title: Cutting edge: inducible costimulator protein regulates both Th1 and Th2 responses to cutaneous leishmaniasis.
abstract: The CD28 family member inducible costimulator protein (ICOS) has an important role in T cell differentiation and Ig class switching. To investigate the role of ICOS in vivo, ICOS-/- mice were infected s.c. with Leishmania mexicana. While wild-type mice developed large, cutaneous lesions, the growth of lesions and tissue histopathology was significantly delayed in ICOS-/- mice. ICOS-/- mice exhibited marked decreases in both Th1 and Th2 cytokine production and profound defects in L. mexicana-specific Ig isotype class switching to IgG1 and IgG2a and reduced total IgE levels. Our findings indicate that ICOS is a key regulator of both Th1 and Th2 responses and has a role in controlling cutaneous L. mexicana infection.
authors.affiliation: Immunology Research Division, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Greenwald
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: McAdam
authors.forename: Diane
authors.initials: D
authors.lastname: Van der Woude
authors.forename: Abhay R
authors.initials: AR
authors.lastname: Satoskar
authors.forename: Arlene H
authors.initials: AH
authors.lastname: Sharpe
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics / Q000502:physiology*; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D005260:Female; D017578:Immunoglobulin Class Switching / Q000235:genetics; D060889:Inducible T-Cell Co-Stimulator Protein; D007894:Leishmania mexicana / Q000276:immunology; D016773:Leishmaniasis, Cutaneous / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism; D018418:Th2 Cells / Q000276:immunology* / Q000378:metabolism
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D016207:Cytokines; C556694:Icos protein, mouse; D060889:Inducible T-Cell Co-Stimulator Protein