Use of H-2:H-7 congenic mice to study H-2-mediated resistance to Friend leukemia virus

Congenic and double congenic mice expressing different H-7 alleles with varying H-2 haplotypes on the C57BL/10 (B10) background were tested for their susceptibility to Friend virus (FV) infection. Mice expressing the H-7^b allele derived from BALB/c were susceptible to FV infection whereas mice expressing the H-7^a allele of B10 were absolutely resistant. Coexpression of H-7^b and the H-2^a and H-2(d) haplotypes determined high susceptibility; mice expressing both H-7^b and H-2^b were relatively resistant compared to H-7^b mice expressing H-2^a or H-2(d). Parallel experiments with BALB/c and BALB.B recipients did not demonstrate differences in susceptibility associated with H-2(d) and H-2^b. Mapping experiments with the H-2(h4) and H-2(i5) recombinants indicated that the gene determining relative resistance to FV-induced spleen focus formation mapped to the K-end (K^bA^b) of H-2^b. Female recipients expressing H-7^b, regardless of their H-2 haplotype, were more susceptible to FV infection than their syngeneic male counterparts. These experiments demonstrate the utility of congenic and double congenic strains that define H-7 and Fv-2 on different H-2 haplotype backgrounds for the analysis of Fv-2:H-7:H-2 interactions in determining susceptibility to FV infection.