Abstract
Innate immunity is the first host defense against invading pathogens and involves the activation of immune cells via Toll-like receptors (TLRs). As close human relatives sharing genomic identity, chimpanzees (98.6%) and baboons (~92%) are important biomedical models. Despite strong genetic relatedness, all three species very differently manifest infectious diseases characterized by strong innate immune activation (HIV-1, hepatitis). To examine potential differences in innate immune responses to TLR-detected pathogens, fresh whole blood from humans, chimpanzees and baboons was stimulated for 90 minutes with Pam3CSK4, Lipomannan from Mycobacterium smegmatis, LPS from E. coli, and LcrV from Yersinia pestis. Immune activation was assessed by measuring cytokine/chemokine induction using real-time PCR. Major differences in cytokine/chemokine induction patterns were observed between species. Baboons preferentially express the chemokine CXCL2, whereas chimpanzees and humans preferentially express CCL3 in response to all agonists. In contrast, chimpanzees initiate a strong IL-8 (CXCL8) response to all agonists while humans and baboons minimally respond with IL-8. Anti-inflammatory responses also differ between species; baboons more strongly induce IL-10 and humans and chimpanzees preferentially induce IL1RN in response to challenge. These observations suggest inter species differences in cell activation and trafficking that may impact the use of these animals as biomedical models.
- Copyright © 2011 by The American Association of Immunologists, Inc.
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