CXCR4 Expression Research Articles

ALKBH5-mediated m 6A RNA demethylation promotes antibacterial innate defense by intrinsically driving neutrophil generation and recruitment

Abstract Neutrophil generation and effective recruitment into the site of infection are essential for innate immune defense against bacterial infection. These processes that directed by extracellular signals such as growth factors or chemokines have been extensively studied, yet the intrinsic and new mechanism for determining neutrophil generation and recruitment needs further investigation. N6-methyladenosine (m 6A) RNA modification and its demethylase alkB homolog 5 (ALKBH5) are key epigenetic regulators of immunity and inflammation, whereas their role in neutrophil generation and recruitment remains unclear. Here, using cecal ligation and puncture-induced sepsis to model systemic bacterial infection, we found that ALKBH5 is required for antibacterial innate defense by intrinsically inducing neutrophil generation and recruitment. Indeed, Alkbh5-deficient mice exhibited increased mortality, higher bacterial burden and proinflammatory cytokine production than wild-type littermates undergoing sepsis. Meanwhile, ALKBH5 depletion significantly impaired the generation of immature neutrophils in bone marrow and also reduced neutrophil recruitment into the infected site of sepsis mice. Mechanistically, ALKBH5 imprinted generation- and recruitment-promoting transcriptome signatures in both mouse and human neutrophils during bacterial infection, specially modulated the protein expression of SOCS3 and CXCR2 through altering m 6A methylation-mediated decay of their mRNAs. Together, our findings reveal a previously unknown role of ALKBH5 in intrinsically driving neutrophil generation and recruitment, indicating neutrophil m 6A RNA modification as potential target for controlling bacterial infections. Supported by grants from the National Natural Science Foundation of China (81788101, 82071793), the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (2021-I2M-1-017), the Beijing Natural Science Foundation (7212069), and the Beijing Nova Program (20220484065).

B1-adrenergic blockers provide cardiac protection through extracellular traps inhibition during widespread inflammation

Sepsis is one of the leading causes of death worldwide, and no therapy is available other than intensive care treatments. Drug development attempts have mainly focused on controlling inflammation or treating dysfunction, without significant improvement in the last decades. Recently, interest has emerged in β1-adrenergic blockade, which has proved beneficial to both parameters. Unfortunately, the specific underlying mechanisms have not been addressed yet. Our study aimed to investigate on mice (adult Swiss male, 30-45g) lipopolyssacharide or cecal ligature and puncture models the effects of atenolol, a β1-adrenergic blocker, currently used in intensive care units for hypertension and arrhythmia. The results demonstrated a beneficial effect of treatment on survival and a preservation of cardiac function including left ventricular ejection fraction (33±2,8% in sepsis group versus 55±5,1% in sepsis-treated group, p<0,05) at a concentration reducing heart rate by approximately 10%.We wondered if beneficial results obtained with atenolol could be due to a modulation of extracellular traps. These components are essential in pathogen spreading control and are increased during sepsis. However, an excess of their production induces vascular occlusions and acute heart injuries.We demonstrated that neutrophils extracellular traps were increased in heart and blood during sepsis and decreased significantly following atenolol administration (blood: 1.1±0,3% in control group, 13,4±1.8% in sepsis group, 6.9±1.2% in sepsis-treated group). This beneficial effect of atenolol was not associated with other modulations of neutrophil function such as their ability to phagocyte (33,6±3,9% in sepsis group versus 25.6±3.6% in sepsis-treated group, p>0,05), to undergo apoptosis (Annexin V+/ L/D-: 13,2±2.1% in sepsis group versus 14.1±2.9% in sepsis-treated group, p>0,05) or to degranulate. Blood neutrophil phenotypes associated with their maturation state (expression of CD62L and CXCR2) or ability to migrate into tissue (expression of adhesion molecules PSGL1, LFA1, VLA4, PECAM1) was also similar between LPS and LPS-treated groups. Although, the modulation of extracellular traps production by atenolol was also observed in other immune cells population able to extrude chromatin fibers in extracellular space such as macrophages. These results suggest a specific beneficial effect of ß1-adrenergic blockers on extracellular traps formation associated with cardiac function preservation and ultimately survival without detrimental effect on heart rate during widespread inflammation. This work was supported by funding from INSERM and Paris-Saclay University-UVSQ. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Determining antigen-specific T cell phenotypes in cases of Hepatitis C virus clearance versus chronic infection.

Abstract Globally, approximately 1.5 million new Hepatitis C virus (HCV) infections occur annually. A vaccine to prevent chronic HCV infection would limit HCV transmission and pathogenesis of HCV. To understand immunity to HCV infection in high risk populations, we prospectively followed HCV antibody negative high-risk people who inject drugs (PWIDs) in a protocol designed for monthly follow-up. We demonstrated previously that HCV reinfection in PWIDs is associated with a reduction in the magnitude and duration of viremia versus the initial infection and broadened cellular immune responses, consistent with protective immunity against chronic disease. We have characterized CD8+ HCV-specific T cells from the acute phase of HCV using high dimensional spectral flow cytometry to define the simultaneous expression of 25 intracellular metabolic and cell surface molecules. We found that HCV-specific CD8+ T cells from those who progress to chronic infection have a unique acute phase phenotype that clusters separately from those who later successfully control HCV. Acute phase CD8+ HCV-specific T cells from those who subsequently clear an initial HCV infection show increased expression of CD127 and CXCR3 and decreased expression of GLUT1, PD-1 and CD39 compared to acute phase T cells in those who later progress to chronic infection. Understanding HCV specific T cell phenotypes in successful control of HCV infection and reinfection will guide goals for vaccine induced immunity to prevent chronic HCV infection. Supported by grants from the NIH (U19 AI159822)

Deletion of protein kinase D1 in myeloid lineage cells suppresses development of IFNγ +IL-17A +CD4 T cells and ameliorates hypersensitivity pneumonitis

Abstract Hypersensitivity pneumonitis (HP) is an extrinsic allergic alveolitis characterized by inflammation of the interstitium, bronchioles, and alveoli of the lung that leads to granuloma formation and ultimately irreversible fibrosis. Previous studies found that exposure to HP inciting antigen S. rectivirgula(SR) leads to the activation of protein kinase D1 (PKD1) in the mouse lung in vivoand that PKD1 contributes to the acute pulmonary inflammation, IL-17A expression in the lungs, and development of HP caused by repeated exposure to SR. In the present study, we investigated whether PKD1 in myeloid cells affects the pathogenic course of the SR-induced HP. Compared to control PKD1-sufficient mice, mice with deficiency of PKD1 in myeloid cells (PKD1mKO) showed significantly suppressed expression of IL-6, TNFα, IFNγ, CCL2, CCL3, CCL4, CXCL1, CXCL2, and CXCL10 and neutrophilic alveolitis after single intranasal exposure to SR. Substantially reduced levels of alveolitis and granuloma formation were observed in the PKD1mKO mice repeatedly exposed to SR. Surface expression of MHC-II and CD86 on myeloid cells, and expression of IFNγ, IL-17A, CCL20, CXCL9, and CXCL10 in lungs were significantly reduced in the PKD1mKO mice repeatedly exposed to SR. In addition, surface expression of CD69, CXCR3, and CCR6 on CD4 T cells and frequency of IFNγ +IL-17A +CD4 T cells in the lungs were significantly reduced in PKD1mKO mice repeatedly exposed to SR. Our results demonstrate PKD1 in myeloid lineage cells plays an essential role in the initial proinflammatory responses and neutrophil influx in the lung after exposed to SR and contributes to the development of IFNγ +IL-17A +CD4 T cells and HP caused by repeated exposure to SR. Supported by grants from NIH (R01 AR064723, R01 AR069010) and UTHSC.

Abstract 106: Single Cell High Dimensional Analysis of Human Peripheral Blood Mononuclear Cells Reveals Unique Intermediate Monocyte Subsets Associated with Sex Differences in Coronary Heart Disease

Monocytes are innate immune cells that are defined by three subsets: classical (cMo), intermediate (iMo) and non-classical (nMo). How these subsets become more heterogeneous in phenotype and function in CVD progression remains elusive. We employed single-cell transcriptome and protein analysis to define how human monocytes differ in subjects with moderate to severe CVD. Peripheral blood mononuclear cells (PBMC) were obtained from 61 human subjects, undergoing coronary angiography as part of the Coronary Assessment of Virginia (CAVA) Cohort. Coronary atherosclerosis severity was quantified using Gensini Score (GS). We analyzed 487 immune-related genes and 49 surface proteins at the single cell level in PBMC from each subject using the BD-Rhapsody platform. WNN Seurat 4.0 was used for high dimensional analysis. Data was normalized using GLMM to control for covariates (age, sex, diabetes, and statin use). We identified cMo, iMo, nMo, plasmacytoid DC, and classical DC. We found a significant increase only in the frequencies of intermediate (iMo) monocytes in subjects with high CVD (GS>30) compared to subjects with low CVD (GS<6) ( p =0.004). Spearman correlation analysis with GS from each subject revealed a positive correlation with iMo frequencies (r=0.314, p =0.014) and further showed sex-dependent positive correlation in female patients (r=0.663, p =0.0037). Interestingly, cMo, thought to be potently atherogenic, did not correlate with CVD severity. Further analysis identified 3 iMo subsets, distinguished by expression of HLA-DR, CD86, CXCR3, and PD-L1. We found that frequencies of two of them, iMo_CXCR3 + PDL1 lo ( p =0.0003) and iMo_HLA-DR + CD86 int ( p =0.019), were associated with CVD severity. The iMo_CXCR3 + PDL1 lo immunoregulatory subset was positively correlated with GS in both females (r=0.66, p =0.004) and males (r=0.315, p =0.037). However, the iMo_HLA-DR + CD86 int subset was positively correlated only in females (r=0.55, p =0.022), illustrating substantial heterogeneity among monocyte subsets in a sex-dependent manner. In sum, we identified novel sex- and CVD-dependent iMo subsets in subjects with CVD. Future functional analysis of iMo populations should provide a deeper understanding of long-known sex-differences in CVD progression.

Abstract 105: Lipid Regulation of Senescent Effector CD8 T Cells in Type 2 Diabetes

Introduction: Atherosclerotic plaques from patients with Type 2 Diabetes (T2D) present a more severe pathology than non-T2D (ND) plaques and response to cholesterol-lowering is compromised. An increased level of circulating senescent CD8 T cells in T2D patients is associated with increased risk for myocardial infarction. However, whether senescent T cells infiltrate human atherosclerotic plaques and how they are regulated by lipid lowering is unknown. Hypothesis: Senescent CD8+ T cells are increased in atherosclerotic plaques and circulation of T2D, and are normalized by aggressive lipid lowering in T2D. Methods: We performed unbiased scRNA-seq analysis (75,049 total cells) of immune cells in plaques from T2D (n=12) and ND patients (n=10) to identify senescent T cells in human atherosclerotic plaques. Using CyTOF we tested the effect of aggressive lipid lowering on circulating CD8 T cells in T2D (n=16) and ND (n=6) patients. Results: We identified senescent T cells within atherosclerotic plaques and found that senescent CD8 T cells largely accumulate in plaques from T2D patients (p<0.001). Plaque CD8 T cells showed a terminally differentiated effector memory phenotype with high expression of CX3CR1 and low expression of SELL and CCR7 genes. CD8 T cell clusters express senescence markers ( B3GAT1,KLRG1,KLRD1,KLRF1 ) and presented senescence associated secretory phenotype with high expression of cytotoxic ( GZMB,PRF1,GNLY ) and proatherogenic ( IFNG,TNFA,CCL5 ) genes. CyTOF analysis showed higher levels of circulating senescent CD57+CD28-CD8 T cells in patients with T2D vs ND controls (p<0.001). Potent lipid lowering with PCSK9 inhibitor + statin/ezetimibe, which reduced LDL-C levels by >70% in all patients at 4 weeks, normalized the frequency of circulating senescent CD8 T cells (p<0.001) in T2D patients to the levels found in ND. Conclusion: Our results show that senescent CD8 T cells accumulated in blood and plaques of T2D patients and that potent lipid lowering diminished circulating aged CD8 T cells, suggesting that CD8 T cell senescence can be improved by aggressive lipid control in high-risk T2D subjects. Further analyses are needed to understand the role of lipid metabolism in the T cell senescence and the impact on atherosclerosis progression.

Single-cell sequencing of PBMC characterizes a distinct inflammatory monocyte subset in Lyme disease patients with Post-Treatment Lyme Disease Syndrome (PTLD)

Abstract Lyme disease (LD) is the most common tick-borne disease in the United States. Most LD patients can return to healthy (RTH) status after antibiotic treatment. Still, 20% of LD patients develop Post-Treatment Lyme Disease Syndrome (PTLD), including fatigue and musculoskeletal pain that persist for a long time. Previous RNA-seq studies showed that most individuals with PTLD had an inflammatory gene expression compared to RTH, but the specific immune components that contribute to PTLD are not well understood. Here, we performed the single-cell sequencing analysis of PBMCs from 6 RTH and 4 PTLD patients collected during multiple clinic visits after antibiotic treatment over two years. We identified a CD14+ monocyte cluster significantly enriched in 4/4 PTLD patients and 2/6 RTH patients from the beginning to 6 months post-treatment. This monocyte cluster displayed distinct inflammatory gene signatures such as CCL3, CCL4, IL1B, CXCL2, CXCL8, and others. RTH patients with such inflammatory monocytes showed low expression of CXCR2 compared to PTLD, suggesting that higher CXCR2 signaling in inflammatory monocytes may contribute to the development of PTLD. In addition, pathway analysis of upregulated genes in PTLD inflammatory monocytes indicated that this subset was induced by molecules of bacterial origin and involved in the regulation of lymphocyte activation. In conclusion, our single-cell study identified a distinct inflammatory monocyte that was enriched and may contribute to PTLD. Tracking this inflammatory monocyte subset could lead to a more accurate prediction of PTLD and identify molecular biomarkers and pathways for therapeutic intervention.

MRNA vaccination induces persistent pharyngeal mucosal B cell responses to SARS-CoV-2 in children

Abstract We recently reported that SARS-CoV-2 infection triggers robust, persistent adaptive immune responses in the tonsils and adenoids of children. However, whether mRNA vaccination induces similar immune responses and how this compares to natural infection in children are unknown. To evaluate these questions, we collected peripheral blood (PBMCs), tonsils, and adenoids from 30 children undergoing tonsillectomy/adenoidectomy primarily in 2022. From questionnaires and serology, we identified 12 vaccinated subjects who had not been infected and compared them to 24 COVID-19 convalescent children from our previous study collected in 2020–2021. We found SARS-CoV-2-specific germinal center and CD27 +switched memory B (B SM) cells, including cells recognizing the spike protein receptor binding domain (RBD) of the original WA-1 strain and RBD from Omicron, in pharyngeal tissues of vaccinated children. PBMCs trended towards having higher percentages of S1 +RBD +B cells post-vaccination than post-infection, while adenoids had more S1 +RBD +B cells post-infection. SARS-CoV-2-specific B SMcells were dominated by IgG isotypes in all tissues, but a higher proportion of IgA +cells were seen post-infection. Furthermore, S1 +RBD +B SMcells showed greater CXCR3 expression post-infection in all tissues. In contrast, S1 +RBD +B SMcells showed higher expression of activation and atypical markers post-vaccination, particularly in PBMCs, implying different characteristics of B cell memory depending on the type of exposure. Our results demonstrate tissue-specific immunity to SARS-CoV-2 in the upper respiratory tract of children after vaccination and provide further evidence that mRNA vaccination induces broad protective B cell memory. This work was supported in part by intramural funds of NIAID, NIH.

Delayed B-cell maturation with extra-follicular B-cell response and broad autoantibody repertoire are characteristic B-cell dysregulation signatures in patients with multi-lineage cytopenia

IntroductionMulti-lineage cytopenia (m-IC) are increasingly recognized as presenting manifestation of inborn errors immunity (IEI). Although around 40% of these patients are associated with known IEI, the underlying immune anomalies at onset of m-IC are poorly understood. Recently, we published a unique immune signature characterized by abnormal expansion of circulating T-follicular helper cells (cTfh), increased T-cell activation and decreased naïve CD4+ T (Kumar et.al Blood 2022). Despite our improved understanding of T-cell immune abnormalities, the underlying B-cell dysfunction is largely undefined at onset of m-IC. MethodsIn this study, we enrolled 20 patients with pES, 30 patients with chronic ITP (cITP) and 18 healthy controls (HCs). High dimensional B cell immunophenotyping was performed to assess B-cell maturation, extrafollicular B cell development, and autoreactivity. Autoantibody profiling was performed using human protein microarrays. Multiplex immunofluorescence staining of lymph nodes was performed to evaluate germinal center reaction. ResultsWe observed that patients with m-IC had increased frequency of CD10+ immature B cells in comparison to cITP and HCs. Despite an expansion of cTfh and elevated levels of plasma CXCL13, we observed decreased frequency of CSMB which suggests underlying defects in B-cell maturation. While canonical B-cell maturation was defective, we noticed aberrant extrafollicular B-cell development characterized by significantly higher proportion of DN2 (CD11c+CD21low) and decreased proportion of DN1 (CD21+ CD11c-) populations (Figure 1A). However, the frequency of parent population i.e., double negative (DN) (IgD- CD27-) B-cells was similar across the cohorts. In addition, we also noted decreased proportion of CXCR5+ B cells in 30% of patients and overall skewed CXCR5 expression on B versus T cells. Furthermore, we noted increase in autoreactivity in B cells as evident by increase in proportion of 9G4+ B cells. To further assess auto-antibody driven pathophysiology, we evaluated the auto-antibody repertoire and found broad auto-antibody repertoire targeting several biological processes (Figure 1B). [Display omitted] ConclusionsTaken together, our findings identified broad B-cell immune abnormalities along with unique auto-antibody repertoire in patients with m-IC. In addition to enhancing our current knowledge of disease pathology, the utility of these findings could further help in disease monitoring and evaluating response to the therapeutics.

Therapeutic Applications of Mesenchymal Stem Cell Loaded with Gold Nanoparticles for Regenerative Medicine.

In the present study, the various concentrations of AuNP (1.25, 2.5, 5, 10 ppm) were prepared to investigate the biocompatibility, biological performances and cell uptake efficiency via Wharton's jelly mesenchymal stem cells and rat model. The pure AuNP, AuNP combined with Col (AuNP-Col) and FITC conjugated AuNP-Col (AuNP-Col-FITC) were characterized by Ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and Dynamic Light Scattering (DLS) assays. For in vitro examinations, we explored whether the Wharton's jelly MSCs had better viability, higher CXCR4 expression, greater migration distance and lower apoptotic-related proteins expression with AuNP 1.25 and 2.5 ppm treatments. Furthermore, we considered whether the treatments of 1.25 and 2.5 ppm AuNP could induce the CXCR4 knocked down Wharton's jelly MSCs to express CXCR4 and reduce the expression level of apoptotic proteins. We also treated the Wharton's jelly MSCs with AuNP-Col to investigate the intracellular uptake mechanisms. The evidence demonstrated the cells uptake AuNP-Col through clathrin-mediated endocytosis and the vacuolar-type H+-ATPase pathway with good stability inside the cells to avoid lysosomal degradation as well as better uptake efficiency. Additionally, the results from in vivo examinations elucidated the 2.5 ppm of AuNP attenuated foreign body responses and had better retention efficacy with tissue integrity in animal model. In conclusion, the evidence demonstrates that AuNP shows promise as a biosafe nanodrug delivery system for development of regenerative medicine coupled with Wharton's jelly MSCs.

Macrophages-derived Factor XIII links coagulation to inflammation in COPD.

The local, extravascular, activation of the coagulation system in response to injury is a key factor mediating the resulting inflammatory response. Coagulation Factor XIIIA (FXIIIA) found in alveolar macrophages (AM) and dendritic cells (DC), by influencing fibrin stability, might be an inflammatory modifier in COPD. To study the expression of FXIIIA in AM and Langerin+DC (DC-1) and their relation to the inflammatory response and disease progression in COPD. In 47 surgical lungs, 36 from smokers (22 COPD and 14 no-COPD) and 11 from non-smokers we quantified by immunohistochemistry FXIIIA expression in AM and DC-1 along with numbers of CD8+Tcells and CXCR3 expression in lung parenchyma and airways. Lung function was measured prior to surgery. The percentage of AM expressing FXIII (%FXIII+AM) was higher in COPD than no-COPD and non-smokers. DC-1 expressed FXIIIA and their numbers were higher in COPD than no-COPD and non-smokers. DC-1 positively correlated with %FXIII+AM (r=0.43; p<0.018). CD8+Tcells, which were higher in COPD than in no-COPD, were correlated with DC-1 (p<0.01) and %FXIII+AM. CXCR3+ cells were increased in COPD and correlated with %FXIII+AM (p<0.05). Both %FXIII+AM (r=-0.6; p=0.001) and DC-1 (r=-0.7; p=0.001) correlated inversely with FEV1. FXIIIA, an important link between the extravascular coagulation cascade and inflammatory response, is significantly expressed in alveolar macrophages and dendritic cells of smokers with COPD, suggesting that it could play an important role in the adaptive inflammatory reaction characteristic of the disease.

Loss of LRP1 in Adult Neural Stem Cells Impairs Migration to Ischemic Lesions.

After ischemia, cells in the brain parenchyma upregulate stromal derived factor 1 (SDF1), driving chemokine receptor CXCR4-mediated migration of adult neural stem cells to the ischemic injury. We discovered a novel regulator of CXCR4 in neural stem cells, low-density lipoprotein receptor related protein 1 (LRP1). We used Nestin-driven knockout of LRP1 and induction of td-tomato in neural stem cells of adult mice. We observed reduced localization of td-tomato positive cells to the lesion, and find disrupted CXCR4-mediated neural stem cell migration in vitro, which is likely driven by LRP1-mediated loss of CXCR4 expression in vivo. Our results suggest that LRP1 is a novel regulator of CXCR4 in neural stem cells. This heretofore unknown interaction between LRP1 and CXCR4 could have significant consequences for multiple aspects of neural stem cell physiology.

Sirolimus suppresses circulating fibrocytes in idiopathic pulmonary fibrosis in a randomized controlled crossover trial.

Fibrocytes are bone marrow-derived circulating cells that traffic to the injured lungs and contribute to fibrogenesis. The mTOR inhibitor, sirolimus, inhibits fibrocyte CXCR4 expression, reducing fibrocyte traffic and attenuating lung fibrosis in animal models. We sought to test the hypothesis that short-term treatment with sirolimus reduces the concentration of CXCR4+ circulating fibrocytes in patients with idiopathic pulmonary fibrosis (IPF). We conducted a short-term randomised double-blind placebo-controlled crossoverpilot trial to assess the safety and tolerability of sirolimus in IPF. Subjects were randomly assigned to sirolimus or placebo for approximately 6 weeks, and after a 4 week washout, assigned to the alternate treatment. Toxicity, lung function, and the concentration of circulating fibrocytes were measured before and after each treatment. In the 28 study subjects, sirolimus resulted in a statistically significant 35% decline in the concentration of total fibrocytes, 34% decline in CXCR4+ fibrocytes, and 42% decline in fibrocytes expressing ɑ-smooth muscle actin, but no significant change in these populations occurred on placebo. Respiratory adverse events occurred more frequently during treatment with placebo than sirolimus; the incidence of adverse events and drug tolerability did not otherwise differ during therapy with drug and placebo. Lung function was unaffected by either treatment with the exception of a small decline in gas transfer during treatment with placebo. As compared with placebo, short-term treatment with sirolimus resulted inreduction of circulating fibrocyte concentrations in subjects with IPF with an acceptable safety profile. gov identifier number NCT01462006FUNDING. NIH R01HL098329 and American Heart Association 18TPA34170486.

Programmed cell death 1 genetic variant and liver damage in nonalcoholic fatty liver disease.

Programmed cell death 1/programmed cell death-ligand 1 (PD-1/PDL-1) axis has been reported to modulate liver inflammation and progression to hepatocellular carcinoma (HCC) in patients with nonalcoholic fatty liver disease (NAFLD). Here, we examined whether the PDCD1 variation is associated with NAFLD severity in individuals with liver biopsy. We examined the impact of PDCD1 gene variants on HCC, as robust severe liver disease phenotype in UK Biobank participants. The strongest genetic association with the rs13023138 G>C variation was subsequently tested for association with liver damage in 2889 individuals who underwent liver biopsy for suspected nonalcoholic steatohepatitis (NASH). Hepatic transcriptome was examined by RNA-Seq in a subset of NAFLD individuals (n = 121). Transcriptomic and deconvolution analyses were performed to identify biological pathways modulated by the risk allele. The rs13023138 C>G showed the most robust association with HCC in UK Biobank (p = 5.28E-4, OR = 1.32, 95% CI [1.1, 1.5]). In the liver biopsy cohort, rs13023138 G allele was independently associated with severe steatosis (OR 1.17, 95% CI 1.02-1.34; p = .01), NASH (OR 1.22, 95% CI 1.09-1.37; p < .001) and advanced fibrosis (OR 1.26, 95% CI 1.06-1.50; p = .007). At deconvolution analysis, rs13023138 G>C allele was linked to higher hepatic representation of M1 macrophages, paralleled by upregulation of pathways related to inflammation and higher expression of CXCR6. The PDCD1 rs13023138 G allele was associated with HCC development in the general population and with liver disease severity in patients at high risk of NASH.

Bujing Yishi tablets alleviate photoreceptor cells death via the P2X7R/CX3CL1/CX3CR1 pathway in Retinitis Pigmentosa rats

BackgroundRetinitis pigmentosa (RP) refers to a group of progressive photoreceptor degenerative diseases. The activation of microglia has been reported to play an important role in the photoreceptor degeneration in RP retinal. Bujing Yishi tablets (BJYS), a Chinese herbal medicine, has been used to treat retinal diseases in China with desirable effect in improving visual function. However, the mechanisms underlying the efficacy of BJYS treatment in RP are not yet fully understood. PurposeBased on the preliminary experiments, this study aimed to investigate the therapeutic mechanism involved in treating N-Methyl-N-Nitrosourea (MNU)-induced retinal degeneration of RP with BJYS. MethodsTo explore the efficacy of BJYS, a rat experimental RP model was established through intraperitoneal injection of MNU (50 mg/kg). Two experiment was carried out. After the treatment, we conducted H&E, TUNEL, retinal cytokine levels and IBA-1 expression in microglia to confirm the impact on RP model. The specific mechanism of action of BJYS tablet was assessed by western blot, real-time polymerase chain reaction (RT-PCR), and immunofluorescence to determine the mRNA and protein expression levels involved in clarifying the effectiveness of BJYS exerted through P2X7R/CX3CL1/CX3CR1 pathway. ResultsSignificant alleviation of retinal morphological structure and photoreceptor degeneration by BJYS treatment was observed in the retinal of MNU-induced RP rats, BJYS prevented the reduction of ONL thickness and decreased the level of apoptotic cells in ONL. It also inhibited microglia overactivation and reduced retinal levels of IL-1β, IL-6, TNF-α. In addition, BJYS decreased the protein expression and mRNA expression of P2X7, CX3CL1 and CX3CR1 and reduced the phosphorylation of p38 MAPK. ConclusionIn summary, this study suggested that BJYS treatment could alleviate photoreceptors degeneration of RP by inhibiting microglia overactivation and inflammation through the P2X7R/CX3CL1/CX3CR1 pathway. These effects suggest that BJYS tablets may serve as a promising oral therapeutic agent for RP.

The histone demethylase Utx controls CD8+ T-cell-dependent antitumor immunity via epigenetic regulation of the effector function.

CD8+ T cells play a central role in antitumor immune responses. Epigenetic gene regulation is essential to acquire the effector function of CD8+ T cells. However, the role of Utx, a demethylase of histone H3K27, in antitumor immunity remains unclear. In this study, we examined the roles of Utx in effector CD8+ T-cell differentiation and the antitumor immune response. In a murine tumor-bearing model, an increased tumor size and decreased survival rate were observed in T-cell-specific Utx KO (Utx KO) mice compared with wild-type (WT) mice. The number of CD8+ T cells in tumor-infiltrating lymphocytes (TILs) was significantly decreased in Utx KO mice. We found that the acquisition of effector function was delayed and attenuated in Utx KO CD8+ T cells. RNA sequencing revealed that the expression of effector signature genes was decreased in Utx KO effector CD8+ T cells, while the expression of naïve or memory signature genes was increased. Furthermore, the expression of Cxcr3, which is required for the migration of effector CD8+ T cells to tumor sites, was substantially decreased in Utx KO CD8+ T cells. These findings suggest that Utx promotes CD8+ T-cell-dependent antitumor immune responses partially through epigenetic regulation of the effector function.

1480 CXCR4 expression by regulatory T cells promotes cutaneous tissue regeneration

1480 CXCR4 expression by regulatory T cells promotes cutaneous tissue regeneration

Nuclear Tubulin Enhances CXCR4 Transcription and Promotes Chemotaxis Through TCF12 Transcription Factor in human Hematopoietic Stem Cells.

Tubulins are cytoskeleton components in all eukaryotic cells and play crucial roles in various cellular activities by polymerizing into dynamic microtubules. A subpopulation of tubulin has been shown to localize in the nucleus, however, the function of nuclear tubulin remains largely unexplored. Here we report that microtubule depolymerization specifically upregulates surface CXCR4 expression in human hematopoietic stem cells (HSCs). Mechanistically, microtubule depolymerization results in accumulation of tubulin subunits in the nucleus, leading to elevated CXCR4 transcription and increased chemotaxis of human HSCs. Treatment with microtubule stabilizer Epothilone B strongly suppresses the phenotypes induced by microtubule depolymerizing agents in human HSCs. Furthermore, chromatin immunoprecipitation assay reveals an increased binding of nuclear tubulin and TCF12 transcription factor at the CXCR4 promoter region. Depletion of TCF12 significantly suppresses microtubule depolymerization mediated upregulation of CXCR4 surface expression. These results demonstrate a previously unknown function of nuclear tubulin in regulating gene transcription through TCF12. New strategy targeting nuclear tubulin-TCF12-CXCR4 axis may be applicable to enhance HSC transplantation.

68Ga-Pentixafor PET/MRI for Treatment Response Assessment in Mantle Cell Lymphoma: Comparison Between Changes in Lesion CXCR4 Expression on PET and Lesion Size and Diffusivity on MRI.

The aim of this study was to compare CXCR4 imaging with 68Ga-pentixafor PET to MRI for treatment response assessment in patients with mantle cell lymphoma (MCL). Twenty-two posttreatment 68Ga-pentixafor PET/MRI scans of 16 patients (7 women and 9 men; mean age, 69.9 ± 7.9) with a total of 67 target lesions on baseline PET/MRI were analyzed. Rates of complete remission per lesion and per scan, according to MRI (based on lesion size) and 68Ga-pentixafor PET (based on SUV decrease to lower than liver and blood pool uptake), were compared using McNemar tests. The t tests and Pearson correlation coefficients (r) were used to compare rates of change in lesion diameter products (DPs) on MRI, and standardized uptake values (SUVmax, SUVmean) on PET, relative to baseline. At interim PET/MRI, 18/32 (56.3%) target lesions met CR criteria on 68Ga-pentixafor PET, and 16/32 (50.0%) lesions met size-based MRI criteria for CR (P = 0.63). At end-of-treatment PET/MRI, 40/57 (70.2%) target lesions met 68Ga-pentixafor PET criteria for CR, and 27/57 (47.4%) lesions met size-based MRI criteria for CR (P = 0.021). Complete remission after treatment was observed more frequently on 68Ga-pentixafor PET (11/22 scans, 54.5%) than on MRI (6/22 scans, 27.3%) (P = 0.031). Rates of change did not differ significantly between lesion DP (-69.20% ± 34.62%) and SUVmax (-64.59% ± 50.78%, P = 0.22), or DP and SUVmean (-60.15 ± 64.58, P = 0.064). Correlations were strong between DP and SUVmax (r = 0.71, P < 0.001) and DP and SUVmean (r = 0.73, P < 0.001). In MCL patients, 68Ga-pentixafor PET may be superior for assessment of complete remission status than anatomic MRI using lesion size criteria, especially at the end of treatment.

Small molecule antagonist of CXCR2 and CXCR1 inhibits tumor growth, angiogenesis, and metastasis in pancreatic cancer

Pancreatic cancer (PC) has a poor prognosis, and current therapeutic strategies are ineffective in advanced diseases. We and others have shown the aberrant expression of CXCR2 and its ligands in PC development and progression. Our objective for this study was to evaluate the therapeutic utility of CXCR2/1 targeting using an small molecule antagonist, SCH-479833, in different PC preclinical murine models (syngeneic or xenogeneic). Our results demonstrate that CXCR2/1 antagonist had both antitumor and anti-metastatic effects in PC. CXCR2/1 antagonist treatment inhibited tumor cell proliferation, migration, angiogenesis, and recruitment of neutrophils, while it increased apoptosis. Treatment with the antagonist enhanced fibrosis, tumor necrosis, and extramedullary hematopoiesis. Together, these findings suggest that selectively targeting CXCR2/1 with small molecule inhibitors is a promising therapeutic approach for inhibiting PC growth, angiogenesis, and metastasis.