Influence of H-2 genes on growth of Mycobacterium tuberculosis in the lungs of chronically infected mice.

Mice infected by intraperitoneal injection of Mycobacterium tuberculosis were studied over a 23-week period. They showed progressive infection in the lung (with increasing microbial count and granuloma size) whereas viable bacillary counts remained largely stationary in the spleen and in the liver. The influence of H-2 genes on the progression of the lung infection was studied in four congenic strains of animals with B10 and three congenic strains of animals with BALB backgrounds. H-2k mice had significantly higher bacterial counts in the lung than H-2b mice on both B10 and BALB backgrounds, BALB. K (H-2k) mice were also more susceptible than BALB/c (H-2d) mice. Results with recombinant strains showed that bacillary counts and granulomatous infiltration were lower in the B10 (KbAbE-Db) compared with B10.A(3R) (KbAbEbDd) strain and in B10.A(4R) (KkAkE-Db) compared with B10.BR (KkAkEkDk) mice. This resistance to the late expansion of tuberculous infection in the lungs may be associated with the lack of an expressed I-E molecular or with the expression of the Db molecule.