Effect of histamine on cellular immunity modulation in vitro

Objective To investigate the influence of histamine on interleukin 2(IL 2) production and proliferation of CD4 T lymphocytes and CD8 T lymphocytes.Methods Density gradient centrifugalization and adsorption technique were respectively applied to detach peripheral blood mononuclear cells (PBMC) and peripheral blood lymphocytes (PBLC).CD4 and CD8 T lymphocytes divided by anti CD4 and anti CD8 antibody were cultured in vitro.IL 2 levels in supernatant were quantified by enzyme linked immunosorbent assay (ELISA),and proliferation index was measured by monotetrazolium (MTT) method.Results IL 2 levels in supernatant and proliferation rate of CD4 and CD8 T lymphocytes treated with histamine were significantly lower than those of their corresponding un stimulated controls (P0.05).IL 2 production and proliferation rate of CD4(CD8) T lymphocytes co cultured with histamine and cimetidine were higher than those of the controls cultured with histamine alone (P0.05).CD4 T lymphocyte produced much more IL 2 than CD8.Conclusion Histamine inhibits T lymphocyte proliferation and IL 2 production,and the inhibitory effect can be stocked by cimetidine.CD8 T lymphocytes also secret IL 2,but less than CD4.