RESUMO
Fusion of CD4+ cells by HIV-1 envelope proteins (Env) is a mechanism of virus spread and cell damage. Production of antibodies able to influence cell-cell fusion in vivo may affect the course of the infection. The effect of sera from 49 HIV-1-positive patients was tested on an in vitro fusion assay using Env-expressing and normal Jurkat T cells labelled with DiI and DiO dyes, and flow cytometry for quantification of cell-cell fusion. Sera varied in their activity on fusion: 69.4 % inhibited, 24.5 % had no effect and 6.1 % enhanced cell fusion. Fusion activity correlated positively with the CD4+ T-cell count and inversely with the viral load. Removal of IgG or IgM from sera reduced or eliminated inhibition and enhancing activities, respectively. Antibodies with inhibitory activity predominate in early and intermediate stages of infection, whereas loss of inhibition or enhancement of fusion correlates with progression to AIDS.
Assuntos
Fusão Celular , Produtos do Gene env/metabolismo , Anticorpos Anti-HIV/imunologia , Infecções por HIV/fisiopatologia , HIV-1/patogenicidade , Progressão da Doença , Produtos do Gene env/farmacologia , Anticorpos Anti-HIV/sangue , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Células JurkatAssuntos
Glicolipídeos/farmacologia , Glicosaminoglicanos/farmacologia , Infecções por HIV/prevenção & controle , HIV-1/efeitos dos fármacos , Leite Humano/química , Antivirais , Células Cultivadas , Glicolipídeos/isolamento & purificação , Glicosaminoglicanos/isolamento & purificação , Humanos , Leucócitos Mononucleares/virologia , Macrófagos/virologiaRESUMO
The presence of serum antibodies to Entamoeba histolytica was detected by indirect hemagglutination in a representative sample of the 32 federal entities of the Mexican Republic. This study was designed to include biologic, geographic, social, economic, and educational variables. The total percentage of positive sera was 8.41%. Seroprevalence varied with geographic zones, with the South Central, South Pacific, and Yucatan Peninsula areas showing the highest values (> or = 9%), and the North, Northeast, and Gulf of Mexico areas showing the lowest values (< or = 8.0%). Seroprevalence of anti-E. histolytica antibodies seemed to increase from the northern regions to the southern areas of Mexico. These results indicated that amebiasis is endemic in the Mexican Republic, with areas of high seroprevalence not related to climatic conditions. Exposure to infectious contact with E. histolytica occurred at all ages, with a higher frequency at school age.
