The natural killer complex regulates severe malarial pathogenesis and influences acquired immune responses to Plasmodium berghei ANKA.
The natural killer complex (NKC) is a genetic region of highly linked genes encoding several receptors involved in the control of NK cell function. The NKC is highly polymorphic, and allelic variability of various NKC loci has been demonstrated in inbred mice. Making use of BALB.B6-Cmv1r congenic mice, in which the NKC from disease-susceptible C57BL/6 mice has been introduced into the disease-resistant BALB/c background, we show here that during murine malaria infection, the NKC regulates a range of pathophysiological syndromes such as cerebral malaria, pulmonary edema, and severe anemia, which contribute to morbidity and mortality in human malaria. Parasitemia levels were not affected by the NKC genotype, indicating that control of malarial fatalities by the NKC cells does not operate through effects on parasite growth rate. Parasite-specific antibody responses and the proinflammatory gene transcription profile, as well as the TH1/TH2 balance, also appeared to be influenced by NKC genotype, providing evidence that this region, known to control innate immune responses via NK and/or NK T-cell activation, can also significantly regulate acquired immunity to infection. To date, NKC-encoded innate system receptors have been shown mainly to regulate viral infections. Our data provide evidence for critical NKC involvement in the broad immunological responses to a protozoan parasite.
Hansen
Diana S
DS
The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia. hansen@wehi.edu.au
Evans
Krystal J
KJ
D'Ombrain
Marthe C
MC
Bernard
Nicholas J
NJ
Sexton
Adrienne C
AC
Buckingham
Lynn
L
Scalzo
Anthony A
AA
Schofield
Louis
L
D000740:Anemia / Q000209:etiology; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001921:Brain / Q000473:pathology; D020869:Gene Expression Profiling; D007371:Interferon-gamma / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000276:immunology*; D008288:Malaria / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010962:Plasmodium berghei / Q000276:immunology*; D011654:Pulmonary Edema / Q000209:etiology; D016212:Transforming Growth Factor beta / Q000096:biosynthesis
D000913:Antibodies, Protozoan; D016212:Transforming Growth Factor beta; D007371:Interferon-gamma