Pasteurella haemolytica leukotoxin inhibits mitogen-induced bovine peripheral blood mononuclear cell proliferation in vitro.

In this study we demonstrate that partially purified Pasteurella haemolytica leukotoxin inhibits the proliferative response of bovine peripheral blood mononuclear cells (PBMC) to mitogens in vitro. Inhibition of PBMC proliferation did not appear to be due to cell death. Addition of a neutralizing anti-leukotoxin monoclonal antibody restored a normal proliferative response.