title: Modulation of the phenotype and function of bovine afferent lymph cells during infection with Trypanosoma congolense.
abstract: Alterations in the phenotype and function of cells isolated from bovine afferent lymph were studied following tsetse-transmitted Trypanosoma congolense infection. Little alteration was observed in the output of the CD2+ T cells in the lymph, and within this population the CD4:CD8 ratio remained relatively constant. By contrast, a marked decrease was observed in the output of gamma delta T cells over the first 7 days following infection. The number of B cells increased between 2 and 6 days post-infection, and thereafter returned to pre-infection values. Little change was observed within the afferent lymph veiled cell population. Examination of activation markers on the lymphocyte fraction of afferent lymph revealed a decrease in the number of cells expressing the Interleukin-2 receptor alpha-chain from Day 5 post-infection. At this time the expression of ACT 1, another early activation marker, was seen to increase. Afferent lymph cells collected pre-infection and on the first 4 days post-infection proliferated in response to stimulation with Concanavalin A in vitro. This response to mitogenic stimulation was completely abrogated from day five post-infection. However, these cells were not capable of suppressing the capacity of normal peripheral blood mononuclear cells to respond to mitogenic stimulus in co-culture assays. These studies suggest that although a degree of lymphocyte activation occurs in the afferent lymph following tsetse-transmitted infection with T. congolense, this may be sub-optimal owing to the immunosuppression which appears to operate at the level of the skin and the lymph nodes.
authors.affiliation: International Laboratory for Research on Animal Diseases (ILRAD), Nairobi, Kenya.
authors.forename: J N
authors.initials: JN
authors.lastname: Flynn
authors.forename: D J
authors.initials: DJ
authors.lastname: McKeever
authors.forename: M
authors.initials: M
authors.lastname: Sileghem
authors.forename: J
authors.initials: J
authors.lastname: Naessens
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D016516:CD4-CD8 Ratio; D002417:Cattle; D002478:Cells, Cultured; D003713:Dendritic Cells; D005434:Flow Cytometry / Q000662:veterinary; D016130:Immunophenotyping / Q000662:veterinary; D008196:Lymph / Q000166:cytology; D008213:Lymphocyte Activation; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014348:Trypanosoma congolense / Q000276:immunology*; D014354:Trypanosomiasis, Bovine / Q000276:immunology*
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta