Immunoglobulins: Mechanistic Approaches in Moderation of Various Inflammatory and Anti-inflammatory Pathways

Immunoglobulins (Igs) are proteins that help fight infections. IgG (IgG1, IgG2, IgG3, IgG4), IgM, IgA, IgD, and IgE are the five Ig subtypes that make up the majority of our immune system. Beneficial effects have been observed on the administration of Ig in diseases like Kawasaki, multiple myositis, chronic inflammatory demyelinating polyneuropathy (CIDP), and immune thrombocytopenic purpura (ITP). The Fc region, FcγRs, and FcRn of the IgG interact to provide both pro- and anti-inflammatory effects. IgM blocks immune-mediated inflammation using N-like glycans. It has been demonstrated that IgM demonstrates its anti-inflammatory activity through IgM anti-leukocyte auto-antibodies (IgM-ALA). Since IgA is the second most prevalent and important Ig that operates on the primary objective in the immune system, which exhibits inhibitory signals in the body and generates inflammation in host cells, it plays a critical role in controlling mucosal homeostasis in the gastrointestinal (GI) tract. Additionally, it has been discovered that activating FcαRI boosts cytokine responses at different levels. IgD, a mysterious class of Ig once discovered, has a role in many disorders, including myeloma and Hodgkin’s disease. The stability of IgD with development shows a different role, which has an advantage for the host's survival. IgE is mainly associated with many allergic diseases (food allergies), mediates type 1 responses, and has defenses against parasitic infections, which makes it an important parameter for monoclonal antibodies. Studies showed the possible roles of Igs, from which it came to light that Igs have their functions as agonists and antagonists in inflammation.