Immunogenetic analysis of variable regions encoding AB1 and gamma-type AB2 antibodies from the NeuGc-containing ganglioside family.
The variable regions from P3, a murine monoclonal antibody (MAb) against NeuGc-containing gangliosides, and two anti-idiotype MAbs directed to P3 MAb were cloned and sequenced. Comparisons with previously reported sequences showed that P3 is a germline antibody encoded by genes from the V(H)Q52 and V(kappa)19 families. Analysis of nucleotides at the heavy chain CDR3 (H-CDR3) showed the presence of an extensive 3' N region that contains almost 50% of the nucleotides of this CDR. In addition, amino acid sequence analysis of the H-CDRs of this MAb revealed the presence of three arginines, two of which are present in the H-CDR3, that could be involved in the interaction of P3 MAb with its electronegative epitope on gangliosides. Anti-idiotype 1E10, which seems to define a "regulatory" idiotope on P3 MAb (it induces Id+ Ab3), represents a germline Ab2 that belongs to the V(H)J558 and V(kappa)10 gene families. By contrary, the anti-idiotype 3B11 is an extensively mutated antibody that belongs to the V(H)3660 and V(kappa)4/5 gene families, defining a "private" idiotope on P3 MAb. Even when different V genes contribute to the variable regions of 1E10 and 3B11 MAbs, they share an acidic motif E/D-D-Y/D-Y-D in H-CDR3, suggesting that both Ab2s recognize paratope positive residues on the Ab1. Therefore, complementary electrostatic interactions involving H-CDR3 from both Ab1 and Ab2, might provide a clue to understand the molecular basis for the generation of gamma-type anti-idiotype antibodies to V regions recognizing glycolylated ganglioside antigens.
Perez
A
A
Department of Antibody Engineering, Center of Molecular Immunology, P.O. Box 16040, Havana 11600, Cuba. alexis@ict.cim.sld.cu
Lombardero
J
J
Mateo
C
C
Mustelier
G
G
Alfonso
M
M
Vazquez
A M
AM
Perez
R
R
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics*; D000918:Antibody Specificity; D001483:Base Sequence; D022801:Complementarity Determining Regions / Q000235:genetics; D017931:DNA Primers / Q000737:chemistry; D000939:Epitopes / Q000032:analysis; D005679:G(M3) Ganglioside / Q000031:analogs & derivatives* / Q000276:immunology*; D006801:Humans; D007125:Immunogenetics; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007130:Immunoglobulin Idiotypes / Q000032:analysis / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D000911:Antibodies, Monoclonal; D022801:Complementarity Determining Regions; D017931:DNA Primers; D000939:Epitopes; D005679:G(M3) Ganglioside; D007143:Immunoglobulin Heavy Chains; D007130:Immunoglobulin Idiotypes; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; C044298:N-glycolylneuraminyllactosylceramide