Antimycobacteria antibodies in M. lepraemurium murine infection

Two groups of BALB/c mice were inoculated with either 10(7) or 10(5) MLM subcutaneously into the lefthind footpad. Mice receiving 10(7) MLM were followed throughout infection for granuloma size, and antibody production against sonicated M. lepraemurium (MLM), whole M. lepraemurium and whole M. triviale, using a radioimmunoassay. All mice were sacrificed at 37 weeks post infection and acid fast bacilli were enumerated in both footpads and in the spleen. Noticeable individual variations were observed in the pattern of progression of the granuloma, and in the resistance to the infection, as assessed by measurements of bacilli local growth and dissemination. Antibody formation against MLM sonicate was detected as early as at 6 weeks post inoculation, a time when granulomas started to develop. Antibody production increased further when the infection progressed, against MLM (sonicate or whole bacilli), as well as against whole M. triviale. No correlation could be found between antibody activity and local bacilli growth or bacilli dissemination. Mice receiving 10(5) MLM s.c. were followed for ganuloma size and antibody production against sonicated MLM or other sonicated mycobacteria (pool of 6 different species). Antibody production could be detected against MLM and other mycobacteria as soon as 4 and 8 weeks after infection respectively, i.e. several weeks prior to the appearance of granulomas, which occurred at 12 weeks of infection.