title: Role played by CD4+FOXP3+ regulatory T Cells in suppression of host responses to Haemophilus ducreyi during experimental infection of human volunteers.
abstract: Haemophilus ducreyi causes chancroid, a genital ulcer disease. Among human volunteers, the majority of experimentally infected individuals fail to clear the infection and form pustules. Here, we investigated the role played by CD4(+)FOXP3(+) regulatory T (T(reg)) cells in the formation of pustules. In pustules, there was a significant enrichment of CD4(+)FOXP3(+) T cells, compared with that in peripheral blood. The majority of lesional FOXP3(+) T cells were CD4(+), CD25(+), CD127(lo/-), and CTLA-4(+). FOXP3(+) T cells were found throughout pustules but were most abundant at their base. Significantly fewer lesional CD4(+)FOXP3(+) T cells expressed interferon gamma, compared with lesional CD4(+)FOXP3(-) effector T cells. Depletion of CD4(+)CD25(+) T cells from the peripheral blood of infected and uninfected volunteers significantly enhanced proliferation of H. ducreyi-reactive CD4(+) T cells. Our results indicate that the population of CD4(+)CD25(+)CD127(lo/-)FOXP3(+) T(reg) cells are expanded at H. ducreyi-infected sites and that these cells may play a role in suppressing the host immune response to the bacterium.
authors.affiliation: Department of Medicine, Laboratory Medicine, Indiana University School of Medicine, Indianapolis, USA. wl1@iupui.edu
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Klara
authors.initials: K
authors.lastname: Tenner-Racz
authors.forename: Paul
authors.initials: P
authors.lastname: Racz
authors.forename: Diane M
authors.initials: DM
authors.lastname: Janowicz
authors.forename: Kate R
authors.initials: KR
authors.lastname: Fortney
authors.forename: Barry P
authors.initials: BP
authors.lastname: Katz
authors.forename: Stanley M
authors.initials: SM
authors.lastname: Spinola
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology*; D051858:Forkhead Transcription Factors / Q000032:analysis*; D006192:Haemophilus Infections / Q000276:immunology*; D006191:Haemophilus ducreyi / Q000276:immunology*; D006805:Human Experimentation; D006801:Humans; D007108:Immune Tolerance; D007371:Interferon-gamma / Q000096:biosynthesis; D008212:Lymphocyte Depletion; D008297:Male; D017192:Skin Diseases, Bacterial / Q000276:immunology / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000737:chemistry / Q000276:immunology*; D055815:Young Adult
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D007371:Interferon-gamma