Inflammasomes play essential roles in immune protection against microbial infections. However, excessive inflammation is implicated in various human diseases, including autoinflammatory syndromes, diabetes, multiple sclerosis, cardiovascular disorders and neurodegenerative diseases. Therefore, precise regulation of inflammasome activities is critical for adequate immune protection while limiting collateral tissue damage. In this review, we focus on the emerging roles of post-translational modifications (PTMs) that regulate activation of the NLRP3, NLRP1, NLRC4, AIM2 and IFI16 inflammasomes. We anticipate that these types of PTMs will be identified in other types of and less well-characterized inflammasomes. Because these highly diverse and versatile PTMs shape distinct inflammatory responses in response to infections and tissue damage, targeting the enzymes involved in these PTMs will undoubtedly offer opportunities for precise modulation of inflammasome activities under various pathophysiological conditions.
To test the role of neutralizing antibodies (nAbs) and receptor adaptation in interspecies transmission of influenza virus, two H5N1 strains, isolated from human and avian hosts, with four amino acid differences in hemagglutinin (HA) and seven HA mutations were studied. We found that a mutation at amino acid position 90 in the H5N1 HA, outside the receptor-binding domain (RBD), could simultaneously induce changes in the RBD conformation to escape from nAb binding and alter the receptor preference through long-range regulation. This mutation was deemed a "key event" for interspecies transmission. It is likely a result of positive selection caused by antibodies, allowing the original invasion by new species-specific variants. A mutation at amino acid position 160 in the RBD only induced a change in receptor preference. This mutation was deemed a "maintaining adaptation", which ensured that influenza virus variants would be able to infect new organisms of a different species successfully. The mutation is the result of adaptation caused by the receptor. Our results suggest that continuing occurrence of these two types of mutations made the variants persist in the new host species.
Spleen T-lymphocytes, especially CD4+ T-cells, have been demonstrated to be involved in broad immunomodulation and host-defense activity in vivo. Apolipoprotein M gene (apoM) may have an important role in the regulation of immunoprocess and inflammation, which could be hypothesized to the apoM containing sphingosine-1-phosphate (S1P). In the present study we demonstrate that the splenic CD4+ T-lymphocytes were obviously decreased in the apoM gene deficient (apoM−/−) mice compared to the wild type (apoM+/+). Moreover, these mice were treated with lipopolysaccharide (LPS) and it was found that even more pronounced decreasing CD4+ T-lymphocytes occurred in the spleen compared to the apoM+/+ mice. The similar phenomena were found in the ratio of CD4+/CD8+ T-lymphocytes. After administration of LPS, the hepatic mRNA levels of tumor necrosis factor-α (TNF-α) and monocyte chemotactic protein-1 (MCP-1) were markedly increased; however, there were no statistical differences observed between apoM+/+ mice and apoM−/− mice. The present study demonstrated that apoM might facilitate the maintenance of CD4+ T-lymphocytes or could modify the T-lymphocytes subgroups in murine spleen, which may further explore the importance of apoM in the regulation of the host immunomodulation, although the detailed mechanism needs continuing investigation.
Interleukin-37 (IL-37), a novel member of the IL-1 family, plays fundamental immunosuppressive roles by broadly reducing both innate inflammation and acquired immunity, but whether it is involved in the pathogenesis of tuberculosis (TB) has not been clearly elucidated. In this study, single nucleotide polymorphism (SNP) analysis demonstrated an association of the genetic variant rs3811047 of IL-37 with TB susceptibility. In line with previous report, a significant elevated IL-37 abundance in the sera and increased expression of IL-37 protein in the peripheral blood mononuclear cells (PBMC) were observed in TB patients in comparison to healthy controls. Moreover, release of IL-37 were detected in either macrophages infected with Mycobacterium tuberculosis (Mtb) or the lung of BCG-infected mice, concurrent with reduced production of proinflammatory cytokines including IL-6 and TNF-α. Furthermore, in contrast to wild-type mice, BCG-infected IL-37-Tg mice manifested with reduced mycobacterial burden and tissue damage in the lung, accompanied by higher frequency of Th1 cell and less frequencies of regulatory T cells and Th17 cells in the spleen. Taken together, our findings demonstrated that IL-37 conferred resistance to Mtb infection possibly involving suppressing detrimental inflammation and modulating T cell responses. These findings implicated that IL-37 may be employed as a new molecular target for the therapy and diagnosis of TB.
In this study, the evolution phenomena and mechanism of porous media were analyzed according to the driving factors, i.e., external force, heat, seepage, coupled chemical reaction and seepage, coupled chemical reaction and heat flow, and live porous media. According to the evolution mechanism, the evolution can be categorized as natural evolution, artificial evolution, and natural-artificial evolution. Taking the dissolution of glauberite ore as the example, the detailed evolution characteristics and behavior were investigated. The evolution characteristics of pores and the residual porous skeleton were investigated using micro-computed tomography. The results indicate that (1) The variation of the dissolution thickness of glauberite with time follows a power function. (2) The total void ratio of the residual porous media remains almost the same and is typically in a range of 20-22 %. The diffusion coefficient of the residual porous skeleton is 0.013 cm 2 /h. (3) In the process of glauberite dissolution, three zones are formed from the interface to the outside: a crystallization completion zone, a crystalline transition zone, and a development zone of dissolution and crystallization. The crystallization completion zone is formed after 15 h dissolution. The thickness of the crystallization transition zone and development zone of dissolution and crystallization is approximately 0.5-1.0 mm.
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