HLA-B27 MODULATES INTRACELLULAR SURVIVAL OF SALMONELLA-ENTERITIDIS INHUMAN MONOCYTIC CELLS

Human major histocompatibility complex class I allele HLA-B27 is assoc iated with a group of diseases called spondyloarthropathies. In reacti ve arthritis (ReA), the disease is triggered by certain infections, e. g. gastroenteritis caused by Salmonella. The host/microbe interaction is abnormal in susceptible individuals leading to inefficient eliminat ion of arthritis-triggering bacteria, fragments of them, or both, afte r the initial infection. Using transfected human monocytic U937 cell l ines, we demonstrate that the expression of the HLA-B27 antigen does n ot influence the uptake of S. enteritidis into U937 cells in vitro. In terestingly, HLA-B27 remarkably impairs the elimination of S. enteriti dis within the HLA-B27 transfected U937 cells. The impaired eliminatio n of ReA-triggering microbes by HLA-B27(+) monocytes may offer an expl anation for the persistence of ReA-triggering microbes in susceptible HLA-B27(+) individuals. This modulation of the host/microbe interactio n by HLA-B27 may have an important role in the pathogenesis of ReA.