T-CELL ALLORECOGNITION AND ENDOGENOUS HLA-B27-BOUND PEPTIDES IN A CELL-LINE WITH DEFECTIVE HLA-B27-RESTRICTED ANTIGEN PRESENTATION

The B2702(+) lymphoblastoid cell line NW is unable to present at leas t some HLA-B27-restricted viral antigens to T cells. This defect was g enetically inherited, and was suggested to be related to the nature of the HLA-B27 binding peptides reaching the endoplasmic reticulum in th ese cells (Pazmany et al., J. Exp. Med. 1992. 175: 361). In the presen t study 17 of 19 HLA-B27-specific alloreactive cytotoxic T lymphocyte clones recognizing the B2702 subtype on other cells also lysed NW cel ls. Only two cytotoxic T lymphocyte clones failed to lyse NW while eff iciently killing other B2702(+) cell lines. The high-performance liqu id chromatography profiles of the B2702(+) bound peptides extracted f rom NW cells was similar, but not identical, to those from two other c ell lines. These results indicate that the HLA-B27-bound peptide reper toire in NW cells is not fundamentally different from those in other B 2702(+) cells. Our data argue against gross differences in peptide pr ocessing or transport as being responsible for the defective presentat ion of particular HLA-B27-restricted viral antigens to T cells, but do not rule out distinct presentation of some endogenous peptides. Diffe rences in the capacity to present certain peptides could cause differe ntial susceptibility among HLA-B27(+) individuals to ankylosing spondy litis.