Understanding IgG: Function and Malfunction
Introduction to IgG Immunoglobulin G (IgG) is a type of antibody, serving as a critical component of the immune system. Antibodies are proteins produced to identify and neutralize foreign objects like bacteria and viruses. IgG is the most abundant antibody in the human body and plays a vital role in immune defense. Functions of IgG Neutralization: IgG antibodies can neutralize pathogens by binding to them and preventing them from infecting cells. This function is particularly crucial for combating viruses and toxins. Opsonization: IgG enhances the phagocytosis of pathogens by marking them for destruction. Phagocytes, such as macrophages and neutrophils, have receptors that bind to the Fc region of IgG, leading to the engulfment and destruction of the pathogen. Complement Activation: IgG can activate the complement system, a series of proteins that assist in destroying pathogens. This system can lead to the formation of a membrane attack complex that lyses bacterial cells. Antibody-D...