IgG1

IgG1 is a subclass of Immunoglobulin G (IgG), which is one of the five classes of antibodies produced by the immune system to fight against foreign substances, known as antigens. IgG1 is the most abundant subclass of IgG in human serum, accounting for approximately 60-70% of the total IgG.

Structure

IgG1, like all other immunoglobulins, is a Y-shaped molecule composed of two identical heavy chains and two identical light chains. The heavy chains of IgG1 are of the γ1 type, hence the name IgG1. Each heavy chain and light chain pair forms an antigen-binding site at their tips, allowing IgG1 to bind to two antigens simultaneously.

Function

IgG1 plays a crucial role in the adaptive immune response, providing long-term protection against pathogens. It is capable of binding to a wide range of antigens, including bacteria, viruses, and toxins. Upon binding to an antigen, IgG1 can neutralize the pathogen directly or mark it for destruction by other immune cells through a process known as opsonization.

IgG1 also plays a role in immune response regulation. It can bind to Fc receptors on immune cells, modulating their activity. Furthermore, IgG1 can cross the placenta, providing passive immunity to the fetus during pregnancy.

Clinical significance

Abnormal levels of IgG1 can be indicative of various health conditions. Elevated levels may be seen in autoimmune diseases, chronic infections, and certain types of cancer. Conversely, low levels of IgG1 can lead to recurrent infections, as seen in immunodeficiency disorders.

See also

• Immunoglobulin G
• Antibody
• Immune system
• Antigen
• Adaptive immune response
• Opsonization
• Fc receptor
• Placenta
• Autoimmune diseases
• Chronic infections
• Cancer
• Immunodeficiency disorders