Macrophages interact with enriched populations of distinct T lymphocyte subsets for the induction of severe

B K DuChateau1, E L Munson, D M England

  • 1Wisconsin State Laboratory of Hygiene, Department of Bacteriology, University of Wisconsin, Madison 53706, USA.

Severe destructive Lyme arthritis was detected in the hind paws of hamsters infused with enriched populations of either CD4+ or CD4- T lymphocytes along with macrophages exposed in vitro to formalin-inactivated Borrelia burgdorferi and then infected with the Lyme spirochete. Swelling was detected 4 days after infection, increased rapidly, peaked on day 8 of infection, and gradually decreased. Similarly, severe destructive arthritis was induced in hamsters infused with enriched populations of unfractionated T lymphocytes and macrophages exposed to spirochetes after infection with B. burgdorferi. Histopathological examination affirmed that hamsters infused with CD4+, CD4-, or unfractionated T lymphocytes and macrophages exposed to B. burgdorferi-induced arthritis. In addition, macrophages exposed in vitro to B. burgdorferi demonstrated both conventional and coiling phagocytosis, suggesting a mechanism by which CD4+ and CD4- T lymphocytes induce arthritis, respectively. These findings demonstrate that both CD4+ and CD4- subpopulations of T lymphocytes are capable of interacting with macrophages for the induction of severe destructive Lyme arthritis.

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