title: Activation of gamma delta T cells by Borrelia burgdorferi is indirect via a TLR- and caspase-dependent pathway.
abstract: Activation of the innate immune system typically precedes engagement of adaptive immunity. Cells at the interface between these two arms of the immune response are thus critical to provide full engagement of host defense. Among the innate T cells at this interface are gammadelta T cells. gammadelta T cells contribute to the defense from a variety of infectious organisms, yet little is understood regarding how they are activated. We have previously observed that human gammadelta T cells of the Vdelta1 subset accumulate in inflamed joints in Lyme arthritis and proliferate in response to stimulation with the causative spirochete, Borrelia burgdorferi. We now observe that murine gammadelta T cells are also activated by B. burgdorferi and that in both cases the activation is indirect via TLR stimulation on dendritic cells or monocytes. Furthermore, B. burgdorferi stimulation of monocytes via TLR, and secondary activation of gammadelta T cells, are both caspase-dependent.
authors.affiliation: Immunobiology Program, Department of Medicine, The University of Vermont College of Medicine, Burlington, VT 50405, USA.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Collins
authors.forename: Cuixia
authors.initials: C
authors.lastname: Shi
authors.forename: Jennifer Q
authors.initials: JQ
authors.lastname: Russell
authors.forename: Karen A
authors.initials: KA
authors.lastname: Fortner
authors.forename: Ralph C
authors.initials: RC
authors.lastname: Budd
mesh_terms: D000818:Animals; D025065:Borrelia burgdorferi / Q000276:immunology*; D020169:Caspases / Q000502:physiology*; D002450:Cell Communication / Q000276:immunology; D002478:Cells, Cultured; D002999:Clone Cells; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000276:immunology; D006801:Humans; D008193:Lyme Disease / Q000201:enzymology / Q000276:immunology / Q000473:pathology; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009000:Monocytes / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis*; D015398:Signal Transduction / Q000276:immunology*; D013583:Synovial Membrane / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000201:enzymology / Q000276:immunology* / Q000382:microbiology*; D051193:Toll-Like Receptors / Q000502:physiology*
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta; D051193:Toll-Like Receptors; D020169:Caspases