MECHANISMS OF NATURAL-RESISTANCE TO MOUSE TYPHOID

Abstract

The early, innate resistance phase in mouse typhoid is largely controlled by a single gene (unlike the later, polygenic immune phase), designated Ity, which may be identical to those controlling resistance to Leishmania (Lsh) and mycobacteria (Bcg). The gene product and its function are unknown. Athymic (nu/nu) mice showed greater early resistance to salmonella infection than euthymic littermates, but only if they were already naturally resistant CBA (Ityr). Athymic susceptible Balb/c (Itys) were not different from the controls. The Ity mechanism is highly radio-resistant: 800 R whole body irradiation does not modify the early Ity phenotype in Balb/c and A/J mice, as measured by early in viv..