Effect of mycoplasmas on phagocytosis and immunocompetence in rats.

The purpose of this study was to evaluate some possible mechanisms by which mycoplasmas may facilitate a subsequent bacterial infection. The effector of M. arthritidis, M. hominis and U. urealyticum on lymphocyte reactivity to mitogens, subsequent antibody response, and the ability of neutrophils to carry out phagocytosis was investigated. In vitro, large doses of M. arthritidis and M. hominis depressed the reactivity of lymphocytes and the phagocytic ability of neutrophils. In vivo, inoculation of myoplasmas had no effect on reactivity of lymphocytes from rats, and antibody response to subsequently injected E. coli was normal. However, peritoneal neutrophils from rats injected intraperitoneally with large doses of M. arthritidis and M. Hominis were invalidated in their ability to cause phagocytosis of E. Coli. U. urealyticum had no observable effect on lymphocytes and neutrophils in vitro and in vivo.