Molecular immunology最新文献

Purpose

Nonalcoholic steatohepatitis (NASH) has been an increasingly significant contributor to hepatocellular carcinoma (HCC). Understanding the progression from NASH to HCC is critical to early diagnosis and elucidating the underlying mechanisms.

Results

5 significant prognostic genes related to NASH-HCC transformation were identified through algorithm selection, which were ME1, TP53I3, SOCS2, GADD45G and CYP7A1. A diagnostic model for NASH prediction was established (AUC=0.988). TP53I3 and SOCS2 were selected as potential critical genes in the progression of NASH-HCC by external dataset validation and in vitro experiments on NASH and HCC cell lines. Immune infiltration analysis illustrated the correlation between 5 significant prognostic genes and immune cells. Single-cell analysis identified hepatocytes related to NASH-HCC transformation markers, revealing their promoting role in the transformation from NASH to HCC.

Conclusion

With bulk-seq analysis and single-cell analysis, 5 significant prognostic genes related to NASH-HCC transformation were identified and validated at both dataset and in vitro experiment level. Among them, TP53I3 and SOCS2 might be potential critical genes in NASH-HCC progression. Single-cell analysis identified and revealed the critical role that NASH-HCC related hepatocytes play in NASH-HCC tansformation. Our research may introduce a new perspective to the diagnosis, treatment of NASH-related HCC.

Microglia play a major role in the immune defense system of the central nervous system and are activated in many neurological diseases. The immunomodulatory cytokine interleukin (IL)-15 is known to be involved in microglia response and inflammatory factors release. Neoprzewaquinone A (NEO) is an active compound isolated from Salvia miltiorrhiza Bunge. Our previous study has shown that NEO significantly inhibit the proliferation of IL-15-treated Mo7e cells. However, the role of NEO in the structure and function of IL-15-treated human microglial cells (HMC3) remains unclear. Thus, our study aimed to quantitatively analyze the beneficial effects of NEO on HMC3 cells following IL-15 treatment. The cell viability, phagocytosis, migration and energy metabolism were evaluated by Cell Counting Kit-8 (CCK8), scratch assay, pHrodo™ Red Zymosan BioParticles™ Conjugate, and Agilent Seahorse XF Cell Mito Test. Cephalothin (CEP) was selected as a positive drug because it has obvious inhibitory effect on IL-15 and IL-15Rɑ. Our results showed that IL-15 stimulated the proliferation, migration and phagocytosis of HMC3 cells in a time-dependent manner. Interestingly, NEO exhibited significant suppressive effects on these IL-15-induced changes, which were even superior to those observed with the CEP. Moreover, IL-15 treatment did not significantly alter energy metabolism, including glycolysis and mitochondrial respiration. NEO and CEP alone effectively reduced glycolysis, non-mitochondrial respiration, basal respiration, ATP turnover, respiration capacity, and H⁺ leak in HMC3 cells. Furthermore, NEO displayed a partial regulatory effect on mitochondrial function in IL-15-treated HMC3 cells. Our study confirms the effectively inhibition of NEO on IL-15-induced microglial activation and provides valuable insights into the therapeutic prospects of NEO in neuropsychiatric disorders associated with IL-15 and microglia.

Background

Cannabidiol (CBD), the major non-psychoactive component of cannabis, exhibits anti-inflammatory properties, but less is known about the immunomodulatory potential of CBD on activated natural killer (NK) cells and/or their targets. Many tumor cells present heat shock protein 70 (Hsp70) on their cell surface in a tumor-specific manner and although a membrane Hsp70 (mHsp70) positive phenotype serves as a target for Hsp70-activated NK cells, a high mHsp70 expression is associated with tumor aggressiveness. This study investigated the immuno-modulatory potential of CBD on NK cells stimulated with TKD Hsp70 peptide and IL-2 (TKD+IL-2) and also on HCT116 p53wt and HCT116 p53-/- colorectal cancer cells exhibiting high and low basal levels of mHsp70 expression.

Results

Apart from an increase in the density of NTB-A and a reduced expression of LAMP-1, the expression of all other activatory NK cell receptors including NKp30, NKG2D and CD69 which are significantly up-regulated after stimulation with TKD+IL-2 remained unaffected after a co-treatment with CBD. However, the release of major pro-inflammatory cytokines by NK cells such as interferon-γ (IFN-γ) and the effector molecule granzyme B (GrzB) was significantly reduced upon CBD treatment. With respect to the tumor target cells, CBD significantly reduced the elevated expression of mHsp70 but had no effect on the low basal mHsp70 expression. Expression of other NK cell ligands such as MICA and MICB remained unaffected, and the NK cell ligands ULBP and B7-H6 were not expressed on these target cells. Consistent with the reduced mHsp70 expression, treatment of both effector and target cells with CBD reduced the killing of high mHsp70 expressing tumor cells by TKD+IL-2+CBD pre-treated NK cells but had no effect on the killing of low mHsp70 expressing tumor cells. Concomitantly, CBD treatment reduced the TKD+IL-2 induced increased release of IFN-γ, IL-4, TNF-α and GrzB, but CBD had no effect on the release of IFN-α when NK cells were co-incubated with tumor target cells.

Conclusion

Cannabidiol (CBD) may potentially diminish the anti-tumor effectiveness of TKD+IL-2 activated natural killer (NK) cells.

Bacterial meningitis is a serious central nervous system (CNS) infection, claiming millions of human lives annually around the globe. The deadly infection involves severe inflammation of the protective sheath of the brain, i.e., meninges, and sometimes also consists of the brain tissue, called meningoencephalitis. Several inflammatory pathways involved in the pathogenesis of meningitis caused by Streptococcus pneumoniae, Neisseria meningitidis, Escherichia coli, Haemophilus influenzae, Mycobacterium tuberculosis, Streptococcus suis, etc. are mentioned in the scientific literature. Many in-vitro and in-vivo analyses have shown that after the disruption of the blood-brain barrier (BBB), these pathogens trigger several inflammatory pathways including Toll-Like Receptor (TLR) signaling in response to Pathogen-Associated Molecular Patterns (PAMPs), Nucleotide oligomerization domain (NOD)-like receptor-mediated signaling, pneumolysin related signaling, NF-κB signaling and many other pathways that lead to pro-inflammatory cascade and subsequent cytokine release including interleukine (IL)-1β, tumor necrosis factor(TNF)-α, IL-6, IL-8, chemokine (C-X-C motif) ligand 1 (CXCL1) along with other mediators, leading to neuroinflammation. The activation of another protein complex, nucleotide-binding domain, leucine-rich–containing family, pyrin domain–containing-3 (NLRP3) inflammasome, also takes place resulting in the maturation and release of IL-1β and IL-18, hence potentiating neuroinflammation. This review aims to outline the inflammatory signaling pathways associated with the pathogenesis of bacterial meningitis leading to extensive pathological changes in neurons, astrocytes, oligodendrocytes, and other central nervous system cells.

Background

The prevalence of food allergies is on the rise, posing a significant challenge to public health. Rodents serve as the predominant animal model in food allergy research; yet, the application of rodent models proves to be a laborious and time-consuming endeavor. It is imperative to develop novel in vivo models.

Methods

Ovalbumin (OVA) was administered as the allergen, following the recommended dosage used in other species. During the sensitization phase, a dosage of 0.25 mg per 10 tails per 1 L was administered twice daily, and during the challenge phase, the dosage was increased to 3 times the initial level. The study explored two dimensions of sensitization: the mode of exposure, which can be either continuous or intermittent, and the duration of exposure, which includes 3 days, 5 days, and 7 days. We examined midgut pathological changes, immunoglobulins contents, and mRNA expressions associated to T helper cells (Th) 2 cytokines following exposure.

Results

A significant 109.3 % increase in the number of eosinophils was observed in the midgut histopathology following intermittent 5-day OVA exposure, which emerged as the most effective model. OVA exposure increased concentrations of immunoglobulin M (IgM) (105.2 %), IgZ (312.1 %), and IgD (304.3 %) in this model. The mRNA expressions of Th2-related interleukin (IL)-4 and IL-13 were also elevated by 132.8 % and 421.0 %, respectively.

Conclusion

The intermittent 5-day OVA exposure was suggested to be the best constructed zebrafish food allergy model, which may be a potential tool for research into food allergies.

Antimicrobial peptides (AMPs) are a promising alternative to antibiotics in the fight against multi-drug resistant and immune system-evading bacterial infections. Protegrins are porcine cathelicidins which have been identified in porcine leukocytes. Protegrin-1 is the best characterized family member and has broad antibacterial activity by interacting and permeabilizing bacterial membranes. Many host defense peptides (HDPs) like LL-37 or chicken cathelicidin 2 (CATH-2) have also been shown to have protective biological functions during infections. In this regard, it is interesting to study if Protegrin-1 has the immune modulating potential to suppress unnecessary immune activation by neutralizing endotoxins or by influencing the macrophage functionality in addition to its direct antimicrobial properties. This study showed that Protegrin-1 neutralized lipopolysaccharide- (LPS) and bacteria-induced activation of RAW macrophages by binding and preventing LPS from cell surface attachment. Furthermore, the peptide treatment not only inhibited bacterial phagocytosis by murine and porcine macrophages but also interfered with cell surface and intracellular bacterial survival. Lastly, Protegrin-1 pre-treatment was shown to inhibit the amastigote survival in Leishmania infected macrophages. These experiments describe an extended potential of Protegrin-1’s protective role during microbial infections and add to the research towards clinical application of cationic AMPs.

Tanshinone I (Tan I) has been proven to exert an anti-inflammatory effect, but the complete mechanism remains unclear. In this study, Tan I was described to have no effect on Syk expression in resting or LPS-stimulated macrophages ex vivo, but dramatically suppressed Syk phosphorylation and CD80, CD86, and IL-1β expression of macrophages. The inflammatory activity of macrophages in ApoC3-transgenic (ApoC3^TG) mice is upregulated by Syk activation. Tan I was determined to downregulate Syk phosphorylation and inflammatory activity of macrophages in ApoC3^TG mice, both ex vivo and in vivo. Intraperitoneal injection of Tan I (4 mg/kg) effectively alleviated DSS-induced colitis in mice, accompanying with suppressing the activation of intestinal macrophages. Mechanistically, Tan I-treated macrophages exhibited a decrease in cytoplasmic ROS, NLRP3, GSDMD, and IL-1β, which suggested that the alternative pathway of inflammasome activation in macrophages was suppressed. The SPR assay demonstrated that Tan I bound to Syk protein with a dissociation constant (KD) of 2.473 × 10⁻⁶ M. When Syk expression was knocked down by its shRNA, the inhibitory effects of Tan I on macrophages were blocked. Collectively, Tanshinone I effectively alleviated DSS-induced colitis in mice by inhibiting Syk-stimulated inflammasome activation, hence suppressing the inflammatory activity of macrophages.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that mainly affects the joints. Studies have shown that memory CD4⁺ T cells play an important role in the pathogenesis of RA. This study investigated the expression and function of CD305 on human memory CD4⁺ T cells and the effects of CD305 activating antibody on collagen-induced arthritis. The results showed that CD305 expression was significantly decreased on circulating memory CD4⁺ T cells from patients with RA and its mean fluorescence intensity (MFI) was negatively correlated with DAS28. Moreover, CD305 inhibited the activation of memory CD4⁺ T cells by down-regulating CD69 and CD25 and the production of IFN-γ, IL-4, and IL-17A induced by anti-CD3/CD28 antibodies. In addition, activation of CD305 inhibited the severity of disease in collagen-induced arthritis. In summary, CD305 reduction may mediate the excessive activation of memory CD4⁺ T cells and participate in the development of RA. It can be used as a predictive marker of disease activity and has potential medicinal value in the treatment of RA.

Background

The treatment of food allergy (FA) needs improvement. The treatment of immune disorders can be improved by regulating epigenetic marks, which is a promising method. The objective of this research is to alleviate experimental FA by employing an inhibitor of DNA methyltransferase-1 (DNMT1).

Methods

Ovalbumin was used as the specific antigen to establish a mouse model of FA. Intestinal IL-35⁺ regulatory B cells (Breg cells) were isolated from FA mice, and characterized using immunological approaches.

Results

FA mice had a lower frequency of IL-35⁺ Breg cells, which was inversely correlated with their FA response. The quantity of IL-35 was lower in intestinal Breg cells from FA mice. Hypermethylation status was detected in the Il35 promoter, which was accompanied with high levels of H3K9me3. Enforced expression of DNMT1 hindered the promoter activity of the IL35 gene. Administration of an inhibitor of DNMT1 (RG108) restored the immune regulatory capacity of FA intestinal Bregs, and effectively suppressed the expression of DNMT1, and attenuated experimental FA.

Conclusions

The elevated quantity of DNMT1 in intestinal Breg cells compromises the expression of IL-35 and affects the immune regulatory functions, which facilitates the development of FA. The immune regulatory functions of intestinal Breg cells are restored and experimental FA is attenuated by inhibiting DNMT1.