Immunoglobulin heavy constant gamma 2 (IGHG2)

Immunoglobulin heavy constant gamma 2 (IGHG2) is the gene encoding the constant region of the heavy chain of immunoglobulin gamma 2, which defines the IgG2 subclass of antibodies in humans[1][4]. These antibodies are secreted by B cells and play a central role in humoral immunity, especially in response to carbohydrate antigens such as polysaccharides from bacterial capsules[5][2]. The IGHG2 constant region mediates effector functions via interaction with Fc gamma receptors and activation of the classical complement pathway[2][4]. The subclass differs from other IgG isotypes in hinge region structure, flexibility, and ability to engage effector pathways[2]. Allelic variation at the IGHG2 locus (notably Gm markers) is associated with differences in immune responsiveness and susceptibility to infections, autoimmunity, and some cancers[3][6]. Genetic or acquired deficiency in IgG2 can lead to recurrent infections, particularly with encapsulated bacteria[1]. IGHG2 is not a classical therapeutic target (i.e., not an enzyme, receptor, or signaling protein), but is crucial for antibody function and engineering of therapeutic monoclonal antibodies that utilize human IgG2 Fc regions for attenuated effector activity.

Other names

Ig gamma-2 chain C regionIg gamma-2 chain C region DOTIg gamma-2 chain C region TILIg gamma-2 chain C region ZIEConstant region of heavy chain of IgG2immunoglobulin gamma 2 (Gm marker)immunoglobulin heavy constant gamma 2 (Gm marker)

Not applicable to IGHG2 as a direct drug target. For therapeutic antibodies utilizing the IGHG2 Fc region, mechanisms may include antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, or modulation of immune responses (based on antibody Fc effector functions).