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Interaction of 2C T Cells with a Hybrid L d Molecule Bearing an α3 Domain Derived from the Class I b Molecule, Qa‐2
Author(s) -
UNGCHUSRI T.,
KETTMAN J. R.,
FORMAN J.
Publication year - 1997
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1046/j.1365-3083.1997.d01-94.x
Subject(s) - cd8 , negative selection , population , biology , t cell receptor , microbiology and biotechnology , cytotoxic t cell , receptor , double negative , in vitro , antigen , t cell , immunology , genetics , immune system , gene , medicine , environmental health , genome
The CD8 co‐receptor interacts with nonpolymorphic residues on class I molecules. L Q3 , a laboratory engineered L d molecule bearing an α3 domain derived from Q7 (Qa‐2), interacts poorly with anti‐L d CD8‐dependent T cells. 2C TCR transgenic mice bear a receptor specific for the p2Ca peptide bound to L d . The authors show that although this peptide interacts with L Q3 , L Q3 APC fail to activate splenic 2C CD8 T cells in vitro in the absence of IL‐2, while control L d APC do. The authors have used this receptor ligand pair to examine negative selection within the thymus of (B6 × C3H.L d )F 1 versus (B6 × C3H.L Q3 )F 1 radiation chimeras repopulated with 2C bone marrow cells. While positive selection occurs normally in (B6 × C3H)F 1 chimeras, animals expressing either L d or L Q3 fail to generate 2C CD8 + cells. Thus, either CD8 is not required for negative selection of this TCR or a weak interaction of CD8 with L Q3 is sufficient. TSA‐1, a developmentally regulated marker, was used to follow the process of negative selection. The results show that deletion of 2C T cells does not occur until thymocytes reach the double positive (DP) stage. Furthermore, the authors noted a small population of DP TSA‐1 hi cells remains, while DP TSA‐1 int and TSA‐1 lo cells are absent. These data support the notion that thymocytes either reach a particular stage of development or locate in an appropriate intrathymic compartment before they undergo negative selection.