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M A Patarroyo

Publications and source records attributed to M A Patarroyo.

10 recordsLinked to original sources
PubMed2006

High polymorphism in Plasmodium vivax merozoite surface protein-5 (MSP5).

A key issue relating to developing multi-component anti-malarial vaccines, lies in studying Plasmodium vivax surface proteins' genetic variation. The present work was aimed at amplifying, cloning and sequencing the gene encoding P. vivax merozoite surface protein 5 (PvMSP5) in samples obtained from infected patients from Colombian areas having varying malaria transmission rates. Nucleotide sequence data reported in this paper are available in the GenBank, EMBL and DDBJ databases under Accessions numbers DQ341586 to DQ341601. Our results have revealed that PvMSP5 is one of the P. vivax surface proteins having greater polymorphism, this being restricted to specific protein regions. The intron and exon II (which includes the GPI anchor and EGF-like domain) were both highly conserved when compared to exon I; exon I displayed the greatest variation and most of the recombination events occurred within it. No geographical grouping was observed. The Nei-Gojobori test revealed significant positive selection in the samples analysed here, whereas Tajima and Fu and Li tests presented a neutral selection pattern. The results reflected a localized variation pattern, recombination between PvMSP5 alleles and also functional and immune pressures, where stronger selective forces might be acting on exon I than on exon II, suggesting that the latter could be an important region to be included in an anti-malarial vaccine.

Amino Acid Sequence↗
PubMed2005

Identification of five different IGHV gene families in owl monkeys (Aotus nancymaae).

In order to characterize immunoglobulin heavy-chain variable (IGHV) genes in Aotus nancymaae monkeys, different mRNAs encoded by five IGHV families in this non-human primate were molecularly analysed considering their paramount importance in antibody production in an immune response. This study reports gene products exhibiting 91% amino acid similarity with IGHV1, IGHV2, IGHV3, IGHV4 and IGHV7 human IGHV families. Our analyses suggest that the IGHV gene has several conserved characteristics in humans and A. nancymaae. Several amino acid residues that are highly conserved in all family members described in humans were also present in these families in A. nancymaae. Antibody diversity in these families has remained the same since divergence of both species. Our study continues to provide evidence supporting the use of A. nancymaae monkey as an animal model for studying antibody response.

Amino Acid Sequence↗
PubMed2004

Isolation and identification of mycobacteria in New World primates maintained in captivity.

The presence of several Mycobacterium species was determined in 68 New World monkeys kept captive in the Cali Zoo. One hundred and thirty-three gastric lavage and blood samples were evaluated for mycobacterial presence by Ziehl-Neelsen (ZN) staining, culture and PCR amplification of the Mycobacterium tuberculosis Mtp40 species-specific gene. Mycobacteria other than tuberculosis (MOTT) were identified by PCR restriction fragment length polymorphism (RFLP). Different species of mycobacteria were detected in 65% of the primate population studied by Alpha Antigen PCR. Eleven percent were positive for Mtp40 PCR amplification, being diagnosed as having M. tuberculosis, and acid-fast bacilli were observed in 23% by ZN staining. MOTT were isolated from samples taken from 37 primates by culturing; according to the RFLP analysis, three strains were classified as belonging to the MAISS complex (Mycobacterium avium-intracellulare-scrofulaceum-simiae) and eight more, isolated from soil inside the cages, were categorized as environmental contaminants. Mycobacterium spp. were detected in 13 different New World primate species showing that PCR amplification of the Mtp40 gene is a better tool than culture for M. tuberculosis detection in captive animals and that RFLP is a useful technique for MOTT identification.

Animals↗
PubMed2004

Plasmodium vivax Duffy binding protein: a modular evolutionary proposal.

The population of malaria-causing parasites is characterized by great genetic diversity. Knowledge of the polymorphism generation mechanism is a central issue for developing effective vaccines against malaria and understanding the parasite population structure. Plasmodium vivax genetic diversity has been explained in terms of two major factors: natural selection and intragenic recombination. A modular organization was found within P. vivax Duffy binding protein in the present work. Four Colombian isolates have identical sequences to Salvador-1 strain amongst dpb regions III-VI analysed, suggesting a high identity between Central and South American isolates. Geographically clustered sectors, corresponding to cysteine-rich regions (II and VI), show a high sequence diversity that could reflect a possible immune response evasion mechanism; both positive and negative selection were detected in these regions. In contrast, other dbp gene regions display a non-geographical clustering pattern, lower sequence diversity and predominant negative selective pressure. Recombination was homogeneously detected all along the molecule. These findings suggest that diversification vs. homogenizing forces, drive dbp gene evolution and determine its mosaic region organization.

Amino Acid Sequence↗
PubMed2003

Alpha1 and alpha2 domains of Aotus MHC class I and Catarrhini MHC class Ia share similar characteristics.

Functional and structural analyses of major histocompatibility complex (MHC) class I molecules of the Aotus genus are necessary to validate it as a solid animal model for biomedical research. We thus isolated, cloned and sequenced exons 2 and 3 from three Aotus species (A. nancymaae, A. nigriceps and A. vociferans). We found 24 sequences, which divided into two different groups (Ao-g1 and Ao-g2). A further sequence was identified as a processed pseudogene (Aona-PS2). Both sequence evolution and variability analyses showed that Ao-g1 and Ao-g2 display similar characteristics to Catarrhini's classical loci, such as positive selection pressure at the peptide binding region (PBR) high variability and a trans-specific evolution pattern.

Amino Acid Sequence↗
PubMed2003

Characterizing T-cell receptor gamma-variable gene in Aotus nancymaae owl monkey peripheral blood.

Gammadelta T lymphocytes have a heterodimeric complex formed by the association of gamma and delta chains as receptor. Proliferation of this lymphocyte population has been observed, when infection by several pathogens such as Mycobacterium tuberculosis and Plasmodium spp. occurs. The New World Monkey Aotus nancymaae has become a very good experimental model for the immunological and physiopathological study of these infectious agents. The A. nancymaae gamma-variable region was characterized from peripheral blood samples by using cDNA and genomic DNA polymerase chain reaction amplification, DNA sequencing, and dot-blot hybridization techniques. Seventeen different T-cell receptor gamma-variable (TCRGV) sequences were obtained. These sequences were distributed among TCRGV subsets 1, 2, or 3, according to human subset classification. Although no subset 4 amplification was obtained, this subset was detected by dot-blot hybridization. The presence of these 4 subsets resembles the behavior displayed by 'gammadelta-low species' (humans and mice), where high diversity among these lymphocytes can be observed. Homologies greater than 70% were found with respect to humans. Sequence convergence between human and A. nancymaae subsets 1 and 3 highlights Aotus as a promising model for studying these lymphocyte functions.

Amino Acid Sequence↗
PubMed2000

Plasmodium vivax: polymorphism in the merozoite surface protein 1 gene from wild Colombian isolates.

The Plasmodium vivax merozoite surface protein-1 (PvMSP-1) has been considered a candidate for a malaria vaccine against erythrocytic stages. PvMSP-1 is immunogenic during natural infections and exhibits antigenic polymorphism. The extent of genetic polymorphism in a region between the so-called interspecies conserved blocks (ICBs) 2 and 4 of the PvMSP-1 was analyzed in 20 isolates taken from patients from two different areas in Colombia. Variation is unevenly distributed along this gene segment among the isolates. Comparative analysis of these sequences led to the definition of five sequence types (ST1 to 5). ST1 to ST4 exhibit a variation pattern associated with sequences present in the Salvador or Belem sequences. However, ST5 has clusters of sequence that have not been previously described. The changes found along the five variants confirm the important role of recombinational and/or gene conversion events in generating allelic diversity.

Amino Acid Sequence↗