title: Failure of CD1D-/- mice to elicit hypersensitive granulomas to mycobacterial cord factor trehalose 6,6'-dimycolate.
abstract: The present study defines pathologic differences in acute and hypersensitive responses to Mycobacterium tuberculosis glycolipid trehalose-6,6'-dimycolate (TDM, cord factor) in normal BALB/c mice and those deficient in group II CD1 molecule CD1d1. Mice immunized against TDM demonstrate hypersensitive responses, yet the mechanisms for TDM presentation remain elusive. Mice lacking CD1d (CD1D(-/-)) demonstrate dysregulated granulomatous response to TDM, compared with CD1D(+/-) heterozygous controls. Because CD1d-restricted T cells can regulate macrophage immune functions at mucosal surfaces, we hypothesized that CD1D(-/-) mice would show deficient TDM-induced hypersensitive pulmonary granulomatous response in which T cells play a central role. Control CD1D(+/+) mice sensitized and subsequently challenged with TDM demonstrated aggressive inflammation defined by monocytic lesions contained by CD3(+) lymphocytic cuffing. CD1D(-/-) mice demonstrated distinctly different pathologies, with edema present concurrent with extended, nonfocal mononuclear cell-based granulomatous reactions. Furthermore, CD1D(-/-) mice did not demonstrate destructive lesions, and CD3(+) lymphocytes were only loosely organized in proximity to reactive pathology. The CD1d-deficient mice demonstrated rapid increases in proinflammatory mRNAs, with significant differences in interferon-gamma (IFN-gamma) compared to the wild-type group. IFN-gamma, interleukin-6 (IL-6), and IL-12 proteins were significantly elevated in the CD1D(-/-) group compared with wild-type mice (p < 0.05) 2 days after TDM challenge. However, by 7 days postadministration, similar production for all cytokines and proinflammatory molecules examined was present in both groups of mice. These experiments provide evidence for a role for CD1d in mediation of pathology during hypersensitive responses to the mycobacterial glycolipid TDM.
authors.affiliation: Department of Pathology, University of Texas-Houston Medical School, Houston, TX 77030, USA.
authors.forename: Tera V
authors.initials: TV
authors.lastname: Guidry
authors.forename: Margaret
authors.initials: M
authors.lastname: Olsen
authors.forename: Ki-Soo
authors.initials: KS
authors.lastname: Kil
authors.forename: Robert L
authors.initials: RL
authors.lastname: Hunter
authors.forename: Yong-Jian
authors.initials: YJ
authors.lastname: Geng
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Actor
mesh_terms: D000276:Adjuvants, Immunologic / Q000378:metabolism*; D000818:Animals; D018949:Antigens, CD1 / Q000235:genetics / Q000378:metabolism*; D055610:Antigens, CD1d; D003311:Cord Factors / Q000276:immunology*; D016207:Cytokines / Q000235:genetics / Q000276:immunology; D006099:Granuloma / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D006801:Humans; D006967:Hypersensitivity / Q000235:genetics / Q000276:immunology*; D008168:Lung / Q000166:cytology / Q000276:immunology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009169:Mycobacterium tuberculosis / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D018949:Antigens, CD1; D055610:Antigens, CD1d; C526877:CD1D protein, human; D003311:Cord Factors; D016207:Cytokines; D012333:RNA, Messenger