Restricted use of cationic germline V(H) gene segments in human Rh(D) red cell antibodies.
The human red cell Rh(D) antigen elicits the production of high-affinity IgG antibodies, which can prevent blood transfusion and cause hemolytic disease of the newborn. It has been known for 20 years that Rh(D) antibodies are among the most positively charged human serum IgGs. Analysis by IEF of 9 human anti-Rh(D) monoclonal antibodies showed that their isoelectric points (pI) (8.3 to 8.6) were also significantly higher than the average pI of serum IgGs (7.0 to 8.5). Sequencing of the anti-Rh(D) H and L chains cDNAs showed a preferential use of V(H)1, V(H)3, J(H)6, and V(kappa)1 gene segments. The high pIs in IEF were correlated with a higher number of cationic amino acid residues in the H chain V regions without clustering in the complementary determining region. Computer analysis indicated that the germline V(H) used in anti-Rh(D) was selected among the most cationic segments available in the human V(H) repertoire or expressed in normal B cells. These results indicate that the selection of cationic V(H) segments may be an important early step in the formation of clinically relevant anti-Rh(D) and other red cell antibodies, possibly to facilitate epitope binding in the negatively charged red cell membrane environment.
Boucher
G
G
The Canadian Red Cross Society, Blood Services, Ste-Foy, Québec, Canada.
Broly
H
H
Lemieux
R
R
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000302:isolation & purification; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D004912:Erythrocytes / Q000276:immunology; D005803:Genes, Immunoglobulin; D006801:Humans; D006825:Hybridomas; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D007143:Immunoglobulin Heavy Chains / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D007132:Immunoglobulin Isotypes / Q000737:chemistry / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D007145:Immunoglobulin kappa-Chains / Q000235:genetics / Q000302:isolation & purification; D007231:Infant, Newborn; D007525:Isoelectric Focusing; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D012204:Rh-Hr Blood-Group System / Q000276:immunology*
D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007132:Immunoglobulin Isotypes; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; D011994:Recombinant Proteins; D012204:Rh-Hr Blood-Group System