Immunoglobulin G (IgG) and Immunoglobulin E (IgE) Switching in Allergy and Microbial Interactions

The immune system is crucial in defending the body against pathogens, with, specifically immunoglobulins G (IgG) and immunoglobulins E (IgE), playing key roles in immune defense and regulation. During infections, B cells can undergo class switching to produce IgG antibodies recognize specific epitopes on microbial antigens and enhance their phagocytosis by immune cells like macrophages and neutrophils. They can engage in opsonization, neutralization, and complement activation, all contributing to the immune response against pathogens. During allergic reactions, class switching of IgE takes place when B cells produce IgE rather than other classes of antibodies. The choice between IgG and IgE antibody production involves intricate regulatory mechanisms influenced by factors such as the type of antigen encountered, the microenvironment, and the presence of cytokines. IgG responses are typically associated with effective microbial clearance and long-term immune memory, while IgE responses are more relevant for defense against parasites and are responsible for allergic disorders. Microbial interactions within the gut can influence the balance between IgG and IgE responses, potentially impacting susceptibility to both infections and allergies. In conclusion, the balance between IgG and IgE responses is essential for maintaining immune homeostasis and effective defense against microbes. A deeper understanding of class-switching mechanisms and factors influencing production is essential for developing strategies to manage allergies and enhance immune responses against infections. This review will focus on the advance research in this field that holds promise for uncovering novel therapeutic approaches that leverage the interplay between IgG, IgE, and microbial interactions. Graphical abstract: Diagrammatic representation of class-switching mechanism during microbial infection. (The class switching process ensures the initiation of the diverse aggregation of antibodies which are capable of mounting effective immune response against wide range of microbes.) (Figure created by using BioRender)