Cellular immunity, but not gamma interferon, is essential for resolution of Babesia microti infection in BALB/c mice.
A new strain of Babesia microti (KR-1) was isolated from a Connecticut resident with babesiosis by hamster inoculation and adapted to C3H/HeJ and BALB/c mice. To examine the relative importance of humoral and cellular immunity for the control of B. microti infection, we compared the course of disease in wild-type BALB/c mice with that in BALB/c SCID mice, JHD-null (B-cell-deficient) mice, and T-cell receptor alphabeta (TCRbeta(-/-)) or gamma interferon (IFN-gamma) (IFN-gamma(-/-)) knockout mice following inoculation with the KR-1-strain. SCID mice and TCRalphabeta knockouts sustained a severe but nonlethal parasitemia averaging 35 to 45% infected erythrocytes. IFN-gamma-deficient mice developed a less severe parasitemia but were able to clear the infection. In contrast, in six of eight JHD-null mice, the levels of parasitemia were indistinguishable from those in the wild-type animals. These data indicate that cellular immunity is critical for the clearance of B. microti in BALB/c mice but that disease resolution can occur even in the absence of IFN-gamma.
Center for Microbial Pathogenesis, University of Connecticut Health Center, Farmington, Connecticut 06030-3710, USA.
Michael L
ML
Clawson
Natalia
N
Paciorkowski
T V
TV
Rajan
Carson
C
La Vake
Conny
C
Pope
Morgan
M
La Vake
Stephen K
SK
Wikel
Peter J
PJ
Krause
Justin D
JD
Radolf
D000328:Adult; D000818:Animals; D001403:Babesia / Q000276:immunology / Q000302:isolation & purification; D001404:Babesiosis / Q000276:immunology* / Q000469:parasitology; D006801:Humans; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D016513:Mice, SCID; D018512:Parasitemia / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000172:deficiency / Q000235:genetics
D016693:Receptors, Antigen, T-Cell, alpha-beta; D007371:Interferon-gamma