Platelets present antigen in the context of MHC class I

• Published in: The Journal of immunology (1950) Vol. 189; no. 2; pp. 916 - 923
• Main Authors: Chapman, Lesley M, Aggrey, Angela A, Field, David J, Srivastava, Kalyan, Ture, Sara, Yui, Katsuyuki, Topham, David J, Baldwin, 3rd, William M, Morrell, Craig N
• Format: Journal Article
• Language: English
• Published: United States 15-07-2012
• Subjects: Animals; Antigen Presentation - immunology; Blood Platelets - immunology; Blood Platelets - metabolism; Blood Platelets - parasitology; CD8-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - parasitology; CD8-Positive T-Lymphocytes - pathology; Cell Movement - immunology; Histocompatibility Antigens Class I - blood; Histocompatibility Antigens Class I - genetics; Histocompatibility Antigens Class I - immunology; Humans; Lymphocyte Activation - immunology; Malaria - blood; Malaria - immunology; Mice; Mice, Inbred C57BL; Plasmodium berghei - immunology
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.1200580

Platelets are most recognized for their vital role as the cellular mediator of thrombosis, but platelets also have important immune functions. Platelets initiate and sustain vascular inflammation in many disease conditions, including arthritis, atherosclerosis, transplant rejection, and severe malaria. We now demonstrate that platelets express T cell costimulatory molecules, process and present Ag in MHC class I, and directly activate naive T cells in a platelet MHC class I-dependent manner. Using an experimental cerebral malaria mouse model, we also demonstrate that platelets present pathogen-derived Ag to promote T cell responses in vivo, and that platelets can be used in a cell-based vaccine model to induce protective immune responses. Our study demonstrates a novel Ag presentation role for platelets.