To document the in vivo interactions occurring between the immune system and HIV replicating cells, we analyzed using in situ hybridization the production of IL-1#, and INF-y in eight hyperplastic lymph nodes from HIV-1 infected patients. Numerous IL-1ft-and IL-6-producing cells associated in clusters were detected in sinuses. Few individual IL-1l#-and IL-6-producing cells were present in interfollicular and follicular areas. IL-2-and INF-'y-producing cells were observed in all lymph node compartments, with a selective enrichment in germinal centers. The amount and distribution of
Intravenous gammaglobulin (IVIgG) was given to seven adults with chronic idiopathic thrombocytopenic purpura (ITP). In parallel with platelet count, we studied Con A induced suppressor cell function for the autologous in vitro B cell response, T cell subsets and PAIgG levels, immediately before and 3-4 d after completion of treatment. Before treatment all patients had normal T cell subsets, decreased T suppressor cell function and increased levels of PAIgG. After IVIgG infusions, two patients were unresponsive and neither suppressor cell function nor PAIgG levels varied. In contrast, in the five responding patients we found an improvement in suppressor cell function and a decrease in PAIgG levels, while T cell subsets remained unmodified. Such results were reproducible in three patients after a second series of gammaglobulin infusions. Our results support the hypothesis that IVIgG infusion, apart from its effects on the reticuloendothelial system, may modulate the immune response by enhancing suppressor T cell function.
Interleukin-12 (IL-12), a cytokine with in vitro and in vivo immunomodulatory effects, is produced mostly by activated monocytes and macrophages. To study the effect of human immunodeficiency virus (HIV) infection on IL-12 production, we investigated the expression of IL-12 at mRNA and protein levels by human monocytes preincubated with HIV-gp120. In these conditions, we show that monocytes have a decreased ability to express IL-12 mRNA subunits and to produce IL-12 p40 and bioactive p70 proteins in response to Staphylococcus aureus strain cowan I (SAC). We showed that in human monocyte cultures, HIV-gp120 induces a significant IL-10 synthesis, which in turn inhibits IL-12 subunits mRNA accumulation and protein secretion after SAC-activation. Similar data were obtained with human macrophages. These results suggest that, during HIV infection, gp120 induces in uninfected monocytes and macrophages IL-10/IL-12 disregulation, which can alter immune response.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.