Reduced expression of CD69 and adhesion molecules of T lymphocytes in asthmatic children receiving immunotherapy

Soluble L-Selectin as an Independent Biomarker of Bronchial Asthma

BACKGROUND

We sought to determine the association of plasma level of soluble L-selectin (sL-selectin) and F206L polymorphism of L-selectin with asthma.

METHODS

A total of 90 asthmatic patients and 90 sex- and age-matched healthy controls were enrolled. The plasma level of sL-selectin was measured by enzyme-linked immunosorbent assay (ELISA) method. An amplification refractory mutation system polymerase chain reaction was performed to detect F206L polymorphism of L-selectin.

RESULTS

The mean plasma levels of sL-selectin was significantly higher in the patients with asthma than the controls (2113 ± 466 vs. 1664 ± 322 ng/ml, P = 0.001). Logistic regression analysis after adjustment for age, sex, and body mass index demonstrated that plasma levels of sL-selectin are an independent biomarkers for asthma (odds ratio [OR], 1.86; 95% confidence interval [95% CI], 1.42-2.24). The area under the receiver operating characteristic (ROC) curve for sL-selectin was 0.792, 95% CI (0.732-0.862), P = 0.0001. Individuals with the minor homozygote of F206L polymorphism of L-selectin demonstrated a higher level of sL-selectin than the major homozygous (2319 ± 732 vs. 1917 ± 453 ng/ml, P = 0.02). No association was found between F206L polymorphism of L-selectin with asthma.

CONCLUSION

Our study suggests that plasma level of sL-selectin is an independent biomarker for asthma.

Viral IL-10-mediated immune regulation in pancreatic islet transplantation

Protection of transplanted pancreatic islet grafts in recipients with autoimmune diabetes depends on the suppression of autoimmune recurrence and allogeneic rejection. The aim of this study was to investigate the efficiency of viral IL-10 gene delivery in the prevention of autoimmune recurrence following islet transplantation. We evaluated the effectiveness of a systemically delivered adeno-associated viral vector (AAV vIL-10) carrying viral IL-10 in protecting islet engraftment. We observed significant prolongation of graft survival after treatment with AAV vIL-10 when using islets from donors lacking autoimmunity. We found that the mechanism of vIL-10-mediated protection was associated with suppression of T cell activation and that donor immune cells that were simultaneously transferred with the islet grafts could induce autoimmune recurrence. AAV vIL-10 gene transfer suppressed previously activated T cells and protected grafted islets from autoimmune-mediated destruction. We conclude that vIL-10 can regulate autoimmune activity and that transfer of its gene may have potential for therapeutic islet transplantation.

Ephrin-A1 suppresses Th2 cell activation and provides a regulatory link to lung epithelial cells

Gene expression screening showed decreased ephrin-A1 expression in CD4+ T cells of asthma patients. Ephrin-A1 is the ligand of the Eph receptor family of tyrosine kinases, forming the largest family of receptor tyrosine kinases. Their immune regulatory properties are largely unknown. This study demonstrates significantly reduced ephrin-A1 expression in T cells of asthma patients using real time-PCR. Immunohistological analyses revealed strong ephrin-A1 expression in lung tissue and low expression in cortical areas of lymph nodes. It is absent in T cell/B cell areas of the spleen. Colocalization of ephrin-A1 and its receptors was found only in the lung, but not in lymphoid tissues. In vitro activation of T cells reduced ephrin-A1 at mRNA and protein levels. T cell proliferation, activation-induced, and IL-2-dependent cell death were inhibited by cross-linking ephrin-A1, and not by engagement of Eph receptors. However, anti-EphA1 receptor slightly enhances Ag-specific and polyclonal proliferation of PBMC cultures. Furthermore, activation-induced CD25 up-regulation was diminished by ephrin-A1 engagement. Ephrin-A1 engagement reduced IL-2 expression by 82% and IL-4 reduced it by 69%; the IFN-gamma expression remained unaffected. These results demonstrate that ephrin-A1 suppresses T cell activation and Th2 cytokine expression, while preventing activation-induced cell death. The reduced ephrin-A1 expression in asthma patients may reflect the increased frequency of activated T cells in peripheral blood. That the natural ligands of ephrin-A1 are most abundantly expressed in the lung may be relevant for Th2 cell regulation in asthma and Th2 cell generation by mucosal allergens.