Diseases association with the polymorphic major histocompatibility complex class I related chain a: MICA gene

• Published in: Transplant immunology 2022-12, Vol.75, p.101665-101665, Article 101665
• Main Authors: Tchacrome, Imane, Zhu, Quan, Saleh, Mohammad Abu, Zou, Yizhou
• Format: Article
• Language: English
• Subjects: Anti-MICA antibodies; Autoimmune diseases; Graftversus-host disease; MIC genes; Soluble MICA
• ISSN: 0966-3274; 1878-5492
• DOI: 10.1016/j.trim.2022.101665

The Major Histocompatibility Complex class I chain-related molecule A (MICA) genes encode a highly polymorphic glycoprotein among the cell surface antigens that trigger an immune response after allograft transplantation. It is encoded by the MICA gene, a member of the glycosylated MIC genes. Discovered in 1994, the MICA gene is located within the MHC class I region. Moreover, its biological function is achieved through the interaction with the NKG2D receptor. Unlike the classical HLA molecules, MICA protein is not associated with β2- microglobulin nor binds peptides. MICA gene expression may result in a cytotoxic response and IFN-γ secretion through the up-regulation by heat shock proteins in response to infection (Human Cytomegalovirus HCMV), mediated by NKG2D-expressing cells. Anti-MICA antibodies were identified as significant risk factors for antibody mediated rejection after being detected in sera of patients with graft rejection. In addition, soluble MICA proteins (sMICA) has been detected in the serum of transplant recipients with cancers. Furthermore, the association of MICA polymorphisms with infectious diseases, various autoimmune diseases, cancer, and allograft rejection or graft-versus-host disease (GVHD) has been studied. Moreover, numerous advanced disease studies centered on MICA polymorphism are independent of HLA association. In this review, we discussed the up-to-date data about MICA and the association of MICA polymorphism with infections, autoimmune diseases, graft-versus-host disease, and cancer. •The Major Histocompatibility Complex class I chain-related molecule A (MICA) genes play an important role in immune responses through their interaction with the NKG2D receptor.•Pre-transplant and post-transplant Anti-MICA antibodies increased acute graft rejection with lower survival after being detected in sera of recipients with graft failure.•In turn, soluble MICA proteins (sMICA) increased in the serum of patients with cancers, therefore considered a prognostic factor of cancers.•MICA polymorphism is associated with infectious diseases, autoimmune diseases, cancer, allograft rejection, graft-versus-host disease (GVHD), … independent of HLA association or not.