Reciprocal Regulation of Glycolysis-Driven Th17 Pathogenicity and Regulatory T Cell Stability by Cdc42

Genetic and epigenetic regulation of Treg cell fitness by autism-related chromatin remodeler CHD8

BACKGROUND

Chromatin remodeler chromodomain helicase DNA-binding protein 8 (CHD8) defines a subtype of autism that is associated with immune disorders. It remains unknown whether CHD8 plays a cell-intrinsic role in immune cells such as regulatory T cells (Tregs) that maintain immune tolerance through suppressing CD4+ and CD8+ effector T cells.

METHODS

Treg-specific conditional CHD8-deficient mice were generated by crossing Chd8Flox/Flox mice with Foxp3YFP-cre transgenic mice. Effects of CHD8 deficiency were investigated using hematoxylin and eosin (H&E) staining, flow cytometry, and multi-omics, including RNA-sequencing (RNA-seq), assay for transposase-accessible chromatin sequencing (ATAC-seq), and chromatin immunoprecipitation sequencing (CHIP-seq).

RESULTS

We found that Treg-specific CHD8 deletion led to early, fatal inflammation owing to increased CD4+ and CD8+ effector T cells. CHD8 deletion did not alter Treg homeostasis but increased their functional plasticity with elevated expression of effector T cell cytokines. CHIP-seq of Tregs uncovered that CHD8 binding genes were enriched in phosphatidylinositol-3 kinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling and several other pathways. RNA-seq and ATAC-seq revealed that CHD8 deletion upregulated a number of pathways, notably mammalian target of rapamycin complex 1 (mTORC1) signaling and its mediated glycolysis that have been reported to promote Treg plasticity. Integrating RNA-seq data with CHIP-seq and ATAC-seq data identified a number of CHD8 target genes whose expression depends on CHD8 direct binding-mediated chromatin remodeling.

CONCLUSIONS

Our findings suggest that CHD8 plays an important role in maintaining Treg fitness through genetic and epigenetic mechanisms to control autoimmunity, which may have important implications in immune changes in autism.

Systemic lupus erythematosus: updated insights on the pathogenesis, diagnosis, prevention and therapeutics

Systemic lupus erythematosus (SLE) is a chronic inflammatory illness with heterogeneous clinical manifestations covering multiple organs. Diversified types of medications have been shown effective for alleviating SLE syndromes, ranging from cytokines, antibodies, hormones, molecular inhibitors or antagonists, to cell transfusion. Drugs developed for treating other diseases may benefit SLE patients, and agents established as SLE therapeutics may be SLE-inductive. Complexities regarding SLE therapeutics render it essential and urgent to identify the mechanisms-of-action and pivotal signaling axis driving SLE pathogenesis, and to establish innovative SLE-targeting approaches with desirable therapeutic outcome and safety. After introducing the research history of SLE and its epidemiology, we categorized primary determinants driving SLE pathogenesis by their mechanisms; combed through current knowledge on SLE diagnosis and grouped them by disease onset, activity and comorbidity; introduced the genetic, epigenetic, hormonal and environmental factors predisposing SLE; and comprehensively categorized preventive strategies and available SLE therapeutics according to their functioning mechanisms. In summary, we proposed three mechanisms with determinant roles on SLE initiation and progression, i.e., attenuating the immune system, restoring the cytokine microenvironment homeostasis, and rescuing the impaired debris clearance machinery; and provided updated insights on current understandings of SLE regarding its pathogenesis, diagnosis, prevention and therapeutics, which may open an innovative avenue in the fields of SLE management.

CDC42 Regulatory Patterns Related To Inflammatory Bowel Disease and Hyperglycemia

As a member of the rat sarcoma virus homolog (Rho) guanosine triphosphatases (GTPases) family, Cdc42 represents a "switch" molecule, by changing from inactive (GDP-associated) to active form (GTP-associated) and vice versa. Cdc42 is activated by the guanine nucleotide exchange factors (GEFs), in contrast to GTPase-activating proteins (GAPs) which are responsable for formation of GDP-binding, inactive form of Cdc42. Some of the fundamental cellular functions are regulated by Cdc42 such as cytosceleton dynamics, cell cycling, transcription and cellular trafficking. In the gastrointestinal system, Cdc42 participates in maintenance of the functional epithelial barrier by controling intestinal epithelial cell polarity and interconnections. In addition, Cdc42 expression in pancreatic β-cells is of great importance for glucose-stimulated insulin secretion. From the pathophysiological point of view, literature data provide some evidence for Cdc42 sigaling in inflammatory bowel disease, as well as in hyperglycemic conditions related to diabetes mellitus. However, whether and by which mechanism Cdc42 contributes to the IBD patophysiology in hyperglycemic conditions is still not fully understood. Therefore, we performed bioinformatics analysis to predict transcriptional factor-gene interactions related to Cdc42 signaling in inflammatory bowel disease in hyperglycemic conditions. In silico analysis predicts various interactions between input genes and output transcriptional factors, and therefore reveals the molecules with the highest predicted effect on particular genes. Based on the predictive interactions with the intracellular molecules, carefully designed in vitro or in vivo studies are required to get better insight in the pathways of interest. Better understanding of Cdc42 molecular pathway in inflammatory bowel disease and hyperglycemia will help identifying potential targets for therapeutical modifications in clinical setting resulting in better control of the disease progression.

Fine-tuning SLE treatment: the potential of selective TYK2 inhibition

In systemic lupus erythematosus (SLE), adaptive immunity is activated by the stimulation of innate immunity, leading to the development of autoreactive T cells and activation and differentiation of B cells. Cytokine signalling plays an essential role in the pathogenesis and progression of this disease. In particular, the differentiation and function of CD4+ T cell subsets, which play a central role in SLE pathology, are significantly altered by cytokine stimulation. Many cytokines transmit signals via the Janus-activated kinase (JAK)-STAT pathway, but there is no one-to-one correspondence between cytokine receptors and JAK/TYK2. Multiple cytokines activate JAK/TYK2, and multiple JAK/TYK2 molecules are simultaneously activated by a single cytokine. Therefore, the modulation of the JAK-STAT pathway has the potential to control immune responses in SLE. Although several JAK/TYK2 inhibitors are currently undergoing clinical trials, more selective drugs that can target cytokine signals according to the specific pathology of the disease are required. TYK2 inhibitors, which are involved in the signal transduction of type I interferon and interleukin-12/23 pathways and are linked to disease susceptibility genes in SLE, may have the potential to fine-tune the differentiation and function of immune cells, particularly CD4+ T cells.

Unveiling shared therapeutic targets and pathological pathways between coronary artery disease and major depressive disorder through bioinformatics analysis

Coronary artery disease (CAD) is a predominant cardiovascular condition influenced by risk factors, with an emphasis on major depressive disorder (MDD). However, the shared mechanisms and therapeutic targets for CAD and MDD remain incompletely comprehended. Functional enrichment analyses were conducted to investigate the pathways associated with the differentially expressed genes (DEGs) in the CAD and MDD datasets. Hub genes were identified utilizing the Protein-Protein Interaction network and Cytoscape software. The single sample gene set variation analysis was applied to assess immune cell infiltration in the CAD and MDD datasets. Weighted gene co-expression network analysis and molecular biological experiments were executed to evaluate these hub genes. Molecular docking was conducted to identify drug candidates targeting these hub genes. The overlapping DEGs between the CAD and MDD datasets were mainly enriched in the Herpes simplex virus 1 infection and the NF-kappa B signaling pathways. CDC42, NDUFB3, and TXN were validated within the eigengenes of the blue module, which exhibited a significant association with the CAD phenotype. The drug candidate GS-9620 was identified as a potential protective agent against both disorders. In conclusion, CDC42, NDUFB3, and TXN held potential as molecular biomarkers and therapeutic targets for the simultaneous treatment of CAD and MDD.

DIAPH1-Deficiency is Associated with Major T, NK and ILC Defects in Humans

Loss of function mutations in Diaphanous related formin 1 (DIAPH1) are associated with seizures, cortical blindness, and microcephaly syndrome (SCBMS) and are recently linked to combined immunodeficiency. However, the extent of defects in T and innate lymphoid cells (ILCs) remain unexplored. Herein, we characterized the primary T, natural killer (NK) and helper ILCs of six patients carrying two novel loss of function mutation in DIAPH1 and Jurkat cells after DIAPH1 knockdown. Mutations were identified by whole exome sequencing. T-cell immunophenotyping, proliferation, migration, cytokine signaling, survival, and NK cell cytotoxicity were studied via flow cytometry-based assays, confocal microscopy, and real-time qPCR. CD4+ T cell proteome was analyzed by mass spectrometry. p.R351* and p.R322*variants led to a significant reduction in the DIAPH1 mRNA and protein levels. DIAPH1-deficient T cells showed proliferation, activation, as well as TCR-mediated signaling defects. DIAPH1-deficient PBMCs also displayed impaired transwell migration, defective STAT5 phosphorylation in response to IL-2, IL-7 and IL-15. In vitro generation/expansion of Treg cells from naïve T cells was significantly reduced. shRNA-mediated silencing of DIAPH1 in Jurkat cells reduced DIAPH1 protein level and inhibited T cell proliferation and IL-2/STAT5 axis. Additionally, NK cells from patients had diminished cytotoxic activity, function and IL-2/STAT5 axis. Lastly, DIAPH1-deficient patients' peripheral blood contained dramatically reduced numbers of all helper ILC subsets. DIAPH1 deficiency results in major functional defects in T, NK cells and helper ILCs underlining the critical role of formin DIAPH1 in the biology of those cell subsets.

Pathways and molecules for overcoming immunotolerance in metastatic gastrointestinal tumors

Worldwide, gastrointestinal (GI) cancer is recognized as one of the leading malignancies diagnosed in both genders, with mortality largely attributed to metastatic dissemination. It has been identified that in GI cancer, a variety of signaling pathways and key molecules are modified, leading to the emergence of an immunotolerance phenotype. Such modifications are pivotal in the malignancy's evasion of immune detection. Thus, a thorough analysis of the pathways and molecules contributing to GI cancer's immunotolerance is vital for advancing our comprehension and propelling the creation of efficacious pharmacological treatments. In response to this necessity, our review illuminates a selection of groundbreaking cellular signaling pathways associated with immunotolerance in GI cancer, including the Phosphoinositide 3-kinases/Akt, Janus kinase/Signal Transducer and Activator of Transcription 3, Nuclear Factor kappa-light-chain-enhancer of activated B cells, Transforming Growth Factor-beta/Smad, Notch, Programmed Death-1/Programmed Death-Ligand 1, and Wingless and INT-1/beta-catenin-Interleukin 10. Additionally, we examine an array of pertinent molecules like Indoleamine-pyrrole 2,3-dioxygenase, Human Leukocyte Antigen G/E, Glycoprotein A Repetitions Predominant, Clever-1, Interferon regulatory factor 8/Osteopontin, T-cell immunoglobulin and mucin-domain containing-3, Carcinoembryonic antigen-related cell adhesion molecule 1, Cell division control protein 42 homolog, and caspases-1 and -12.

Linkage of CDC42 and T-helper cell ratio with anxiety, depression and quality of life in ST-elevation myocardial infarction

Objective: To investigate the correlations between CDC42 and T-cell subsets concerning anxiety, depression and quality of life in ST-elevation myocardial infarction patients undergoing percutaneous coronary intervention. Methods: Sera from 156 participants were analyzed for CDC42 levels and Th1, Th2, Th17 and Treg cells. Results: CDC42 correlated with reduced Th1/Th2 and Th17/Treg ratios, lower anxiety and depression, and higher EuroQol visual analog scale (EQ-VAS) score. The Th17/Treg ratio correlated with elevated anxiety, depression, EuroQol-5 dimensions score and decreased EQ-VAS score. The Th1/Th2 ratio was positively related to the EQ-VAS score. Conclusion: CDC42 correlates with reduced Th1/Th2 and Th17/Treg ratios, reduced anxiety and depression, and improved quality of life in ST-elevation myocardial infarction patients undergoing percutaneous coronary intervention.

Correlation of the serum cell division cycle 42 with CD4+ T cell subsets and in-hospital mortality in Stanford type B aortic dissection patients

Objective

Cell division cycle 42 (CDC42) regulates CD4+ T-cell differentiation and participates in vascular stiffness and atherosclerosis and is involved in the progression of Stanford type B aortic dissection (TBAD). This study aimed to explore the correlation between serum CDC42 level and CD4+ T cell subsets and in-hospital mortality in TBAD patients.

Methods

Serum CDC42 and peripheral blood T-helper (Th) 1, Th2, and Th17 cells were detected in 127 TBAD patients by enzyme-linked immunosorbent assay and flow cytometry, respectively. Serum CDC42 was also quantified in 30 healthy controls.

Results

Serum CDC42 was decreased in TBAD patients vs. healthy controls (median [interquartile range (IQR)]: 418.0 (228.0-761.0) pg/ml vs. 992.0 (716.3-1,445.8) pg/ml, P < 0.001). In TBAD patients, serum CDC42 was negatively correlated with Th17 cells (P = 0.001), but not Th1 (P = 0.130) or Th2 cells (P = 0.098). Seven (5.5%) patients experienced in-hospital mortality. Serum CDC42 was reduced in patients who experienced in-hospital mortality vs. those who did not (median (IQR): 191.0 (145.0-345.0) pg/ml vs. 451.5 (298.3-766.8) pg/ml, P = 0.006). By receiver operating characteristic analysis, serum CDC42 showed a good ability for estimating in-hospital mortality [area under curve = 0.809, 95% confidence interval (CI) = 0.662-0.956]. By the multivariate logistic regression analysis, elevated serum CDC42 [odd ratio (OR) = 0.994, 95% CI = 0.998-1.000, P = 0.043] was independently correlated with lower risk of in-hospital mortality, while higher age (OR = 1.157, 95% CI = 1.017-1.316, P = 0.027) was an independent factor for increased risk of in-hospital mortality.

Conclusion

Serum CDC42 negatively associates with Th17 cells and is independently correlated with decreased in-hospital mortality risk in TBAD patients.

Navigating the landscape of Rho GTPase signalling system in autoimmunity: A bibliometric analysis spanning over three decades (1990 to 2023)

Ras-homologous (Rho) guanosine triphosphatases (GTPases) are considered a central player in regulating various biological processes, extending to immune regulation. Perturbations in Rho GTPase signalling have been implicated in immune-related dysregulation, contributing to the development of autoimmunity. This study presents a scientometric analysis exploring the interlink between the Rho GTPase signalling system and autoimmunity, while also delving into the trends of past studies. A total of 967 relevant publications from 1990 to 2023 were retrieved from the Web of Science Core Collection database after throrough manual filtering of irrelevant articles. The findings show an upward trajectory in publications related to this field since 2006. Over the past three decades, the United States of America (41.68%) emerged as the primary contributor in advancing our understanding of the association between the Rho GTPase signalling system and autoimmunity. Research in autoimmunity has mainly centered around therapeutic interventions, with an emphasis on studying leukocyte (macrophage) and endothelial remodelling. Interestingly, within the domains of multiple sclerosis and rheumatoid arthritis, the current focus has been directed towards comprehending the role of RhoA, Rac1, and Cdc42. Notably, certain subfamilies of Rho (such as RhoB and RhoC), Rac (including Rac2 and RhoG), Cdc42 (specifically RhoJ), and other atypical Rho GTPases (like RhoE and RhoH) consistently demonstrating compelling link with autoimmunity, but still warrants emphasis in the future study. Hence, strategic manipulation of the Rho signalling system holds immense promise as a pivotal approach to addressing the global challenge of autoimmunity.

The clinical utility of circulating cell division control 42 in small-vessel coronary artery disease patients undergoing drug-coated balloon treatment

BACKGROUND

Cell division control 42 (CDC42) regulates atherosclerosis, blood lipids, and inflammation and thus affects coronary artery disease (CAD), but its utility in drug-coated balloon (DCB)-treated small-vessel CAD (SV-CAD) patients is unclear. This study intended to evaluate the change and prognostic role of CDC42 in SV-CAD patients underwent DCB.

METHODS

Serum CDC42 was measured by enzyme-linked immunosorbent assay in 211 SV-CAD patients underwent DCB at baseline, day (D) 1, D3, and D7, as well as in 50 healthy controls (HCs).

RESULTS

CDC42 was decreased in SV-CAD patients compared to HCs (P < 0.001), and it was negatively associated with total cholesterol (P = 0.015), low-density lipoprotein cholesterol (P = 0.003), C-reactive protein (P = 0.001), multivessel disease (P = 0.020), and American college of cardiology/American heart association type B2/C lesions (P = 0.039) in SV-CAD patients. Longitudinally, CDC42 decreased from baseline to D1 and then gradually increased to D7 (P < 0.001) in SV-CAD patients after DCB. Interestingly, high CDC42 (cut-off value = 500 pg/mL) at baseline (P = 0.047), D3 (P = 0.046), and D7 (P = 0.008) was associated with a lower accumulating target lesion failure (TLF) rate; high CDC42 at D3 (P = 0.037) and D7 (P = 0.041) was related to a lower accumulating major adverse cardiovascular event (MACE) rate in SV-CAD patients underwent DCB. Importantly, CDC42 at D7 (high vs. low) independently predicted lower accumulating TLF (hazard ratio (HR) = 0.145, P = 0.021) and MACE (HR = 0.295, P = 0.023) risks in SV-CAD patients underwent DCB.

CONCLUSIONS

Circulating CDC42 level relates to milder disease conditions and independently estimates lower risks of TLF and MACE in SV-CAD patients underwent DCB, but further validation is still needed.

Linkage of blood cell division cycle 42 with T helper cells, and their correlation with anxiety, depression, and cognitive impairment in stroke patients

Cell division cycle 42 (CDC42) regulates T helper (Th) cell differentiation and is related to psychological disorders. This study aimed to assess the correlation between blood CDC42 and Th cells, and their association with mental issues in stroke patients. Peripheral blood samples were obtained from 264 stroke patients and 50 controls. Then, serum CDC42 was measured by enzyme-linked immunosorbent assay, and Th1, Th2, and Th17 cells were detected by flow cytometry. Hospital Anxiety and Depression Scale (HADS) and Mini Mental State Examination (MMSE) were applied to patients. CDC42 was decreased (P<0.001), Th1 (P=0.013) and Th17 (P<0.001) cells were elevated, while Th2 cells (P=0.108) showed no difference in stroke patients compared to controls. In addition, CDC42 was negatively associated to Th1 (P=0.013) and Th17 (P<0.001) cells in stroke patients but were not associated with Th2 cells (P=0.223). Interestingly, CDC42 was negatively associated with HADS-anxiety (P<0.001) and HADS-depression scores (P=0.034) and positively associated with MMSE score (P<0.001) in stroke patients. Lower CDC42 was associated to lower occurrence of anxiety (P=0.002), depression (P=0.001), and cognitive impairment (P=0.036) in stroke patients. Furthermore, increased Th17 cells were positively correlated with HADS-anxiety and HADS-depression scores and inversely correlated with MMSE score, which were also associated with higher occurrence of anxiety, depression, and cognitive impairment in stroke patients (all P<0.05). Blood CDC42 and Th17 cells were correlated, and both of them were linked to the risk of anxiety, depression, and cognitive impairment. However, the findings need further large-scale validation, and the implicated mechanism needs more investigation.

Longitudinal change in CDC42 in psoriasis: correlation with disease activity and treatment response

Objective: To investigate longitudinal CDC42 change and its correlation with disease activity and treatment response in patients with psoriasis. Methods: This prospective study detected serum CDC42 at months (M) 0, M1, M3 and M6 in 150 patients with psoriasis with current initiation of topical therapy/phototherapy/systemic therapy. Results: CDC42 was positively related to systemic biologic treatment history (p = 0.025) but negatively associated with psoriatic area (p = 0.010) and Psoriasis Area Severity Index (PASI; p < 0.001). CDC42 continuously elevated from M0 to M6 (p < 0.001). CDC42 at M1/M3/M6 was enhanced in patients with current systemic biologic therapy and PASI 75 or 90 response at M6 versus those without (all p < 0.050). Conclusion: Increased serum CDC42 level reflects reduced disease severity and better treatment response in patients with psoriasis.

The clinical role of serum cell division control 42 in coronary heart disease

Cell division control 42 (CDC42) regulates blood lipids, atherosclerosis, T cell differentiation and inflammation, which is involved in the process of coronary heart disease (CHD). This study aimed to evaluate the CDC42 level and its correlation with clinical features, the T-helper 17 (Th17)/regulatory-T (Treg) cell ratio and prognosis in CHD patients. In total, 210 CHD patients, 20 healthy controls and 20 disease controls were enrolled. Serum CDC42 levels of all participants were measured by enzyme-linked immunosorbent assay. In CHD patients, Th17 and Treg cells were discovered by flow cytometry; CHD patients were followed-up for a median of 16.9 months (range of 2.5-38.2 months). CDC42 level was lowest in CHD patients (median (interquartile range (IQR)): 402.5 (287.3-599.0) pg/mL), moderate in disease controls (median (IQR): 543.5 (413.0-676.3) pg/mL) and highest in healthy controls (median (IQR): 668.0 (506.5-841.3) pg/mL) (p < .001). Moreover, in CHD patients, lower CDC42 level was related to more prevalent diabetes mellitus (p = .021), and higher levels of C-reactive protein (p = .001), Gensini score (p = .006), Th17 cells (p = .001) and Th17/Treg ratio (p < .001) but was associated with lower Treg cells (p = .018). Furthermore, CDC42 low level [below the median level (402.5 pg/mL) of CDC42 in CHD patients] was correlated with higher accumulating major adverse cardiovascular event (MACE) risk (p = .029), while no correlation was found between the quartile of CDC42 level and accumulating MACE risk in CHD patients (p = .102). The serum CDC42 level is decreased and its low level is related to higher Th17/Treg ratio and increased accumulating MACE risk in CHD patients.

Role of Rho GTPases in inflammatory bowel disease

Rat sarcoma virus homolog (Rho) guanosine triphosphatases (GTPases) function as "molecular switch" in cellular signaling regulation processes and are associated with the pathogenesis of inflammatory bowel disease (IBD). This chronic intestinal tract inflammation primarily encompasses two diseases: Crohn's disease and ulcerative colitis. The pathogenesis of IBD is complex and considered to include four main factors and their interactions: genetics, intestinal microbiota, immune system, and environment. Recently, several novel pathogenic components have been identified. In addition, potential therapies for IBD targeting Rho GTPases have emerged and proven to be clinically effective. This review mainly focuses on Rho GTPases and their possible mechanisms in IBD pathogenesis. The therapeutic possibility of Rho GTPases is also discussed.

Looking Beyond Th17 Cells: A Role for Th17.1 Cells in Thyroid-associated Ophthalmopathy?

Thyroid-associated ophthalmopathy (TAO), an ordinary extrathyroid syndrome of Graves' disease (GD), is closely associated with immunity. T helper (Th) 17, Th1, and Th2 cells in Th lineages are thought to be related to the disease pathogenesis. Recently, there has been growing evidence that Th17.1 cells are involved in the development and progression of TAO. The characteristics of this pathology are similar to those of Th1 and Th17 lymphocytes, which secrete interferon (IFN)-γ and interleukin (IL)-17A. This paper reviews the potential role of the Th17.1 subgroup pathogenesis of TAO. The therapeutic effects of drugs that can modulate Th17.1 cell populations are also highlighted. Rich Th17.1 cells exist in peripheral blood and ocular tissues of patients suffering from thyroid eye disease (TED), especially those with severe or steroid-resistant TAO. The bias of Th17.1 cells to secrete cytokines partly determines the pathological outcome of TAO patients. Th17.1 cells are important in regulating fibrosis, adipocyte differentiation, and hyaluronic acid production. In summary, the Th17.1 subpopulation is essential in the onset and progression of TED, and targeting Th17.1 cell therapy may be a promising therapeutic approach.

Identification of an immune-related gene prognostic index for predicting prognosis, immunotherapeutic efficacy, and candidate drugs in amyotrophic lateral sclerosis

Rationale and objectives

Considering the great insufficiency in the survival prediction and therapy of amyotrophic lateral sclerosis (ALS), it is fundamental to determine an accurate survival prediction for both the clinical practices and the design of treatment trials. Therefore, there is a need for more accurate biomarkers that can be used to identify the subtype of ALS which carries a high risk of progression to guide further treatment.

Methods

The transcriptome profiles and clinical parameters of a total of 561 ALS patients in this study were analyzed retrospectively by analysis of four public microarray datasets. Based on the results from a series of analyses using bioinformatics and machine learning, immune signatures are able to be used to predict overall survival (OS) and immunotherapeutic response in ALS patients. Apart from other comprehensive analyses, the decision tree and the nomogram, based on the immune signatures, were applied to guide individual risk stratification. In addition, molecular docking methodology was employed to screen potential small molecular to which the immune signatures might response.

Results

Immune was determined as a major risk factor contributing to OS among various biomarkers of ALS patients. As compared with traditional clinical features, the immune-related gene prognostic index (IRGPI) had a significantly higher capacity for survival prediction. The determination of risk stratification and assessment was optimized by integrating the decision tree and the nomogram. Moreover, the IRGPI may be used to guide preventative immunotherapy for patients at high risks for mortality. The administration of 2MIU IL2 injection in the short-term was likely to be beneficial for the prolongment of survival time, whose dosage should be reduced to 1MIU if the long-term therapy was required. Besides, a useful clinical application for the IRGPI was to screen potential compounds by the structure-based molecular docking methodology.

Conclusion

Ultimately, the immune-derived signatures in ALS patients were favorable biomarkers for the prediction of survival probabilities and immunotherapeutic responses, and the promotion of drug development.

Targeting of Cdc42 GTPase in regulatory T cells unleashes antitumor T-cell immunity

BACKGROUND

Cancer immunotherapy has taken center stage in cancer treatment. However, the current immunotherapies only benefit a small proportion of patients with cancer, necessitating better understanding of the mechanisms of tumor immune evasion and improved cancer immunotherapy strategies. Regulatory T (Treg) cells play an important role in maintaining immune tolerance through inhibiting effector T-cell function. In the tumor microenvironment, Treg cells are used by tumor cells to counteract effector T cell-mediated tumor suppression. Targeting Treg cells may thus unleash the antitumor activity of effector T cells. While systemic depletion of Treg cells can cause excessive effector T-cell responses and subsequent autoimmune diseases, controlled targeting of Treg cells may benefit patients with cancer.

METHODS

Treg cells from Treg cell-specific heterozygous Cdc42 knockout mice, C57BL/6 mice treated with a Cdc42 inhibitor CASIN, and control mice were examined for their homeostasis and stability by flow cytometry. The autoimmune responses in Treg cell-specific heterozygous Cdc42 knockout mice, CASIN-treated C57BL/6 mice, and control mice were assessed by H&E staining and ELISA. Antitumor T-cell immunity in Treg cell-specific heterozygous Cdc42 knockout mice, CASIN-treated C57BL/6 mice, humanized NSGS mice, and control mice was assessed by challenging the mice with MC38 mouse colon cancer cells, KPC mouse pancreatic cancer cells, or HCT116 human colon cancer cells.

RESULTS

Treg cell-specific heterozygous deletion or pharmacological targeting of Cdc42 with CASIN does not affect Treg cell numbers but induces Treg cell instability, leading to antitumor T-cell immunity without detectable autoimmune reactions. Cdc42 targeting causes an additive effect on immune checkpoint inhibitor anti-programmed cell death protein-1 antibody-induced T-cell response against mouse and human tumors. Mechanistically, Cdc42 targeting induces Treg cell instability and unleashes antitumor T-cell immunity through carbonic anhydrase I-mediated pH changes.

CONCLUSIONS

Rational targeting of Cdc42 in Treg cells holds therapeutic promises in cancer immunotherapy.

Relation of CDC42, Th1, Th2, and Th17 cells with cognitive function decline in Alzheimer's disease

OBJECTIVE

Cell division cycle 42 (CDC42) regulates neurite outgrowth, neurotransmitter, and T help (Th) cell-mediated neuroinflammation, while its clinical implication in Alzheimer's disease (AD) is not clear. The present study aimed to investigate the correlation of CDC42 with Th1, Th2, and Th17 cells, as well as CDC42' longitudinal change and relation to cognitive function decline in AD patients.

METHODS

150 AD patients were enrolled, then their blood Th1, Th2, and Th17 cells were quantified by flow cytometry at baseline; CDC42 was detected by RT-qPCR and MMSE score was assessed at baseline and during 3-year follow-up. Meanwhile, CDC42, Th1, Th2, and Th17 cells were quantified in 30 Parkinson's disease (PD) patients and 30 healthy controls (HCs).

RESULTS

CDC42 (p < 0.001) and Th2 cells (p < 0.001) were lowest in AD patients, followed by PD patients, highest in HCs; but Th1 cells (p = 0.001) and Th17 cells (p < 0.001) showed opposite trends. CDC42 was not related to Th1 cells (p = 0.134), positively correlated with Th2 cells (p = 0.023) and MMSE (p < 0.001), while negatively associated with Th17 cells (p < 0.001) in AD patients. CDC42 was only related to Th17 cells (p = 0.048) and MMSE (p = 0.048) in PD patients; and it was not linked with Th1, Th2, Th17 cells, or MMSE in HCs (all p > 0.05). During a 3-year follow-up, CDC42 was gradually declined in AD patients (p < 0.001), its decline was positively correlated with MMSE decline at 1 year (p = 0.004), 2 years (p = 0.005), and 3 years (p = 0.026).

INTERPRETATION

CDC42 might have the potency to serve as a biomarker for estimating AD risk and progression.

Tunneling Nanotubes Facilitate Intercellular Protein Transfer and Cell Networks Function

The past decade witnessed a huge interest in the communication machinery called tunneling nanotubes (TNTs) which is a novel, contact-dependent type of intercellular protein transfer (IPT). As the IPT phenomenon plays a particular role in the cross-talk between cells, including cancer cells as well as in the immune and nervous systems, it therefore participates in remodeling of the cellular networks. The following review focuses on the placing the role of tunneling nanotube-mediated protein transfer between distant cells. Firstly, we describe different screening methods used to study IPT including tunneling nanotubes. Further, we present various examples of TNT-mediated protein transfer in the immune system, cancer microenvironment and in the nervous system, with particular attention to the methods used to verify the transfer of individual proteins.

Aberrant blood cell division cycle 42 expression and its correlation with disease severity, inflammation and mortality risk in patients with acute pancreatitis

Cell division cycle 42 (CDC42) can inhibit inflammation by regulating the activity of macrophage and T cells, which contributes to the pathophysiology of acute pancreatitis (AP). Therefore, CDC42 may have application as a potential biomarker for AP. The present study aimed to explore this possibility. Peripheral blood mononuclear cells (PBMCs) were collected from 149 patients with AP and 50 healthy controls (HCs). Subsequently, CDC42 expression in the PBMCs was measured using RT-qPCR; C-reactive protein (CRP), TNF-α and IL-6 in the serum of patients with AP were measured using ELISA. Meanwhile, Mann-Whitney U test, Kruskal-Wallis test, and Spearman's rank correlation test were performed on the data. The CDC42 expression levels were lower in patients with AP compared with those in HCs (P<0.001). CDC42 expression was declined in patients with moderate-severe AP (MSAP) vs. patients with mild AP (MAP) (P=0.029), and in patients with severe AP (SAP) vs. patients with MAP (P=0.004). CDC42 expression correlated negatively with the Ranson's score (P<0.001), APACEH II score (P=0.011) and SOFA score (P<0.001) in patients with AP. CDC42 expression also correlated negatively with CRP (P<0.001) and TNF-α (P=0.004) levels but not with IL-6 levels (P=0.177). Furthermore, CDC42 expression was lower in deceased patients with AP vs. AP survivors (P<0.001) and in deceased patients with SAP vs. SAP survivors (P=0.026). CDC42 had good potential in predicting mortality from AP, with AUC of 0.829 and a 95% CI of 0.731-0.927, and it also had certain potential in predicting mortality from SAP and MSAP, with AUC (95% CI) of 0.794 (0.616-0.973) and 0.757 (0.558-0.956), respectively. In conclusion, data from the present study suggest that lower CDC42 expression levels correlate with higher disease susceptibility, disease severity, inflammation, and mortality risk in patients with AP.

Blood CDC42 overexpression is associated with an increased risk of acute exacerbation, inflammation and disease severity in patients with chronic obstructive pulmonary disease

It has been previously reported that cell division control 42 (CDC42) protein can regulate macrophage recruitment, T cell-associated inflammation and lung injury. However, its role in chronic obstructive pulmonary disease (COPD) remain poorly understood. Therefore, the present study aimed to investigate the possible association among CDC42 expression, the risk of acute exacerbation and disease features in patients with COPD. Peripheral blood mononuclear cells (PBMCs) and serum samples were collected from 60 patients with acute exacerbation COPD (AE-COPD), 60 patients with stable COPD (S-COPD) and 60 healthy control (HCs) individuals. The mRNA expression levels of CDC42 in PBMCs were then measured using reverse transcription-quantitative PCR. The serum levels of TNF-α, IL-1β, IL-6 and IL-17 were measured using ELISA. The results showed that the expression of CDC42 was dysregulated among patients with AE-COPD and S-COPD compared with that in HCs. Specifically, the expression level of CDC42 was the highest in patients with AE-COPD, followed by those with S-COPD and the lowest in HCs (P<0.001). Furthermore, receiver operating characteristic curve analysis demonstrated that CDC42 expression was associated with an increased risk of acute exacerbation in COPD with an area under curve of 0.690 (95% confidence interval=0.595-0.785). CDC42 was found to be positively associated with Global Initiative for Chronic Obstructive Lung Disease staging in patients with AE-COPD (P<0.01) and S-COPD (P<0.05). Additionally, CDC42 expression associated positively with the serum levels of TNF-α, IL-1β, IL-6 and IL-17 in patients with AE-COPD (all P<0.05). However, this association was weaker in patients with S-COPD and became negligible in HCs. In conclusion, data from the present study suggest that CDC42 is associated with an increased risk of acute exacerbation, inflammation and disease severity in patients with COPD, implicating its application as a potential biomarker for COPD.

Cell division control protein 42 correlates with lower disease risk and its elevation predicts better treatment response, and inhibits T-helper 17 cell differentiation in rheumatoid arthritis

OBJECTIVE

Previous research reports that cell division control protein 42 (CDC42) is dysregulated in rheumatoid arthritis (RA). This study aimed to further explore the linkage of CDC42 with T-helper (Th) 1 and Th17 cell differentiation, and its implication in RA management.

METHODS

After enrolling 80 RA patients, their blood CDC42, Th1 and Th17 cells were detected by RT-qPCR and flow cytometry, respectively, IFN-γ and IL-17A were detected by ELISA. Based on the treatment response at week 12, the patients were classified as response patients and no response patients. In addition, blood CDC42 was also detected after enrolling 40 healthy controls. Subsequently, naïve CD4⁺ T cells from RA patients were transfected with control, CDC42 overexpression and knockdown lentivirus, followed by differentiation assay.

RESULTS

CDC42 was reduced in RA patients versus healthy controls (P < 0.001). In RA patients, CDC42 was negatively correlated with IFN-γ (P = 0.023), Th17 cells (P = 0.011) and IL-17A (P = 0.003) but not Th1 cells (P = 0.200). CDC42 presented an increasing trend after treatment (P < 0.001); besides, CDC42 at week 8 (P = 0.027) and week 12 (P < 0.001) were increased in response patients versus no response patients. Subsequent experiment showed that in RA CD4⁺ T cells, CDC42 overexpression reduced IFN-γ and IL-17A (both P < 0.05), while CDC42 knockdown elevated IL-17A (P < 0.05) but not IFN-γ (P > 0.05). Moreover, CDC42 overexpression inhibited, while CDC42 knockdown increased Th17 cell percentage (P < 0.05) but not Th1 cell percentage (P > 0.05).

CONCLUSIONS

CDC42 negatively correlates with disease risk and its elevation predicts better treatment response; it also inhibits Th17 but not Th1 cell differentiation in RA.

Longitudinal Variations of CDC42 in Patients With Acute Ischemic Stroke During 3-Year Period: Correlation With CD4+ T Cells, Disease Severity, and Prognosis

Objective

Cell division cycle 42 (CDC42) modulates CD4⁺ T-cell differentiation, blood lipids, and neuronal apoptosis and is involved in the pathogenesis of acute ischemic stroke (AIS); however, the clinical role of CDC42 in AIS remains unanswered. This study aimed to evaluate the expression of CDC42 in a 3-year follow-up and its correlation with disease severity, T helper (Th)1/2/17 cells, and the prognosis in patients with AIS.

Methods

Blood CDC42 was detected in 143 patients with AIS at multiple time points during the 3-year follow-up period and in 70 controls at admission by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In addition, blood Th1, Th2, and Th17 cells and their secreted cytokines (interferon-γ (IFN-γ), interleukin-4 (IL-4), and interleukin-17A (IL-17A)) in patients with AIS were detected by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively.

Results

Compared with controls (p < 0.001), CDC42 was reduced in patients with AIS. CDC42 was negatively correlated with the National Institutes of Health Stroke Scale (NIHSS) score (p < 0.001), whereas, in patients with AIS (all p < 0.050), it was positively associated with Th2 cells and IL-4 but negatively correlated with Th17 cells and IL-17A. CDC42 was decreased from admission to 3 days and gradually increased from 3 days to 3 years in patients with AIS (P<0.001). In a 3-year follow-up, 24 patients with AIS recurred and 8 patients died. On the 3rd day, 7th day, 1st month, 3rd month, 6th month, 1st year, 2nd year, and 3rd year, CDC42 was decreased in recurrent patients than that in non-recurrent patients (all p < 0.050). CDC42 at 7 days (p = 0.033) and 3 months (p = 0.023) was declined in reported deceased patients than in survived patients.

Conclusion

CDC42 is used as a biomarker to constantly monitor disease progression and recurrence risk of patients with AIS.

Clostridioides difficile Toxin B Activates Group 3 Innate Lymphocytes

Group 3 innate lymphocytes (ILC3s) are rare immune cells localized in mucosal tissues, especially the gastrointestinal (GI) tract. Despite their rarity, they are a major source of the cytokine interleukin-22 (IL-22), which protects the GI epithelium during inflammation and infection. Although ILC3s have been demonstrated to be important for defense against Clostridioides difficile infection, the exact mechanisms through which they sense productive infection and become activated to produce IL-22 remain poorly understood. In this study, we identified a novel mechanism of ILC3 activation after exposure to C. difficile. Toxin B (TcdB) from C. difficile directly induced production of IL-22 in ILC3s, and this induction was dependent on the glucosyltransferase activity of the toxin, which inhibits small GTPases. Pharmacological inhibition of the small GTPase Cdc42 also enhanced IL-22 production in ILC3s, indicating that Cdc42 is a negative regulator of ILC3 activation. Further gene expression analysis revealed that treatment with TcdB modulated the expression of several inflammation-related genes in ILC3s. These findings demonstrate that C. difficile toxin-mediated inhibition of Cdc42 leads to the activation of ILC3s, providing evidence for how these cells are recruited into the immune response against the pathobiont.

PBMC CDC42 reveals the disease activity and treatment efficacy of TNF inhibitor in patients with ankylosing spondylitis

OBJECTIVE

Cell division cycle 42 (CDC42) regulates the polarization of M2 macrophage and maintains the T cell homeostasis, to participate in multiple autoimmune diseases, while its clinical involvement in ankylosing spondylitis (AS) remains unclear. Hence, the current study aimed to investigate the correlation of CDC42 with clinical characteristics and treatment outcome in AS patients receiving tumor necrosis factor (TNF) inhibitor therapy.

METHODS

Peripheral blood mononuclear cell (PBMC) CDC42 expression was detected at baseline, week (W) 4, W8, and W12 after TNF inhibitor treatment in 91 AS patients and in 50 HCs after enrollment. Furthermore, serum TNF-α, interferon-γ (IFN-γ), interleukin-10 (IL-10), and interleukin-17A (IL-17A) from AS patients were detected at baseline.

RESULTS

Blood CDC42 was lower in AS patients compared with HCs (p < 0.001). Additionally, blood CDC42 was negatively linked with CRP (r = -0.349, p = 0.001), BASDAI score (r = -0.243, p = 0.020), and ASDASCRP score (r = -0.238, p = 0.023) in AS patients; however, blood CDC42 was not correlated with other clinical characteristics. Besides, CDC42 was negatively correlated with TNF-α (r = -0.237, p = 0.024) and IL-17A (r = -0.339, p = 0.001) but not with IFN-γ (p = 0.083) or IL-10 (p = 0.280). Moreover, blood CDC42 was elevated after TNF inhibitor treatment (p < 0.001). Meanwhile, blood CDC42 was not varied at baseline and W4 between response patients and non-response patients, while it was higher at W8 (p = 0.019) and W12 (p = 0.002) in response patients than in non-response patients after treatment.

CONCLUSION

Blood CDC42 deficiency links with elevated pro-inflammatory cytokines, disease activity and unsatisfying response to TNF inhibitor in AS patients.

The role of cell division control protein 42 in tumor and non-tumor diseases: A systematic review

Rho-GTPases control a variety of cellular functions mainly by regulating microtubule and actin dynamics, affecting the cytoskeleton, and are important regulators of the structural plasticity of dendrites and spines. Members of the Rho-GTPase family include Ras-related C3 botulinum toxin substrate 1 (Rac1), RhoA (Ras homologous), and cell division control protein 42 (Cdc42). Cdc42 is involved in the regulation of a variety of tumor and non-tumor diseases through a cascade of multiple signaling pathways. Active Cdc42 can regulate intercellular adhesion, cytoskeleton formation, and cell cycle, thus affecting cell proliferation, transformation, and dynamic balance as well as migration and invasion of tumor cells by regulating the expression of effector proteins. Here we discuss the role of Cdc42 in promoting metastasis, invasion, epithelial-mesenchymal transformation and angiogenesis in malignant tumors. The significant role of Cdc42 in non-tumor diseases is also discussed. Since Cdc42 plays a central role in the development of various diseases, small molecule inhibitors targeting Cdc42 have important clinical significance in the prevention and treatment of these diseases.

The relationship of blood CDC42 level with Th1 cells, Th17 cells, inflammation markers, disease risk/activity, and treatment efficacy of rheumatoid arthritis

BACKGROUND

Cell division control protein 42 (CDC42) is reported to be involved in multiple inflammation processes by regulating T cell differentiation, maintaining immune cell homeostasis, and altering their function, while no relevant studies explored its clinical role in patients with rheumatoid arthritis (RA). Therefore, this study aimed to explore the correlation of CDC42 with Th1 and Th17 cells and its association with disease risk, activity, and treatment outcomes of RA.

METHODS

After the enrollment of 95 active RA patients and 50 healthy subjects (HC), their CDC42, Th1 cells, and Th17 cells were assayed by RT-qPCR and flow cytometry, accordingly. For RA patients only, CDC42 was also detected at W6, and W12 after treatment. The treatment response and remission status were evaluated at W12.

RESULTS

Compared to HC, CDC42 was reduced (P < 0.001), while Th1 cells (P = 0.021) and Th17 cells (P < 0.001) were increased in RA patients. Besides, CDC42 was negatively correlated with Th17 cells (P < 0.001), erythrocyte sedimentation rate (ESR) (P = 0.012), C-reactive protein (P = 0.002), and disease activity score in 28 joints (DAS28) (P = 0.007), but did not relate to Th1 cells or other disease features (all P > 0.05) in RA patients. Furthermore, CDC42 was elevated during treatment in RA patients (P < 0.001). Moreover, CDC42 increment at W12 correlated with treatment response (P = 0.004). Besides, CDC42 elevation at W0 (P = 0.038), W6 (P = 0.001), and W12 (P < 0.001) also linked with treatment remission.

CONCLUSION

CDC42 has the potential to serve as a biomarker to monitor disease activity and treatment efficacy in patients with RA.

The relation of circulating cell division cycle 42 expression with Th1, Th2, and Th17 cells, adhesion molecules, and biochemical indexes in coronary heart disease patients

BACKGROUND

Cell division cycle 42 (CDC42) regulates macrophage polarization, vascular inflammation, atherosclerosis progression, and modifies differentiation of T helper (Th) cells, while its potential as a biomarker in coronary heart disease (CHD) patients is still lacking. This study aimed to evaluate CDC42 expression, its correlation with Th1, Th2, and Th17 cells, adhesion molecules, and biochemical indexes in CHD patients.

METHODS

One hundred two CHD patients and 50 controls were enrolled. CDC42 expression in peripheral blood mononuclear cells was assessed by reverse transcription quantitative polymerase chain reaction in all participants. In CHD patients, Th1, Th2, and Th17 cells were detected by flow cytometric analysis; meanwhile, serum levels of inflammatory cytokines and adhesion molecules were detected by enzyme-linked immunosorbent assay.

RESULTS

CDC42 was lower in CHD patients (median (interquartile range (IQR)) = 0.431 (0.304-0.722)) than in controls (median (IQR) = 0.985 (0.572-1.760)) (p < 0.001). CDC42 was positively associated with Th2 cells (p = 0.016) and interleukin (IL)-10 (p = 0.034), but negatively correlated with Th17 cells (p < 0.001) and IL-17A (p < 0.001) in CHD patients. However, no association was found in CDC42 with Th1 cells (p = 0.199) or interferon-γ (p = 0.367) in CHD patients. Besides, CDC42 was negatively correlated with vascular cell adhesion molecule-1 (p = 0.013) and intercellular cell adhesion molecule-1 (p = 0.001) in CHD patients. Additionally, CDC42 negatively associated with C-reactive protein (p < 0.001), Gensini score (p < 0.001), total cholesterol (p = 0.039), and low-density lipoprotein cholesterol (p = 0.014), but not with other biochemical indexes (p > 0.05) in CHD patients.

CONCLUSION

CDC42 correlates with Th2 cells, Th17 cells, and adhesion molecules, also reflects inflammation, coronary stenosis degree, and cholesterol level in CHD patients.

Graded RhoA GTPase Expression in Treg Cells Distinguishes Tumor Immunity From Autoimmunity

RhoA of the Rho GTPase family is prenylated at its C-terminus. Prenylation of RhoA has been shown to control T helper 17 (Th17) cell-mediated colitis. By characterizing T cell-specific RhoA conditional knockout mice, we have recently shown that RhoA is required for Th2 and Th17 cell differentiation and Th2/Th17 cell-mediated allergic airway inflammation. It remains unclear whether RhoA plays a cell-intrinsic role in regulatory T (Treg) cells that suppress effector T cells such as Th2/Th17 cells to maintain immune tolerance and to promote tumor immune evasion. Here we have generated Treg cell-specific RhoA-deficient mice. We found that homozygous RhoA deletion in Treg cells led to early, fatal systemic inflammatory disorders. The autoimmune responses came from an increase in activated CD4⁺ and CD8⁺ T cells and in effector T cells including Th17, Th1 and Th2 cells. The immune activation was due to impaired Treg cell homeostasis and increased Treg cell plasticity. Interestingly, heterozygous RhoA deletion in Treg cells did not affect Treg cell homeostasis nor cause systemic autoimmunity but induced Treg cell plasticity and an increase in effector T cells. Importantly, heterozygous RhoA deletion significantly inhibited tumor growth, which was associated with tumor-infiltrating Treg cell plasticity and increased tumor-infiltrating effector T cells. Collectively, our findings suggest that graded RhoA expression in Treg cells distinguishes tumor immunity from autoimmunity and that rational targeting of RhoA in Treg cells may trigger anti-tumor T cell immunity without causing autoimmune responses.

Single Cell RNA-Seq Analysis Identifies Differentially Expressed Genes of Treg Cell in Early Treatment-Naive Rheumatoid Arthritis By Arsenic Trioxide

Objective: Early treatment-naïve rheumatoid arthritis (RA) has defective regulatory T (Treg) cells and increased inflammation response. In this study, we aim to illustrate the regulation of Treg cells in pathogenesis of early rheumatoid arthritis by arsenic trioxide (As₂O₃).

Methods: We studied the effects of As₂O₃ on gene expression in early treatment-naïve RA Treg cells with single cell RNA-seq (scRNA-seq). Treg cells were sorted from peripheral blood mononuclear cells (PBMCs) and purified by fluorescence-activated cell sorting (FACS) and cultured with or without As₂O₃ (at 0.1 µM) for 24 h. Total RNA was isolated and sequenced, and functional analysis was performed against the Gene Ontology (GO) database. Results for selected genes were confirmed with RT-qPCR.

Results: As₂O₃ exerts no significant effect on CD4⁺ T-cell apoptosis under physical condition, and selectively modulate ^CD4+ T cells toward Treg cells not Th17 cells under special polarizing stimulators. As₂O₃ increased the expression of 200 and reduced that of 272 genes with fold change (FC) 2.0 or greater. Several genes associated with inflammation, Treg-cell activation and differentiation as well as glucose and amino acids metabolism were among the most strongly affected genes. GO function analysis identified top ten ranked significant biological process (BPs), molecular functions (MFs), and cell components (CCs) in treatment and nontreatment Treg cells. In GO analysis, genes involved in the immunoregulation, cell apoptosis and cycle, inflammation, and cellular metabolism were enriched among the significantly affected genes. The KEGG pathway enrichment analysis identified the forkhead box O (FoxO) signal pathway, apoptosis, cytokine–cytokine receptor interaction, cell cycle, nuclear factor-kappa B (NF-κB) signaling pathway, tumor necrosis factor α (TNF-α), p53 signaling pathway, and phosphatidylinositol 3′-kinase (PI3K)-Akt signaling pathway were involved in the pathogenesis of early treatment-naïve RA.

Conclusion: This is the first study investigating the genome-wide effects of As₂O₃ on the gene expression of treatment-naïve Treg cells. In addition to clear anti-inflammatory and immunoregulation effects, As₂O₃ affect amino acids and glucose metabolism in Treg cells, an observation that might be particularly important in the metabolic phenotype of treatment-naïve RA.

Metabolic rewiring: a new master of Th17 cell plasticity and heterogeneity

T helper type 17 (Th17) cells are characterized by inherent plasticity and heterogeneity displaying both pathogenic and tissue-protective functions. Emerging evidence has illuminated a pivotal role for metabolic reprogramming in shaping Th17 cell fate determination. Metabolic responses are regulated by a constellation of factors and environmental triggers, including cytokines, nutrients, oxygen levels, and metabolites. Dysregulation of metabolic pathways not only influences Th17 cell plasticity and effector function but also affects the outcome of Th17-linked autoimmune, inflammatory, and antitumor responses. Understanding the molecular mechanisms underpinning metabolic reprogramming can allow the enhancement of protective Th17 cell-mediated responses during infections and cancer, concomitant with the suppression of detrimental Th17 processes during autoimmune and inflammatory diseases. In the present review, we describe major metabolic pathways underlying the differentiation of Th17 cells and their crosstalk with intracellular signaling mediators, we discuss how metabolic reprogramming affects Th17 cell plasticity and functions, and, finally, we outline current advances in the exploitation of metabolic checkpoints for the development of novel therapeutic interventions for the management of tissue inflammation, autoimmune disorders, and cancer.

RhoA and Cdc42 in T cells: Are they targetable for T cell-mediated inflammatory diseases?

Many inflammatory diseases are not curable, necessitating a better understanding of their pathobiology that may help identify novel biological targets. RhoA and Cdc42 of Rho family small GTPases regulate a variety of cellular functions such as actin cytoskeletal organization, cell adhesion, migration, proliferation, and survival. Recent characterization of mouse models of conditional gene knockout of RhoA and Cdc42 has revealed their physiological and cell type-specific roles in a number of cell types. In T lymphocytes, which play an important role in the pathogenesis of most, if not all, of the inflammatory diseases, we and others have investigated the effects of T cell-specific knockout of RhoA and Cdc42 on T cell development in the thymus, peripheral T cell homeostasis, activation, and differentiation to effector and regulatory T cells, and on T cell-mediated allergic airway inflammation and colitis. Here we highlight the phenotypes resulting from RhoA and Cdc42 deletion in T cells and discuss whether pharmacological targeting of RhoA and Cdc42 is feasible in treating asthma that is driven by allergic airway inflammation and colitis.

Rho GTPases as Key Molecular Players within Intestinal Mucosa and GI Diseases

Rho proteins operate as key regulators of the cytoskeleton, cell morphology and trafficking. Acting as molecular switches, the function of Rho GTPases is determined by guanosine triphosphate (GTP)/guanosine diphosphate (GDP) exchange and their lipidation via prenylation, allowing their binding to cellular membranes and the interaction with downstream effector proteins in close proximity to the membrane. A plethora of in vitro studies demonstrate the indispensable function of Rho proteins for cytoskeleton dynamics within different cell types. However, only in the last decades we have got access to genetically modified mouse models to decipher the intricate regulation between members of the Rho family within specific cell types in the complex in vivo situation. Translationally, alterations of the expression and/or function of Rho GTPases have been associated with several pathological conditions, such as inflammation and cancer. In the context of the GI tract, the continuous crosstalk between the host and the intestinal microbiota requires a tight regulation of the complex interaction between cellular components within the intestinal tissue. Recent studies demonstrate that Rho GTPases play important roles for the maintenance of tissue homeostasis in the gut. We will summarize the current knowledge on Rho protein function within individual cell types in the intestinal mucosa in vivo, with special focus on intestinal epithelial cells and T cells.

T Cell Metabolism: A New Perspective on Th17/Treg Cell Imbalance in Systemic Lupus Erythematosus

The Th17/T-regulatory (Treg) cell imbalance is involved in the occurrence and development of organ inflammation in systemic lupus erythematosus (SLE). Metabolic pathways can regulate T cell differentiation and function, thus contributing to SLE inflammation. Increasingly, data have shown metabolism influences and reprograms the Th17/Treg cell balance, and the metabolic pattern of T cells is different in SLE. Notably, metabolic characteristics of SLE T cells, such as enhanced glycolysis, lipid synthesis, glutaminolysis, and highly activated mTOR, all favored Th17 differentiation and function, which underlie the Th17/Treg cell imbalance in SLE patients. Targeting metabolic pathways to reverse Th17/Treg imbalance offer a promising method for SLE therapy.

Genome-Wide CRISPR Screen Identifies Host Factors Required by Toxoplasma gondii Infection

Toxoplasma gondii are obligate intracellular protoza, and due to their small genome and limited encoded proteins, they have to exploit host factors for entry, replication, and dissemination. Such host factors can be defined as host dependency factors (HDFs). Though HDFs are inessential for cell viability, they are critical for pathogen infection, and potential ideal targets for therapeutic intervention. However, information about these HDFs required by T. gondii infection is highly deficient. In this study, the genes of human foreskin fibroblast (HFF) cells were comprehensively edited using the lentiviral CRISPR-Cas9-sgRNA library, and then the lentivirus-treated cells were infected with T. gondii at multiplication of infection 1 (MOI = 1) for 10 days to identify HDFs essential for T. gondii infection. The survival cells were harvested and sent for sgRNA sequencing. The sgRNA sequence matched genes or miRNAs were potential HDFs. Some cells in the lentivirus-treated group could survive longer than those in the untreated control group after T. gondii infection. From a pool of 19,050 human genes and 1,864 human pri-miRNAs, 1,193 potential HDFs were identified, including 1,183 genes and 10 pri-miRNAs (corresponding with 17 mature miRNAs). Among them, seven genes and five mature miRNAs were validated with siRNAs, miRNA inhibitors, and mimics, respectively. Bioinformatics analysis revealed that, among the 1,183 genes, 53 potential HDFs were associated with regulation of host actin cytoskeleton and 23 potential HDFs coded immune negative regulators. This result indicated that actin dynamics were indispensable for T. gondii infection, and some host immune negative regulators may be involved in disarming host defenses. Our findings contribute to the current limited knowledge about host factors required by T. gondii infection and provide us with new targets for medication therapy and vaccine exploitation.

Molecular control of pathogenic Th17 cells in autoimmune diseases

IL-17A-producing CD4⁺ T helper cells (Th17) are crucial for the development of inflammatory and autoimmune diseases and thus are exploited for clinical immunotherapies. Emerging evidence suggests Th17 cells are heterogeneous and able to adopt both pathogenic and non-pathogenic phenotypes which are shaped by environmental and genetic factors. On one hand, IL-6 in concert with TGFβ1 can induce non-pathogenic Th17 cells (non-pTh17), which are not effective in inducing tissue inflammation. On the other hand, IL-6, IL-1β with IL-23 induce pathogenic Th17 cells (pTh17) to induce immune pathologies in various tissues. Th17 cells could be both pathogenic and non-pathogenic in a content-dependent manner in vivo. Understanding how the generation and pathogenicity of pTh17 cells are regulated will aid us to devise more effective immunotherapy. In this review, we summarize recent advances in the differentiation and regulation of Th17 cells especially pTh17 cells in vitro and in vivo. The emerging results revealing the specific molecular control of pTh17 cells are highlighted.

Differential Helicobacter pylori Plasticity in the Gastric Niche of Subjects at Increased Gastric Cancer Risk

Helicobacter pylori (H. pylori) represents an independent risk factor for Gastric Cancer (GC). First Degree Relatives (FDR) of GC subjects and Autoimmune Gastritis (AG) patients are both at increased risk for GC. H. pylori genetic heterogeneity within the gastric niche of FDR and AG individuals has been little explored. To understand whether they exploit an increased H. pylori stability and virulence, 14 AG, 25 FDR, 39 GC and 13 dyspeptic patients (D) were investigated by a cultural PCR-based approach characterizing single colonies-forming-units. We chose three loci within the Cytotoxin-associated gene-A Pathogenicity Island (CagPAI) (cagA,cagE,virB11), vacA, homA and homB as markers of virulence with reported association to GC. Inflammatory/precancerous lesions were staged according to Sydney System. When compared to D, FDR, similarly to GC patients, were associated to higher atrophy (OR = 6.29; 95% CI:1.23-31.96 in FDR; OR = 7.50; 95% CI:1.67-33.72 in GC) and a lower frequency of mixed infections (OR = 0.16; 95% CI:0.03-0.81 in FDR; OR = 0.10; 95% CI:0.02-0.48 in GC). FDR presented also an increased neutrophil infiltration (OR = 7.19; 95% CI:1.16-44.65). Both FDR and GC carried a higher proportion of CagPAI⁺vacAs1i1mx⁺homB⁺ profiles (OR = 2.71; 95% CI: 1.66-4.41 and OR = 3.43; 95% CI: 2.16-5.44, respectively). Conversely, AG patients presented a lower frequency of subtypes carrying a stable CagPAI and vacAs1i1mx. These results underline different H. pylori plasticity in FDR and AG individuals, and thus, a different host-bacterium interaction capacity that should be considered in the context of eradication therapies.

Rational targeting Cdc42 restrains Th2 cell differentiation and prevents allergic airway inflammation

BACKGROUND

Asthma is an allergic airway inflammation-driven disease that affects more than 300 million people world-wide. Targeted therapies for asthma are largely lacking. Although asthma symptoms can be prevented from worsening, asthma development cannot be prevented. Cdc42 GTPase has been shown to regulate actin cytoskeleton, cell proliferation and survival.

OBJECTIVES

To investigate the role and targeting of Cdc42 in Th2 cell differentiation and Th2-mediated allergic airway inflammation.

METHODS

Post-thymic Cdc42-deficient mice were generated by crossing Cdc42^flox/flox mice with dLck^icre transgenic mice in which Cre expression is driven by distal Lck promoter. Effects of post-thymic Cdc42 deletion and pharmacological targeting Cdc42 on Th2 cell differentiation were evaluated in vitro under Th2-polarized culture conditions. Effects of post-thymic Cdc42 deletion and pharmacological targeting Cdc42 on allergic airway inflammation were evaluated in ovalbumin- and/or house dust mite-induced mouse models of asthma.

RESULTS

Post-thymic deletion of Cdc42 led to reduced peripheral CD8⁺ T cells and attenuated Th2 cell differentiation, with no effect on closely related Th1, Th17 and induced regulatory T (iTreg) cells. Post-thymic Cdc42 deficiency ameliorated allergic airway inflammation. The selective inhibition of Th2 cell differentiation by post-thymic deletion of Cdc42 was recapitulated by pharmacological targeting of Cdc42 with CASIN, a Cdc42 activity-specific chemical inhibitor. CASIN also alleviated allergic airway inflammation. CASIN-treated Cdc42-deficient mice showed comparable allergic airway inflammation to vehicle-treated Cdc42-deficient mice, indicative of negligible off-target effect of CASIN. CASIN had no effect on established allergic airway inflammation.

CONCLUSION AND CLINICAL RELEVANCE

Cdc42 is required for Th2 cell differentiation and allergic airway inflammation, and rational targeting Cdc42 may serve as a preventive but not therapeutic approach for asthma control.

Metabolic regulation of innate and adaptive lymphocyte effector responses

Innate and adaptive lymphocytes employ diverse effector programs that provide optimal immunity to pathogens and orchestrate tissue homeostasis, or conversely can become dysregulated to drive progression of chronic inflammatory diseases. Emerging evidence suggests that CD4+ T helper cell subsets and their innate counterparts, the innate lymphoid cell family, accomplish these complex biological roles by selectively programming their cellular metabolism in order to instruct distinct modules of lymphocyte differentiation, proliferation, and cytokine production. Further, these metabolic pathways are significantly influenced by tissue microenvironments and disease states. Here, we summarize our current knowledge on how cell-intrinsic metabolic factors modulate the context-dependent bioenergetic pathways that govern innate and adaptive lymphocytes. Further, we propose that a greater understanding of these pathways may lead to the identification of unique features in each population and provoke the development of novel therapeutic strategies to modulate lymphocytes in health and disease.