Physical and epitope analysis of a recombinant human T-cell receptor V alpha/V beta construct support the similarity to immunoglobulin.
The genetic organization and protein structure of T-cell receptors (TCR) and immunoglobulins (Ig) are remarkably similar. Through recombinant, physical, and peptide-based immunological studies we demonstrated that rabbit antisera generated against a recombinant single-chain TCR (scTCR) react with defined peptide epitopes of their constituent TCR alpha and beta chains. These antisera cross-react with the lambda light-chain Mcg as well as with peptides duplicating its covalent structure. Conversely, rabbit antisera generated to human lambda light chains cross-reacted with the recombinant scTCR. Rabbit anti-lambda antibodies purified on an scTCR affinity column bound to T-cell lines and to T and B lymphocytes from peripheral blood. Circular dichroism analysis demonstrated plots characteristic of beta-sheets for both Mcg and recombinant scTCR. Antisera directed against TCR alpha-chain synthetic peptides reacted with scTCR, Mcg lambda light-chain protein, synthetic peptides from regions of sequence homology in beta-chains, and Mcg. Based upon this homology and the serological cross-reactions which reflect conformational determinants, we suggest that the V alpha/V beta antigen-binding domain of this particular monoclonal scTCR construct is substantially similar to the conformational structure of lambda light chains.
Lake
D F
DF
Department of Microbiology and Immunology, University of Arizona, Tucson 85724, USA.
Helgerson
S
S
Landsperger
W J
WJ
Marchalonis
J J
JJ
D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D003429:Cross Reactions; D005434:Flow Cytometry; D006801:Humans; D007106:Immune Sera / Q000737:chemistry; D016056:Immunodominant Epitopes / Q000032:analysis* / Q000378:metabolism; D007146:Immunoglobulin lambda-Chains / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D007136:Immunoglobulins / Q000032:analysis*; D019169:Jurkat Cells; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D011817:Rabbits; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000032:analysis; D013050:Spectrometry, Fluorescence
D007106:Immune Sera; D016056:Immunodominant Epitopes; D007146:Immunoglobulin lambda-Chains; D007136:Immunoglobulins; D010455:Peptides; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011994:Recombinant Proteins