The family of IL‐10‐related cytokines includes several human members, IL‐19, IL‐20, IL‐22, IL‐24 and IL‐26, and a series of herpesviral and poxviral paralogs. Some of these cytokines share common receptor subunits. In this study, we investigated the effects of these cytokines on naive T cell differentiation, antigen‐specific T cell suppression, survival ad expression of surface markers in comparison to IL‐10 and cytomegalovirus (CMV)‐IL‐10. Human CD45RA⁺ T cells were stimulated in the presence of IL‐10‐family cytokines in sequential 12‐day cycles. After three to four cycles of stimulation, IL‐10 and CMV‐IL‐10 led to increased IFN‐γ and IL‐10 but decreased IL‐4 and IL‐13. Interestingly, long‐term exposure of T cells to IL‐19, IL‐20 and IL‐22 down‐regulated IFN‐γ but up‐regulated IL‐4 and IL‐13 in T cells and supported the polarization of naive T cells to Th2‐like cells. In contrast, neutralization of endogenous IL‐22 activity by IL‐22‐binding protein decreased IL‐4, IL‐13 and IFN‐γ synthesis. The antigen‐specific suppressor activity of IL‐10 and CMV‐IL‐10 was not observed for any of the other IL‐10‐family cytokines. These data demonstrate that IL‐19, IL‐20 and IL‐22 may participate in T cell‐mediated diseases by distinct regulation of T cell cytokine profiles.

—Atherogenesis is a multifactorial chronic inflammatory disease in which low plasma levels of HDLs are a strong predictor of the condition. Although the mechanism of protection by HDLs is not precisely known, HDLs have been shown to influence many of the events involved in the development of atherosclerosis. Previously we have shown that HDLs inhibited the cytokine-induced expression of adhesion molecules (E-selectin, VCAM-1, and ICAM-1) by endothelial cells (ECs). As the complete transcriptional regulation of all 3 genes requires the NF-κB family of transcription factors, we examined the effect of HDLs on activation of NF-κB. We also investigated the effect of HDLs on 2 other cytokine-induced genes, granulocyte-macrophage colony-stimulating factor (GM-CSF) and cyclooxygenase (Cox-2; prostaglandin H₂synthase, EC0.1.14.99.1). E-selectin expression in response to tumor necrosis factor-α (TNFα) was, as expected, inhibited in ECs that had been preincubated with HDLs. However, the level of secretion of GM-CSF in the same cultures was no different from control. In a similar manner, although HDLs had no effect on steady-state mRNA levels of GM-CSF, the levels of E-selectin were significantly inhibited by HDLs. In transient cotransfection experiments we found that HDLs inhibited the cytokine-induced expression of a reporter gene driven by the E-selectin proximal promoter (−383 to 80) but had no effect on the expression of a reporter gene driven under the control of the proximal promoter of GM-CSF (−627 to 28). As would be predicted from this differential response, HDLs did not influence the nuclear translocation or DNA binding of NF-κB, or alter the kinetics of degradation and resynthesis of the inhibitory protein IκBα. We found that HDLs synergized with cytokine to enhance the expression of Cox-2 and induce the synthesis of its main EC product, prostacyclin (PGI₂), a potent inhibitor of platelet and leukocyte functions. In conclusion, HDL induces an antiinflammatory phenotype in cytokine-induced ECs, synergizing with cytokine to induce elevation of Cox-2 in addition to inhibiting adhesion molecule expression. Our studies show that these differential effects are mediated in a manner that is likely to be independent of NF-κB per se.

Genetic manipulation of donor cornea prior to transplantation has the potential to modulate the allogeneic response, as well as the endothelial cell function. This study examined the feasibility of gene transfer to corneal endothelial cells using replication-defective recombinant adenoviral vectors. Adult rabbit corneas were infected with recombinant adenovirus RAd35, containing the Escherichia coli β-galactosidase(lacZ) gene. Localization of gene transfer was assessed by histochemica staining for β-galactosidase and recombinant protein production was quantified by a soluble assay. In initial experiments, the efficiency of gene transfer and kinetics of expression were studied ex vivo, using organ culture of transfected corneas. Following coculture of whole corneal fragments with RAd35, high levels of gene expression were evident on days 1-7, diminishing after that time. Gene transfer was found to be almost entirely restricted to corneal endothelial cells, with scattered expression in epithelial cells. Following these ex vivo studies, geneticaly modified corneas were transplanted as orthotopic allografts in rabbits. Similar kinetics of gene expression were seen after transplantation as in the ex vivo experiment, with maximal levels of gene expression in endothelial cells on days 1-4 after grafting. Corneal function following transplantation was not affected by the gene transfer, with the corneas attaining clarity within 1 day of grafting, and thereafter showing the expected thinning on ultrasonic pachymetry. In the absence of any immunosuppression, no inflammation was evident in graft recipient eyes, with the exception of allograft rejection in 1 animal 23 days after grafting. In this study we show that gene transfer to nonreplicating corneal endothelial cells is feasible using recombinant adenovirus vectors, and so may have potential application in the setting of corneal transplantation.

Background: Obstructive sleep apnea syndrome (OSAS)-induced hypoxic stress modulates circulating inflammatory mediators causing accelerated atherogenesis. Objectives: We hypothesized that OSAS-induced hypoxia might result in cardiovascular disease due to increased expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the endothelial surface. Methods: Thirty-nine subjects with moderate-to-severe OSAS and 34 non-apneic controls matched for age, gender, body mass index (BMI), smoking history, and cardiovascular disease were included in this prospective study. Overnight polysomnography was performed. Circulating ICAM-1 and VCAM-1 levels in the serum were measured by enzyme-linked immunosorbent assay. Results: Circulating levels of both ICAM-1 (480.1 ± 216.7 vs. 303.4 ± 98.6 ng/ml, p < 0.0001) and VCAM-1 (1,156.6 ± 79.8 vs. 878.8 ± 71.1 ng/ml, p = 0.002) were significantly increased in the OSAS group compared to the control group. For an ICAM-1 cutoff level of 375 ng/ml, predictive sensitivity and specificity for OSAS were 69.2% (95% confidence interval, CI: 52.4–83.0%) and 82.4% (95% CI: 65.5–93.2%), respectively. For a VCAM-1 cutoff level of 859 ng/ml, predictive sensitivity and specificity for OSAS were 74.4% (95% CI: 57.9–86.9%) and 64.7% (95% CI: 46.5–80.2%), respectively. There was a significant positive correlation between circulating levels of ICAM-1 and ln of AHI (r = 0.276, p = 0.018). Multiple logistic regression analyses showed that OSAS was associated with high ICAM-1 and high VCAM-1 levels independent of age, gender, BMI, smoking status and cardiovascular disease. Conclusion: We conclude that OSAS can independently increase circulating levels of adhesion molecules.