IL-36γ signaling controls the induced regulatory T cell-Th9 cell balance via NFκB activation and STAT transcription factors.

Regulatory and effector T helper (Th) cells are abundant at mucosal surfaces, especially in the intestine, where they control the critical balance between tolerance and inflammation. However, the key factors that reciprocally dictate differentiation along these specific lineages remain incompletely understood. Here we report that the interleukin-1 (IL-1) family member IL-36γ signals through IL-36 receptor, myeloid differentiation primary response gene 88, and nuclear factor-κBp50 in CD4+ T cells to potently inhibit Foxp3-expressing induced regulatory T cell (Treg) development, while concomitantly promoting the differentiation of Th9 cells via a IL-2-STAT5- (signal transducer and activator of transcription factor 5) and IL-4-STAT6-dependent pathway. Consistent with these findings, mice deficient in IL-36γ were protected from Th cell-driven intestinal inflammation and exhibited increased colonic Treg cells and diminished Th9 cells. Our findings thus reveal a fundamental contribution for the IL-36/IL-36R axis in regulating the Treg-Th9 cell balance with broad implications for Th cell-mediated disorders, such as inflammatory bowel diseases and particularly ulcerative colitis.

Easy assessment of ES cell clone potency for chimeric development and germ-line competency by an optimized aggregation method.

Production of germ-line competent chimeric mice from embryonic stem (ES) cells is an inevitable step in establishing gene-manipulated mouse lineages. A common method used for creating chimeric mice is the injection of ES cells into the blastocoelic cavity (blastocyst injection). The aggregation method is an alternative way to introduce ES cells to the host embryo which is less difficult than blastocyst injection. Here we re-examined the condition of embryo-ES cell coculture on the aggregation method and found improvement of germ-line competent chimeric production by a simple modification of the coculture medium. Moreover, R1 ES cell and its 10 gene-manipulated subclones were tested by this method. Although all ES cell clones showed good morphology and a normal karyotype, the efficiency of chimeric development and germ-line transmission varied among clones and were classified into three grades according to germ-line competency. In the first group (class A), both the incidence of chimera with high ES cell contribution and the rate of germ-line transmission were fairly high. Germ-line competent chimeras were obtained but with rather low efficiency in the second group (class B), while another group (class C) showed an absence of high ES cell-contributed chimeras and no germ-line transmission. These results suggest the usefulness of this modified aggregation method to predict the potency of ES cell clones for germ-line competency.

[Effects of pectin and cellulose on somatomedin C levels and proteoglycan synthesis rate in rat muscle and cartilage]. / Efeito da pectina e celulose nos níveis de somatomedina C e síntese de proteoglicano no músculo e cartilagem de ratos.

The inclusion of 15% pectin in a diet causes growth retardation in rats, but the mechanism for the impaired growth has not been established. Serum concentration of IGF-I and proteoglycan synthesis rate on muscle and the tibial epiphysis, an estimate of biological response to IGF-I in a target tissue, were compared in weaning rat fed with 8.5% protein and levels of 7.5 and 15% of pectin and cellulose, respectively. In experiment 1 (G1-G6) was used cellulose as source of fiber and in experiment 2 (G7-G11) pectin. A marked reduction in weight, muscle and bone growth was observed for the groups fed on 15% pectin. Plasma IGF-I concentration correlated with both protein and tibial proteoglycan synthesis rate in the group with 15% pectin diet. However, in the group fed with cellulose the most of the parameters were well maintained, with exception the group fed with beans and rice (G5 e G6). Our study suggest that the inclusion of pectin in a experimental diet impairs growth by a combination of reduced food intake, a reduced anabolic response to food due to a reduced protein and proteoglycan synthesis possibly reflecting impaired IGF-I action and secretion.