Protein translocation and retro-translocation across the endoplasmic reticulum are crucial to inflammatory effector CD4+ T cell function

Identification of lipid metabolism-related gene markers and construction of a diagnostic model for multiple sclerosis: An integrated analysis by bioinformatics and machine learning

BACKGROUND

Multiple sclerosis (MS) is an autoimmune inflammatory disorder that causes neurological disability. Dysregulated lipid metabolism contributes to the pathogenesis of MS. This study aimed to identify lipid metabolism-related gene markers and construct a diagnostic model for MS.

METHODS

Gene expression profiles for MS were obtained from the Gene Expression Omnibus database. Differentially expressed lipid metabolism-related genes (LMRGs) were identified and performed functional enrichment analysis. Least absolute shrinkage and selection operator (LASSO), random forest (RF), and protein-protein interaction (PPI) analysis were employed to screen hub genes. The predictive power of hub genes was evaluated using receiver operating characteristic (ROC) curves. We developed an artificial neural network (ANN) model and validated its performance in three test sets. Immune cell infiltration analysis, Gene set enrichment analysis, and ceRNA network construction were performed to explore the role of lipid metabolism in the pathogenesis of MS. Drugs prediction and molecular docking were utilized to identify potential therapeutic drugs.

RESULTS

We identified 40 differentially expressed LMRGs, with significant enrichment in Arachidonic acid metabolism, Steroid hormone biosynthesis, Fatty acid elongation, and Sphingolipid metabolism. AKR1C3, NFKB1, and ABCA1 were identified as gene markers for MS, and their expression was upregulated in the MS group. The areas under the ROC curve (AUCs) for AKR1C3, NFKB1, and ABCA1 in the training set were 0.779, 0.703, and 0.726, respectively. The ANN model exhibited good discriminative ability in both the training and test sets, achieving an AUC of 0.826 on the training set and AUC values of 0.822, 0.890, and 0.833 on the test sets. Gamma.delta.T.cell, Natural.killer.T.cell, Plasmacytoid.dendritic.cell, Regulatory.T.cell, and Type.1.T.helper.cell were highly expressed in the MS group. A ceRNA network showed a complex regulatory interplay involving hub genes. Luteolin, isoflavone, and thalidomide had good binding affinities to the hub genes.

CONCLUSION

Our study emphasized the crucial role of lipid metabolism in MS, identifing AKR1C3, NFKB1, and ABCA1 as gene markers. The ANN model exhibited good performance on both the training and testing sets. These findings offer valuable insights into the molecular mechanisms underlying MS, and establish a scientific foundation for future research.

Exploring in vivo combinatorial chemo-immunotherapy: Addressing p97 suppression and immune reinvigoration in pancreatic cancer with tumor microenvironment-responsive nanoformulation

Pancreatic ductal adenocarcinoma (PDAC) has an extremely devastating nature with poor prognosis and increasing incidence, making it a formidable challenge in the global fight against cancer-related mortality. In this innovative preclinical investigation, the VCP/p97 inhibitor CB-5083 (CB), miR-142, a PD-L1 inhibitor, and immunoadjuvant resiquimod (R848; R) were synergistically encapsulated in solid lipid nanoparticles (SLNs). These SLNs demonstrated features of peptides targeting PD-L1, EGFR, and the endoplasmic reticulum, enclosed in a pH-responsive polyglutamic (PGA)-polyethylene glycol (PEG) shell. The homogeneous size and zeta potential of the nanoparticles were stable for 28 days at 4°C. The study substantiated the concurrent modulation of key pathways by the CB, miR, and R-loaded nanoformulation, prominently affecting VCP/Bip/ATF6, PD-L1/TGF-β/IL-4, -8, -10, and TNF-α/IFN-γ/IL-1, -12/GM-CSF/CCL4 pathways. This adaptable nanoformulation induced durable antitumor immune responses and inhibited Panc-02 tumor growth by enhancing T cell infiltration, dendritic cell maturation, and suppressing Tregs and TAMs in mice bearing Panc-02 tumors. Furthermore, tissue distribution studies, biochemical assays, and histological examinations highlighted enhanced safety with PGA and peptide-modified nanoformulations for CB, miR, and/or R in Panc-02-bearing mice. This versatile nanoformulation allows tailored adjustment of the tumor microenvironment, thereby optimizing the localized delivery of combined therapy. These compelling findings advocate the potential development of a pH-sensitive, three-in-one PGA-PEG nanoformulation that combines a VCP inhibitor, a PD-L1 inhibitor, and an immunoadjuvant for cancer treatment via combinatorial chemo-immunotherapy.

Cutting Edge: Serpine1 Negatively Regulates Th1 Cell Responses in Experimental Autoimmune Encephalomyelitis

Th1 cells are critical in experimental autoimmune encephalomyelitis (EAE). Serine protease inhibitor clade E1 (Serpine1) has been posited as an inhibitor of IFN-γ from T cells, although its role in autoimmunity remains unclear. In this study, we show that Serpine1 knockout (KO) mice develop EAE of enhanced severity relative to wild-type (WT) controls. Serpine1 overexpression represses Th1 cell cytokine production and pathogenicity, whereas Serpine1-KO:2D2 Th1 cells transfer EAE of increased severity in comparison with WT 2D2 Th1 cells. Notably, polarized Serpine1-KO Th1 cells display delayed expression of the Th1-specific inhibitory receptor, Tim-3 (T cell Ig and mucin-domain containing-3). Serpine1-KO:Tim-3-Tg Th1 cells, which transgenically overexpress Tim-3, showed increased expression of IFN-γ and reduced expression of the checkpoint molecules Lag-3 and PD-1 relative to WT Tim-3-Tg counterparts. Furthermore, Serpine1 deficiency restored the EAE phenotype of Tim-3-Tg mice that normally develop mild disease. Taken together, we identify Serpine1 as a negative regulator of Th1 cells.

K48- and K27-mutant ubiquitin regulates adaptive immune response by affecting cross-presentation in bone marrow precursor cells

K48-linked ubiquitination determines antigen degradation and plays vital roles in the process of cross-presentation of bone marrow precursor cell (BMPC)-derived dendritic cells (DCs). Although previous studies revealed that K48 and K27-linked ubiquitination regulates innate immunity, the exact roles of K48 and K27-linked ubiquitination in cross-presentation and BMPC-based adaptive immunity are still uncertain. In this study, we investigated the effects of K48- and K27-mutant ubiquitin (Ub) on BMPC-based adaptive immune response by observing the effects of MG132, Ub deficiency, and K48/K27-mutant Ub on cross-presentation, T cell proliferation, IFN-γ secretion, BMPC-based CTL priming, and thereby the efficiency of cytolytic capacity of BMPC-activate T cells. We demonstrated that MG132, Ub deficiency, and K48-mutant Ub impair cross-presentation, T cell proliferation, IFN-γ secretion, BMPC-based CTL priming, and the cytolytic capacity of BMPC-activated T cells. Moreover, although K27-only Ub decreases cross-presentation, the replenishment of K27-mutant Ub restores Ub deficiency impaireds the abilities of T cell proliferation, IFN-γ secretion, CTL priming, and the cytolytic capacity of BMPC-activated T cells. Thus, these data suggest that K48- and K27-linked ubiquitination contributes to BMPC-mediated adaptive immune response by affecting BMPC cross-presentation and the cytolytic capacity by up-regulating both perforin and granzyme B in BMPC-activated T cells. K48- and K27-mutant Ub might have potential clinical therapeutic function in adaptive immune response-associated diseases.