Immunoglobulin heavy variable 4-28 (IGHV4-28)

Immunoglobulin heavy variable 4-28 (IGHV4-28) is a protein coding gene segment located within the immunoglobulin heavy-chain (IGH) locus on chromosome 14. This locus encodes the variable (V), diversity (D), joining (J), and constant (C) gene segments necessary for the biosynthesis of the antibody heavy chain, a key molecule of the adaptive immune system. The protein product of IGHV4-28 forms part of the variable region of antibody heavy chains, contributing to the antigen-binding site in combination with a light chain. This variable region is generated by V-(D)-J recombination and further diversified through somatic hypermutation, enabling broad antibody specificity and affinity maturation. In the recognition phase of humoral immunity, membrane-bound immunoglobulins containing IGHV4-28 act as B cell receptors that bind antigens and trigger B-cell clonal expansion and differentiation. IGHV4-28 gene usage may vary between individuals (allelic/polymorphic variation) and is involved in clonal expansions under pathological conditions, such as immune thrombocytopenia. However, IGHV4-28 itself is not a therapeutic target; instead, it is an essential genetic element for antibody diversity and effective immune responses.

Other names

IGHV4-28IGHV428HV428VHimmunoglobulin heavy chain variable regionImmunoglobulin Heavy Variable 4-28