MHC Class II Specific Neutra™ Antibody Products

Major Histocompatibility Complex class II (MHC II) molecules are critical in the immune system by presenting antigens to CD4⁺ T cells, initiating an adaptive immune response. MHC II molecules are located on the surface of antigen-presenting cells (APCs), such as B cells, dendritic cells, and macrophages. MHC II molecules are heterodimers formed of two chains: α chain and β chain. These chains form a peptide-binding groove, which captures and presents antigens to T cells. The expression of MHC II molecules is regulated and can be induced by various immune stimuli, including interferon-γ.

Functions of MHC II

The primary function of MHC II molecules is to present exogenous antigens derived from extracellular pathogens to CD4⁺ T cells. This interaction activates T cells, resulting in cytokine release and recruitment of additional immune cells to eliminate the pathogen. MHC II molecules are critical for the initiation of an effective immune response against bacteria, viruses, and other pathogens that do not infect host cells directly. Importantly, MHC II molecules are involved in immune surveillance and immune tolerance. They facilitate the recognition and elimination of foreign antigens while also participating in the regulation of self-tolerance to prevent autoimmune responses.

General Pathway of MHC II Antigen Presentation

The general pathway of MHC II antigen presentation involves several steps. First, extracellular pathogens are engulfed by APCs via phagocytosis or endocytosis. Within the endocytic pathway, antigens are degraded into peptide fragments by proteases. These peptide fragments subsequently attach to MHC II molecules within the endosomal compartments. MHC II molecules, loaded with antigenic peptides, travel to the cell membrane and present to CD4⁺ T cells. Upon identification of the antigen-MHC II complex by a CD4⁺ T cell receptor, along with co-stimulatory signals, CD4⁺ T cells become activated, leading to the initiation of an adaptive immune response against the pathogen.

Fig.1 The MHC-II antigen presentation pathways.¹

Pathways Controlling MHC II Antigen Presentation

Several signaling pathways have been linked to the regulation of MHC II antigen presentation. One such pathway involves the phosphoinositide 3-kinase regulatory subunit PIK3R2, which has been shown to play a role in MHC II expression and antigen processing. The lipid kinase PIP5K1 has also been implicated in MHC II regulation, as it is required for the formation of endosomal compartments that facilitate efficient antigen presentation. PSD4, a scaffolding protein involved in membrane trafficking, has been shown to regulate the localization of MHC II molecules within APCs, affecting their ability to present antigens. Additionally, the small GTPases ARL14/ARF7 and ARF7EP/MYO1E have been implicated in MHC II antigen presentation, with ARL14/ARF7 playing a role in endosomal maturation and ARF7EP/MYO1E involved in the transport of MHC II-containing vesicles to the cell surface. Taken together, these pathways play crucial roles in the regulation of MHC II antigen presentation, ensuring an effective immune response against invading pathogens.

Antibodies Targeting MHC II

Antibodies targeting MHC II molecules have been extensively studied in immunological research. These antibodies play a crucial role in understanding MHC II function and are commonly used as research tools to study MHC II expression, antigen presentation, and T cell activation. Additionally, specific antibodies against MHC II have been utilized in diagnostic assays to detect MHC II-related diseases and monitor immune responses. Moreover, antibodies against MHC II have been utilized to investigate their role in modulating immune responses, treating autoimmune disorders, and enhancing anti-tumor immune responses. Furthermore, MHC II-targeting antibodies are being explored as potential therapeutics for infectious diseases such as tuberculosis.

Fig.2 Potential modes of action of peptide-MHC (pMHC) monoclonal antibodies in cancer, infection, and autoimmunity.²

Creative Biolabs offers eight kinds of anti-MHC class II antibody products that can be used for eleven applications to meet your various research needs.

REFERENCES

1. Couture, Alexandre, et al. "HLA-class II artificial antigen presenting cells in CD4⁺ T cell-based immunotherapy." Frontiers in immunology 10 (2019): 447508. Distributed under Open Access license CC BY 4.0, without modification.
2. Høydahl, Lene Støkken, et al. "Targeting the MHC ligandome by use of TCR-like antibodies." Antibodies 8.2 (2019): 32. Distributed under Open Access license CC BY 4.0, without modification.