Comparison of Susceptibility to Phagocytosis by Mouse Peritoneal Macrophages between Corynebacterium renale Piliated and Non-Piliated Clones

Abstract

Piliated (P⁺) and non-piliated (P^-) bacteria of Corynebacterium renale strain No. 115 were compared in their susceptibility to phagocytosis by mouse peritoneal macrophages. In the absence of opsonins, P⁺ bacteria were less phagocytized than P^- bacteria (P<0.001). Complement at 20% concentraTion enhanced the uptakes of P⁺ and P^- bacteria (P<0.01). In the presence of anti-pili serum, P⁺ bacteria were phagocytized at a significantly higher rate than P^- bacteria (P<0.01), regardless of the presence of complement. The anti-pili monoclonal antibodies 16/5 and 13/4 were also opsonic for P⁺ bacteria, regardless of the presence of complement, but there was less effect than that of anti-pili polyclonal antibody. In the presence of anti-P⁺ bacteria serum and complement, P⁺ bacteria were more significantly phagocytized than P^- bacteria (P<0.05), which was possibly due to presence of anti-pili antibody in the anti-P⁺ bacteria serum. In the presence of anti-P^- bacteria serum, the uptake of P⁺ bacteria was unexpectedly enhanced and bacame nearly equal to that of P^- bacteria. The uptake of P^- bacteria was nearly constant in all the experiments, except that it was slightly enhanced by the presence of complement.