title: Expansion and activation of CD4(+)CD25(+) regulatory T cells in Heligmosomoides polygyrus infection.
abstract: Regulatory T cell responses to infectious organisms influence not only immunity and immunopathology, but also responses to bystander antigens. Mice infected with the gastrointestinal nematode parasite Heligmosomoides polygyrus show an early Th2-dominated immune response (days 7-14), but by day 28 a strongly regulatory profile is evident with antigen-specific IL-10 release and elevated frequency of CD4(+) T cells bearing surface TGF-beta. CD4(+)CD25(+) T cells from infected mice show enhanced capacity to block in vitro effector T cell proliferation. CD4(+)CD25(+) cell numbers expand dramatically during infection, with parallel growth of both CD25(+)Foxp3(+) and CD25(+)Foxp3(-) subsets. CTLA-4 and glucocorticoid-induced tolerance-associated receptor, also associated with regulatory T cell function, become more prominent, due to both expanded CD25(+) cell numbers and increased expression among the CD25(-) population. Both intensity and frequency of CD103 expression by CD4(+) T cells rise significantly, with greatest expansion among CD25(+)Foxp3(+) cells. While TGF-beta expression is observed among both CD25(+)Foxp3(+) and CD25(+)Foxp3(-) subsets, it is the latter population which shows higher TGF-beta staining following infection. These data demonstrate in a chronic helminth infection that Foxp3(+) regulatory T cells are stimulated, increasing CD103 expression in particular, but that significant changes occur to other populations including expansion of CD25(+)TGF-beta(+)Foxp3(-) cells, and induction of CTLA-4 on CD25(-) non-regulatory lymphocytes.
authors.affiliation: Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, UK.
authors.forename: Constance A M
authors.initials: CA
authors.lastname: Finney
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Taylor
authors.forename: Mark S
authors.initials: MS
authors.lastname: Wilson
authors.forename: Rick M
authors.initials: RM
authors.lastname: Maizels
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000276:immunology*; D000943:Antigens, Differentiation / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology; D060908:CTLA-4 Antigen; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000276:immunology*; D039001:Integrin alpha Chains / Q000276:immunology*; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009351:Nematospiroides dubius / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017206:Strongylida Infections / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D015704:CD4 Antigens; D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D039001:Integrin alpha Chains; D053645:Interleukin-2 Receptor alpha Subunit; D016212:Transforming Growth Factor beta; C091367:alpha E integrins