CD28null T cells in aging and diseases: From biology to assessment and intervention.

CD28null T cells, an atypical subset characterized by the loss of CD28 costimulatory molecule expression, exhibit functional variants and progressively expand with age. Moreover, T cells with these phenotypes are found in both typical and atypical humoral immune responses. Consequently, they accumulate during infectious diseases, autoimmune disorders, cardiovascular conditions, and neurodegenerative ailments. To provide an in-depth review of the current knowledge regarding CD28null T cells, we specifically focus on their phenotypic and functional characteristics as well as their physiological roles in aging and diseases. While uncertainties regarding the clinical utility remains, we will review the following two crucial research perspectives to explore clinical translational applications of the research on this specific T cell subset: 1) addressing the potential utility of CD28null T cells as immunological markers for prognosis and adverse outcomes in both aging and disease, and 2) speculating on the potential of targeting CD28null T cells as an interventional strategy for preventing or delaying immune aging processes and disease progression.

DHCR24 Insufficiency Promotes Vascular Endothelial Cell Senescence and Endothelial Dysfunction via Inhibition of Caveolin-1/ERK Signaling.

Endothelial cells (ECs) senescence is critical for vascular dysfunction, which leads to age-related disease. DHCR24, a 3ß-hydroxysterol δ 24 reductase with multiple functions other than enzymatic activity, has been involved in age-related disease. However, little is known about the relationship between DHCR24 and vascular ECs senescence. We revealed that DHCR24 expression is chronologically decreased in senescent human umbilical vein endothelial cells (HUVECs) and the aortas of aged mice. ECs senescence in endothelium-specific DHCR24 knockout mice was characterized by increased P16 and senescence-associated secretory phenotype, decreased SIRT1 and cell proliferation, impaired endothelium-dependent relaxation, and elevated blood pressure. In vitro, DHCR24 knockdown in young HUVECs resulted in a similar senescence phenotype. DHCR24 deficiency impaired endothelial migration and tube formation and reduced nitric oxide (NO) levels. DHCR24 suppression also inhibited the caveolin-1/ERK signaling, probably responsible for increased reactive oxygen species production and decreased eNOS/NO. Conversely, DHCR24 overexpression enhanced this signaling pathway, blunted the senescence phenotype, and improved cellular function in senescent cells, effectively blocked by the ERK inhibitor U0126. Moreover, desmosterol accumulation induced by DHCR24 deficiency promoted HUVECs senescence and inhibited caveolin-1/ERK signaling. Our findings demonstrate that DHCR24 is essential in ECs senescence.

Counteracting Age-Related Netrin-1 Signaling Insufficiency Ameliorates Endothelial Cell Senescence and Angiogenesis Impairment.

Senescent cells that accumulate are regarded as promising therapeutic targets. However, senolytic therapy failed to achieve satisfactory results. We previously discovered that young human plasma improved vascular endothelial cell senescence, and UNC5B might be a novel intervention target. Netrin-1, as a natural ligand of UNC5B, plays roles in multiple age-related vascular disorders, but its involvement in aging is still unclear. Here, we observed a significant decrease in plasma Netrin-1 levels in old healthy subjects compared to the young. In vivo, adeno-associated-virus-mediated delivery of Netrin-1 into aged mice significantly improved functional recovery in a model of hindlimb ischemia, promoted angiogenesis in ischemic tissues, and activated the endothelial nitric oxide synthase. Furthermore, we revealed that low-dose Netrin-1 recombinant protein significantly reduced senescence-associated-ß-galactosidase-positive cells, inhibited the P53 pathway, promoted cell migration, increased tubule formation, and elevated nitric oxide production in senescent endothelial cells. However, UNC5B inhibition blocked the pro-angiogenesis effect of low-dose Netrin-1 on senescent cells or aortic rings. In summary, this study depicts that modulating Netrin-1 signaling can result in improved vascular health and Netrin-1 may have therapeutic potential for age-related ischemic diseases.

Selection of characteristic wavelengths using SMA for laser induced fluorescence spectroscopy of power transformer oil.

As the core component of the power system, the accurate analysis of its state and fault type is very important for the maintenance and repair of the transformer. The detection method represented by the transformer oil dissolved gas has the disadvantages of complicated processing steps and high operation requirements. Here, laser induced fluorescence (LIF) spectroscopy was applied for the analysis of transformer oil. Specifically, the slime mould algorithm (SMA) was used to select the characteristic wavelengths of the transformer oil fluorescence spectrum, and on this basis, a transformer fault diagnosis model was constructed. First, samples of transformer oil in different states were collected, and the fluorescence spectrum of the transformer oil was obtained with the help of the LIF acquisition system. Then, different spectral pretreatments were performed on the original fluorescence spectra, and it was found that the pretreatment effect of Savitzky-Golay smoothing (SG) was the best. Then, SMA was used to screen the characteristic wavelengths of the fluorescence spectrum, and 137 characteristic wavelengths were screened out to realize the accurate identification of the fluorescence spectrum of the transformer oil. In addition, the advantages of SMA for feature wavelength screening of transformer oil fluorescence spectra were demonstrated by comparing with traditional feature extraction strategies using principal components analysis (PCA). The research results show that it is effective to use SMA to screen the characteristic wavelengths of the LIF spectroscopy of transformer oil and use it for transformer fault diagnosis, which is of great significance for promoting the development of transformer fault diagnosis technology.

Close association between lifestyle and circulating FGF21 levels: A systematic review and meta-analysis.

Background: The impact of lifestyle factors on circulating fibroblast growth factor 21 (cFGF21) remains unclear. We conducted this systematic review and meta-analysis to evaluate the association between lifestyle factors and cFGF21 levels. Methods: We included studies that evaluated the effects of different lifestyles on cFGF21 concentration in adults, which included smoking, exercise, diets, alcohol consumption and weight loss. Random effects models or fixed effects models were used for meta-analysis to calculate the standardized mean difference (SMD) and 95% confidence interval according to the heterogeneity among studies. Study quality was assessed using the Newcastle-Ottawa Scale for cohort studies, the Joanna Briggs Institution Checklist for cross-sectional studies, and the PEDro scale for experimental studies. Results: A total of 50 studies with 1438 individuals were included. Overall, smoking, a hypercaloric carbohydrate-rich diet, a hypercaloric fat-rich diet, amino acid or protein restriction, excessive fructose intake and alcohol consumption significantly upregulated cFGF21 levels (p<0.05), whereas fish oil intake and calorie restriction with sufficient protein intake significantly decreased cFGF21 (p<0.05). Compared to the preexercise cFGF21 level, the cFGF21 level significantly increased within 3 hours postexercise (p<0.0001), while it significantly decreased in the blood sampled >6 h postexercise (p=0.01). Moreover, higher exercise intensity resulted in higher upregulation of cFGF21 at 1-hour post exercise (p=0.0006). Conclusion: FGF21 could serve as a potential biomarker for the assessment of different lifestyle interventions. When it is used for this purpose, a standard study protocol needs to be established, especially taking into consideration the intervention types and the sampling time post-intervention. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021254758, identifier CRD42021254758.

A novel diagnostic approach for the classification of small B-cell lymphoid neoplasms based on the NanoString platform.

Small B-cell lymphoid neoplasms (SBCLNs) are a heterogeneous group of diseases characterized by malignant clonal proliferation of mature B-cells. However, the classification of SBCLNs remains a challenge, especially in cases where histopathological analysis is unavailable or those with atypical laboratory findings or equivocal pathologic data. In this study, gene expression profiling of 1039 samples from 27 gene expression omnibus (GEO) datasets was first investigated to select highly and differentially expressed genes among SBCLNs. Samples from 57 SBCLN cases and 102 nonmalignant control samples were used to train a classifier using the NanoString platform. The classifier was built by employing a cascade binary classification method based on the random forest algorithm with 35 refined gene signatures. Cases were successively classified as chronic lymphocytic leukemia/small lymphocytic lymphoma, conventional mantle cell lymphoma, follicular lymphoma, leukemic non-nodal mantle cell lymphoma, marginal zone lymphoma, lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia, and other undetermined. The classifier algorithm was then validated using an independent cohort of 197 patients with SBCLNs. Under the distribution of our validation cohort, the overall sensitivity and specificity of proposed algorithm model were >95%, respectively, for all the cases with tumor cell content greater than 0.72. Combined with additional genetic aberrations including IGH-BCL2 translocation, MYD88 L265P mutation, and BRAF V600E mutation, the optimal sensitivity and specificity were respectively found at 0.88 and 0.98. In conclusion, the established algorithm demonstrated to be an effective and valuable ancillary diagnostic approach for the sub-classification and pathologic investigation of SBCLN in daily practice.

Inherited Genetic Susceptibility to Nonimmunosuppressed Epstein-Barr Virus-associated T/NK-cell Lymphoproliferative Diseases in Chinese Patients.

Epstein-Barr virus (EBV) T/NK-cell lymphoproliferative diseases are characterized by clonal expansion of EBV-infected T or NK cells, including chronic active EBV infection of T/NK-cell type (CAEBV+T/NK), EBV-associated hemophagocytic lymphohistiocytosis (EBV+HLH), extranodal NK/T-cell lymphoma of nasal type (ENKTL), and aggressive NK-cell leukemia (ANKL). However, the role of inherited genetic variants to EBV+T/NK-LPDs susceptibility is still unknown. A total of 171 nonimmunosuppressed patients with EBV+T/NK-LPDs and 104 healthy donors were retrospectively collected and a targeted sequencing study covering 15 genes associated with lymphocyte cytotoxicity was performed. The 94 gene variants, mostly located in UNC13D, LYST, ITK, and PRF1 genes were detected, and mutations covered 28/50 (56.00%) of CAEBV-T/NK, 31/51 (60.78%) of EBV+HLH, 13/28 (46.42%) of ENKTL, and 13/48 (27.09%) of ANKL. Most mutations represented monoallelic and missense. Three-year overall survival rate of patients with CAEBV-T/NK and EBV+HLH was significantly lower in patients with germline mutations than in those without germline mutations (P=0.0284, P=0.0137). Our study provided novel insights into understanding a spectrum of nonimmunosuppressed EBV+T/NK-LPDs with respect to genetic defects associated with lymphocyte cytotoxicity and reminded us that the gene sequencing may be an auxiliary test for diagnosis and risk stratification of EBV+T/NK-LPDs.

Clinical Utility of Droplet Digital PCR to Monitor BCR-ABL1 Transcripts of Patients With Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Post-chimeric Antigen Receptor19/22 T-Cell Cocktail Therapy.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) accounts for 20-30% of adult patients with ALL, characterized by translocation of t (9, 22). Tyrosine kinase inhibitors (TKIs) have significantly improved the outcome even though there are still some problems including relapse due to drug-resistant mutations and suboptimal molecular remission depth. Previously, we reported the safety and efficacy of sequential infusion of CD19/22 chimeric antigen receptor T-cell (CAR-T) immunotherapy in the treatment of relapsed/refractory (R/R) B-cell neoplasms including cases with Ph+ ALL. Given possible deeper reaction, more patients were expected to reach optimal minimal residual disease (MRD) response. An alternative method, duplex droplet digital PCR (ddPCR) with high sensitivity was established, which could provide absolute quantification of MRD without the need for calibration curves. Here, we retrospectively collected 95 bone marrow samples from 10 patients with R/R Ph+, who received 19/22 CAR-T-cell cocktail therapy. Notably, sequential molecular remission for more than 3 months (SMR3), a significant indicator based on ddPCR after CAR-T infusion was established, which was defined as a sequential molecular remission for not <3 months with negative MRD. In this cohort, no recurrence was observed in six patients achieving SMR3, where four of whom accepted allogeneic hematopoietic stem cell transplantation (allo-HSCT) after CAR-T cell regimen. Unfortunately, the other four patients who did not reach SMR3 relapsed, and did not receive extra specific treatment except CAR-T regimen. To sum up, ddPCR may be an alternative, especially when nucleic acid was insufficient in clinical practice. No achievement of SMR3 may be an early warning of potential relapse after CAR-T and indicating the initiation of other therapies including allo-HSCT.

Understanding the Mechanisms of Resistance to CAR T-Cell Therapy in Malignancies.

Taking advantage of the immune system to exert an antitumor effect is currently a novel approach in cancer therapy. Adoptive transfer of T cells engineered to express chimeric antigen receptors (CARs) targeting a desired antigen has shown extraordinary antitumor activity, especially in refractory and relapsed B-cell malignancies. The most representative in this respect, as well as the most successful example, is CD19 CAR T-cell therapy in B-cell acute lymphoblastic leukemia (B-ALL). However, with the widespread use of CAR T-cell therapy, problems of resistance and relapse are starting to be considered. This review provides a comprehensive picture of the mechanisms of resistance to CAR T-cell therapy from three aspects, namely, CAR T-cell factors, tumor factors, and tumor microenvironment factors, offering insights for improving CAR T-cell therapy.

[Threshold Flux and Membrane Fouling Analysis of the Hybrid Pre-ozonation and CNTs Membrane Modification Process].

Polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration membranes were modified with carbon nanotubes (CNT). Hybrid pre-ozonation and CNT modification were investigated by experimentally manipulating the ozonation process, threshold flux, and membrane fouling. The results showed that the threshold fluxes of the unmodified membrane and hybrid process were 45 L·(m2·h)-1 and 81 L·(m2·h)-1, respectively. Additionally, the fouling rate of the hybrid process was about 0.00137 kPa·min-1·L-1·m2·h, which was notably lower compared to other process. The results showed that the filtration volume under threshold flux was higher than that under critical flux with the same CNT loading mass and ozone dosage. This comparison indicated that membrane fouling was alleviated under threshold flux and that the corresponding operation period was extended. Through the carbon balance experiment, the fouling capacity and recoverability improved remarkably after CNT modification. Additionally, ozonation could enhance the recoverability of membranes. The hybrid process examined in this study could dramatically improve the permeability and extend the operation time of the ultrafiltration membrane.

[Effect of Hybrid Process of Pre-ozonation and CNT Modification on Hollow Fiber Membrane Fouling Control].

Polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration membranes were modified with carbon nanotube (CNT). Combined with the ozonation process, the effect of the hybrid pre-ozonation and CNT modification on fouling alleviation was investigated. The impacts of CNT loading mass and ozone dosage on the variation of flux and antifouling ability of the membrane modules were evaluated. Under a critical flux of 144 L·(m2·h)-1, CNT loading mass of 3 g·m-2, and ozone dosage(O3/DOC) of 0.22 mg·mg-1, the results revealed that the filtration volume of the hybrid process was promoted to 850 L·m-2, which was about 4.5 times higher than that of the original unmodified membrane. With a flux of 18 L·(m2·h)-1 and 15 day operation, the filtration volume was promoted to 3000 L·m-2, which was 10 times that of the unmodified membrane. The fouling membrane surface was observed using confocal laser scanning electron microscopy (CLSM). The results demonstrated that more living bacteria were present on the membrane surface of the unmodified membrane, which showed a rapid transmembrane pressure (TMP) increase. Both pre-ozonation and CNT modification decreased the total amount of microorganisms and the amount of the living bacteria as well, which mitigated the increase in TMP. After pre-ozonation, the presence of a CNT layer on the membrane surface further decreased the number of living bacteria. Although the CNT layer captured some dead bacteria, it had no obvious relationship with the increase in TMP.

[Effect of PVDF Hollow Fiber Ultrafiltration Membranes Modification with Carbonnanotube on Membrane Fouling Control During Ultrafiltration of Sewage Effluent].

The modification of hollow fiber ultrafiltration membranes with carbon nanotube (CNTs) on fouling control was investigated.Considering the antifouling ability of the CNT-modified membranes and the stability of CNTs layer,several factors were analyzed and evaluated,including the concentration of ethanol-dispersion,the diameter of CNTs,and the loading mass of CNTs.Besides,DOC,UV254,and fluorescence characteristics of the permeate from the CNT-modified membrane were analyzed.The results revealed that the optimal modification method included a 50%(volume fraction) ethanol-dispersion,a 30-50 nm diameter-CNTs,and 3 g·m-2 CNTs' loading.Compared with the virgin membrane,the removal rates of DOC and UV254 by the CNT-modified membrane were increased by 37% and 56%,respectively.Meanwhile,it was proved that the humic-like and protein-like materials were more easily removed by the CNT-modified membrane.