Comparison of Target Antigens of Monoclonal Reagents OKT5, OKT8, and Leu2A, which Inhibit Effector Function of Human Cytotoxic T Lymphocytes

Snow, Peter M.; Spits, Hergen; Vries, JE de; Terhorst, Cox

doi:10.1089/hyb.1983.2.187

Cited by 26 publications

(13 citation statements)

References 22 publications

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“…The existence of two forms of the CD8 molecule (75 kDa and 67 kDa) was previously reported by others [14,371. However, both molecules were believed to represent a/a homodimers with different intrachain disulfide bonds [38]. The present data demonstrate that the 75-kDa and 67-kDa molecules are composed of different subunits and that both isoforms can be co-expressed on unstimulated T cells and T cell clones.…”

Section: Nd N Dmentioning

confidence: 58%

Expression of different CD8 isoforms on distinct human lymphocyte subpopulations

Moebius¹,

Kober²,

Griscelli³

et al. 1991

Eur J Immunol

149

101

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Human CD8+ lymphocyte subpopulations were analyzed for their expression of CD8 alpha and CD8 beta subunits. Investigations with uncloned peripheral blood lymphocytes as well as cloned human natural killer and T cell subpopulations demonstrate that CD3- natural killer cells, T cell receptor gamma/delta, and CD4+CD8+ T cell clones express exclusively CD8 alpha gene products. Structural analysis of CD8 molecules demonstrates that CD8 alpha+/beta- T lymphocytes surface express 75-kDa CD8 alpha/alpha homodimers whereas CD8 alpha/beta lymphocytes express concomittantly two CD8 isoforms of different molecular masses (67 kDa and 75 kDa, respectively). Peptide mapping of these latter two isoforms suggests that CD8 is expressed as alpha/alpha homodimers and alpha/beta heterodimers on CD8 alpha/beta+ cells. Importantly, we found that the two CD8 isoforms behave functionally different. Thus, in contrast to CD8 alpha/beta+/CD8 alpha/alpha+ T lymphocytes, cytolytic activity of CD8 alpha/beta-/CD8 alpha/alpha+ T cell clones was not inhibited by anti-CD8 monoclonal antibodies and the latter were not induced to proliferate following CD3/CD8 cross-linking.

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Section: Nd N Dmentioning

confidence: 58%

Expression of different CD8 isoforms on distinct human lymphocyte subpopulations

Moebius¹,

Kober²,

Griscelli³

et al. 1991

Eur J Immunol

149

101

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“…This recognition appears to be a complex process, and at least one additional cell surface component, the CD8 molecule, is implicated (4, 9-11). CD8 has been characterized as a 32-to 34-kDa integral membrane protein in its reduced form (12,13). Under nonreducing conditions, CD8 has been identified in a series of multimeric forms differing in inter-or intrachain disulfide bonding (13).…”

Section: Introductionmentioning

confidence: 99%

“…CD8 has been characterized as a 32-to 34-kDa integral membrane protein in its reduced form (12,13). Under nonreducing conditions, CD8 has been identified in a series of multimeric forms differing in inter-or intrachain disulfide bonding (13).…”

mentioning

confidence: 99%

Physical association between the CD8 and HLA class I molecules on the surface of activated human T lymphocytes.

Bushkin¹,

Demaria²,

Le³

et al. 1988

Proc. Natl. Acad. Sci. U.S.A.

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Immune recognition by cytotoxic effector T cells requires participation of the CD8 and major histocompatibility complex class I antigens. We found that the CD8 molecule is noncovalently associated with the HLA class I heavy chain on the surface of human T cells activated by Con A. Accordingly, anti-CD8 monoclonal antibodies precipitated a heterodimer containing polypeptides of32 and 43 kDa from the lysates of activated T cells. tigen and polymorphic MHC determinants (5-8). This recognition appears to be a complex process, and at least one additional cell surface component, the CD8 molecule, is implicated (4, 9-11). CD8 has been characterized as a 32-to 34-kDa integral membrane protein in its reduced form (12,13). Under nonreducing conditions, CD8 has been identified in a series of multimeric forms differing in inter-or intrachain disulfide bonding (13). Studies have suggested (1-4, 14-16) that CD8 can bind to MHC class I molecules and thereby increase T-cell-target or T-cell-accessory-cell avidity that allows recognition of antigen and T-cell activation. To date, however, the actual physical interaction between CD8 and MHC class I molecules on T-cell surface is not well understood. This report demonstrates a noncovalent association between CD8 and HLA heavy chain molecules on the surface of activated human T cells.MATERIALS AND METHODS Cells. Human thymocytes and peripheral blood T cells isolated by forming rosettes with sheep erythrocytes (17) were used directly for radioiodination. For Con A activation, T cells were incubated at 106 cells per ml with 10' non-T cells per ml in complete medium [RPMI 1640 medium with 5% (vol/vol) fetal bovine serum, glutamine (0.06 mg/ml), streptomycin (100 tg/ml), and penicillin (100 units/ml)] with Con A (10 pkg/ml) for 2 days. Before radioiodination, the Con A-activated T cells were washed once with 50 mM a-methyl mannoside (Sigma) and twice with isotonic phosphatebuffered saline (pH 7.2). For allogeneic activation of T cells, unseparated peripheral blood lymphocytes from two healthy donors were incubated in complete medium at 2 x 106 cells per ml for 5 days. A natural killer (NK)-enriched cell population obtained by discontinuous Percoll gradient centrifugation (18) was 80% positive for CD16, recognized by monoclonal antibody B73.1 (19). A cloned CTL line (CD3 +, CD4 -, CD8 '), derived from peripheral blood lymphocytes sensitized with irradiated allogeneic non-T cells, was maintained in RPMI 1640 medium with 20% (vol/vol) pooled human AB serum (Flow Laboratories) and human interleukin 2 (20 units/ml) (Boehringer Mannheim). The human T-cell leukemia line HPB-ALL was from J. Minowada (Roswell Park Memorial Institute, Buffalo, NY) and was maintained in complete medium.Antibodies. The monoclonal antibodies OKT8A (Ortho Diagnostics), anti-Leu-2a (Becton Dickinson), and C8 (20) (a gift of C. Y. Wang, United Biomedical, Lake Success, NY) recognize CD8. The anti-HLA-A, -B, and -C monoclonal antibodies W6/32 (21) and A1.4 (22) The publication costs of this article were defr...

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“…On peripheral T cells and some T lymphomas, a small fraction of Lyt-2 exist also as homodimers (unpublished observations). The Leu-2 antigen is similarly found on a 32-kDa chain, which is disulfide-linked with another polypeptide (CD1 or T6) on thymocytes or with another Leu-2 peptide on peripheral blood lymphocytes to form heterodimers or homodimers (12,13).…”

mentioning

confidence: 99%

Molecular cloning of Lyt-2, a membrane glycoprotein marking a subset of mouse T lymphocytes: molecular homology to its human counterpart, Leu-2/T8, and to immunoglobulin variable regions.

Nakauchi¹,

Nolan²,

Hsu³

et al. 1985

Proc. Natl. Acad. Sci. U.S.A.

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The sequence of Lyt-2 cDNA shows that it is a new member of the immunoglobulin super gene family. Analysis of the predicted amino acid sequence indicates that the Lyt-2 polypeptide is synthesized with a 27-amino acid leader, and that the mature protein has an immunoglobulin variable region (Ig V)-related sequence of 100 amino acids, an extracellular spacer of 43, a transmembrane region of 38, and an intracytoplasmic region of 27 amino acids. Lyt-2 and its human analogue Leu-2 are 56% homologous; analysis indicates that the Ig V-related domains of the two molecules have evolved away from each other faster than the carboxyl-terminal half of the proteins.

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Comparison of Target Antigens of Monoclonal Reagents OKT5, OKT8, and Leu2A, which Inhibit Effector Function of Human Cytotoxic T Lymphocytes

Cited by 26 publications

References 22 publications

Expression of different CD8 isoforms on distinct human lymphocyte subpopulations

Expression of different CD8 isoforms on distinct human lymphocyte subpopulations

Physical association between the CD8 and HLA class I molecules on the surface of activated human T lymphocytes.

Molecular cloning of Lyt-2, a membrane glycoprotein marking a subset of mouse T lymphocytes: molecular homology to its human counterpart, Leu-2/T8, and to immunoglobulin variable regions.

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