Skip to main content

MHC Class II Presentation

Meaning

MHC Class II Presentation is a fundamental immunological process where specialized antigen-presenting cells (APCs), such as dendritic cells and macrophages, display fragments of extracellular proteins (antigens) on their surface using Major Histocompatibility Complex Class II molecules. This presentation is the essential initiating step for the adaptive immune response, specifically activating helper T-lymphocytes (CD4+ T cells). In the context of hormonal health, aberrant or overzealous MHC Class II presentation of self-antigens, such as thyroid peroxidase or insulin, is a core mechanism driving the pathogenesis of many autoimmune endocrine disorders.