title: Infliximab inhibits activation and effector functions of peripheral blood T cells in vitro from patients with clinically active ulcerative colitis.
abstract: Many patients with inflammatory bowel disease (IBD) are undergoing therapy with infliximab, an antibody specific for TNF. However, the exact mechanisms of action of infliximab are not completely understood. The aim of this study was to determine the in vitro effects of infliximab on blood T cells derived from anti-TNF therapy-naïve ulcerative colitis (UC) patients with clinically active disease. Peripheral blood mononuclear cells were stimulated polyclonally or by antigen in the presence or absence of infliximab. The T cell phenotype was investigated by flow cytometry, cytokine secretion was determined by ELISA, and cell proliferation was determined by thymidine assay or CFSE dye. Presence of infliximab resulted in reduced expression of CD25 in CD4(+) and CD8(+) T cell populations and inhibited secretion of IFN-γ, IL-13, IL-17A, TNF as well as granzyme A. Infliximab also suppressed CD4(+) and CD8(+) T cell proliferation. These effects of infliximab were recorded both in T cells activated by polyclonal and antigen-specific stimulation. The effects of infliximab on T cell apoptosis and induction of FOXP3(+) CD4(+) T regulatory cells were ambiguous and depended on the originating cellular source and/or the stimulation mode and strength. In conclusion, infliximab is able to reduce T cell activation as measured by CD25, proliferation and cytokine secretion in vitro from UC patients with clinically active disease. These data suggest that suppression of T cell activity may be important for infliximab-mediated disease remission in patients with UC.
authors.affiliation: Department of Internal Medicine and Clinical Nutrition, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Dahlén
authors.forename: H
authors.initials: H
authors.lastname: Strid
authors.forename: A
authors.initials: A
authors.lastname: Lundgren
authors.forename: S
authors.initials: S
authors.lastname: Isaksson
authors.forename: S
authors.initials: S
authors.lastname: Raghavan
authors.forename: M K
authors.initials: MK
authors.lastname: Magnusson
authors.forename: M
authors.initials: M
authors.lastname: Simrén
authors.forename: H
authors.initials: H
authors.lastname: Sjövall
authors.forename: L
authors.initials: L
authors.lastname: Öhman
mesh_terms: D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D003093:Colitis, Ulcerative / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D053804:Granzymes / Q000378:metabolism; D006801:Humans; D000069285:Infliximab; D007371:Interferon-gamma / Q000378:metabolism; D018793:Interleukin-13 / Q000378:metabolism; D020381:Interleukin-17 / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D048069:Tumor Necrosis Factors / Q000378:metabolism; D055815:Young Adult
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000911:Antibodies, Monoclonal; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D018793:Interleukin-13; D020381:Interleukin-17; D053645:Interleukin-2 Receptor alpha Subunit; D048069:Tumor Necrosis Factors; D007371:Interferon-gamma; D000069285:Infliximab; D053804:Granzymes