Effects of exogenous recombinant interleukin-12 on immune responses and protection against Brucella abortus in a murine model.
This study determined if murine interleukin-12 (IL-12) would influence immunity in mice vaccinated with live or killed Brucella abortus strain RB51 (SRB51). Mice received live or gamma-irradiated SRB51 bacteria alone, or with IL-12 (0.5 or 1.0 microg, 2x or 3x), whereas other mice received saline or IL-12 alone. Post-vaccination antibody responses to live or killed SRB51 and clearance of live SRB51 from splenic tissue were not influenced by IL-12 treatments. Mice were challenged at 12 weeks with 4 x 10(4) cfu of B. abortus strain 2308 (S2308) and were euthanized 2 weeks later. The highest IL-12 treatment increased (P < 0.05) post-challenge antibody responses when co-administered with killed SRB51. Co-administration of 1.0 microg of IL-12 with live SRB51, but not killed SRB51, reduced (P < 0.05) S2308 colonization of splenic tissues. Our data suggest that although IL-12 may augment protective immunity induced by live SRB51, it does not influence protection induced by vaccination with killed SRB51.
Lee
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IK
Bacterial Diseases Research Unit, National Animal Disease Center, Agriculture Research Service, United States Department of Agriculture, Ames, Iowa 50010, USA.
Olsen
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SC
Bolin
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CA
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001428:Bacterial Vaccines / Q000008:administration & dosage* / Q000276:immunology; D002003:Brucella abortus / Q000276:immunology* / Q000472:pathogenicity; D002006:Brucellosis / Q000517:prevention & control / Q000662:veterinary*; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D005260:Female; D018664:Interleukin-12 / Q000008:administration & dosage*; D008099:Liver / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000382:microbiology / Q000473:pathology; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology
D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D015164:Vaccines, Inactivated; D018664:Interleukin-12