Spontaneous Inflammatory Disease in HLA-B27 Transgenic Mice Does Not Require Transporter of Antigenic Peptides

HLA-B27 is strongly linked with a group of human diseases called spondyloarthropathies. Even though HLA-B27 as an MHC class I molecule would be expected to present endogenously processed peptides such as cytosolic or viral proteins, many of the B27-linked diseases begin after an infection with an enterobacteria, an exogenous antigen. In our previous studies, we have described development of spontaneous inflammatory disease in HLA-B27 transgenic mice expressing β2m free heavy chains on the cell surface. In order to address the role of endogenous versus exogenous antigens and a role for Tap genes in the development of spontaneous diseases, mice lacking Tap-1 (knockout) were mated to HLA-B27/human β2m transgenic mice. B27+/human β2m+ double-transgenic mice (without mouse β2m) lacking the Tap-1 gene developed spontaneous inflammatory disease similar to wild-type Tap-1 gene-expressing counterparts. Our data demonstrate that peptide transporters (Tap) were not involved in the development of spontaneous inflammatory disease in B27+/human β2m transgenic animals.