Phosphorylated peptides are naturally processed and presented by major histocompatibility complex class I molecules in vivo - PubMed (original) (raw)

Phosphorylated peptides are naturally processed and presented by major histocompatibility complex class I molecules in vivo

A L Zarling et al. J Exp Med. 2000.

Abstract

Posttranslational modification of peptide antigens has been shown to alter the ability of T cells to recognize major histocompatibility complex (MHC) class I-restricted peptides. However, the existence and origin of naturally processed phosphorylated peptides presented by MHC class I molecules have not been explored. By using mass spectrometry, significant numbers of naturally processed phosphorylated peptides were detected in association with several human MHC class I molecules. In addition, CD8(+) T cells could be generated that specifically recognized a phosphorylated epitope. Thus, phosphorylated peptides are part of the repertoire of antigens available for recognition by T cells in vivo.

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Figures

Figure 1

Figure 1

MS/MS spectrum of the HLA-A*0201–associated peptide RLDpSYVRSL. Predicted masses for the ions of type b and y are shown above and below the sequence, respectively. Those observed are underlined. ▵, loss of phosphoric acid from the corresponding ion of type b or y.

Figure 2

Figure 2

Discrimination of phosphorylated peptides by CD8+ T lymphocytes. (A) IFN-γ production by phosphopeptide-specific CD8+ T cells. CD8+ T cells (generated by long-term culture with the indicated peptides as described in Materials and Methods) were stimulated for 5 h with CIR-AAD that had been pulsed with 25 μM of one of the indicated phosphorylated peptides and then assayed for the intracellular accumulation of IFN-γ. Nonspecific IFN-γ accumulation was determined by the stimulation of CD8+ T cells with unpulsed CIR-AAD and was <100/105 CD8+ T cells. (B) Specificity of GLDpSYVRSL-specific CTLs. CD8+ T cells elicited by stimulation with 1 μM GLDpSYVRSL were analyzed for cytolytic activity using 51Cr-labeled CIR-AAD targets (E/T ratio of 3:1) that had been pulsed with the indicated concentrations of phosphorylated GLDpSYVRSL, RLDpSYVRSL, GLDpYYVRSL, and GLDpTYVRSL, or nonphosphorylated GLDSYVRSL. Specific lysis of unpulsed CIR-AAD targets was <2%.

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References

    1. Germain R.N., Margulies D.H. The biochemistry and cell biology of antigen processing and presentation. Annu. Rev. Immunol. 1993;11:403–450. - PubMed
    1. Cresswell P., Bangia N., Dick T., Diedrich G. The nature of the MHC class I peptide loading complex. Immunol. Rev. 1999;172:21–28. - PubMed
    1. Engelhard V.H. Structure of peptides associated with MHC class I molecules. Curr. Opin. Immunol. 1994;6:13–23. - PubMed
    1. Skipper J.C., Gulden P.H., Hendrickson R.C., Harthun N., Caldwell J.A., Shabanowitz J., Engelhard V.H., Hunt D.F., Slingluff C.L., Jr. Mass-spectrometric evaluation of HLA-A*0201-associated peptides identifies dominant naturally processed forms of CTL epitopes from MART-1 and gp100. Int. J. Cancer. 1999;82:669–677. - PubMed
    1. Hunt D.F., Henderson R.A., Shabanowitz J., Sakaguchi K., Michel H., Sevilir N., Cox A.L., Appella E., Engelhard V.H. Characterization of peptides bound to the class I MHC molecule HLA-A2.1 by mass spectrometry. Science. 1992;255:1261–1264. - PubMed

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