TY - JOUR
T1 - Biochemical characterization of the human t6 antigen
T2 - A comparison between T6 and murine TL
AU - Bushkin, Yuri
AU - Chorney, Michael J.
AU - Diamante, Edson
AU - Shu Man Fu, Man Fu
AU - Chang Yi Wang, Yi Wang
N1 - Funding Information:
Among a series of monoclonal antibodies reacting with human T-cell antigens, T6 is a characteristic marker of irnrna ture ~T-ceIIs and is present on approximately 70% of thymocytes (Reinherz and Schloss-man, 1980; Reinherz et al., 1980). In addition to thymocytes, the ‘I% antigen is also expressed on some T-leukemias (Reinherz ef ui., 19x0; Cotner et nl., 1981). Two monoclonal antibodies, NAlJ34 (McMichael et al., 1979) and OKT6 (Reinherz et al., 1980). have been used to immunoprecipitate T6 molecules from thymocyte and T-ceil leukemia Iysates. Both antibodies appeared to recognize the same *This work is supported in part by National Institutes of Health Grants AI-18231, CA-34546 and the Levine Laboratory Fund. It was presented at the 5th Inter-national Congress of Immunology, August 1983. Kyoto, Japan.--ICurrent address: Deoartment of Human Genetics, Yale ScbooI of Medic&. New Haven, CT 06510, U.S.A. SAbbreviations: PZM, p2-microglobulin; 2D, two-dimensional; IEF, isoelectric focusing; Ig, immuno-globulin; NP-40, Nonidet P-40; PAGE, polyacrylamide gel electrophoresis; PBS, phosphate-buffered saline; pl, isoelectric point; SDS, sodium dodecyl s&fate; TCA, trichioroacetic acid; TL, thymus leukemia.
PY - 1984/10
Y1 - 1984/10
N2 - The human T6 antigen was studied by two monoclonal antibodies: OKT6 and Leu-6. A third monoclonal antibody, C56 (developed in our laboratory), was found to have similar properties to those of OKT6. On SDS-PAGE, all three antibodies precipitated a 48,000-12,000-dalton heterodimer. Two-dimensional gel electrophoresis and chymotryptic peptide map analysis revealed that these antibodies precipitated in identical 48,000-dalton heavy chain which was distinguishable from the HLA-A,B,C heavy chains. The single 12,000-dalton light chain precipitated with OKT6 antibody was shown to be distinct from β2-microglobulin by its pI. The two light chains precipitated with Leu-6 antibody were resolved by charge into β2-microglobulin and the more basic 12,000-dalton peptide identical to that precipitated with OKT6. In addition to β2-microglobulin, the latter component (presumably βt) was also found in the light-chain fraction precipitated from the thymocytes with a monoclonal antibody recognizing the framework of HLA-A,B,C heavy chains. Using chymotryptic peptide mapping, no polymorphism was detected among the heavy chains of the T6 antigen isolated from thymocytes of four individuals. All three monoclonal antibodies failed to precipitate murine TL from ASL1 leukemia cell lysates. Similarly, none of the six monoclonal and two conventional anti-TL antibodies reacted with T6. Although a high degree of homology was found by peptide map analysis among the TL molecules encoded by the Tlaa, Tlad and Tlae alleles, a comparison between their peptide maps and that of T6 revealed no similarity. Despite previous suggestions that T6 is homologous to murine TL, the present biochemical studies do not support this hypothesis.
AB - The human T6 antigen was studied by two monoclonal antibodies: OKT6 and Leu-6. A third monoclonal antibody, C56 (developed in our laboratory), was found to have similar properties to those of OKT6. On SDS-PAGE, all three antibodies precipitated a 48,000-12,000-dalton heterodimer. Two-dimensional gel electrophoresis and chymotryptic peptide map analysis revealed that these antibodies precipitated in identical 48,000-dalton heavy chain which was distinguishable from the HLA-A,B,C heavy chains. The single 12,000-dalton light chain precipitated with OKT6 antibody was shown to be distinct from β2-microglobulin by its pI. The two light chains precipitated with Leu-6 antibody were resolved by charge into β2-microglobulin and the more basic 12,000-dalton peptide identical to that precipitated with OKT6. In addition to β2-microglobulin, the latter component (presumably βt) was also found in the light-chain fraction precipitated from the thymocytes with a monoclonal antibody recognizing the framework of HLA-A,B,C heavy chains. Using chymotryptic peptide mapping, no polymorphism was detected among the heavy chains of the T6 antigen isolated from thymocytes of four individuals. All three monoclonal antibodies failed to precipitate murine TL from ASL1 leukemia cell lysates. Similarly, none of the six monoclonal and two conventional anti-TL antibodies reacted with T6. Although a high degree of homology was found by peptide map analysis among the TL molecules encoded by the Tlaa, Tlad and Tlae alleles, a comparison between their peptide maps and that of T6 revealed no similarity. Despite previous suggestions that T6 is homologous to murine TL, the present biochemical studies do not support this hypothesis.
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U2 - 10.1016/0161-5890(84)90135-4
DO - 10.1016/0161-5890(84)90135-4
M3 - Article
C2 - 6438495
AN - SCOPUS:0021723380
SN - 0161-5890
VL - 21
SP - 821
EP - 829
JO - Molecular Immunology
JF - Molecular Immunology
IS - 10
ER -