Specificity of human T lymphocytes expressing a γ/δ T cell antigen receptor. Recognition of a polymorphic determinant of HLA class I molecules by a γ/δ clone

Two-dimensional gel electrophoresis of in vitro phosphorylated proteins coprecipitated by CD2 monoclonal antibody (mAb) from Brij58 lysates of resting human T lymphocytes and natural killer (NK) cells resulted in the identification of a novel 29/30-kD disulfide-linked dimer (pp29/30). Comparative two-dimensional analysis of CD2, CD3, CD4, CD5, and CD8 immunoprecipitates revealed that pp29/30 associates with these signaling receptor complexes but not with CD18, CD27, and CD29 in human T lymphocytes. Analysis of CD2 immunoprecipitates prepared from T cell antigen receptor/CD3-modulated T lymphocytes indicated that pp29/30 preferentially associates and comodulates with the human T cell antigen receptor (TCR). Since tyrosine phosphorylated pp29/30 selectively interacts with the Src homology type 2 domains (SHZ) of the protein tyrosine kinases p56lck and p59fyn but not ZAP70 the present data suggest that pp29/30 represents a novel signaling receptor associated phosphoprotein likely involved in the activation of human T lymphocytes and NK cells.

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Fas-Independent Apoptosis of Activated T Cells Induced by Antibodies to the HLA Class I α1 Domain

Blood ◽

10.1182/blood.v90.9.3629 ◽

1997 ◽

Vol 90 (9) ◽

pp. 3629-3639 ◽

Cited By ~ 32

Author(s):

Laurent Genestier ◽

Romain Paillot ◽

Nathalie Bonnefoy-Berard ◽

Geneviéve Meffre ◽

Monique Flacher ◽

...

Keyword(s):

Cell Proliferation ◽

T Cells ◽

T Cell ◽

T Lymphocytes ◽

Heavy Chain ◽

Hla Class I ◽

Class I ◽

T Cell Proliferation ◽

Activated T Cells ◽

Hla Class I Molecules

Abstract In addition to their major function in antigen presentation and natural killer cell activity regulation, HLA class I molecules may modulate T-cell activation and proliferation. Monoclonal antibodies (MoAbs) that recognize distinct epitopes of HLA class I molecules were reported to interfere with T-cell proliferation. We show here that two MoAbs (mouse MoAb90 and rat YTH862) that bind to an epitope of the α1 domain of HLA class I heavy chain induce apoptotic cell death of activated, but not resting, peripheral T lymphocytes. Other reference anti-HLA class I antibodies specific for distinct epitopes of the α1 (B9.12.1), α2 (W6/32), or α3 (TP25.99) domains of the heavy chain decreased T-cell proliferation but had little or no apoptotic effect. Apoptosis shown by DNA fragmentation, phosphatidylserine externalization, and decrease of mitochondrial transmembrane potential was observed whatever the type of T-cell activator. Apoptosis did not result from Fas/Fas-L interaction and distinct though partly overlapping populations of activated T cells were susceptible to Fas– and HLA class I–mediated apoptosis, respectively. Induction of apoptosis did not require HLA class I cross-linking inasmuch as it could be observed with monovalent Fab′ fragments. The data indicate that MoAb90 and YTH862 directed against the α1 domain of HLA class I trigger apoptosis of activated T lymphocytes by a pathway which does not involve Fas-ligand.

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The T cell antigen receptor complex expressed on normal peripheral blood CD4-, CD8- T lymphocytes. A CD3-associated disulfide-linked gamma chain heterodimer.

Journal of Experimental Medicine ◽

10.1084/jem.165.4.1076 ◽

1987 ◽

Vol 165 (4) ◽

pp. 1076-1094 ◽

Cited By ~ 96

Author(s):

L L Lanier ◽

N A Federspiel ◽

J J Ruitenberg ◽

J H Phillips ◽

J P Allison ◽

...

Keyword(s):

T Cell ◽

T Lymphocytes ◽

Cell Lines ◽

Peripheral Blood ◽

Antigen Receptor ◽

Receptor Complex ◽

T Cell Antigen Receptor ◽

Normal Peripheral Blood ◽

Cell Antigen Receptor ◽

Cell Antigen

IL-2-dependent cell lines were established from normal peripheral blood T lymphocytes that express neither CD4 nor CD8 differentiation antigens. CD3+,4-,8- cell lines from 15 different donors failed to react with WT31, an mAb directed against the T cell antigen receptor alpha/beta heterodimer. Anti-Leu-4 mAb was used to isolate the CD3/T cell antigen receptor complex from 125I-labeled CD3+,4-,8- (WT31-) T cells. Using detergent conditions that preserved the CD3/T cell antigen receptor complex, an approximately 90 kD disulfide-linked heterodimer, composed of approximately 45- and approximately 40- (or approximately 37-) kD subunits, was coimmunoprecipitated with the invariant 20-29-kD CD3 complex. Analysis of these components by nonequilibrium pH gradient electrophoresis indicated that the approximately 40-kD and approximately 37-kD subunits were similar, and quite distinct from the more basic approximately 45-kD subunit. None of these three subunits reacted with an antibody directed against a beta chain framework epitope. Heteroantiserum against a T cell receptor gamma chain peptide specifically reacted with both the approximately 37- and approximately 40-kD CD3-associated proteins, but not with the approximately 45-kD subunit. CD3+,4-,8- cells failed to transcribe substantial amounts of functional 1.3-kb beta or 1.6-kb alpha mRNA, but produced abundant 1.6-kb gamma mRNA. Southern blot analysis revealed that these CD3+,4-,8- cell lines rearranged both gamma and beta genes, and indicated that the populations were polyclonal. The expression of a CD3-associated disulfide-linked heterodimer on CD3+,4-,8- T cell lines established from normal, adult peripheral blood contrasts with prior reports describing a CD3-associated non-disulfide-linked heterodimer on CD3+/WT31- cell lines established from thymus and peripheral blood obtained from patients with immunodeficiency diseases. We propose that this discrepancy may be explained by preferential usage of the two C gamma genes in T lymphocytes.

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