Recent advances in molecular understanding of IgM and IgA

<p indent="0mm">Immunoglobulins (Igs) play a vital role in the immune system and are categorized into five major classes: IgM, IgD, IgG, IgE, and IgA. IgM is the first antibody produced in response to pathogen invasion, while IgA is predominantly found on mucosal surfaces. Both IgM and IgA are critical for immune defense in their polymeric forms; however, the mechanisms underlying their assembly and functionality remain poorly understood. Recent advancements in cryo-electron microscopy have enabled the determination of high-resolution structures of both IgM and IgA, providing new insights into their assembly processes, receptor binding characteristics, and molecular interactions with pathogen proteins. These discoveries enhance our understanding of the complex roles these antibodies play in immune responses.