Associations of HLA DR and DQ molecules with Lyme borreliosis in Latvian patients

Copyright: Copyright 2012 Elsevier B.V., All rights reserved.Background: Many autoimmune diseases are associated with variants of HLA genes such as those encoding the MHC complex. This correlation is not absolute, but may help in understanding of the molecular mechanism of disease. The purpose of this study was to determine HLA-DR,-DQ alleles in Latvian patients with Lyme borreliosis and control (healthy) persons. Case patients and control subjects were similar in age, gender and ethnic heritage and differed only as regards the presence of Borrelia burgdorferi infection. The study included 25 patients with clinical stage - erythema migrans and 30 control (healthy) persons. HLA genotyping was performed by PCR with sequence-specific primers. Results: The results show difference in HLA-DRB1 alleles distribution between patients and control subjects. The frequencies of HLA-DRB1 *04 (OR 11.24; p<0.007) and HLA-DRB1 *17 (03) (OR 8.05; p<0.033) were increased in the Lyme disease patients. And the frequency of allele DRB1*13 (OR 0.12; p<0.017) was lower in Borreliosis patients and higher in control group. But, significant differences in frequencies of HLA-DQ alleles we did not detect. Conclusions: HLA predisposition to Lyme borreliosis appears not to be limited to HLA molecules, but some HLA-DR alleles also have a significant influence, and, may have implications in our understanding of pathogenesis of this disease. In particular, HLA-DRB1*04 and DRB1 *17 (03) may contribute to the Lyme borreliosis development in Latvian population.publishersversionPeer reviewe

Ligation of cell surface CD4 inhibits activation-induced death of human T lymphocytes at the level of Fas ligand expression.

Abstract Cross-linking of cell surface CD4 molecules by anti-CD4 mAb or HIV-1 gp120/anti-gp120 Ab primes resting T lymphocytes for activation-induced cell death (AICD) triggered via the CD3/TCR complex. In striking contrast, we demonstrate here that preincubation of activated human CD4+ T cells with anti-CD4 mAb consistently inhibited AICD triggered via anti-CD3 mAb or Staphylococcus aureus enterotoxin A superantigen. Inhibition of AICD of CD4+ T cell clones was also observed with F(ab')2, but not with Fab, of anti-CD4 mAb. Moreover, soluble HIV-1 gp120, but not rIL-16, inhibited AICD stimulated by S. aureus enterotoxin A. In susceptible clones, CD4 ligation prevented the up-regulation of Fas ligand mRNA and cell surface expression in response to anti-CD3 mAb or superantigen stimulation. CD3/TCR-dependent protein tyrosine phosphorylation and cytokine production were also prevented by preceding CD4 ligation. The inhibition of AICD due to the prevention of Fas ligand upregulation reveals a novel immunoregulatory consequence of CD4 ligation that might play a role in HIV infection and in the therapeutic application of anti-CD4 mAb.</jats:p

Dominant recognition of a Borrelia burgdorferi outer surface protein A peptide by T helper cells in patients with treatment-resistant Lyme arthritis

In an earlier study, we found that T-cell lines (TCL) from five patients with treatment-resistant Lyme arthritis preferentially recognized Borrelia burgdorferi outer surface protein A (OspA), but TCL from four patients with treatment-responsive arthritis only rarely recognized this protein. Dominant T-cell recognition of an arthritogenic OspA epitope is one way in which the immune response against OspA might be involved in the pathogenesis of treatment-resistant Lyme arthritis. In an effort to test this hypothesis, we mapped the epitopes of 31 OspA-specific TCL and five T-cell clones derived from the synovial fluid or peripheral blood samples of three patients with treatment-resistant Lyme arthritis. Although each patient's TCL recognized a broad array of OspA peptides with different individual patterns, two regions of OspA were dominantly recognized. Each patient's TCL dominantly recognized a C-terminal epitope of OspA, ranging from amino acids (aa) 214 to 233 in one patient to 244 to 263 in another, and the TCL of all three patients dominantly recognized an epitope between aa 84 and 113. These dominant regions were confirmed by clonal analysis in one patient. Thus, the region of OspA between aa 84 and 113 was the dominant T-cell epitope shared by these three patients with treatment-resistant Lyme arthritis. If the T-cell response to OspA is involved in the pathogenesis of treatment-resistant Lyme arthritis, and epitope contained within aa 84 to 113 is a potentially arthritogenic epitope.</jats:p