title: Chronic brucellosis patients retain low frequency of CD4+ T-lymphocytes expressing CD25 and CD28 after Escherichia coli LPS stimulation of PHA-cultured PBMCs.
abstract: Chronic brucellosis patients display a defective Th1 response to PHA. We have previously shown that heat-killed B. abortus (HKBA) can downregulate the PHA-induced increase of CD4+/CD25+ and CD14+/CD80+ cells of brucellosis patients. In the present study, we investigate the effect of E. coli LPS, as a potent stimulant of monocytes and autologous T-lymphocytes, on the PHA-cultured PBMCs of the same groups of patients. Thirteen acute brucellosis (AB) patients, 22 chronic brucellosis (CB) patients, 11 "cured" subjects, and 15 healthy volunteers were studied. The percentage of CD4+/CD25+ and CD4+/CD28+ T-lymphocytes as well as CD14+/CD80+ monocytes were analyzed by flow cytometry after PBMCs culture with PHA plus E. coli LPS. A significant decrease in the percentage of CD4+/CD25+ and CD4+/CD28+ T-lymphocytes was observed in CB compared to AB. In HKBA cultures, compared to E. coli LPS-cultures, there was a significant reduction of CD4+/CD25+ T-lymphocytes in all groups and CD14+/CD80+ in patients groups. We suggest that Brucella can modulate host immune response, leading to T-cell anergy and chronic infection.
authors.affiliation: Clinical Immunology Unit, 2nd Department of Internal Medicine, Hippokration General Hospital, Aristotle University of Thessaloniki, Konstantinoupoleos Street 49, 546 42 Thessaloniki, Greece.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Skendros
authors.forename: Alexandros
authors.initials: A
authors.lastname: Sarantopoulos
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Tselios
authors.forename: Panagiota
authors.initials: P
authors.lastname: Boura
mesh_terms: D018122:B7-1 Antigen / Q000378:metabolism; D002003:Brucella abortus / Q000276:immunology*; D002006:Brucellosis / Q000097:blood / Q000276:immunology*; D018106:CD28 Antigens; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D002908:Chronic Disease; D016207:Cytokines / Q000378:metabolism; D004926:Escherichia coli / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D053645:Interleukin-2 Receptor alpha Subunit; D008070:Lipopolysaccharides / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D010835:Phytohemagglutinins / Q000276:immunology / Q000494:pharmacology
chemical_list: D018122:B7-1 Antigen; D018106:CD28 Antigens; D016207:Cytokines; D053645:Interleukin-2 Receptor alpha Subunit; D008070:Lipopolysaccharides; D010835:Phytohemagglutinins