Antibodies

This overview addresses Antibodies, with particular emphasis on the main classes of antibodies and their unique functions in immune defense, focusing on their molecular structure and mechanisms of action. We will explore how antibodies are produced by B cells, the processes of activation and class switching, and how antibodies neutralize and eliminate pathogens. The lecture will also discuss how antibodies contribute to health, their uses in diagnostics and therapy, and the impact of antibody-related disorders. Finally, we will highlight ongoing research that advances our understanding of antibodies and their importance in medicine.. Antibodies, or immunoglobulins, are proteins central to our adaptive immune response. Found in the bloodstream and on B cells, they protect us from many pathogens. There are five main classes: IgG, the most abundant, provides long-term immunity; IgM is first produced in infection and activates complement; IgA protects mucosal areas like the gut and airways; IgE is involved in allergies and defenses against parasites; and IgD, found mainly on immature B cells, helps with their activation. Despite their differences, all antibody classes play essential roles in immune surveillance and protection. Let’s examine the molecular structure of an antibody. Each Y-shaped molecule has two identical heavy and two identical light chains. The arms have variable regions with unique amino acid sequences from B cell gene rearrangement, providing antigen specificity.