Susceptibility of severe combined immuno-deficient (SCID) mice to Trypanosoma brucei gambiense and T. b. rhodesiense.
Susceptibility of severe combined immunodeficient (SCID) mice to 7 isolates of Trypanosoma brucei gambiense and 2 isolates of T. b. rhodesiense was examined in terms of their infectivity, course of parasitaemia, packed cell volume (PCV) and survival period in comparison with that of normal immunocompetent (BALB/c) mice. All isolates of T. b. gambiense and T. b. rhodesiense caused high (> 1 x 10(8) parasites/ml) parasitaemia in the SCID mice, the survival periods ranged from 5 to 47 days. On the other hand, 5 of 7 isolates of T. b. gambiense developed chronic infection in the BALB/c mice with sporadic but persistent parasitaemia with less than 5 x 10(6) parasites/ml. All the mice tested in this group survived more than 60 days after infection. In contrast, the 2 remaining isolates of T. b. gambiense and both isolates of T. b. rhodesiense showed high virulence in the BALB/c mice and killed all of them within 30 days after infection. The results demonstrate that the SCID mice, in which functional B- and T-cell-mediated immunities are congenitally lacking, are highly susceptible for 'low-virulence' T. b. gambiense. This makes SCID mice useful tools for the isolation of parasites from T. b. gambiense sleeping sickness patients and the propagation of large amounts of such parasites.
Inoue
N
N
The Research Centre for Protozoan Molecular Immunology, Obihiro University of Agriculture and Veterinary Medicine, Obihiro Hokkaido, Japan.
Narumi
D
D
Mbati
P A
PA
Hirumi
K
K
Situakibanza
N T
NT
Hirumi
H
H
D000818:Animals; D004198:Disease Susceptibility; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID / Q000469:parasitology*; D016019:Survival Analysis; D014346:Trypanosoma brucei brucei / Q000472:pathogenicity*; D014347:Trypanosoma brucei gambiense / Q000472:pathogenicity; D014353:Trypanosomiasis, African / Q000209:etiology*