Lack of general immunosuppression during visceral Leishmania tropica infection in BALB/c mice: augmented antibody response to thymus-independent antigens and polyclonal activation.
Leishmania tropica causes a lethal visceral disease in highly susceptible BALB/c mice, with many immunopathologic features resembling those in human kala-azar. The responses to thymus-independent antigens of Type 1 and 2 (TI-1, TI-2) were compared in infected mice of susceptible BALB/c and resistant C57BL/6 strains at various times after infection. The infected BALB/c mice had an augmented response to both types of antigens at 45 days after infection. Later (day 76), the response to trinitrophenylated lipopolysaccharide (TNP-LPS, a TI-1 antigen) was diminished but that to dinitrophenylated Ficoll (DNP-Ficoll, a TI-2 antigen) remained statistically above the response of uninfected mice. The response of the resistant strain to either antigen was not modified as a result of the infection. Both strains showed significant polyclonal activation, which was considerably greater in the BALB/c than in the C57BL/6 mice. The observations presented here are in contrast to the widely held belief that a generalized nonspecific immunosuppression occurs in L. tropica infected BALB/c mice.
D000818:Animals; D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000276:immunology; D000955:Antigens, T-Independent / Q000008:administration & dosage*; D001402:B-Lymphocytes / Q000276:immunology*; D005260:Female; D005362:Ficoll / Q000031:analogs & derivatives / Q000276:immunology; D006462:Hemolytic Plaque Technique; D007700:Kinetics; D007898:Leishmaniasis, Visceral / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D014301:Trinitrobenzenes / Q000276:immunology
D000955:Antigens, T-Independent; C031007:DNP-Ficoll; D014301:Trinitrobenzenes; D005362:Ficoll