Anti-human CD63 monoclonal antibody COS3A upregulates monocyte-induced IL-10 excretion leading to diminution of CD3-mediated T cell response

• Main Authors: Siriwan Wansook, Kodchakorn Mahasongkram, Nuttaphol Chruekamlow, Supansa Pata, Watchara Kasinrerk, Panida Khunkaewla
• Format: Journal
• Published: 2020
• Subjects: Biochemistry, Genetics and Molecular Biology; Immunology and Microbiology
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85072214951&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/67612
• Institution: Chiang Mai University

© 2019 Elsevier Ltd Human CD63 has been reported to play a role either as an inhibitor or as a co-stimulator of T- cell responses, although the mechanism of this is unclear. In this study, an anti-human CD63 monoclonal antibody (mAb) COS3A was used to monitor the role of CD63 in T-cell activation. MAb COS3A could inhibit CD3-mediated T-cell proliferation and CD25 expression in peripheral blood mononuclear cells (PBMCs), used as a study model, but the suppressive effect was not observed when purified T-cells were used instead of PBMCs. The inhibitory phenomenon was associated with downregulation of IL-2 and IFN-γ by T-cells, but upregulation of IL-10 by monocytes. Neutralizing IL-10 with anti-IL-10 mAb improved the T-cell response, indicating the role of IL-10 in T-cell suppression. In this study, monocytes were demonstrated to play a role in impeding T-cell activation by the anti-CD63 mAb COS3A. This is the first evidence that anti-CD63 mAb induces IL-10 secretion by monocytes, which later play a role in T-cell hypo-responsiveness.