Wild-Type Gross Leukemia Virus. II. Influence of Immunogenetic Factors on Natural Transmission and on the Consequences of Infection2

Abstract

To determine the influence of host genotype and other factors on the transmission of wild-type Gross virus and on the subsequent course of infection, mice of various inbred, F₁ hybrid, and segregating populations were tested individually for the presence of Gross soluble antigen (GSA) or Gross (G) natural antibody in the blood. GSA was invariably present in mice of strains with a high incidence of leukemia. Among the hybrid progeny of various crosses between G+ and G− strains the proportion of mice with GSA in the plasma was influenced by a) the genotype contributed by the G− parent (whether resistant or sensitive to Passage A Gross virus) and b) the direction of the cross (whether G+♀ × G−♂ or G−♀ × G+♂). Naturally occurring G antibody was most frequent in C57BL/6 mice, which are highly resistant to Passage A Gross virus, and in the progeny of hybrids with C57BL/6. G antibody was rare in C3Hf/Bi mice, a G− strain that is sensitive to Gross virus, and in C3Hf/Bi hybrids. In populations segregating for H-2 antigens, the genotype H-2^k favored the occurrence of GSA, indicating immunological tolerance, and H-2^b, the occurrence of G antibody, indicating lack of tolerance.