title: Down-regulation of Th1 type of response in early human American cutaneous leishmaniasis.
abstract: This study examined the T cell responses in the early phase of Leishmania braziliensis infection. Cytokine profiles, lymphoproliferative responses, and skin test results in 25 patients with early cutaneous leishmaniasis (ECL; illness duration <60 days) were compared with those in persons with late cutaneous leishmaniasis (LCL; illness duration >2 months). Absent or low lymphoproliferative responses were observed in 8 (32%) of 25 patients and an absence of interferon (IFN)-gamma production in 9 (41%) of 22 patients prior to therapy. IFN-gamma production in ECL (mean +/- SD) was lower than in LCL (293+/-346 vs. 747+/-377 pg/mL, respectively; P<.01). In contrast, interleukin (IL)-10 production in ECL (mean +/- SD) was higher than in LCL (246+/-56 vs. 50+/-41 pg/mL, respectively; P<.01). Restoration of lymphoproliferative responses and IFN-gamma production was achieved when monoclonal antibody to IL-10 or IL-12 was added to the cultures. These results show that T cell responses during early-phase infection are down-regulated by IL-10 and may facilitate parasite multiplication.
authors.affiliation: Serviço de Imunologia do Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, Salvador-Bahia, Brazil.
authors.forename: P N
authors.initials: PN
authors.lastname: Rocha
authors.forename: R P
authors.initials: RP
authors.lastname: Almeida
authors.forename: O
authors.initials: O
authors.lastname: Bacellar
authors.forename: A R
authors.initials: AR
authors.lastname: de Jesus
authors.forename: D C
authors.initials: DC
authors.lastname: Filho
authors.forename: A C
authors.initials: AC
authors.lastname: Filho
authors.forename: A
authors.initials: A
authors.lastname: Barral
authors.forename: R L
authors.initials: RL
authors.lastname: Coffman
authors.forename: E M
authors.initials: EM
authors.lastname: Carvalho
mesh_terms: D000818:Animals; D015536:Down-Regulation; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D007892:Leishmania braziliensis / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000469:parasitology; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D013997:Time Factors
chemical_list: D016753:Interleukin-10; D007371:Interferon-gamma