Plasticity of immune responses suppressing parasitemia during acute Plasmodium chabaudi malaria.
gammadelta T cells have a crucial role in cell-mediated immunity (CMI) against P. chabaudi malaria, but delta-chain knockout (KO) (deltao/o) mice and mice depleted of gammadelta T cells with mAb cure this infection. To address the question of why mice deficient in gammadelta T cells resolve P. chabaudi infections, we immunized deltao/o mice by infection with viable blood-stage parasites. Sera from infection-immunized mice were tested for their ability to protect JHo/o, deltao/o double KO mice passively against P. chabaudi challenge infection. The onset of parasitemia was significantly delayed in mice receiving immune sera, compared with saline or uninfected serum controls. Immune sera were then fractionated into Ig-rich and Ig-depleted fractions by HPLC on a protein G column. Double KO mice were passively immunized with either fraction and challenged with P. chabaudi. The onset of parasitemia was significantly delayed in recipients of the Ig-rich fraction compared with recipients of the Ig-poor fraction of immune sera. We conclude that deltao/o mice, which are unable to activate CMI against the parasite, suppress P. chabaudi infection by a redundant Ab-mediated process.
Weidanz
W P
WP
Department of Medical Microbiology and Immunology, University of Wisconsin Medical School, Madison 53706, USA. wweidanz@facstaff.wisc.edu
Kemp
J R
JR
Batchelder
J M
JM
Cigel
F K
FK
Sandor
M
M
Heyde
H C
HC
D000208:Acute Disease; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D001402:B-Lymphocytes / Q000473:pathology; D001426:Bacterial Proteins / Q000737:chemistry; D005260:Female; D007108:Immune Tolerance / Q000235:genetics / Q000276:immunology*; D007111:Immunity, Cellular / Q000235:genetics; D007116:Immunization, Passive; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007274:Injections, Intraperitoneal; D008231:Lymphopenia / Q000235:genetics / Q000276:immunology; D008288:Malaria / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000517:prevention & control; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D018512:Parasitemia / Q000235:genetics / Q000276:immunology; D016788:Plasmodium chabaudi / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics / Q000276:immunology
D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; C034284:IgG Fc-binding protein, Streptococcus; D007143:Immunoglobulin Heavy Chains; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta