host cell binding activity (cHABPs); however, cHABPsare immunologically silent and must be specially modified (mHABPs) to induce a perfectfit into majorhistocompatibility complex (MHC) molecules (HLA in humans). Since malarial immunity is mainlyantibody-mediated and controlled by the HLA-DRB genetic region, ~1000Aotushave been molecularlycharacterised for MHC-DRB, revealing striking similarity between human andAotusMHC-DRB reper-tories. Such convergence suggested that a large group of immune protection-inducing protein structures(IMPIPS), highly immunogenic and protection inducers against malarial intravenous challenge inAotus,could easily be used in humans for inducing full protection against malaria. We highlight the value of alogical and rational methodology for developing a vaccine in an appropriate animal model:Aotusmonkeys

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

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Browsing by Author "Patarroyo, Manuel Elkin"

A comparative analysis of SLA-DRB1 genetic diversity in Colombian (creoles and commercial line) and worldwide swine populations ﻿

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

Association of HIV status with infection by multiple HPV types ﻿

Behavior and abundance of Anopheles darlingi in communities living in the Colombian Amazon riverside ﻿

A Comprehensive Review of the Immunological Response against Foot-and-Mouth Disease Virus Infection and Its Evasion Mechanisms ﻿

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 ﻿

Erratum: Publisher Correction: Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements ﻿

Functionally relevant proteins in Plasmodium falciparum host cell invasion ﻿

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

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

Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements ﻿

Multiple high-risk HPV genotypes are grouped by type and are associated with viral load and risk factors ﻿

p-Methoxyphenol: A potent and effective scavenger for solid-phase peptide synthesis ﻿

Plasmodium falciparum pre-erythrocytic stage vaccine development ﻿

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

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 ﻿

Structural analysis of owl monkey MHC-DR shows that fully-protective malaria vaccine components can be readily used in humans ﻿

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

Envíos recientes

A comparative analysis of SLA-DRB1 genetic diversity in Colombian (creoles and commercial line) and worldwide swine populations

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

Association of HIV status with infection by multiple HPV types

Behavior and abundance of Anopheles darlingi in communities living in the Colombian Amazon riverside

A Comprehensive Review of the Immunological Response against Foot-and-Mouth Disease Virus Infection and Its Evasion Mechanisms

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

Erratum: Publisher Correction: Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements

Functionally relevant proteins in Plasmodium falciparum host cell invasion

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

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

Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements

Multiple high-risk HPV genotypes are grouped by type and are associated with viral load and risk factors

p-Methoxyphenol: A potent and effective scavenger for solid-phase peptide synthesis

Plasmodium falciparum pre-erythrocytic stage vaccine development

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

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

Structural analysis of owl monkey MHC-DR shows that fully-protective malaria vaccine components can be readily used in humans

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

A comparative analysis of SLA-DRB1 genetic diversity in Colombian (creoles and commercial line) and worldwide swine populations

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

Association of HIV status with infection by multiple HPV types

Behavior and abundance of Anopheles darlingi in communities living in the Colombian Amazon riverside

A Comprehensive Review of the Immunological Response against Foot-and-Mouth Disease Virus Infection and Its Evasion Mechanisms

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

Erratum: Publisher Correction: Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements

Functionally relevant proteins in Plasmodium falciparum host cell invasion

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

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

Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements

Multiple high-risk HPV genotypes are grouped by type and are associated with viral load and risk factors

p-Methoxyphenol: A potent and effective scavenger for solid-phase peptide synthesis

Plasmodium falciparum pre-erythrocytic stage vaccine development

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

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

Structural analysis of owl monkey MHC-DR shows that fully-protective malaria vaccine components can be readily used in humans

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