Evidence for participation of the macrophage in Shiga-like toxin II-induced lethality in mice.

Seven strains of inbred mice were compared for their susceptibility to the lethal effects of Shiga-like toxin II (SLT II). A/J mice, which are unable to produce the C5 component of complement, did not differ from C5 normal mice in susceptibility to SLT II. CBA/NJ mice (hemizygous for X-linked immunodeficiency) did not differ from the B-cell sufficient CBA/J strain. C3H/HeJ mice, defective in macrophage response to lipopolysaccharide (Lpsd), showed a consistently and significantly longer mean time to death than did the normally responsive C3H/HeN strain. C57BL/10ScN mice, which also carry the Lpsd allele, showed a similar but smaller difference in mean time to death compared with the C57BL/10SnJ strain. Production of tumor necrosis factor could be induced in vitro by SLT II treatment of C3H/HeN, but not C3H/HeJ macrophages. These results imply that antibody and complement production do not modulate SLT II lethality in mice, but that the macrophage may contribute to SLT II-induced injury.