title: Deciphering new mechanisms on T-cell costimulation by human mast cells.
abstract: It is well established that full activation of T cells to recognize a specific antigen requires additional signals. These secondary signals are generated by the interaction of costimulatory molecules expressed on APCs. Classical APCs include DCs, macrophages, Langerhans cells, and B cells. However, in recent years, several haematopoietic and nonhaematopoietic cells have been described to express MHC class II antigens and, in appropriate conditions, costimulatory molecules. In this issue, Suurmond et al. [Eur. J. Immunol. 2016. 46: 1132-1141] show, for the first time, that human mast cells not only express costimulatory molecules of the TNF-receptor and CD28 families, but can also costimulate T cells through a yet-to-be-defined CD28-independent interaction.
authors.affiliation: Laboratory of Immunology, Department of Medical and Biological Sciences, University of Udine, Udine, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Frossi
authors.affiliation: Laboratory of Immunology, Department of Medical and Biological Sciences, University of Udine, Udine, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Mion
authors.affiliation: Laboratory of Immunology, Department of Medical and Biological Sciences, University of Udine, Udine, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Pucillo
mesh_terms: D015703:Antigens, CD; D001402:B-Lymphocytes / Q000276:immunology; D018122:B7-1 Antigen / Q000276:immunology*; D018106:CD28 Antigens / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D008407:Mast Cells / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D018106:CD28 Antigens
keywords: APC; T-cell activation; costimulation; mast cell