Intranasal administration of abatacept enhances IL-35+ and IL-10+ producing Bregs in lung tissues of ovalbumin-sensitized asthmatic mice model.

BACKGROUNDS: Treating asthmatic rheumatoid arthritis patients with abatacept has been shown to associate with better control of asthma symptoms. However, the mechanism behind that is not investigated. METHODS: Ovalbumin (OVA)- sensitized BALB/c female mice were treated intranasally (IN) or intraperitoneally (IP) with abatacept 4 hrs before the OVA challenge. The effects of abatacept IN or IP on the lungs and blood levels of Tregs and Bregs and their production of immunosuppressive cytokines, were determined using FACS analysis and ELISA assay. RESULTS: Treating OVA- sensitized asthmatic mice model with abatacept, IN or IP, reduced lung inflammation. IN treatment with abatacept increased the frequency of IL-35 and IL-10 producing Bregs in the lung tissues to a higher level compared to IP treatment. Moreover, the frequency of lungs LAG3+ Tregs was significantly increased following treatment. This was also associated with a reduction in lung tissue and serum IL-17 levels of treated mice. CONCLUSIONS: These results suggest that abatacept by enhancing IL-35+IL-10+ Bregs and LAG3+ Tregs might reverse IL-17 induced lung inflammation during asthma.

Salamander-derived, human-optimized nAG protein suppresses collagen synthesis and increases collagen degradation in primary human fibroblasts.

Unlike humans, salamanders regrow their amputated limbs. Regeneration depends on the presence of regenerating axons which upregulate the expression of newt anterior gradient (nAG) protein. We had the hypothesis that nAG might have an inhibitory effect on collagen production since excessive collagen production results in scarring, which is a major enemy to regeneration. nAG gene was designed, synthesized, and cloned. The cloned vector was then transfected into primary human fibroblasts. The results showed that the expression of nAG protein in primary human fibroblast cells suppresses the expression of collagen I and III, with or without TGF- ß 1 stimulation. This suppression is due to a dual effect of nAG both by decreasing collagen synthesis and by increasing collagen degradation. Furthermore, nAG had an inhibitory effect on proliferation of transfected fibroblasts. It was concluded that nAG suppresses collagen through multiple effects.