Abstract

Class II major histocompatibility complex (MHC) molecules play a crucial role in the adaptive immune response by presenting antigens to CD4+ T cells. This intricate process of antigen presentation not only facilitates effective immune recognition and response but also contributes to immune regulation and tolerance. In this article, we delve into the complexities of Class II MHC molecules, highlighting their structure, function, and the mechanisms involved in antigen presentation. We discuss the diverse repertoire of peptides that can be presented by Class II MHC molecules and their implications in immune surveillance and disease pathogenesis. Furthermore, we explore the intricate interplay between Class II MHC molecules, antigen-presenting cells, and T cell receptors, shedding light on the fundamental mechanisms underlying immune recognition and activation. Additionally, we examine the role of Class II MHC molecules in immune regulation, including their involvement in regulatory T cell function and tolerance induction. Finally, we discuss recent advancements and future perspectives in the field, aiming to provide a comprehensive understanding of Class II MHC molecules and their significance in the immune system.