Lymphatic mast cells in response to in vitro stimulation by non-specific T-cell mitogens.

Activation of lymph nodes by the T-cell mitogens PHA and Con A is correlated with a depletion of lymphatic mast cells. This result, and our earlier reports on the depletion of mast cells in lymph nodes stimulated by allogeneic and tumour cells, as well as on the elevation of mast cell number in thymus-less 'nude' mice, lead us to the conclusion that antigen- or mitogen-stimulated T lymphocytes produce lymphokine(s) which degranulates mast cells and/or is responsible for their negative chemotaxis.