Induction of alternative splicing of HLA-B27 by bacterial invasion

Objective. Alternative splicing of certain class I major histocompatibility complex pre–messenger RNA (pre-mRNA) is known to lead to generation of a cell-free soluble protein analog. This study was undertaken to examine whether this process occurs with HLA–B27, whether the process is modified by arthritis-causing bacteria, and whether the assembly of the soluble molecules follows the same pathway as the integral parent molecules. Methods. Alternative splicing of pre-mRNA was analyzed by reverse transcriptase-polymerase chain reaction, and assembly of soluble HLA–B27 by immunoprecipitation followed by sodium dodecyl sulfatepolyacrylamide gel electrophoresis and autoradiography. Results. There was alternative splicing of the pre-mRNA of HLA–B27. The process could be amplified by invasion with Salmonella or Yersinia bacteria. The soluble HLA–B27 was assembled in a pathway similar to that of the parent molecule. Conclusion. The association between arthritiscausing bacteria and HLA–B27 positive cells is a complex event. Soluble HLA–B27 is a potential key player.