H1 histamine receptor antagonist inhibits constitutive growth of Jurkat T cells and antigen-specific proliferation of ovalbumin-specific murine T cells

Histamine is produced from histidine by histidine decarboxylase (HDC) in ma ny cells including normal and malignant lymphocytes. We examined the expres sion of HDC and the effect of histamine receptor antagonists on the prolife ration of a human T cell line, Jurkat and on antigen-driven proliferation o f lymphocytes from ovalbumin-immunized mice. Our results demonstrate that H DC is inducible in Jurkat cells by anti-CD3. The H1 receptor antagonist tri prolidine dose dependently inhibits proliferation of both Jurkat cells and ovalbumin-stimulated murine lymphocytes, while the H2 antagonist ranitidine was ineffective. Alpha-fluoro-methyl-histidine blocking HDC activity did n ot inhibit the T cell proliferation, suggesting an existing pool of histami ne in T cells.