RESUMEN
Variations of the expression of CXCR4 and CCR5 HIV co-receptors after non stimulated culture of peripheral blood mononuclear cells (PBMC) from HIV+ patients were studied. Expression of CCR5 on both CD4+ and CD8+ T lymphocytes was reduced after 7 days and remained low throughout the culture. CXCR4 levels remained stable in both lymphocyte subpopulations. No significant changes were observed in control HIV- PBMC cultures. In order to ascertain if the CCR5 changes were associated to in vitro HIV replication, 6 days pre-cultured HIV- PBMC were infected with HIV+ culture supernatants. After 3 days CCR5 expression was reduced both in CD4+ and in CD8+ T lymphocytes, while CXCR4 expression was not, coincident with initiation of HIV replication in culture. These results suggest that CCR5 down modulation in CD4+ or CD8+ T lymphocytes is a consequence of HIV replication.
RESUMEN
Generalized activation of the immune system after HIV infection leads to an exacerbation of all apoptotic mechanisms. CD4+, CD8+ T lymphocytes and B lymphocytes are sensitized to apoptotic stimuli. Macrophages are important in the removal of apoptotic cells, they prevent apoptotic cell accumulation during in vitro culture and they may lead to enhanced CD4+ T lymphocyte cell death through indirect mechanisms. A simple procedure for prolonged culture of peripheral blood mononuclear cells from HIV+ patients is discussed, in relation to its convenience to evaluate apoptosis, cell to cell interaction and HIV replication in the absence of exogenously added stimuli or co-culture of allogeneic cells. In this system, HIV replication takes place primarily in cells of macrophage lineage that may be activated into differentiation through removal of apoptotic debris during the culture.
Asunto(s)
Humanos , Linfocitos T CD4-Positivos/fisiología , Infecciones por VIH/virología , VIH/fisiología , Apoptosis , Fagocitos/fisiología , Fagocitosis/fisiología , Replicación Viral , Activación de Linfocitos , Comunicación Celular , Técnicas de Cultivo de Célula/métodos , Carga ViralRESUMEN
Generalized activation of the immune system after HIV infection leads to an exacerbation of all apoptotic mechanisms. CD4+, CD8+ T lymphocytes and B lymphocytes are sensitized to apoptotic stimuli. Macrophages are important in the removal of apoptotic cells, they prevent apoptotic cell accumulation during in vitro culture and they may lead to enhanced CD4+ T lymphocyte cell death through indirect mechanisms. A simple procedure for prolonged culture of peripheral blood mononuclear cells from HIV+ patients is discussed, in relation to its convenience to evaluate apoptosis, cell to cell interaction and HIV replication in the absence of exogenously added stimuli or co-culture of allogeneic cells. In this system, HIV replication takes place primarily in cells of macrophage lineage that may be activated into differentiation through removal of apoptotic debris during the culture.
RESUMEN
A new method of culture of peripheral blood leukocytes (PBMC) from HIV+ patients, in the absence of exogenous stimuli (allogeneic cells or cytokines) (PBMC w/s) was used for the detection of persistent viral infection in HIV patients who had undergone successful highly active antiretroviral therapy (HAART) lowering their viral burden to undetectable levels (< 50 RNA copies/ml). Infected cells were always of the monocyte/macrophage lineage (M). No infection could be detected in these patients using the classical system (co-culture with HIV-CMP activated with PHA and IL-2). Differences in the class of target cells (higher proportion of proliferating M and CCR5 expressing cells in the PBMC w/s system than in PBMC-PHA cultures) may determine the relative sensitivity of each technique to achieve successful isolation of HIV from different patients.
RESUMEN
Apoptosis is a physiologic process whereby undesired cells are eliminated in a non-inflammatory way. It is characterized by cellular retraction, clumping of nuclear chromatin and DNA retraction followed by DNA degradation into oligonucleosomes formed by 180-185 base pairs or multiples of these units that can be identified electrophoretically. The plasma membrane and organelles are well conserved until the final stages of the process. Apoptosis is central to many of the functions of the immune system. A review of its role in the immune system as well as in AIDS is presented, as well as a brief description of the methodology that can be followed for the assay of apoptosis.
RESUMEN
We present studies on the evolution of HIV-1 infection in 638 hemophilic patients receiving commercial antihemophilic concentrates (CAH) at the Institute of Hematological Research and the Argentine Foundation of Hemophilia between 1983 and 1990. Positive serology for HIV-1 was detected in 30
of the patients studied. Prevalence of HIV-1 infection was higher (about 70
) in the group with severe hemophilia requiring more CAH, but there were no differences between patients with hemophilia A or B. Sexual transmission was demonstrated in 8/64 women (13
) with stable sexual relationship with HIV-1 + hemophilic patients. Three of them became pregnant, and HIV-1 infection was demonstrated in two of the three children. In general, the clinical evolution, as well as the hematologic and immunologic parameters of infected patients were similar to those described for the hemophilic population in other occidental countries. Opportunistic infections were also those observed elsewhere (with predominance of P. carinii pneumonia and disseminated Candida infections). However, the presence of fatal chagasic encephalitis in two of the patients with AIDS is unusual. Thus, central nervous system localization of T. cruzi (which can be observed during the acute period of T. cruzi infection or in immunosuppressed patients), must be considered as a possible severe complication of HIV-1 disease in T. cruzi infected patients.
RESUMEN
We present studies on the evolution of HIV-1 infection in 638 hemophilic patients receiving commercial antihemophilic concentrates (CAH) at the Institute of Hematological Research and the Argentine Foundation of Hemophilia between 1983 and 1990. Positive serology for HIV-1 was detected in 30
of the patients studied. Prevalence of HIV-1 infection was higher (about 70
) in the group with severe hemophilia requiring more CAH, but there were no differences between patients with hemophilia A or B. Sexual transmission was demonstrated in 8/64 women (13
) with stable sexual relationship with HIV-1 + hemophilic patients. Three of them became pregnant, and HIV-1 infection was demonstrated in two of the three children. In general, the clinical evolution, as well as the hematologic and immunologic parameters of infected patients were similar to those described for the hemophilic population in other occidental countries. Opportunistic infections were also those observed elsewhere (with predominance of P. carinii pneumonia and disseminated Candida infections). However, the presence of fatal chagasic encephalitis in two of the patients with AIDS is unusual. Thus, central nervous system localization of T. cruzi (which can be observed during the acute period of T. cruzi infection or in immunosuppressed patients), must be considered as a possible severe complication of HIV-1 disease in T. cruzi infected patients.
RESUMEN
The immunological competence of eleven patients with undetermined leprosy was compared with that of ten normal volunteers of the same age and sex distribution; these controls have not had previous contact with leprosy. The following parameters were studied in peripheral blood cells: 1) percentage of lymphocyte bearing surface immunoglobulins, as revealed by immunofluorescence; 2) percentage of lymphocyte bearing complement receptors, as studied by antibody and complement coated erithrocyte rosetting; 3) percentage of T cells, as revealed by spontaneous sheep erithrocyte rosettes; 4) blastogenic and mytogenic response of cultured lymphocytes to PHA and 5) cell migration inhibition test using lepromine (80 x 10(6) bacilli/ml) as antigen. Skin reactions to lepromine were also assayed. In the six lepromine-positive patients with undetermined leprosy, no major immunological alterations could be detected. On the contrary, the five lepromine-negative patients showed important alterations which could well be considered as precursors of lepromatous leprosy.
RESUMEN
The immunological competence of eleven patients with undetermined leprosy was compared with that of ten normal volunteers of the same age and sex distribution; these controls have not had previous contact with leprosy. The following parameters were studied in peripheral blood cells: 1) percentage of lymphocyte bearing surface immunoglobulins, as revealed by immunofluorescence; 2) percentage of lymphocyte bearing complement receptors, as studied by antibody and complement coated erithrocyte rosetting; 3) percentage of T cells, as revealed by spontaneous sheep erithrocyte rosettes; 4) blastogenic and mytogenic response of cultured lymphocytes to PHA and 5) cell migration inhibition test using lepromine (80 x 10(6) bacilli/ml) as antigen. Skin reactions to lepromine were also assayed. In the six lepromine-positive patients with undetermined leprosy, no major immunological alterations could be detected. On the contrary, the five lepromine-negative patients showed important alterations which could well be considered as precursors of lepromatous leprosy.
RESUMEN
Concanavalin A (Con-A)-induced suppression of T cell proliferation was studied in 48 patients with severe hemophilia. Two groups of patients were defined according to the proliferative response when increasing numbers of Con A-induced cells were added to a constant number of phytohemagglutinin (PHA)-stimulated autologous T cells: In group A (60
) and in normal controls, higher suppression was achieved when more Con A-induced cells were added; in Group B, increasing numbers of Con A-induced cells produced no suppression of stimulated PHA-triggered proliferation. This effect could be corrected in Group B by inducing suppression in the presence of inhibitors of the oxidative metabolism of arachidonic acid. No correlation was found between the suppression profile and HIV-1 or HBV serology. Clinical evolution, as judged by signs and symptoms of AIDS related complex tended to be better in Group B than in Group A patients. It is suggested that decreased Con A-induced suppression in Group B may represent part of a normal regulatory process that involves products of arachidonic acid oxidative metabolism.