PubMed · 7910041
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A Gringeri. 1994. Beriate-P study.. https://doi.org/10.1007/bf01774534
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Recent advances in class II tetramer staining technology have allowed reliable direct ex vivo visualization of antigen-specific CD4 T cells. In order to define the frequency and phenotype of a prototype response to a nonpersistent pathogen, we have used such techniques to analyze influenza virus-specific memory CD4 T cells directly from blood. These responses are stably detectable ex vivo at low frequencies (range, 0.00012 to 0.0061% of CD4 T cells) and display a distinct "central memory" CD62L(+) phenotype.
OBJECTIVES: In order to evaluate the role played by cytokine profile as a co-factor involved in the resistance to HIV infection in couples serodiscordant for HIV, we studied HIV-seronegative subjects with multiple unprotected sexual exposures. DESIGN AND METHODS: Twenty-one HIV-exposed seronegative subjects (HEPS), their 21 HIV-seropositive partners and 10 HIV-seronegative unexposed individuals were studied for T helper (Th) types 1-2 cell pattern and CCR5 receptor. RESULTS: Twelve out of 21 HIV-seropositive partners of HEPS showed a CD4 cell count below 200 lymphocytes/microl. HIV strains were isolated from peripheral blood mononuclear cells (PBMC) in 17 patients (81%): seven subjects with syncytium-inducing strains and 10 with non-syncytium-inducing isolates. Low Th1 cytokine production and high levels of IL-4 were detected in HIV-seropositive subjects. A significant reduction of IL-2 and IFN-gamma expression in the CD4 and CD8 cells of HEPS was found compared with HIV-seronegative unexposed individuals. Similar levels of low IL-4 were present in both HEPS and controls. The partial deletion of a single allele (wild type/delta32) of CCR5 was found in only one HEPS. CONCLUSION: The downregulated Th1 profile we observed in HEPS could be related to a cellular anergy state with a protective role in the transmission rate of HIV. Low levels of IL-2 and IFN-gamma could be involved in a low-grade activation state of CD4 lymphocytes. A decrease of IFN-gamma levels could render macrophage cells incapable of antigen presentation, thus resulting in a reduction of the cell-to-cell spread of infection.
Several pesticides used as herbicides, insecticides and fungicides are known to be endocrine disrupting chemicals (EDCs). In three pair-matched studies we found changes in sex hormone concentrations and T-lymphocytes in relation to acute and chronic pesticide exposure. After acute exposure, 1 day later the concentrations of testosterone and especially estradiol decreased. T4- and T8-lymphocytes slightly increased. Effects of chronic occupational pesticide exposure were expressed by a higher level of testosterone and a larger ratio of T4-/T8-lymphocytes in comparison to control persons. Concentrations of LH in exposed men were higher after exposure than before. We assume an inhibition of the aromatase system by testosterone metabolites. The studies show two effects with regard to the duration of exposure: a hormonal and immune suppression after acute exposure and an activation of both systems following chronic exposure.