Rat IL-12/P70(Interleukin 12 p70) ELISA Kit

In the central nervous system and in the liver, the macrophage populations are represented exclusively by descendants of the hematopoietic progenitor cells of the yolk sac. The reasons for such differential distribution of macrophages are not fully understood. We found that, as can be judged by corresponding changes in the expression of CD86 and CD163 markers, the transient macrophages of monocytic lineage are more sensitive to activating stimuli. The two macrophage populations have distinct patterns of gene expression, which is particularly noticeable for M1- and M2-associated genes. For instance, Kupffer cells more readily develop and longer maintain the elevated expression levels of Il4, Il10, and Il13 upon the activation; by contrast, the macrophages of monocytic lineage express Il1b, Il12a, and Tnf upon the activation. The obtained results allow us to conclude that the in vitro activated Kupffer cells of the liver are committed to M2 phenotype, whereas the in vitro activated monocyte-derived macrophages show a typical M1 behavior. These observations are likely to reflect the situation in the in vivo microenvironments.

Regulatory T (T-reg) cells are a critical sub-population of CD4(+) T cells that are essential for maintaining self tolerance and preventing autoimmunity(1,2), for limiting chronic inflammatory diseases, such as asthma and inflammatory bowel disease(3,4), and for regulating homeostatic lymphocyte expansion(5). However, they also suppress natural immune responses to parasites(6) and viruses(7) as well as anti-tumour immunity induced by therapeutic vaccines(8). Although the manipulation of T-reg function is an important goal of immunotherapy, the molecules that mediate their suppressive activity remain largely unknown. Here we demonstrate that Epstein-Barr-virus-induced gene 3 (Ebi3, which encodes IL-27 beta) and interleukin-12 alpha (Il12a, which encodes IL-2 alpha/p35) are highly expressed by mouse Foxp3(+) ( forkhead box P3) Treg cells but not by resting or activated effector CD4(+) T (T-eff) cells, and that an Ebi3-IL-12 alpha heterodimer is constitutively secreted by T-reg but not T-eff cells. Both Ebi3 and Il12a messenger RNA are markedly upregulated in T-reg cells co-cultured with T-eff cells, thereby boosting Ebi3 and IL-12 alpha production in trans. T-reg-cell restriction of this cytokine occurs because Ebi3 is a downstream target of Foxp3, a transcription factor that is required for T-reg-cell development and function. Ebi3(-/-) and Il12a(-/-) T-reg cells have significantly reduced regulatory activity in vitro and fail to control homeostatic proliferation and to cure inflammatory bowel disease in vivo. Because these phenotypic characteristics are distinct from those of other IL-12 family members, this novel Ebi3-IL-12 alpha heterodimeric cytokine has been designated interleukin-35 ( IL-35). Ectopic expression of IL-35 confers regulatory activity on naive T cells, whereas recombinant IL-35 suppresses T-cell proliferation. Taken together, these data identify IL-35 as a novel inhibitory cytokine that may be specifically produced by T-reg cells and is required for maximal suppressive activity.