LACK OF VIRAL SELECTION IN HIV-1 MOTHER TO CHILD TRANSMISSION WITH PRIMOINFECTION DURING LATE PREGNANCY AND/OR BREASTFEEDING

ANA CEBALLOS; GUADALUPE ANDREANI1; CHIARA RIPAMONTI2; DARIO DILERNIA; RAMIRO MENDEZ; SCARLATTI GABRIELA; LILIANA MARTINEZ PERALTA

JOURNAL OF GENERAL VIROLOGY

SOC GENERAL MICROBIOLOGY

Año: 2008 vol. 89 p. 2773 - 2782

0022-1317

Summary Mother-to-child transmission of HIV-1 as described for women with established infection was, in most cases, associated with transmission of few maternal variants. We analyzed the viral variability in four cases of maternal primoinfection occurring during pregnancy and/or breastfeeding. Estimated time of seroconversion was at fourth months of pregnancy for one woman (early seroconversion) and during the last months of pregnancy and/or breastfeeding for the remaining three (late seroconversion). The C2V3 envelope region was analyzed in samples of mother-child pairs by molecular cloning and sequencing. Comparisons of both nucleotide and amino acid sequences as well as phylogenetic analysis were performed. Our results showed low variability in both mother and child?s viral population. Maximum likelihood analysis showed that in the early pregnancy seroconversion case, a minor viral variant with further evolution in the child was transmitted, which could show a selection event in mother-to-child transmission or a stochastic event, whereas in the late seroconversion cases, mother and child?s sequences were intermingled, which is compatible with the transmission of multiple viral variants from the mother?s major population. Our results could be explained by the less pronounced selective pressure exerted by the immune system in early stages of the mother?s infection, which could play a role in MTCT of HIV-1. Mother-to-child transmission of HIV-1 as described for women with established infection was, in most cases, associated with transmission of few maternal variants. We analyzed the viral variability in four cases of maternal primoinfection occurring during pregnancy and/or breastfeeding. Estimated time of seroconversion was at fourth months of pregnancy for one woman (early seroconversion) and during the last months of pregnancy and/or breastfeeding for the remaining three (late seroconversion). The C2V3 envelope region was analyzed in samples of mother-child pairs by molecular cloning and sequencing. Comparisons of both nucleotide and amino acid sequences as well as phylogenetic analysis were performed. Our results showed low variability in both mother and child?s viral population. Maximum likelihood analysis showed that in the early pregnancy seroconversion case, a minor viral variant with further evolution in the child was transmitted, which could show a selection event in mother-to-child transmission or a stochastic event, whereas in the late seroconversion cases, mother and child?s sequences were intermingled, which is compatible with the transmission of multiple viral variants from the mother?s major population. Our results could be explained by the less pronounced selective pressure exerted by the immune system in early stages of the mother?s infection, which could play a role in MTCT of HIV-1. Mother-to-child transmission of HIV-1 as described for women with established infection was, in most cases, associated with transmission of few maternal variants. We analyzed the viral variability in four cases of maternal primoinfection occurring during pregnancy and/or breastfeeding. Estimated time of seroconversion was at fourth months of pregnancy for one woman (early seroconversion) and during the last months of pregnancy and/or breastfeeding for the remaining three (late seroconversion). The C2V3 envelope region was analyzed in samples of mother-child pairs by molecular cloning and sequencing. Comparisons of both nucleotide and amino acid sequences as well as phylogenetic analysis were performed. Our results showed low variability in both mother and child?s viral population. Maximum likelihood analysis showed that in the early pregnancy seroconversion case, a minor viral variant with further evolution in the child was transmitted, which could show a selection event in mother-to-child transmission or a stochastic event, whereas in the late seroconversion cases, mother and child?s sequences were intermingled, which is compatible with the transmission of multiple viral variants from the mother?s major population. Our results could be explained by the less pronounced selective pressure exerted by the immune system in early stages of the mother?s infection, which could play a role in MTCT of HIV-1. Mother-to-child transmission of HIV-1 as described for women with established infection was, in most cases, associated with transmission of few maternal variants. We analyzed the viral variability in four cases of maternal primoinfection occurring during pregnancy and/or breastfeeding. Estimated time of seroconversion was at fourth months of pregnancy for one woman (early seroconversion) and during the last months of pregnancy and/or breastfeeding for the remaining three (late seroconversion). The C2V3 envelope region was analyzed in samples of mother-child pairs by molecular cloning and sequencing. Comparisons of both nucleotide and amino acid sequences as well as phylogenetic analysis were performed. Our results showed low variability in both mother and child?s viral population. Maximum likelihood analysis showed that in the early pregnancy seroconversion case, a minor viral variant with further evolution in the child was transmitted, which could show a selection event in mother-to-child transmission or a stochastic event, whereas in the late seroconversion cases, mother and child?s sequences were intermingled, which is compatible with the transmission of multiple viral variants from the mother?s major population. Our results could be explained by the less pronounced selective pressure exerted by the immune system in early stages of the mother?s infection, which could play a role in MTCT of HIV-1. Mother-to-child transmission of HIV-1 as described for women with established infection was, in most cases, associated with transmission of few maternal variants. We analyzed the viral variability in four cases of maternal primoinfection occurring during pregnancy and/or breastfeeding. Estimated time of seroconversion was at fourth months of pregnancy for one woman (early seroconversion) and during the last months of pregnancy and/or breastfeeding for the remaining three (late seroconversion). The C2V3 envelope region was analyzed in samples of mother-child pairs by molecular cloning and sequencing. Comparisons of both nucleotide and amino acid sequences as well as phylogenetic analysis were performed. Our results showed low variability in both mother and child?s viral population. Maximum likelihood analysis showed that in the early pregnancy seroconversion case, a minor viral variant with further evolution in the child was transmitted, which could show a selection event in mother-to-child transmission or a stochastic event, whereas in the late seroconversion cases, mother and child?s sequences were intermingled, which is compatible with the transmission of multiple viral variants from the mother?s major population. Our results could be explained by the less pronounced selective pressure exerted by the immune system in early stages of the mother?s infection, which could play a role in MTCT of HIV-1.