MHC Class II Presentation in Autoimmunity

卷:12

Review

关键词: MYELIN BASIC-PROTEIN;    T-CELL-RECEPTOR;    HLA-DQ MOLECULES;    SELF-PEPTIDE;    RHEUMATOID-ARTHRITIS;    INTERFERON-GAMMA;    THYMIC SELECTION;    CROSS-REACTIVITY;    HIGH-AFFINITY;    UP-REGULATION;   

DOI  :  10.3390/cells12020314

来源: SCIE

【 摘 要 】

Antigen presentation by major histocompatibility complex class II (MHC-II) molecules is crucial for eliciting an efficient immune response by CD4(+) T cells and maintaining self-antigen tolerance. Some MHC-II alleles are known to be positively or negatively associated with the risk of the development of different autoimmune diseases (ADs), including those characterized by the emergence of autoreactive T cells. Apparently, the MHC-II presentation of self-antigens contributes to the autoimmune T cell response, initiated through a breakdown of central tolerance to self-antigens in the thymus. The appearance of autoreactive T cell might be the result of (i) the unusual interaction between T cell receptors (TCRs) and self-antigens presented on MHC-II; (ii) the posttranslational modifications (PTMs) of self-antigens; (iii) direct loading of the self-antigen to classical MHC-II without additional nonclassical MHC assistance; (iv) the proinflammatory environment effect on MHC-II expression and antigen presentation; and (v) molecular mimicry between foreign and self-antigens. The peculiarities of the processes involved in the MHC-II-mediated presentation may have crucial importance in the elucidation of the mechanisms of triggering and developing ADs as well as for clarification on the protective effect of MHC-II alleles that are negatively associated with ADs.