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Peptide-independent recognition by alloreactive cytotoxic T lymphocytes (CTL).

Smith PA, Brunmark A, Jackson MR, Potter TA - J. Exp. Med. (1997)

Bottom Line: Furthermore, this reactivity was not increased by the addition of an extract containing peptides from C57BL/6 (H-2(b)) spleen cells, nor was the reactivity decreased by treating the target cells with acid to remove peptides bound to MHC molecules.Moreover, reconstitution experiments demonstrated that the peptide-independent CTL clones were capable of mediating rapid and complete rejection of H-2-incompatible skin grafts.These findings provide evidence that not all allorecognition is peptide dependent.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206-2761, USA.

ABSTRACT
We have isolated several H-2K(b)-alloreactive cytotoxic T cell clones and analyzed their reactivity for several forms of H-2K(b). These cytotoxic T lymphocytes (CTL) were elicited by priming with a skin graft followed by in vitro stimulation using stimulator cells that express an H-2K(b) molecule unable to bind CD8. In contrast to most alloreactive T cells, these CTL were able to recognize H-2K(b) on the surface of the antigen processing defective cell lines RMA-S and T2. Furthermore, this reactivity was not increased by the addition of an extract containing peptides from C57BL/6 (H-2(b)) spleen cells, nor was the reactivity decreased by treating the target cells with acid to remove peptides bound to MHC molecules. The CTL were also capable of recognizing targets expressing the mutant H-2K(bm8) molecule. These findings suggested that the clones recognized determinants on H-2K(b) that were independent of peptide. Further evidence for this hypothesis was provided by experiments in which H-2K(b) produced in Drosophila melanogaster cells and immobilized on the surface of a tissue culture plate was able to stimulate hybridomas derived from these alloreactive T cells. Precursor frequency analysis demonstrated that skin graft priming, whether with skin expressing the wild-type or the mutant H-2K(b) molecule, is a strong stimulus to elicit peptide-independent CTL. Moreover, reconstitution experiments demonstrated that the peptide-independent CTL clones were capable of mediating rapid and complete rejection of H-2-incompatible skin grafts. These findings provide evidence that not all allorecognition is peptide dependent.

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Cytotoxic reactivity of the six H-2Kb–specific alloreactive  CTL clones for RMA-S target cells. The clones are denoted by the following symbols: (filled squares) 20; (filled triangles) 34; (filled circles) 39; (open  squares) 40; (open triangles) 41; (open circles) 59.
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Figure 6: Cytotoxic reactivity of the six H-2Kb–specific alloreactive CTL clones for RMA-S target cells. The clones are denoted by the following symbols: (filled squares) 20; (filled triangles) 34; (filled circles) 39; (open squares) 40; (open triangles) 41; (open circles) 59.

Mentions: Although the T2 cell line does not express serologically detectable levels of HLA molecules on its surface, transfection of mouse class I genes, such as H-2Kb, leads to very high levels of serologically detectable product on the surface of the T2 cells. We examined whether our CTL clones would recognize H-2Kb on the surface of the H-2b cell line RMA-S, which also is defective in antigen processing and, when cultured at 37°C, does not express any serologically detectable H-2Kb. Despite this low level of expression of H-2Kb on RMA/S, they were readily killed by the CTL clones (Fig. 6). The ability of the CTL clones to recognize H-2Kb on the surface of T2 and RMA-S cells also suggests that these CTL do not require the presence of a particular peptide derived from a particular cytosolic protein.


Peptide-independent recognition by alloreactive cytotoxic T lymphocytes (CTL).

Smith PA, Brunmark A, Jackson MR, Potter TA - J. Exp. Med. (1997)

Cytotoxic reactivity of the six H-2Kb–specific alloreactive  CTL clones for RMA-S target cells. The clones are denoted by the following symbols: (filled squares) 20; (filled triangles) 34; (filled circles) 39; (open  squares) 40; (open triangles) 41; (open circles) 59.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196245&req=5

Figure 6: Cytotoxic reactivity of the six H-2Kb–specific alloreactive CTL clones for RMA-S target cells. The clones are denoted by the following symbols: (filled squares) 20; (filled triangles) 34; (filled circles) 39; (open squares) 40; (open triangles) 41; (open circles) 59.
Mentions: Although the T2 cell line does not express serologically detectable levels of HLA molecules on its surface, transfection of mouse class I genes, such as H-2Kb, leads to very high levels of serologically detectable product on the surface of the T2 cells. We examined whether our CTL clones would recognize H-2Kb on the surface of the H-2b cell line RMA-S, which also is defective in antigen processing and, when cultured at 37°C, does not express any serologically detectable H-2Kb. Despite this low level of expression of H-2Kb on RMA/S, they were readily killed by the CTL clones (Fig. 6). The ability of the CTL clones to recognize H-2Kb on the surface of T2 and RMA-S cells also suggests that these CTL do not require the presence of a particular peptide derived from a particular cytosolic protein.

Bottom Line: Furthermore, this reactivity was not increased by the addition of an extract containing peptides from C57BL/6 (H-2(b)) spleen cells, nor was the reactivity decreased by treating the target cells with acid to remove peptides bound to MHC molecules.Moreover, reconstitution experiments demonstrated that the peptide-independent CTL clones were capable of mediating rapid and complete rejection of H-2-incompatible skin grafts.These findings provide evidence that not all allorecognition is peptide dependent.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206-2761, USA.

ABSTRACT
We have isolated several H-2K(b)-alloreactive cytotoxic T cell clones and analyzed their reactivity for several forms of H-2K(b). These cytotoxic T lymphocytes (CTL) were elicited by priming with a skin graft followed by in vitro stimulation using stimulator cells that express an H-2K(b) molecule unable to bind CD8. In contrast to most alloreactive T cells, these CTL were able to recognize H-2K(b) on the surface of the antigen processing defective cell lines RMA-S and T2. Furthermore, this reactivity was not increased by the addition of an extract containing peptides from C57BL/6 (H-2(b)) spleen cells, nor was the reactivity decreased by treating the target cells with acid to remove peptides bound to MHC molecules. The CTL were also capable of recognizing targets expressing the mutant H-2K(bm8) molecule. These findings suggested that the clones recognized determinants on H-2K(b) that were independent of peptide. Further evidence for this hypothesis was provided by experiments in which H-2K(b) produced in Drosophila melanogaster cells and immobilized on the surface of a tissue culture plate was able to stimulate hybridomas derived from these alloreactive T cells. Precursor frequency analysis demonstrated that skin graft priming, whether with skin expressing the wild-type or the mutant H-2K(b) molecule, is a strong stimulus to elicit peptide-independent CTL. Moreover, reconstitution experiments demonstrated that the peptide-independent CTL clones were capable of mediating rapid and complete rejection of H-2-incompatible skin grafts. These findings provide evidence that not all allorecognition is peptide dependent.

Show MeSH