title: Activating NK-cell receptors co-stimulate CD4(+)CD28(-) T cells in patients with rheumatoid arthritis.
abstract: Effector T-cell responses can be modulated by competing positive or negative signals transduced by NK-cell receptors (NKR). In the CD4(+) T-cell population, the expression of NKR is primarily found in the CD4(+)CD28(-) T-cell subset, also known as CD28(null) T cells. These T cells are frequently found in rheumatoid arthritis (RA) and other inflammatory disorders, suggesting that signaling through NKR may play a role in the autoimmune reaction. Here we aimed to dissect the phenotype and function of NKR-expressing CD4(+)CD28(-) T cells in patients with RA. By analyzing a broad array of NKR on CD4(+)CD28(-) T cells we found a significant expression of the co-activating receptors 2B4 (CD244), DNAM-1 (CD226), and CRACC. Pair-wise ligations of 2B4 with DNAM-1 and/or NKG2D lead to increased effector functions of primary CD4(+)CD28(-) T cells to suboptimal levels of anti-CD3 stimulation. Using multi-parameter flow cytometry, we demonstrate that such co-ligation led to an increased magnitude in overall responsiveness without changing qualitative aspects of the response. Altogether these results demonstrate a pattern of additive effects in NKR-mediated functional modulation of CD4(+)CD28(-) T cells in RA. This may have consequences for the inflammatory responses imposed by these cells, thus influencing disease manifestations.
authors.affiliation: Rheumatology Unit, Department of Medicine, Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden.
authors.forename: Andreas E R
authors.initials: AE
authors.lastname: Fasth
authors.forename: Niklas K
authors.initials: NK
authors.lastname: Björkström
authors.forename: Minna
authors.initials: M
authors.lastname: Anthoni
authors.forename: Karl-Johan
authors.initials: KJ
authors.lastname: Malmberg
authors.forename: Vivianne
authors.initials: V
authors.lastname: Malmström
mesh_terms: D000368:Aged; D000906:Antibodies / Q000276:immunology / Q000494:pharmacology; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000473:pathology; D018106:CD28 Antigens / Q000378:metabolism; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011485:Protein Binding; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D055607:Receptors, Natural Killer Cell / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology*; D000071176:Signaling Lymphocytic Activation Molecule Family; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D000098862:T Lineage-Specific Activation Antigen 1
chemical_list: D000906:Antibodies; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D000098862:T Lineage-Specific Activation Antigen 1; C084093:CD244 protein, human; D018106:CD28 Antigens; D017252:CD3 Complex; D011971:Receptors, Immunologic; D055607:Receptors, Natural Killer Cell; C448987:SLAMF7 protein, human; D000071176:Signaling Lymphocytic Activation Molecule Family; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma