TRANSFORMING GROWTH-FACTOR-BETA IS PROTECTIVE IN HOST-RESISTANCE AGAINST LISTERIA-MONOCYTOGENES INFECTION IN MICE

The role of transforming growth factor beta (TGF-beta) in host resista nce against Listeria monocytogenes infection was studied with mice. Th e constitutive expression of TGF-beta 1 mRNA was observed in the splee ns and livers of mice before and after infection. Injecting the mice w ith anti-TGF-beta 1 peptide serum resulted in diminished antilisterial resistance, whereas the administration of human platelet-derived TGF- beta 1 enhanced the resistance. Moreover, mice were protected against lethal infection when treated with TGF-beta 1. These results suggest t hat TGF-beta 1 might be involved in antilisterial resistance. On the o ther hand, injecting the mice with TGF-beta 1 resulted in a decrease i n the titers of endogenous gamma interferon, tumor necrosis factor alp ha, and interleukin-6, which are crucial in antilisterial resistance, in sera and in extracts of spleen and liver. Thus, a complicated mecha nism might be involved in the role of TGF-beta 1 in host resistance ag ainst L. monocytogenes infection.