Genetics of resistance to the African trypanosomes. V. Qualitative and quantitative differences in interferon production among susceptible and resistant mouse strains
de Gee, A.L.; Sonnenfeld, G.; Mansfield, J.M.
Journal of Immunology 134(4): 2723-2726
1985
ISSN/ISBN: 0022-1767 PMID: 2579155 Document Number: 257766
The induction of interferon (IFN) was examined in different inbred mouse strains infected with Trypanosoma brucei rhodesiense. Relatively susceptible C3HeB/FeJ mice that do not exhibit variant-specific immunity or control parasitaemia did not exhibit detectable IFN throughout the infection. Relatively resistant B10.BR mice that exhibit variant-specific immunity and control the first peak of parasitaemia exhibited detectable IFN at 2 intervals. The appearance of IFN in B10.BR serum first coincided with the onset of the parasitaemia 4 days after infection and then disappeared; this IFN peak was predominantly IFN- alpha / beta . The 2nd time of appearance coincided with high titres of antibody and remission of the parasitaemia. This IFN was predominantly IFN- gamma . Intermediately susceptible CBA/J mice also exhibited 2 detectable peaks of IFN; the first IFN- alpha / beta peak coincided with the onset of the parasitaemia as in B10.BR mice. The 2nd peak of IFN in the serum of CBA mice, however, was delayed in appearance and lower in concentration compared with B10.BR mice. This peak was characterized as being predominantly IFN alpha / beta . BALB/c mice (also intermediately susceptible) did not exhibit a first peak of IFN- alpha / beta production, but the 2nd peak of IFN- alpha / beta production was similar to that seen in CBA mice. In contrast to infected mice, IFN was induced in both susceptible (C3H) and resistant (B10.BR) mice after immunization with glutaraldehyde-fixed trypanosomes or after chemotherapy of infection. It is concluded that both the levels of IFN as well as the type of IFN induced during infection with T. b. rhodesiense depend upon the genetic background of the mouse strain infected. The induction of IFN- gamma in mice of the C57BL background may be linked functionally to more effective parasite control and to the presence of an effective immune response to T. b. rhodesiense.