Microglia serve as the principal instigators of neuroinflammatory cascades following ischemic stroke. We here demonstrated that PRMT2IP (previously named as 1700017B05Rik in mice and C15orf39 in humans) is essential for modulating microglial activation and functional responses in ischemic stroke. Mendelian randomization (MR) analysis demonstrated a causal relationship between downregulation of human PRMT2IP expression and an elevated risk of ischemic stroke. Mouse PRMT2IP expression was downregulated in ischemic microglia. Critically, PRMT2IP overexpression provided a protective role in reducing cerebral ischemia injury, while PRMT2IP knockout showed significantly worsened outcomes. Mechanistically, PRMT2IP interacts with PRMT2 and inhibits the activation of the NF-κB signaling pathway by PRMT2-IκBα signaling axis, ultimately reducing the expression of inflammatory factors IL-6 and TNFα. In conclusion, our results suggest that microglial PRMT2IP, as a key negative regulator of microglial inflammatory response, alleviates ischemia-induced brain injury. Thus, up-regulation of PRMT2IP expression may provide a therapeutic strategy to attenuate deleterious neuroinflammation post-stroke.

Therapeutic interventions for hematopoietic acute radiation syndrome (H-ARS) remain limited in both variety and efficacy, falling short of achieving durable recovery of the hematopoietic system. Here, we develop 2B9F, a novel thrombopoietin-mimetic peptide engineered for enhanced stability and designed with the intention of achieving low immunogenicity. A single subcutaneous dose of 2B9F administered postexposure achieved complete survival in a lethal murine irradiation model, surpassing the efficacy of the clinically approved agent romiplostim. Treatment with 2B9F accelerated the recovery of peripheral blood counts and bone marrow nucleated cells, expanded functional hematopoietic stem cells (HSCs), and enhanced both in vitro clonogenic potential and in vivo competitive repopulation capacity. Mechanistic studies revealed that 2B9F promoted HSC quiescence and survival through transcriptional modulation of apoptosis and cell-cycle regulators. Importantly, a single low dose of 2B9F also conferred durable protection, mitigating delayed bone marrow suppression for up to six months postirradiation. These findings position 2B9F as a promising single-dose, low-immunogenicity therapeutic candidate for H-ARS, indicating strong potential for clinical translation in nuclear emergencies.

OBJECTIVES:Our aim was to gain deeper insight into the genetic susceptibility of iron deficiency anemia (IDA). METHODS:We performed the first multi-ancestry meta-analysis of genome-wide association study (GWAS), which included 113 055 IDA cases and 1 783 936 healthy controls. RESULTS:Through multi-ancestry meta-analysis, 31 risk loci were identified, alongside 703 candidate genes indicated and 47 genes prioritized for IDA. Heritability analyses demonstrated that the liability scale heritability was 3.1% ± 0.2%, whereas an estimated 43.92 million effective sample size would be required to explain 90% of the phenotypic variance. Gene enrichment analysis, gene-set analyses, and genetic correlation studies revealed that IDA-related genes were enriched in whole blood, influenced the role of HFE (hemochromatosis gene) in regulating systemic iron homeostasis, and showed positive correlations with inflammatory diseases, psychological diseases, and cardiovascular diseases. Finally, gene-based prioritized analysis and gene-drug interaction analysis identified some potential targets (e.g., BLK), while drug repurposing approaches highlighted exploratory drug candidates (e.g., folic acid) for IDA. CONCLUSION:We identified 31 novel risk loci for IDA and further characterized its genetic architecture.

Systemic lupus erythematosus (SLE) is a chronic life-threatening and relapsing-remitting multisystem autoimmune disease. However, the genetic susceptibility of SLE has not been fully elucidated. This study will explore the genetic risk loci of SLE. We performed the larger multi-ancestry meta-analysis of genome-wide association study (GWAS) including 22,494 cases with SLE and 1,568,102 healthy controls. Multi-ancestry meta-analysis identified 101 risk loci including 12 novel loci. Across 101 loci, 2,209 likely causal genes are indicated and 265 genes are prioritized, based on eight biological prioritization criteria. The most significantly locus were located on 6p21.32, whereas the highest-ranked candidate causal gene was BLK. Heritability analyses demonstrated a liability scale of the heritability is 25.49

Radiotherapy is constricted by collateral normal tissue injury during treatment, particularly the gastrointestinal tracts, which is usually referred as radiation-induced gastrointestinal syndrome (RIGS). Currently, there is no FDA-approved agent for the prevention or treatment of RIGS. By using a mice model of RIGS, we demonstrated that 1,2-propanediol (1,2-PD) prevents radiation-induced fatal intestinal injury and significantly increases mice survival following lethal doses of radiation. 1,2-PD pretreatment also enhanced the survival of Lgr5+ISCs and improved crypts regeneration after radiation. Moreover, we confirmed 1,2-PD induces dormant cell cycle arrest in enterocytes and ameliorates DNA damage both in vitro and in vivo. Although we did have observed 1,2-PD pretreatment inhibiting P53-PUMA signal pathway, but fail to prove its relation with radiation resistance. In RNA sequencing, we have observed 1,2-PD pretreatment significantly upregulates the Hif-2α, Hif-3α and PPARα target gene ACOX2, whilst downregulating the cell cycle drivers E2f3 and Cyclin D2. These results demonstrate that ISCs play a key role in radiation-induced intestinal regeneration and that 1,2-PD acts as a potent intestinal radioprotector.

Radiotherapy is constricted by collateral normal tissue injury during treatment, particularly the gastrointestinal tracts, which is usually referred as radiation-induced gastrointestinal syndrome (RIGS). Currently, there is no FDA-approved agent for the prevention or treatment of RIGS. By using a mice model of RIGS, we demonstrated that 1,2-propanediol (1,2-PD) prevents radiation-induced fatal intestinal injury and significantly increases mice survival following lethal doses of radiation. 1,2-PD pretreatment also enhanced the survival of Lgr5 + ISCs and improved crypts regeneration after radiation. Moreover, we confirmed 1,2-PD induces dormant cell cycle arrest in enterocytes and ameliorates DNA damage both in vitro and in vivo. 1,2-PD pretreatment specifically blocked crypt apoptosis via inhibiting P53-PUMA signal pathway. We also proved that P53 deficiency aggravated intestinal injury and impaired the intestinal radioprotection of 1,2-PD. These results demonstrate that ISCs play a key role in radiation-induced intestinal regeneration and that 1,2-PD acts as a potent intestinal radioprotector by promoting resting of intestinal crypt cells and blocking P53-PUMA mediated crypt apoptosis after irradiation.

BACKGROUND:Psoriasis is a common chronic, recurrent, immune-mediated disease involved in the skin or joints or both. However, deeper insight into the genetic susceptibility of psoriasis is still unclear. METHODS:Here we performed the largest multi-ancestry meta-analysis of genome-wide association study including 28,869 psoriasis cases and 443,950 healthy controls. RESULTS:We identified 74 genome-wide significant loci for psoriasis. Of 74 loci, 32 were novel psoriasis risk loci. Across 74 loci, 801 likely causal genes are indicated and 164 causal genes are prioritized. SNP-based heritability analyses demonstrated that common variants explain 15% of genetic risk for psoriasis. Gene-set analyses and the genetic correlation revealed that psoriasis-related genes have the positive correlations with autoimmune diseases such as ulcerative colitis, inflammatory bowel diseases, and Crohn's disease. Gene-drug interaction analysis suggested that psoriasis-associated genes overlapped with targets of current medications for psoriasis. Finally, we used the multi-ancestry meta-analysis to explore drug repurposing and the potential targets for psoriasis. CONCLUSIONS:We identified 74 genome-wide significant loci for psoriasis. Based on 74 loci, we provided new biological insights to the etiology of psoriasis. Of clinical interest, we gave some hints for 76 potential targets and drug repurposing for psoriasis.

Lipid droplet accumulation in microglia, microglia-mediated neuroinflammation, and subsequent neuronal damage are hallmark features of high-fat diet (HFD)-induced cognitive impairment. In this analysis, this is proposed that a new molecule feimin (B230219D22Rik in mice) is a key negative regulator of LD accumulation and the inflammatory response in HFD-induced cognitive impairment. To test this hypothesis, BV2 microglia is exposed to palmitic acid (PA) in vitro, mimicking the effects of an HFD. This is found that feimin expression is significantly increased following high-lipid stimulation. Feimin-specific knockdown in BV2 cells led to enhanced LD accumulation, exacerbated inflammatory responses and neuronal apoptosis, whereas feimin overexpression has the opposite effect. Mechanistically, immunoprecipitation (IP) assays revealed that an interaction between feimin and AKT suppressed the AKT-mTOR signaling pathway. To further investigate the role of feimin in vivo, microglial feimin-conditional knockout mice (feiminMic-/-) is developed. In the HFD model, feiminMic-/- mice exhibited increased LD accumulation in hippocampal microglia, enhanced inflammation, and neuronal apoptosis, resulting in significant cognitive decline. In conclusion, this findings identified feimin as a key negative regulator of HFD-induced LD accumulation and the microglia-mediated inflammation response, suggesting that it is an attractive therapeutic target for cognitive decline associated with HFDs.

Olfactory receptors (Olfr) are G protein–coupled receptors that are normally expressed on olfactory sensory neurons to detect volatile chemicals or odorants. Interestingly, many Olfrs are also expressed in diverse tissues and function in cell–cell recognition, migration, and proliferation as well as immune responses and disease processes. Here, we showed that many Olfr genes were expressed in the mouse spleen, linked to Plasmodium yoelii genetic loci significantly, and/or had genome-wide patterns of LOD scores (GPLSs) similar to those of host Toll-like receptor genes. Expression of specific Olfr genes such as Olfr1386 in HEK293T cells significantly increased luciferase signals driven by IFN-β and NF-κB promoters, with elevated levels of phosphorylated TBK1, IRF3, P38, and JNK. Mice without Olfr1386 were generated using the CRISPR/Cas9 method, and the Olfr1386 −/− mice showed significantly lower IFN-α/β levels and longer survival than wild-type (WT) littermates after infection with P. yoelii YM parasites. Inhibition of G protein signaling and P38 activity could affect cyclic AMP-responsive element promoter-driven luciferase signals and IFN-β mRNA levels in HEK293T cells expressing the Olfr1386 gene, respectively. Screening of malaria parasite metabolites identified nicotinamide adenine dinucleotide (NAD) as a potential ligand for Olfr1386, and NAD could stimulate IFN-β responses and phosphorylation of TBK1 and STAT1/2 in RAW264.7 cells. Additionally, parasite RNA (pRNA) could significantly increase Olfr1386 mRNA levels. This study links multiple Olfrs to host immune response pathways, identifies a candidate ligand for Olfr1386, and demonstrates the important roles of Olfr1386 in regulating type I interferon (IFN-I) responses during malaria parasite infections.

Influenza A viruses (IAVs) continue to pose a huge threat to public health, and their prevention and treatment remain major international issues. Neuraminidase (NA) is the second most abundant surface glycoprotein on influenza viruses, and antibodies to NA have been shown to be effective against influenza infection. In this study, we generated a monoclonal antibody (mAb), named FNA1, directed toward N1 NAs. FNA1 reacted with H1N1 and H5N1 NA, but failed to react with the NA proteins of H3N2 and H7N9. In vitro, FNA1 displayed potent antiviral activity that mediated both NA inhibition (NI) and blocking of pseudovirus release. Moreover, residues 219, 254, 358, and 388 in the NA protein were critical for FNA1 binding to H1N1 NA. However, further validation is necessary to confirm whether FNA1 mAb is indeed a good inhibitor against NA for application against H1N1 and H5N1 viruses.

BackgroundCD2v, a critical outer envelope glycoprotein of the African swine fever virus (ASFV), plays a central role in the hemadsorption phenomenon during ASFV infection and is recognized as an essential immunoprotective protein. Monoclonal antibodies (mAbs) targeting CD2v have demonstrated promise in both diagnosing and combating African swine fever (ASF). The objective of this study was to develop specific monoclonal antibodies against CD2v.MethodsIn this investigation, Recombinant CD2v was expressed in eukaryotic cells, and murine mAbs were generated through meticulous screening and hybridoma cloning. Various techniques, including indirect enzyme-linked immunosorbent assay (ELISA), western blotting, immunofluorescence assay (IFA), and bio-layer interferometry (BLI), were employed to characterize the mAbs. Epitope mapping was conducted using truncation mutants and epitope peptide mapping.ResultsAn optimal antibody pair for a highly sensitive sandwich ELISA was identified, and the antigenic structures recognized by the mAbs were elucidated. Two linear epitopes highly conserved in ASFV genotype II strains, particularly in Chinese endemic strains, were identified, along with a unique glycosylated epitope. Three mAbs, 2B25, 3G25, and 8G1, effectively blocked CD2v-induced NF-κB activation.ConclusionsThis study provides valuable insights into the antigenic structure of ASFV CD2v. The mAbs obtained in this study hold great potential for use in the development of ASF diagnostic strategies, and the identified epitopes may contribute to vaccine development against ASFV.

Natural killer (NK) cells represent key player in immune surveillance to eliminate transformed or malignant cells. One of mechanisms of action of NK cells is antibody-dependent cell-mediated cytotoxicity (ADCC) by recognizing tumor antigens on the surface of cancer cells. However, the heterogeneity of tumor antigens and the scarcity of membrane surface targets significantly restrict this strategy. Recently, we constructed a new cargo by tethering a low pH insertion peptide (pHLIP) to the C terminus of the ectodomain of programed death ligand-1 (PD-L1) and demonstrated its ability to modulate immune responses. Herein, the potential application of PD-L1-pHLIP in cancer therapy was determined. pHLIP tethering had no effect on the binding capacity of PD-L1 protein to an anti-PD-L1 antibody (i.e. avelumab). Association of pHLIP rendered PD-L1 segment display on the surface of cellular membrane in the acidic buffer instead of the neutral solution. Importantly, plate-coated or beads-coupled PD-L1-pHLIP enable robust activation and expression of cytotoxic mediators of NK cells via engaging avelumab. Overall, this work provides proof of concept that recombinant PD-L1 protein decorated on the cellular membrane driven by pHLIP in combination with appropriate monoclonal antibody has potentials to elicit NK cytotoxicity, which may represent a novel and promising therapeutic avenue in cancer.

PDF file - 429K, Fig. S1: GMCSFR expression in primary and transformed CEC. Fig S2: Receptors for IL-1, IL-6 and VEGF in CT26 cells. Fig. S3: GMCSF elicits IL-1β and IL-6. Fig. S4: Blocking GMCSF or VEGF decreases the number of proliferative epithelial cells. Fig. S5: Blocking GMCSF or VEGF regulates cell cycle gene expression in CEC. Fig. S6: GMCSF elicits VEGF expression in HCT116 cells. Fig. S7: TLR4 expression in primary and transformed CEC.

Smallpox is an infectious disease caused by the variola virus, and it has a high mortality rate. Historically it has broken out in many countries and it was a great threat to human health. Smallpox was declared eradicated in 1980, and Many countries stopped nation-wide smallpox vaccinations at that time. In recent years the potential threat of bioterrorism using smallpox has led to resumed research on the treatment and prevention of smallpox. Effective ways of preventing and treating smallpox infection have been reported, including vaccination, chemical drugs, neutralizing antibodies, and clinical symptomatic therapies. Antibody treatments include anti-sera, murine monoclonal antibodies, and engineered humanized or human antibodies. Engineered antibodies are homologous, safe, and effective. The development of humanized and genetically engineered antibodies against variola virus via molecular biology and bioinformatics is therefore a potentially fruitful prospect with respect to field application. Natural smallpox virus is inaccessible, therefore most research about prevention and/or treatment of smallpox were done using vaccinia virus, which is much safer and highly homologous to smallpox. Herein we summarize vaccinia virus epitope information reported to date, and discuss neutralizing antibodies with potential value for field application.

Hematopathologic characteristics of analyzed experimental mice.

In this study, we test the therapeutic effects of rapamycin in a murine model of SLE-like experimental lupus nephritis induced by chronic graft-versus-host disease (cGVHD). Our results suggest that rapamycin treatment reduced autoantibody production, inhibited T lymphocyte and subsequent B cell activation, and reduced inflammatory cytokine and chemokine production, thereby protecting renal function and alleviating histological lupus nephritis by reducing the occurrence of albuminuria. To explore the potential mechanism of rapamycin’s reduction of kidney damage in mice with lupus nephritis, a series of functional assays were conducted. As expected, rapamycin remarkably inhibited the lymphocytes’ proliferation within the morbid mice. Interestingly, significantly increased proportions of peripheral CD4+FOXP3+ and CD4+CD25high T cells were observed in rapamycin-treated group animals, suggesting an up-regulation of regulatory T cells (Tregs) in the periphery by rapamycin treatment. Furthermore, consistent with the results regarding changes in mRNA abundance in kidney by real-time PCR analysis, intracellular cytokine staining demonstrated that rapamycin treatment remarkably diminished the secretion of Th1 and Th2 cytokines, including IFN-γ, IL-4 and IL-10, in splenocytes of the morbid mice. However, the production of IL-2 from splenocytes in rapamycin-treated mice was significantly higher than in the cells from control group animals. These findings suggest that rapamycin treatment might alleviate systemic lupus erythematosus (SLE)-like experimental lupus nephritis through the recovery of IL-2 production, which promotes the expansion of regulatory T cells while inhibiting effector T cell activation. Our studies demonstrated that, unlike other commonly used immunosuppressants, rapamycin does not appear to interfere with tolerance induction but permits the expansion and suppressive function of Tregs in vivo.

Protein ubiquitination is an important posttranslational regulation mechanism that mediates Plasmodium development and modifies parasite responses to antimalarial drugs. Although mutations in several parasite ubiquitination enzymes have been linked to increased drug tolerance, the molecular mechanisms by which ubiquitination pathways mediate these parasite responses remain largely unknown.

PDF file - 171K, Primer list.

Description of additional methods and procedures used in the study.

The non-classical Major Histocompatibility Complex class II (MHCII) protein, H2-M, edits peptides bound to conventional MHCII in favor of stable peptide/MHCII (p/MHCII) complexes. Here, we show that H2-M deficiency affects B-1 cell survival, reduces cell renewal capacity, and alters immunoglobulin repertoire, allowing for the selection of cells specific for highly abundant epitopes, but not low-frequency epitopes. H2-M-deficient B-1 cells have shorter CDR3 length, higher content of positively charged amino acids, shorter junctional regions, less mutation frequency, and a skewed clonal distribution. Mechanistically, H2-M loss reduces plasma membrane p/MHCII association with B cell receptors (BCR) on B-1 cells and diminishes integrated BCR signal strength, a key determinant of B-1 cell selection, maturation, and maintenance. Thus, H2-M:MHCII interaction serves as a cell-intrinsic regulator of BCR signaling and influences the selection of the B-1 cell clonal repertoire.