Inhibition of lymphocyte circulation in mice by pertussis toxin

Publisher Website
Google Scholar
Abstract
Pertussis toxin (PT), a protein toxin of Bordetella pertussis, also called pertussigen, has a wide range of biological activities, including the induction of lymphocytosis. This phenomenon was investigated by studying lymphocyte circulation in mice. Lymph node cell suspensions were exposed to PT in vitro and then injected intravenously. A double radiolabel technique was employed, in which PT-treated and control cells were injected into the same animals. The protocol used in these experiments was chosen to demonstrate a direct effect of PT on the injected cells. After exposure to PT in vitro, cells were profoundly excluded from lymph nodes over the succeeding six days. Entry into both mesenteric and peripheral lymph nodes, but not into the spleen was inhibited by PT, and there was an accumulation of the PT-treated cells in the blood. Cells were excluded from the lymph nodes after treatment with as little as 2 ng/mL of PT. This dose was over two orders of magnitude lower than the threshold dose of the same PT preparation required to induce lymphocyte mitogenesis in vitro. The findings in the present communication are consistent with studies using genetically modified PT in which the ADP-ribosylating capacity of the A-subunit was necessary for the effect of PT on lymphocytosis.