Accessory function of aging Kupffer cells with different lymphocyte populations.

The present studies show that rat Kupffer cells are capable of both suppression and enhancement of mitogen responses. Studies were conducted using the T-cell mitogens concanavalin A and phytohemmaglutinin, as well as the rat B-cell mitogen Mycoplasma neurolyticum. Whereas Kupffer cell concentrations of 1 X 10(5)/well significantly suppressed the T- and B-mitogen response of both spleen nonadherent and peripheral blood lymphocytes, enhancement was restricted to the T-cell mitogen responses. No tissue-related differences were found in the suppression. However, both tissue differences and age-related changes were observed with enhancement. Age-related changes in the Kupffer cell resulted in a decreased enhancement of the proliferative response of spleen to concanavalin A and an increased response of peripheral blood lymphocytes.