Susceptibility of inbred mice to Leishmania major infection: genetic analysis of macrophage activation and innate resistance to disease in individual progeny of P/J (susceptible) and C3H/HeN (resistant) mice.

We tested the possibility that two phenotypic traits, defective activation of macrophage antileishmanial activities and susceptibility to infection with Leishmania major, were controlled by the same gene. We used P/J (susceptible) and C3H/HeN (resistant) mice to breed F1, backcross (Bx), and F2 mice that were tested individually for both traits, each of which is known to be controlled by a single autosomal gene. We found no correlation between the macrophage defect and cutaneous disease. There was a correlation between development of systemic disease and defective macrophage activation in Bx mice; this correlation, however, was not confirmed in the F2 population.