Tumour-reactive plasma cells in antitumour immunity: current insights and future prospects

Tumour-reactive plasma cells (TRPCs) have been reported to be positively associated with the long-term survival of patients with various cancers. However, unlike tumour-specific antigen (TSA)-induced T cells which have precise effects against tumours, plasma cells require TSA to obtain specific responses. Therefore, the search for a TSA suitable for B-cell recognition is urgent. In this review, we discuss the functions of tumour-reactive plasma cells. Further, this review also explores the concept of screening for neoantigen-reactive plasma cells, drawing inspiration from T-cell screening methods. While challenges exist, such as epitope prediction and efficient screening, the development of novel techniques may lead to the discovery of highly specific plasma cells for adoptive cell therapy. In conclusion, tumour-reactive plasma cells are emerging as powerful players in cancer immunotherapy. Their ability to produce antibodies against a variety of antigens, especially neoantigens, opens new avenues for personalised treatments. Overcoming challenges in epitope prediction and screening will be crucial in harnessing the full potential of these plasma cells for the benefit of cancer patients.

Genomic profiling and associated B cell lineages delineate the efficacy of neoadjuvant anti-PD-1-based therapy in oesophageal squamous cell carcinoma

BACKGROUND

Neoadjuvant chemoimmunotherapy has offered novel therapeutic options for patients with locally advanced oesophageal squamous cell carcinoma (ESCC). Depicting the landscape of genomic and immune profiles is critical in predicting therapeutic responses.

METHODS

We integrated whole-exome sequencing, single-cell RNA sequencing, and immunofluorescence data of ESCC samples from 24 patients who received neoadjuvant treatment with PD-1 inhibitors plus paclitaxel and platinum-based chemotherapy to identify correlations with therapeutic responses.

FINDINGS

An elevation of small insertions and deletions was observed in responders. DNA mismatch repair (MMR) pathway alternations were highly frequent in patients with optimal responses and correlated with tumour infiltrating lymphocytes (TILs). Among the TILs in ESCC, dichotomous developing trajectories of B cells were identified, with one lineage differentiating towards LMO2+ germinal centre B cells and another lineage differentiating towards CD55+ memory B cells. While LMO2+ germinal centre B cells were enriched in responding tumours, CD55+ memory B cells were found to correlate with inferior responses to combination therapy, exhibiting immune-regulating features and impeding the cytotoxicity of CD8+ T cells. The comprehensive evaluation of transcriptomic B cell lineage features was validated to predict responses to immunotherapy in patients with cancer.

INTERPRETATION

This comprehensive evaluation of tumour MMR pathway alternations and intra-tumoural B cell features will help to improve the selection and management of patients with ESCC to receive neoadjuvant chemoimmunotherapy.

FUNDING

National Science Foundation of China (82373371, 82330053), Eastern Scholar Program at Shanghai Institutions of Higher Learning, National Science and Technology Major Project of China (2023YFA1800204, 2020YFC2008402), and Science and Technology Commission of Shanghai Municipality (22ZR1410700, 20ZR1410800).

Application of waste derived magnetic acid-base bifunctional CoFe/biochar/CaO as an efficient catalyst for biodiesel production from waste cooking oil

The loss of active components, weak acid resistance, and low recover efficiency of common Ca-based catalysts limited its further development and application. In this study, to effectively produce biodiesel from waste cooking oil (WCO), a green and recyclable magnetic acid-base bifunctional CoFe/biochar/CaO catalyst was prepared from sargassum and river snail shell waste via hydrothermal method. The catalysts' structure and properties were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), CO2/NH3 temperature programmed desorption (CO2/NH3 TPD), etc., The prepared catalyst mainly consisted of the carbon skeleton, CoFe alloy, and CaO. CoFe alloy provided catalyst's ferromagnetism for magnetic separation as well as acid sites for transesterification of WCO. Ca and other metal species with nanoscale (∼5.64 nm) were dispersively anchored on sargassum biochar surface, thereby leading to good catalytic activity (99.21% biodiesel yield) and stability (91.70% biodiesel yield after the 5th cycle). In addition, response surface methodology-Box-Behnken design (RSM-BBD) revealed the optimal operational conditions were 16:1 methanol/oil molar ratio, 3 wt% catalyst dosage, 73 °C for 157 min. The maximum biodiesel yield predicted value was 98.29% and the experimental value was 99.21%, indicating good satisfaction of the established model. Moreover, the quality of WCO biodiesel met the ASTM D6751 standards. This study benefits magnetic waste-derived acid-base bifunctional catalysts for the disposal of WCO towards sustainable biodiesel production.

Oxidative stress-initiated one-carbon metabolism drives the generation of interleukin-10-producing B cells to resolve pneumonia

The metabolic reprogramming underlying the generation of regulatory B cells during infectious diseases remains unknown. Using a Pseudomonas aeruginosa-induced pneumonia model, we reported that IL-10-producing B cells (IL-10+ B cells) play a key role in spontaneously resolving infection-mediated inflammation. Accumulated cytosolic reactive oxygen species (ROS) during inflammation were shown to drive IL-10+ B-cell generation by remodeling one-carbon metabolism. Depletion of the enzyme serine hydroxymethyltransferase 1 (Shmt1) led to inadequate one-carbon metabolism and decreased IL-10+ B-cell production. Furthermore, increased one-carbon flux elevated the levels of the methyl donor S-adenosylmethionine (SAM), altering histone H3 lysine 4 methylation (H3K4me) at the Il10 gene to promote chromatin accessibility and upregulate Il10 expression in B cells. Therefore, the one-carbon metabolism-associated compound ethacrynic acid (EA) was screened and found to potentially treat infectious pneumonia by boosting IL-10+ B-cell generation. Overall, these findings reveal that ROS serve as modulators to resolve inflammation by reprogramming one-carbon metabolism pathways in B cells.

Temporal trends in sleep pattern among Chinese adults between 2010 and 2018: findings from five consecutive nationally representative surveys

OBJECTIVES

This study aimed to comprehensively analyze the time trends in average sleep duration and prevalence of short sleep, poor sleep quality, and high sleep debt among Chinese adults.

STUDY DESIGN

This was a cross-sectional study.

METHODS

The study used nationally representative data from Chinese Family Panel Survey (CFPS) among adults aged ≥18 years. Linear regression and logistic regression were used to calculate P-values for trends across waves, and absolute difference in prevalences were calculated by linear regression. Poisson regression analysis was used to calculate the prevalence ratios of sleep-related problems.

RESULTS

In 2018, the estimated average sleep duration in adults was 7.6 h/d. A shorter sleep duration, higher proportion of short sleep, and poor sleep quality were observed in people aged ≥65 years, women, people with primary school education or below, and residents in Liaoning province. The average sleep duration slightly decreased from 8.2 h/d in 2010 to 7.6 h/d in 2016, and then remained stable from 2016 to 2018. The prevalence of short sleep duration has markedly increased from 11.8% in 2010 to 24.1% in 2016, and then there was a decline in prevalence from 2016 to 2018, although this decrease was not significant. The prevalence of high sleep debt among employed people increased from 6.2% in 2010 to 8.6% in 2018 (absolute difference, 2.4 p.p; P trend = 0.063). In addition, the prevalence of poor sleep quality increased from 15.6% in 2012 to 21.3% in 2018 (absolute difference of 5.7 p.p; P trend<0.001). For all the sleep-related variables, the degree of changes varied by sociodemographic subgroups.

CONCLUSIONS

In this nationally representative survey of the Chinese population, the average sleep duration slightly decreased from 2010 to 2016, and then remained stable from 2016 to 2018. Poor sleep quality, and high sleep debt increased among most of the sociodemographic subgroups. Future studies are needed to understand the drivers of changes in sleep health among Chinese adults.

A novel in vitro prognostic model of bladder cancer based on urine-derived living tumor cells

Bladder cancer (BLCA) remains a difficult malignancy to manage because of its high recurrence, intense follow-up, and invasive diagnostic and treatment techniques. Immune checkpoint inhibitors (ICIs) have forged a new direction for the treatment of BLCA, but it is currently challenging to predict whether an individual patient will be sensitive to ICIs. We collected 43 urine/tumor samples from BLCA patients for primary bladder cancer cells (BCCs) culturing using our previously reported BCC culture platform. We used flow cytometry (FCM) to measure the expression levels of Programmed Death-Ligand 1 (PD-L1) on BCCs before and after interferon-gamma (IFN-γ) treatment and found that PD-L1 expression and the sensitivities to IFN-γ varied among patients. RNA-sequencing, western blotting, and programmed death-1 (PD-1) binding assays confirmed that the BCC FCM-based PD-L1 detection platform (BC-PD-L1) was reliable and was not hindered by the  glycosylation of PD-L1. In the subsequent retrospective study, we found that IFN-γ-stimulated PD-L1 (sPD-L1) expression on BCCs detected by BC-PD-L1 could predict the prognosis of BLCA patients. Importantly, the prognostic value was similar or even better in urine-derived BC-PD-L1 (UBC-PD-L1). Transcriptome analysis showed that BCCs with high sPD-L1 tended to enrich genes associated with the collagen-containing extracellular matrix, cell-cell adhesion, and positive regulation of the immune system. In addition, the UBC-PD-L1 also exhibited predictive value for ICI response in BLCA patients. In conclusion, as a novel personalized urine-detection method, UBC-PD-L1 may provide a rapid, accurate, and non-invasive tool for monitoring tumor progression, predicting therapeutic responses, and helping improve BLCA clinical treatment in future.

Fasting-Mimicking Diet Drives Antitumor Immunity against Colorectal Cancer by Reducing IgA-Producing Cells

As a safe, feasible, and inexpensive dietary intervention, fasting-mimicking diet (FMD) exhibits excellent antitumor efficacy by regulating metabolism and boosting antitumor immunity. A better understanding of the specific mechanisms underlying the immunoregulatory functions of FMD could help improve and expand the clinical application of FMD-mediated immunotherapeutic strategies. In this study, we aimed to elucidate the role of metabolic reprogramming induced by FMD in activation of antitumor immunity against colorectal cancer. Single-cell RNA sequencing analysis of intratumoral immune cells revealed that tumor-infiltrating IgA+ B cells were significantly reduced by FMD treatment, leading to the activation of antitumor immunity and tumor regression in murine colorectal cancer models. Mechanistically, FMD delayed tumor growth by repressing B-cell class switching to IgA. Therefore, FMD-induced reduction of IgA+ B cells overcame the suppression of CD8+ T cells. The immunoregulatory and antitumor effects of FMD intervention were reversed by IgA+ B-cell transfer. Moreover, FMD boosted fatty acid oxidation (FAO) to trigger RUNX3 acetylation, thus inactivating Cα gene transcription and IgA class switching. IgA+ B-cell expansion was also impeded in patients placed on FMD, while B-cell expression of carnitine palmitoyl transferase 1A (CPT1A), the rate-limiting enzyme of FAO, was increased. Furthermore, CPT1A expression was negatively correlated with both IgA+ B cells and IgA secretion within colorectal cancer. Together, these results highlight that FMD holds great promise for treating colorectal cancer. Furthermore, the degree of IgA+ B cell infiltration and FAO-associated metabolic status are potential biomarkers for evaluating FMD efficacy.

SIGNIFICANCE

Metabolic reprogramming of B cells induced by fasting-mimicking diet suppresses IgA class switching and production to activate antitumor immunity and inhibit tumor growth. See related commentary by Bush and Perry, p. 3493.

Nano-hydroxyapatite/Polyamide 66 cage in anterior cervical corpectomy and fusion: a comprehensive systematic review and meta-analysis

OBJECTIVE

This study aimed to conduct a meta-analysis to compare the effectiveness and safety between titanium mesh cage (TMC) and nano-hydroxyapatite/polyamide 66 cage (n-HA/PA66) in the surgical treatment of cervical spondylotic myelopathy (CSM) through anterior cervical corpectomy and fusion (ACCF).

MATERIALS AND METHODS

We implemented a comprehensive search strategy across multiple databases, including Wanfang, China Knowledge Network, China Biomedical Literature Database, Wipu, PubMed, Cochran, Embase, and Web of Science. To ensure a thorough examination of available literature, the databases were searched from their inception to January 2023. Two independent researchers evaluated the quality of the included studies by using established criteria. We used RevMan 5.4 (Review Manager Web, The Cochrane Collaboration, Copenhagen, Denmark) to facilitate data extraction and analysis.

RESULTS

This analysis included seven controlled clinical studies. The meta-analysis results showed no statistically significant differences between the two groups in terms of operating time, intraoperative bleeding, preoperative Japanese Orthopedic Association (JOA) score, preoperative visual analog scale (VAS) score, preoperative and final follow-up C2-7 Cobb angles, and intervertebral fusion rate (p > 0.05). However, a significant difference was observed between the two groups in terms of the final follow-up JOA [MD = 0.77, 95% CI (0.58, 0.97), p < 0.00001], VAS [MD = -0.50, 95% CI (-0.71, -0.30), p < 0.00001], and sedimentation rate [RR = 0.30, 95% CI (0.18, 0.48), p < 0.00001].

CONCLUSIONS

The use of n-HA/PA66 in ACCF for treating CSM is safe and effective treatment with positive clinical efficacy. In addition, n-HA/PA66 has both effective clinical efficacy and significantly lower fusion settling rates compared to TMC.

Strategies for overcoming bottlenecks in allogeneic CAR-T cell therapy

Patient-derived autologous chimeric antigen receptor (CAR)-T cell therapy is a revolutionary breakthrough in immunotherapy and has made impressive progress in both preclinical and clinical studies. However, autologous CAR-T cells still have notable drawbacks in clinical manufacture, such as long production time, variable cell potency and possible manufacturing failures. Allogeneic CAR-T cell therapy is significantly superior to autologous CAR-T cell therapy in these aspects. The use of allogeneic CAR-T cell therapy may provide simplified manufacturing process and allow the creation of 'off-the-shelf' products, facilitating the treatments of various types of tumors at less delivery time. Nevertheless, severe graft-versus-host disease (GvHD) or host-mediated allorejection may occur in the allogeneic setting, implying that addressing these two critical issues is urgent for the clinical application of allogeneic CAR-T cell therapy. In this review, we summarize the current approaches to overcome GvHD and host rejection, which empower allogeneic CAR-T cell therapy with a broader future.

A precise molecular subtyping of ulcerative colitis reveals the immune heterogeneity and predicts clinical drug responses

BACKGROUND AND AIMS

We sought to identify novel molecular subtypes of ulcerative colitis (UC) based on large-scale cohorts and establish a clinically applicable subtyping system for the precision treatment of the disease.

METHODS

Eight microarray profiles containing colon samples from 357 patients were utilized. Expression heterogeneity was screened out and stable subtypes were identified among UC patients. Immune infiltration pattern and biological agent response were compared among subtypes to assess the value in guiding treatment. The relationship between PRLR and TNFSF13B genes with the highest predictive value was further validated by functional experiments.

RESULTS

Three stable molecular subtypes were successfully identified. Immune cell infiltration analysis defined three subtypes as innate immune activated UC (IIA), whole immune activated UC (WIA), and immune homeostasis like UC (IHL). Notably, the response rate towards biological agents (infliximab/vedolizumab) in WIA patients was the lowest (less than 10%), while the response rate in IHL patients was the highest, ranging from 42 to 60%. Among the featured genes of subtypes, the ratio of PRLR to TNFSF13B could effectively screen for IHL UC subtype suitable for biological agent therapies (Area under curve: 0.961-0.986). Furthermore, we demonstrated that PRLR expressed in epithelial cells could inhibit the expression of TNFSF13B in monocyte-derived macrophages through the CXCL1-NF-κB pathway.

CONCLUSIONS

We identified three stable UC subtypes with a heterogeneous immune pattern and different response rates towards biological agents for the first time. We also established a precise molecular subtyping system and classifier to predict clinical drug response and provide individualized treatment strategies for UC patients.

Acyloxyacyl hydrolase promotes pulmonary defense by preventing alveolar macrophage tolerance

Although alveolar macrophages (AMs) play important roles in preventing and eliminating pulmonary infections, little is known about their regulation in healthy animals. Since exposure to LPS often renders cells hyporesponsive to subsequent LPS exposures ("tolerant"), we tested the hypothesis that LPS produced in the intestine reaches the lungs and stimulates AMs, rendering them tolerant. We found that resting AMs were more likely to be tolerant in mice lacking acyloxyacyl hydrolase (AOAH), the host lipase that degrades and inactivates LPS; isolated Aoah-/- AMs were less responsive to LPS stimulation and less phagocytic than were Aoah+/+ AMs. Upon innate stimulation in the airways, Aoah-/- mice had reduced epithelium- and macrophage-derived chemokine/cytokine production. Aoah-/- mice also developed greater and more prolonged loss of body weight and higher bacterial burdens after pulmonary challenge with Pseudomonas aeruginosa than did wildtype mice. We also found that bloodborne or intrarectally-administered LPS desensitized ("tolerized") AMs while antimicrobial drug treatment that reduced intestinal commensal Gram-negative bacterial abundance largely restored the innate responsiveness of Aoah-/- AMs. Confirming the role of LPS stimulation, the absence of TLR4 prevented Aoah-/- AM tolerance. We conclude that commensal LPSs may stimulate and desensitize (tolerize) alveolar macrophages in a TLR4-dependent manner and compromise pulmonary immunity. By inactivating LPS in the intestine, AOAH promotes antibacterial host defenses in the lung.

Ten-eleven translocation-2 inactivation restrains IL-10-producing regulatory B cells to enable antitumor immunity in hepatocellular carcinoma

BACKGROUND AND AIMS

IL-10-producing regulatory B cells (IL-10 + B cells), a dominant regulatory B cell (Breg) subset, foster tumor progression. However, the mechanisms underlying their generation in HCC are poorly understood. Ten-eleven translocation-2 (TET2), a predominant epigenetic regulatory enzyme in B cells, regulates gene expression by catalyzing demethylation of 5-methylcytosine into 5-hydroxymethyl cytosine (5hmC). In this study, we investigated the role of TET2 in IL-10 + B cell generation in HCC and its prospects for clinical application.

APPROACH AND RESULTS

TET2 activation in B cells triggered by oxidative stress from the HCC microenvironment promoted IL-10 expression, whereas adoptive transfer of Tet2 -deficient B cells suppressed HCC progression. The aryl hydrocarbon receptor is required for TET2 to hydroxylate Il10 . In addition, high levels of IL-10, TET2, and 5hmc in B cells indicate poor prognosis in patients with HCC. Moreover, we determined TET2 activity using 5hmc in B cells to evaluate the efficacy of anti-programmed death 1 (anti-PD-1) therapy. Notably, TET2 inhibition in B cells facilitates antitumor immunity to improve anti-PD-1 therapy for HCC.

CONCLUSIONS

Our findings propose a TET2-dependent epigenetic intervention targeting IL-10 + B cell generation during HCC progression and identify the inhibition of TET2 activity as a promising combination therapy with immune checkpoint inhibitors for HCC.

Response of sugar metabolism in the cotyledons and roots of Ricinus communis subjected to salt stress

Ricinus communis is an important oilseed crop worldwide and is also considered one of the best potential plants for salt-affected soil improvement in northeast China. However, little is known about photosynthesis and carbohydrate metabolism in this plant, nor the distribution of carbohydrates in cotyledons and roots under salinity stress. In the present study, seedling growth, gas exchange parameters (P_N , E, g_s and C_i ), carbohydrate (fructose, sucrose, glucose, soluble sugar and starch) metabolism and related enzymes and genes were measured in Ricinus plants. Under salt stress, P_N of cotyledons decreased significantly (P < 0.05), resulting in weak photosynthetic capacity. Furthermore, salt stress increased sucrose and glucose content in cotyledons, but decreased soluble sugar and starch content. However, sucrose increased and starch decreased in roots. This may be correlated with the increasing sugar metabolism under salinity, including notable changes in sugar-related enzyme activities (SPS, SuSy, α-amylase and β-amylase) and gene expression of RcINV, RcSUS, RcAmY, RcBAM and RcGBE1. The results suggest that salinity reduces photosynthesis of cotyledons, alters carbohydrate allocation between cotyledons and roots and also promotes starch utilization in cotyledons and starch biosynthesis in roots, leading to a functional imbalance between cotyledons and roots. Together, these findings provide insights into the crucial role of sugar metabolism in improving salt-tolerance of Ricinus during the early seedling growth stage.

Single-cell landscape and clinical outcomes of infiltrating B cells in colorectal cancer

B cells constitute a major component of infiltrating immune cells in colorectal cancer (CRC). However, the characteristics of B cells and their clinical significance remain unclear. In this study, using single-cell RNA sequencing and multicolour immunofluorescence staining experiments, we identified five distinct subtypes of B cells with their marker genes, distribution patterns and functional properties in the CRC tumour microenvironment. Meanwhile, we found a higher proportion of IgG plasma cells in tumour sites than that in adjacent normal mucosal tissues. In addition, the CXCL13-producing CD8⁺ T cells in the tumour tissues could promote the formation of tertiary lymphoid structure (TLS) B cells, and the CCL28-CCR10 axis is pivotal for IgG plasma cell migration from the periphery of TLSs to the tumour stroma. Finally, we identified four distinct colon immune classes (CICs: A-D) and found that CD20⁺ B cells within TLSs were enriched in one immune-inflamed or hot tumour group (CIC D). This B cell-rich group, which was characterized by strong antigen presentation, IgG plasma cells accumulation, microsatellite instability-high (MSI-H) and high tumour mutation burden (TMB-H), as well as immunosuppressive property in particular, might become a potential predictive biomarker for future immunotherapy. Additionally, in an immunotherapy cohort, patients with the enrichment of B cells and TLSs were demonstrated to obtain significant therapeutic advantages. Together, our findings provide the detailed landscape of infiltrating B cells and their potential clinical significance in CRC.

Mortality-Air Pollution Associations in Low Exposure Environments (MAPLE): Phase 2

INTRODUCTION

Mortality is associated with long-term exposure to fine particulate matter (particulate matter ≤2.5 μm in aerodynamic diameter; PM2.5), although the magnitude and form of these associations remain poorly understood at lower concentrations. Knowledge gaps include the shape of concentration-response curves and the lowest levels of exposure at which increased risks are evident and the occurrence and extent of associations with specific causes of death. Here, we applied improved estimates of exposure to ambient PM2.5 to national population-based cohorts in Canada, including a stacked cohort of 7.1 million people who responded to census year 1991, 1996, or 2001. The characterization of the shape of the concentration-response relationship for nonaccidental mortality and several specific causes of death at low levels of exposure was the focus of the Mortality-Air Pollution Associations in Low Exposure Environments (MAPLE) Phase 1 report. In the Phase 1 report we reported that associations between outdoor PM2.5 concentrations and nonaccidental mortality were attenuated with the addition of ozone (O3) or a measure of gaseous pollutant oxidant capacity (Ox), which was estimated from O3 and nitrogen dioxide (NO2) concentrations. This was motivated by our interests in understanding both the effects air pollutant mixtures may have on mortality and also the role of O3 as a copollutant that shares common sources and precursor emissions with those of PM2.5. In this Phase 2 report, we further explore the sensitivity of these associations with O3 and Ox, evaluate sensitivity to other factors, such as regional variation, and present ambient PM2.5 concentration-response relationships for specific causes of death.

METHODS

PM2.5 concentrations were estimated at 1 km2 spatial resolution across North America using remote sensing of aerosol optical depth (AOD) combined with chemical transport model (GEOS-Chem) simulations of the AOD:surface PM2.5 mass concentration relationship, land use information, and ground monitoring. These estimates were informed and further refined with collocated measurements of PM2.5 and AOD, including targeted measurements in areas of low PM2.5 concentrations collected at five locations across Canada. Ground measurements of PM2.5 and total suspended particulate matter (TSP) mass concentrations from 1981 to 1999 were used to backcast remote-sensing-based estimates over that same time period, resulting in modeled annual surfaces from 1981 to 2016.

Annual exposures to PM2.5 were then estimated for subjects in several national population-based Canadian cohorts using residential histories derived from annual postal code entries in income tax files. These cohorts included three census-based cohorts: the 1991 Canadian Census Health and Environment Cohort (CanCHEC; 2.5 million respondents), the 1996 CanCHEC (3 million respondents), the 2001 CanCHEC (3 million respondents), and a Stacked CanCHEC where duplicate records of respondents were excluded (Stacked CanCHEC; 7.1 million respondents). The Canadian Community Health Survey (CCHS) mortality cohort (mCCHS), derived from several pooled cycles of the CCHS (540,900 respondents), included additional individual information about health behaviors. Follow-up periods were completed to the end of 2016 for all cohorts. Cox proportional hazard ratios (HRs) were estimated for nonaccidental and other major causes of death using a 10-year moving average exposure and 1-year lag. All models were stratified by age, sex, immigrant status, and where appropriate, census year or survey cycle. Models were further adjusted for income adequacy quintile, visible minority status, Indigenous identity, educational attainment, labor-force status, marital status, occupation, and ecological covariates of community size, airshed, urban form, and four dimensions of the Canadian Marginalization Index (Can-Marg; instability, deprivation, dependency, and ethnic concentration). The mCCHS analyses were also adjusted for individual-level measures of smoking, alcohol consumption, fruit and vegetable consumption, body mass index (BMI), and exercise behavior.

In addition to linear models, the shape of the concentration-response function was investigated using restricted cubic splines (RCS). The number of knots were selected by minimizing the Bayesian Information Criterion (BIC). Two additional models were used to examine the association between nonaccidental mortality and PM2.5. The first is the standard threshold model defined by a transformation of concentration equaling zero if the concentration was less than a specific threshold value and concentration minus the threshold value for concentrations above the threshold. The second additional model was an extension of the Shape Constrained Health Impact Function (SCHIF), the eSCHIF, which converts RCS predictions into functions potentially more suitable for use in health impact assessments. Given the RCS parameter estimates and their covariance matrix, 1,000 realizations of the RCS were simulated at concentrations from the minimum to the maximum concentration, by increments of 0.1 μg/m3. An eSCHIF was then fit to each of these RCS realizations. Thus, 1,000 eSCHIF predictions and uncertainty intervals were determined at each concentration within the total range.

Sensitivity analyses were conducted to examine associations between PM2.5 and mortality when in the presence of, or stratified by tertile of, O3 or Ox. Additionally, associations between PM2.5 and mortality were assessed for sensitivity to lower concentration thresholds, where person-years below a threshold value were assigned the mean exposure within that group. We also examined the sensitivity of the shape of the nonaccidental mortality-PM2.5 association to removal of person-years at or above 12 μg/m3 (the current U.S. National Ambient Air Quality Standard) and 10 μg/m3 (the current Canadian and former [2005] World Health Organization [WHO] guideline, and current WHO Interim Target-4). Finally, differences in the shapes of PM2.5-mortality associations were assessed across broad geographic regions (airsheds) within Canada.

RESULTS

The refined PM2.5 exposure estimates demonstrated improved performance relative to estimates applied previously and in the MAPLE Phase 1 report, with slightly reduced errors, including at lower ranges of concentrations (e.g., for PM2.5 <10 μg/m3).

Positive associations between outdoor PM2.5 concentrations and nonaccidental mortality were consistently observed in all cohorts. In the Stacked CanCHEC analyses (1.3 million deaths), each 10-μg/m3 increase in outdoor PM2.5 concentration corresponded to an HR of 1.084 (95% confidence interval [CI]: 1.073 to 1.096) for nonaccidental mortality. For an interquartile range (IQR) increase in PM2.5 mass concentration of 4.16 μg/m3 and for a mean annual nonaccidental death rate of 92.8 per 10,000 persons (over the 1991-2016 period for cohort participants ages 25-90), this HR corresponds to an additional 31.62 deaths per 100,000 people, which is equivalent to an additional 7,848 deaths per year in Canada, based on the 2016 population. In RCS models, mean HR predictions increased from the minimum concentration of 2.5 μg/m3 to 4.5 μg/m3, flattened from 4.5 μg/m3 to 8.0 μg/m3, then increased for concentrations above 8.0 μg/m3. The threshold model results reflected this pattern with -2 log-likelihood values being equal at 2.5 μg/m3 and 8.0 μg/m3. However, mean threshold model predictions monotonically increased over the concentration range with the lower 95% CI equal to one from 2.5 μg/m3 to 8.0 μg/m3. The RCS model was a superior predictor compared with any of the threshold models, including the linear model.

In the mCCHS cohort analyses inclusion of behavioral covariates did not substantially change the results for both linear and nonlinear models. We examined the sensitivity of the shape of the nonaccidental mortality-PM2.5 association to removal of person-years at or above the current U.S. and Canadian standards of 12 μg/m3 and 10 μg/m3, respectively. In the full cohort and in both restricted cohorts, a steep increase was observed from the minimum concentration of 2.5 μg/m3 to 5 μg/m3. For the full cohort and the <12 μg/m3 cohort the relationship flattened over the 5 to 9 μg/m3 range and then increased above 9 μg/m3. A similar increase was observed for the <10 μg/m3 cohort followed by a clear decline in the magnitude of predictions over the 5 to 9 μg/m3 range and an increase above 9 μg/m3. Together these results suggest that a positive association exists for concentrations >9 μg/m3 with indications of adverse effects on mortality at concentrations as low as 2.5 μg/m3.

Among the other causes of death examined, PM2.5 exposures were consistently associated with an increased hazard of mortality due to ischemic heart disease, respiratory disease, cardiovascular disease, and diabetes across all cohorts. Associations were observed in the Stacked CanCHEC but not in all other cohorts for cerebrovascular disease, pneumonia, and chronic obstructive pulmonary disease (COPD) mortality. No significant associations were observed between mortality and exposure to PM2.5 for heart failure, lung cancer, and kidney failure.

In sensitivity analyses, the addition of O3 and Ox attenuated associations between PM2.5 and mortality. When analyses were stratified by tertiles of copollutants, associations between PM2.5 and mortality were only observed in the highest tertile of O3 or Ox. Across broad regions of Canada, linear HR estimates and the shape of the eSCHIF varied substantially, possibly reflecting underlying differences in air pollutant mixtures not characterized by PM2.5 mass concentrations or the included gaseous pollutants. Sensitivity analyses to assess regional variation in population characteristics and access to healthcare indicated that the observed regional differences in concentration-mortality relationships, specifically the flattening of the concentration-mortality relationship over the 5 to 9 μg/m3 range, was not likely related to variation in the makeup of the cohort or its access to healthcare, lending support to the potential role of spatially varying air pollutant mixtures not sufficiently characterized by PM2.5 mass concentrations.

CONCLUSIONS

In several large, national Canadian cohorts, including a cohort of 7.1 million unique census respondents, associations were observed between exposure to PM2.5 with nonaccidental mortality and several specific causes of death. Associations with nonaccidental mortality were observed using the eSCHIF methodology at concentrations as low as 2.5 μg/m3, and there was no clear evidence in the observed data of a lower threshold, below which PM2.5 was not associated with nonaccidental mortality.

Leucine-tRNA-synthase-2-expressing B cells contribute to colorectal cancer immunoevasion

Immunoregulatory B cells impede antitumor immunity through unknown features and mechanisms. We report the existence of leucine-tRNA-synthase-2 (LARS2)-expressing B cell (LARS B) subset with a transforming growth factor-β1 (TGF-β1)-dominant regulatory feature in both mouse and human progressive colorectal cancer (CRC). Of note, LARS B cells exhibited a leucine nutrient preference and displayed active mitochondrial aminoacyl-tRNA biosynthesis. They were located outside the tertiary lymphoid structure and correlated with colorectal hyperplasia and shortened survival in CRC patients. A leucine diet induced LARS B cell generation, whereas LARS B cell deletion by Lars2 gene ablation or leucine blockage repressed CRC immunoevasion. Mechanistically, LARS2 programmed mitochondrial nicotinamide adenine dinucleotide (NAD⁺) regeneration and oxidative metabolism, thus determining the regulatory feature of LARS B cells in which the NAD-dependent protein deacetylase sirtuin-1 (SIRT1) was involved. We propose a leucine-dieting scheme to inhibit LARS B cells, which is safe and useful for CRC therapy.

RNF4 silencing induces cell growth arrest and DNA damage by promoting nuclear targeting of p62 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the largest causes of cancer-related deaths worldwide owing to the limitation of effective treatment options. The ubiquitin-proteasome system has been rapidly recognized as a frequent target of deregulation leading to cancers. Enhanced DNA damage response (DDR) promotes HCC growth and prevents chemosensitivity, and ubiquitin E3 ligases are key modulators in DDR. Therefore, a better understanding of how E3 ligases regulate cell growth and DNA damage may provide novel insights in understanding the oncogenic mechanism and improving the efficacy of DNA damage therapeutic agents. Here, we performed a high-content RNAi screening targeting 52 DDR-related E3 ligases in HCC and found that ring finger protein 4 (RNF4) was essential for HCC growth. RNF4 was highly expressed in HCC tissues, and the expression levels of RNF4 were associated with poor outcomes. RNF4 silencing significantly suppressed the cell growth, and subsequently induced G2/M arrest and apoptosis of HCC cells in vitro; RNF4 silencing also demonstrated the tumor-suppressive efficacy on HCC in vivo. Moreover, RNF4 silencing increased DNA damage, and rendered HCC cells more sensitive to DNA damage drugs and radiation. We found RNF4 functionally interacts with p62, and mechanistic analyses indicated that RNF4 silencing triggered the nuclear enrichment of p62. Moreover, the p62 nuclear targeting was required for increased DNA damage and growth suppression mediated by RNF4 silencing. Thus, our findings suggest RNF4 is essential for HCC proliferation via preventing nuclear translocation of p62. RNF4 silencing promotes DNA damage and may serve as a novel strategy to suppress cell growth and increase the sensitivity of DNA damage therapeutic agents in HCC.

[Dihydromyricetin reverses Herceptin resistance by up-regulating miR-98-5p and inhibiting IGF1R/HER2 dimer formation in SKBR3 cells]

OBJECTIVE

To explore the effect of dihydromyricetin on the expression of miR-98-5p and its mechanism in the development of Herceptin resistance in SKBR3 cells.

METHODS

The expression of IGF2 and miR-98-5p and their interaction relationship were analyzed by bioinformatics analysis through TargetScan online databases. SKBR3 cells and drug-resistant SKBR3-R cells were cultured in cell experiments. Xenograft tumor mice were constructed by SKBR3 and SKBR3-R cells. Proteins were detected by western blotting and immunohistochemistry. Transfected cells were constructed by shRNA lentivirus vectors. RT-QPCR was used to detect RNA. Cell proliferation was detected by MTS method. Cell jnvasion was detected by Transwell assay. Luciferase reporting assays were used to verify RNA interactions. IGF-1R/HER2 heterodimer was determined by immunocoprecipitation.

RESULTS

The expression of IGF2, p-IGF1R, p-Akt and p-S6K in SKBR3-R cells were significantly higher than those in SKBR3 cells, while the expression of PTEN protein was lower in SKBR3-R cells (P < 0.05). IGF1R/HER2 heterodimer in SKBR3-R cells was significantly increased (P < 0.01).The expression of IGF2 and invasion ability were significantly reduced while transfected with miR-98-5p in SKBR3-R cells (P < 0.05), but the IGF2 mRNA were no difference in both cells (P > 0.05). The expression of miR-98-5p was up-regulated and IGF2 was decreased in drug-resistant xenograft tumor mice after feeding with dihydromyricetin, and the tumor became more sensitivity to Herceptin (P < 0.05).

CONCLUSION

Dihydromyricetin could induce the expression of miR-98-5p, which binds to IGF2 mRNA to reduce IGF2 expression, inhibit the IGF-1R/HER2 formation, thereby reversing cell resistance to Herceptin in SKBR3-R cells.

Chondrocyte Adipogenic Differentiation in Softening Osteoarthritic Cartilage

A chondrocyte-to-osteoblast lineage continuum exists in the growth plate. Adipogenic differentiation of chondrocytes in vivo should be investigated. Here, unilateral anterior crossbite (UAC), which can induce osteoarthritic lesions in the temporomandibular joint (TMJ), was applied to 6-wk-old C57BL/6 mice. Matrix loss in TMJ cartilage was obvious, as demonstrated by safranin O staining, and the condylar cartilage elastic modulus values, detected by using atomic force microscopy (AFM), were reduced, indicating cartilage softening that might be linked with loss of the highly charged proteoglycan. By crossing the Rosa26/tdTomato (TdT) mice with Sox9;Cre^ERT2 mice or with Col10;Cre^ERT2 mice, we obtained the Sox9-TdT and Col10-TdT strains, respectively, in which the Sox9- or Col10-expressing cells, accordingly, were labeled by TdT. A few TdT-labeled cells in both strains expressed AdipoQ or DMP-1. The Sox9-TdT⁺AdipoQ⁺ cells were primarily located in the deep zone cartilage and then in the whole cartilage. Col10-TdT⁺AdipoQ⁺ cells, Sox9-TdT⁺DMP-1⁺ cells, and Col10-TdT⁺DMP-1⁺ cells were located in the deep zone region. UAC promoted AdipoQ and DMP-1 expression in cartilage. The percentages of Sox9-TdT⁺AdipoQ⁺ and Col10-TdT⁺AdipoQ⁺ cells to Sox9-TdT⁺ and Col10-TdT⁺ cells, respectively, were increased (both P < 0.05), implying that more chondrocytes were undergoing adipogenic differentiation in the UAC group, the cartilage of which was softened. The percentages of Sox9-TdT⁺DMP-1⁺ and Col10-TdT⁺DMP-1⁺ cells to Sox9-TdT⁺ cells and Col10-TdT⁺ cells, respectively, were increased (both P < 0.05), consistent with our report that UAC enhanced deep zone cartilage calcification, causing stiffening of the deep zone cartilage. Our present data demonstrated that TMJ chondrocyte descendants can become adipogenic in vivo in addition to becoming osteogenic. This potential was promoted in osteoarthritic cartilage, in which deep zone cartilage calcification-associated cartilage stiffening and proteoglycan loss-associated cartilage softening were both stimulated.

Pro- and Anti- Effects of Immunoglobulin A- Producing B Cell in Tumors and Its Triggers

B cells are well known as key mediators of humoral immune responses via the production of antibodies. Immunoglobulin A (IgA) is the most abundantly produced antibody isotype and provides the first line of immune protection at mucosal surfaces. However, IgA has long been a divisive molecule with respect to tumor progression. IgA exerts anti- or pro-tumor effect in different tumor types. In this review, we summarize emerging evidence regarding the production and effects of IgA and IgA⁺ cells in the tumor microenvironment (TME). Moreover, we discuss that the TME cytokines, host diet, microbiome, and metabolites play a pivotal role in controlling the class-switch recombination (CSR) of IgA. The analysis of intratumoral Ig repertoires and determination of metabolites that influence CSR may help establish novel therapeutic targets for the treatment of cancers.

Intestinal CD11b+ B Cells Ameliorate Colitis by Secreting Immunoglobulin A

The intestinal mucosal immune environment requires multiple immune cells to maintain homeostasis. Although intestinal B cells are among the most important immune cells, little is known about the mechanism that they employ to regulate immune homeostasis. In this study, we found that CD11b⁺ B cells significantly accumulated in the gut lamina propria and Peyer's patches in dextran sulfate sodium-induced colitis mouse models and patients with ulcerative colitis. Adoptive transfer of CD11b⁺ B cells, but not CD11b^-/- B cells, effectively ameliorated colitis and exhibited therapeutic effects. Furthermore, CD11b⁺ B cells were found to produce higher levels of IgA than CD11b^- B cells. CD11b deficiency in B cells dampened IgA production, resulting in the loss of their ability to ameliorate colitis. Mechanistically, CD11b⁺ B cells expressed abundant TGF-β and TGF-β receptor II, as well as highly activate phosphorylated Smad2/3 signaling pathway, consequently promoting the class switch to IgA. Collectively, our findings demonstrate that CD11b⁺ B cells are essential intestinal suppressive immune cells and the primary source of intestinal IgA, which plays an indispensable role in maintaining intestinal homeostasis.

A highly conserved host lipase deacylates oxidized phospholipids and ameliorates acute lung injury in mice

Oxidized phospholipids have diverse biological activities, many of which can be pathological, yet how they are inactivated in vivo is not fully understood. Here, we present evidence that a highly conserved host lipase, acyloxyacyl hydrolase (AOAH), can play a significant role in reducing the pro-inflammatory activities of two prominent products of phospholipid oxidation, 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine. AOAH removed the sn-2 and sn-1 acyl chains from both lipids and reduced their ability to induce macrophage inflammasome activation and cell death in vitro and acute lung injury in mice. In addition to transforming Gram-negative bacterial lipopolysaccharide from stimulus to inhibitor, its most studied activity, AOAH can inactivate these important danger-associated molecular pattern molecules and reduce tissue inflammation and injury.

A host lipase prevents lipopolysaccharide-induced foam cell formation

Although microbe-associated molecular pattern (MAMP) molecules can promote cholesterol accumulation in macrophages, the existence of a host-derived MAMP inactivation mechanism that prevents foam cell formation has not been described. Here, we tested the ability of acyloxyacyl hydrolase (AOAH), the host lipase that inactivates gram-negative bacterial lipopolysaccharides (LPSs), to prevent foam cell formation in mice. Following exposure to small intraperitoneal dose(s) of LPSs, Aoah -/- macrophages produced more low-density lipoprotein receptor and less apolipoprotein E and accumulated more cholesterol than did Aoah +/+ macrophages. The Aoah -/- macrophages also maintained several pro-inflammatory features. Using a perivascular collar placement model, we found that Aoah -/- mice developed more carotid artery foam cells than did Aoah +/+ mice after they had been fed a high fat, high cholesterol diet, and received small doses of LPSs. This is the first demonstration that an enzyme that inactivates a stimulatory MAMP in vivo can reduce cholesterol accumulation and inflammation in arterial macrophages.

Mineral deposition intervention through reduction of phosphorus intake suppresses osteoarthritic lesions in temporomandibular joint

OBJECTIVE

To explore the suppressing impact of low phosphorus intake on osteoarthritic temporomandibular joint and the possible mechanisms of nuclear acid injury in the insulted chondrocytes.

DESIGN

Chondrocytes were loaded with fluid flow shear stress (FFSS) with or without low phosphorus medium. Seventy-two mice (sampled at 3-, 7- and 11-wk, n = 6) and forty-eight rats (sampled at 12-wks for different testing purpose, n = 6) were applied with unilateral anterior crossbite (UAC) with or without low phosphorus diet. In the FFSS model, the Ca and P content, molecules related to nucleic acid degradation and the mineral-producing responses in chondrocytes were detected. The effect of culture dish stiffness on chondrocytes osteogenic differentiation was measured. In the UAC model, the content of Ca and P in serum were tested. The condylar cartilage ossification and stiffness were detected using micro-CT, scanning electron microscope and atomic force microscope.

RESULTS

FFSS induced nucleic acid degradation, Pi accumulation and mineral-producing responses in the cultured chondrocytes, all were alleviated by low P medium. Stiffer dish bottoms promoted the osteogenic differentiation of the cultured chondrocytes. UAC stimulated cartilage degeneration and chondrocytes nucleic acid damage, increased PARP 1 and serum P content, and enhanced ossification and stiffening of the cartilage, all were suppressed by low phosphorus diet (all, P < 0.05).

CONCLUSION

Nucleic acid damage takes a role in phosphorus production in osteoarthritic cartilage, contributing to the enhanced mineralization and stiffness of the cartilage that in turn promotes cartilage degradation, which can be alleviated by low phosphorus intake.

[An optimized protocol of meniscus cell extraction for single-cell RNA sequencing]

OBJECTIVE

To optimize the protocol of meniscus cell extraction to enhance the efficiency of cell suspension preparation and maintain a high cell viability for single-cell RNA sequencing.

METHODS

We compared the efficiency of the routine cell extraction methods (short-time digestion and long-time digestion) and the optimized protocol for obtaining meniscus cell suspensions by evaluating the cell number obtained and the cell viability. Single-cell RNA sequencing datasets were analyzed to evaluate the stability of the cell suspension prepared using the optimized protocol. The reliability of the optimized protocol was assessed by comparing the single-cell RNA sequencing dataset obtained by the optimized protocol with published single-cell RNA sequencing datasets of the meniscus.

RESULTS

The optimized protocol harvested a greater number of cells (over 1×10⁵) than the routine protocols. The cell suspension prepared with the optimized protocol showed a cell viability higher than 80%, the highest among the 3 methods. Analysis of single-cell RNA sequencing datasets showed that the ratio of the mitochondrial genes was below 20% in over 80% of the cells. CD34⁺ cells, MCAM⁺ cells and COL1A1⁺ cells were identified in the datasets. Comparison with the publish datasets showed that the optimized protocol was capable of harvesting COL3A1⁺, COL1A1⁺, MYLK⁺, BMP2⁺, CD93⁺ and CDK1⁺ cells.

CONCLUSION

Single-cell suspension prepared from the meniscus can be stably obtained using the optimized protocol for single-cell RNA sequencing using the 10× Genomics platform.

Extracellular Acidity Reprograms Macrophage Metabolism and Innate Responsiveness

Although organ hypofunction and immunosuppression are life-threatening features of severe sepsis, the hypofunctioning organs and immune cells usually regain normal functionality if patients survive. Because tissue interstitial fluid can become acidic during the septic response, we tested the hypothesis that low extracellular pH (pHe) can induce reversible metabolic and functional changes in peritoneal macrophages from C57BL/6J mice. When compared with macrophages cultured at normal pHe, macrophages living in an acidic medium used less glucose and exogenous fatty acid to produce ATP. Lactate, glutamine, and de novo-synthesized fatty acids supported ATP production by mitochondria that gained greater mass, maximal oxygen consumption rate, and spare respiratory capacity. The cells transitioned to an M2-like state, with altered immune responses to LPS and slightly decreased phagocytic ability, yet they regained basal energy production, normal mitochondrial function, and proinflammatory responsiveness when neutral pHe was restored. Low pHe induces changes that support macrophage survival while rendering the cells less proinflammatory (more "tolerant") and less able to phagocytose bacteria. Macrophage responses to low interstitial pH may contribute to the reversible organ hypofunction and immunoparalysis noted in many patients with sepsis.

MicroRNAs: immune modulators in cancer immunotherapy

MicroRNA (miRNA) is a class of endogenous small non-coding RNA of 18–25 nucleotides and plays regulatory roles in both physiological and pathological processes. Emerging evidence support that miRNAs function as immune modulators in tumors. MiRNAs as tumor suppressors or oncogenes are also found to be able to modulate anti-tumor immunity or link the crosstalk between tumor cells and immune cells surrounding. Based on the specific regulating function, miRNAs can be used as predictive, prognostic biomarkers, and therapeutic targets in immunotherapy. Here, we review new findings about the role of miRNAs in modulating immune responses, as well as discuss mechanisms underlying their dysregulation, and their clinical potentials as indicators of tumor prognosis or to sensitize cancer immunotherapy.

Gut microbiota shape B cell in health and disease settings

Recent accumulating evidence supports the hypothesis that the intricate interaction between gut microbiota and the immune system profoundly affects health and disease in humans and mice. In this context, microbiota plays an important role in educating and shaping the host immune system which, in turn, regulates gut microbiota diversity and function to maintain homeostasis. Studies have demonstrated that intestinal microbiota participates in shaping B cells in health and disease settings. Herein, we review the recent progress in understanding how microbiota regulates B-cell development, focusing on early-life B-cell repertoire generation in GALT and how microbial products, including microbial antigens and metabolites, affect B-cell activation and differentiation to ultimately regulate B-cell function. We also discuss the interaction between gut microbiota and B cells under pathogenic conditions and highlight new approaches that can be applied to treat various diseases.

Optimization of T Cell Redirecting Strategies: Obtaining Inspirations From Natural Process of T Cell Activation

Chimeric antigen receptors (CARs) or bispecific antibodies (bsAbs) redirected T cell against tumors is one of the most promising immunotherapy approaches. However, insufficient clinical outcomes are still observed in treatments of both solid and non-solid tumors. Limited efficacy and poor persistence are two major challenges in redirected T cell therapies. The immunological synapse (IS) is a vital component during the T cell response, which largely determines the clinical outcomes of T cell-based therapies. Here, we review the structural and signaling characteristics of IS formed by natural T cells and redirected T cells. Furthermore, inspired by the elaborate natural T cell receptor-mediated IS, we provide potential strategies for higher efficacy and longer persistence of redirected T cells.

Safety and clinical efficacy of BCMA CAR-T-cell therapy in multiple myeloma

Background

B-cell maturation antigen (BCMA)-targeted chimeric antigen receptor (CAR)-T-cell therapy is an emerging treatment option for multiple myeloma. The aim of this systematic review and meta-analysis was to determine its safety and clinical activity and to identify factors influencing these outcomes.

Methods

We performed a database search using the terms “BCMA,” “CAR,” and “multiple myeloma” for clinical studies published between 01/01/2015 and 01/01/2020. The methodology is further detailed in PROSPERO (CRD42020125332).

Results

Twenty-three different CAR-T-cell products have been used so far in 640 patients. Cytokine release syndrome was observed in 80.3% (69.0–88.2); 10.5% (6.8–16.0) had neurotoxicity. A higher neurotoxicity rate was reported in studies that included more heavily pretreated patients: 19.1% (13.3–26.7; I² = 45%) versus 2.8% (1.3–6.1; I² = 0%) (p < 0.0001). The pooled overall response rate was 80.5% (73.5–85.9); complete responses (CR) were observed in 44.8% (35.3–54.6). A pooled CR rate of 71.9% (62.8–79.6; I² = 0%) was noted in studies using alpaca/llama-based constructs, whereas it was only 18.0% (6.5–41.1; I² = 67%) in studies that used retroviral vectors for CAR transduction. Median progression-free survival (PFS) was 12.2 (11.4–17.4) months, which compared favorably to the expected PFS of 1.9 (1.5–3.7) months (HR 0.14; p < 0.0001).

Conclusions

Although considerable toxicity was observed, BCMA-targeted CAR-T-cell therapy is highly efficacious even in advanced multiple myeloma. Subgroup analysis confirmed the anticipated inter-study heterogeneity and identified potential factors contributing to safety and efficacy. The results of this meta-analysis may assist the future design of CAR-T-cell studies and lead to optimized BCMA CAR-T-cell products.

β-arrestin 2 quenches TLR signaling to facilitate the immune evasion of EPEC

The protein translocated intimin receptor (Tir) from enteropathogenic Escherichia coli shares sequence similarity with the host cellular immunoreceptor tyrosine-based inhibition motifs (ITIMs). The ITIMs of Tir are required for Tir-mediated immune inhibition and evasion of host immune responses. However, the underlying molecular mechanism by which Tir regulates immune inhibition remains unclear. Here we demonstrated that β-arrestin 2, which is involved in the G-protein-coupled receptor (GPCR) signal pathway, interacted with Tir in an ITIM-dependent manner. For the molecular mechanism, we found that β-arrestin 2 enhanced the recruitment of SHP-1 to Tir. The recruited SHP-1 inhibited K63-linked ubiquitination of TRAF6 by dephosphorylating TRAF6 at Tyr288, and inhibited K63-linked ubiquitination and phosphorylation of TAK1 by dephosphorylating TAK1 at Tyr206, which cut off the downstream signal transduction and subsequent cytokine production. Moreover, the inhibitory effect of Tir on immune responses was diminished in β-arrestin 2-deficient mice and macrophages. These findings suggest that β-arrestin 2 is a key regulator in Tir-mediated immune evasion, which could serve as a new therapeutic target for bacterial infectious diseases.

HSP70, a Novel Regulatory Molecule in B Cell-Mediated Suppression of Autoimmune Diseases

B cells have recently emerged as playing regulatory role in autoimmune diseases. We have previously demonstrated that human peripheral blood CD19⁺CD24^hiCD27⁺ B cells have regulatory function both in healthy donors and in patients with autoimmune disease. However, the mechanism of this regulation is still not fully understood. In this study, microarrays were utilized to compare gene expression of CD19⁺CD24^hiCD27⁺ B cells (regulatory B cells, Bregs) with CD19⁺CD24^loCD27^- B cells (non-Bregs) in human peripheral blood. We found that heat shock protein 70 (HSP70) expression was significantly upregulated in Bregs. In vitro studies explored that HSP70 inhibition impaired the regulatory function of peripheral blood Bregs. In mouse models of autoimmune disease, using HSP70-deficient mice or HSP70 inhibitors, Bregs suppressed effector cells and rescued disease-associated phenotypes that were dependent on HSP70. Mechanistically, Bregs secreted HSP70, directly suppressing effector cells, such as T effect cells. These findings reveal that HSP70 is a novel factor that modulates Breg function and suggest that enhancing Breg-mediated production of HSP70 could be a viable therapy for autoimmune disease.

Epigenetic induction of tumor stemness via the lipopolysaccharide-TET3-HOXB2 signaling axis in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell cancer (ESCC) is one kind of frequent digestive tumor. The inflammatory environment plays an important role in the tumorigenesis and development of ESCC. Cancer stem cells are a small group of tumor cells with stem cell characteristics, which can potentially hinder the tumor management and treatment.

METHODS

ELISA was performed to detect the lipopolysaccharide concentration in cancer tissues. qPCR, Western blot, FACS, Immunohistochemistry, Immunofluorescence and Dot blot were applied to detect target genes expression. CCK-8, Colony-formation, Transwell, Sphere and Xenograft were conducted to investigate the function of cells, influenced by risk factors. The survival curve was drawn with the Kaplan-Meier product limit estimator. Nano-hmC-Seal-seq was utilized to detect the downstream target of TET3. ChIP-qPCR was adopted to demonstrate the transcriptional regulation of stem cell-associated genes by HOXB2.

RESULTS

Lipopolysaccharide concentration was significantly up-regulated in ESCC. High concentration of lipopolysaccharide stimulation induced the stemness of ESCC cells. TET3 expression was elevated with lipopolysaccharide stimulation via p38/ERK-MAPK pathway in ESCC and negatively correlated with patients' survival. TET3 induced the stemness of ESCC cells. Nano-hmC-Seal-seq showed that TET3 overexpression led to a significant increase in 5hmC levels of HOXB2 gene region, which was thus identified as the downstream target of TET3. The binding of HOXB2 to NANOG and cMYC was verified by ChIP-qPCR.

CONCLUSIONS

Lipopolysaccharide served as a tumor promotor in ESCC by inducing cancer cell stemness through the activation of a LPS-TET3-HOXB2 signaling axis, which might provide a novel therapeutic strategy for ESCC. Video Abstract.

Regulatory B Cells

B cells are typically characterized by their ability to produce antibodies, function as secondary antigen-present cells, and produce various immunoregulatory cytokines. The regulatory B (Breg)-cell population is now widely accepted as an important modulatory component of the immune system that suppresses inflammation. Recent studies indicate that Breg-cell populations are small under physiological conditions but expand substantially in both human patients and murine models of chronic inflammatory diseases, autoimmune diseases, infection, transplantation, and cancer. Almost all B-cell subsets can be induced to form Breg cells. In addition, there are unique Breg-cell subsets such as B10 and Tim-1⁺ B cells. Immunoregulatory function may be mediated by production of cytokines such as IL-10 and TGF-β and ensuing suppression of T cells, by direct cell-cell interactions, and (or) by altering the immune microenvironment. In this chapter, we describe in detail the discovery of Breg cells, their phenotypes, differentiation, function, contributions to disease, and therapeutic potential.

Mortality-Air Pollution Associations in Low-Exposure Environments (MAPLE): Phase 1

INTRODUCTION

Fine particulate matter (particulate matter ≤2.5 μm in aerodynamic diameter, or PM2.5) is associated with mortality, but the lower range of relevant concentrations is unknown. Novel satellite-derived estimates of outdoor PM2.5 concentrations were applied to several large population-based cohorts, and the shape of the relationship with nonaccidental mortality was characterized, with emphasis on the low concentrations (<12 μg/m3) observed throughout Canada.

METHODS

Annual satellite-derived estimates of outdoor PM2.5 concentrations were developed at 1-km2 spatial resolution across Canada for 2000-2016 and backcasted to 1981 using remote sensing, chemical transport models, and ground monitoring data. Targeted ground-based measurements were conducted to measure the relationship between columnar aerosol optical depth (AOD) and ground-level PM2.5. Both existing and targeted ground-based measurements were analyzed to develop improved exposure data sets for subsequent epidemiological analyses.

Residential histories derived from annual tax records were used to estimate PM2.5 exposures for subjects whose ages ranged from 25 to 90 years. About 8.5 million were from three Canadian Census Health and Environment Cohort (CanCHEC) analytic files and another 540,900 were Canadian Community Health Survey (CCHS) participants. Mortality was linked through the year 2016. Hazard ratios (HR) were estimated with Cox Proportional Hazard models using a 3-year moving average exposure with a 1-year lag, with the year of follow-up as the time axis. All models were stratified by 5-year age groups, sex, and immigrant status. Covariates were based on directed acyclical graphs (DAG), and included contextual variables (airshed, community size, neighborhood dependence, neighborhood deprivation, ethnic concentration, neighborhood instability, and urban form). A second model was examined including the DAG-based covariates as well as all subject-level risk factors (income, education, marital status, indigenous identity, employment status, occupational class, and visible minority status) available in each cohort. Additional subject-level behavioral covariates (fruit and vegetable consumption, leisure exercise frequency, alcohol consumption, smoking, and body mass index [BMI]) were included in the CCHS analysis.

Sensitivity analyses evaluated adjustment for covariates and gaseous copollutants (nitrogen dioxide [NO2] and ozone [O3]), as well as exposure time windows and spatial scales. Estimates were evaluated across strata of age, sex, and immigrant status. The shape of the PM2.5-mortality association was examined by first fitting restricted cubic splines (RCS) with a large number of knots and then fitting the shape-constrained health impact function (SCHIF) to the RCS predictions and their standard errors (SE). This method provides graphical results indicating the RCS predictions, as a nonparametric means of characterizing the concentration-response relationship in detail and the resulting mean SCHIF and accompanying uncertainty as a parametric summary.

Sensitivity analyses were conducted in the CCHS cohort to evaluate the potential influence of unmeasured covariates on air pollution risk estimates. Specifically, survival models with all available risk factors were fit and compared with models that omitted covariates not available in the CanCHEC cohorts. In addition, the PM2.5 risk estimate in the CanCHEC cohort was indirectly adjusted for multiple individual-level risk factors by estimating the association between PM2.5 and these covariates within the CCHS.

RESULTS

Satellite-derived PM2.5 estimates were low and highly correlated with ground monitors. HR estimates (per 10-μg/m3 increase in PM2.5) were similar for the 1991 (1.041, 95% confidence interval [CI]: 1.016-1.066) and 1996 (1.041, 1.024-1.059) CanCHEC cohorts with a larger estimate observed for the 2001 cohort (1.084, 1.060-1.108). The pooled cohort HR estimate was 1.053 (1.041-1.065). In the CCHS an analogous model indicated a HR of 1.13 (95% CI: 1.06-1.21), which was reduced slightly with the addition of behavioral covariates (1.11, 1.04-1.18). In each of the CanCHEC cohorts, the RCS increased rapidly over lower concentrations, slightly declining between the 25th and 75th percentiles and then increasing beyond the 75th percentile. The steepness of the increase in the RCS over lower concentrations diminished as the cohort start date increased. The SCHIFs displayed a supralinear association in each of the three CanCHEC cohorts and in the CCHS cohort.

In sensitivity analyses conducted with the 2001 CanCHEC, longer moving averages (1, 3, and 8 years) and smaller spatial scales (1 km2 vs. 10 km2) of exposure assignment resulted in larger associations between PM2.5 and mortality. In both the CCHS and CanCHEC analyses, the relationship between nonaccidental mortality and PM2.5 was attenuated when O3 or a weighted measure of oxidant gases was included in models. In the CCHS analysis, but not in CanCHEC, PM2.5 HRs were also attenuated by the inclusion of NO2. Application of the indirect adjustment and comparisons within the CCHS analysis suggests that missing data on behavioral risk factors for mortality had little impact on the magnitude of PM2.5-mortality associations. While immigrants displayed improved overall survival compared with those born in Canada, their sensitivity to PM2.5 was similar to or larger than that for nonimmigrants, with differences between immigrants and nonimmigrants decreasing in the more recent cohorts.

CONCLUSIONS

In several large population-based cohorts exposed to low levels of air pollution, consistent associations were observed between PM2.5 and nonaccidental mortality for concentrations as low as 5 μg/m3. This relationship was supralinear with no apparent threshold or sublinear association.

Reactive oxygen species: The signal regulator of B cell

Reactive oxygen species (ROS) are indispensable for determining the fate of immune cells in both physiological and pathogenic environments, thus stimulating the interest of immunologists and clinicians. B cells are essential in maintaining immune homeostasis, and studies have indicated that ROS affect the maturation, activation and differentiation of B cells by controlling the signaling molecules in various molecular pathways. In the present review, we aimed to summarize the biological properties of ROS and the mechanisms by which ROS regulate B cell signaling pathways. We propose that ROS and their mediated signal transduction can be a new approach for manipulating B cell immune functions.

Restoring T-helper 17 cell/regulatory T-cell balance and decreasing disease activity by rapamycin and all-trans retinoic acid in patients with systemic lupus erythematosus

OBJECTIVE

This study aimed to investigate the effect of rapamycin (RAPA) alone or in combination with all-trans retinoic acid (ATRA) on the T-helper 17 (Th17) cell/regulatory T-cell (Treg) balance in patients with systemic lupus erythematosus (SLE) and to evaluate the clinical efficacy.

METHODS

Seventy patients with SLE were enrolled. They were randomly and equally divided into RAPA and RAPA + ATRA groups. The number of Th17 and Treg cells was measured by flow cytometry before and after treatment for 6, 12 and 24 weeks. The SLE Disease Activity Index (SLEDAI) score and the prednisone dose before and after treatment were used to evaluate the efficacy between the two groups.

RESULTS

In both groups, at different time points after treatment, the number of Th17 cells (p = 0.003) and Th17/Treg ratio (p = 0.044) reduced, while the number of Treg cells (p = 0.574) tended to increase. The SLEDAI score and the dose of prednisone decreased significantly (p < 0.001). There was no significant difference in the number of Th17 cells (p = 0.089), Treg cells (p = 0.059), Th17/Treg ratio (p = 0.580), SLEDAI score (p = 0.127) and the dose of prednisone (p = 0.329) between the two groups.

CONCLUSION

Disease activity in SLE patients reduced with RAPA alone or in conjunction with ATRA, reducing glucocorticoid requirement. One of its mechanisms of action may be regulating the Th17/Treg cell balance, which provides a new model for the pathogenesis and potential treatment of SLE.

Augmenting the therapeutic efficacy of adenosine against pancreatic cancer by switching the Akt/p21-dependent senescence to apoptosis

Background

There are many reports of the anti-tumour effects of exogenous adenosine in gastrointestinal tumours. Gemcitabine, a first line agent for patients with poor performance status, and adenosine have structural similarities. For these reasons, it is worth exploring the therapeutic efficacy of adenosine and its underlying mechanism in pancreatic cancer.

Methods

Tumour volumes and survival periods were measured in a patient-derived xenograft (PDX) model of pancreatic cancer. The Akt-p21 signalling axis was blocked by p21 silencing or by the Akt inhibitor GSK690693. The combined effect of GSK690693 and adenosine was calculated by the Chou-Talalay equation and verified by measuring fluorescent areas in orthotopic models.

Findings

Among the PDX mice, the tumour volume in the adenosine treatment group was only 61% of that in the saline treatment group. Adenosine treatment in combination with the Akt inhibitor, GSK690693, or the silencing of p21 to interfere with the Akt-p21 axis can switch the senescence-to-apoptosis signal and alleviate drug resistance. A GSK690693-adenosine combination caused 37.4% further reduction of tumour fluorescent areas in orthotopic models compared with that observed in adenosine monotherapy.

Interpretation: Our data confirmed the therapeutic effect of adenosine on pancreatic cancer, and revealed the potential of Akt inhibitors as sensitization agents in this treatment.

Fund

The work is supported by grants from the National Natural Science Foundation of China to Dongqin Yang (81572336, 81770579) and Jie Liu (81630016, 81830080), and jointly by the Development Fund for Shanghai Talents (201660).

Chimeric Antigen Receptor-Modified T Cell Therapy in Multiple Myeloma: Beyond B Cell Maturation Antigen

Chimeric antigen receptor (CAR)-modified T cell therapy is a rapidly emerging immunotherapeutic approach that is revolutionizing cancer treatment. The impressive clinical results obtained with CAR-T cell therapy in patients with acute lymphoblastic leukemia and lymphoma have fueled the development of CAR-T cells targeting other malignancies, including multiple myeloma (MM). The field of CAR-T cell therapy for MM is still in its infancy, but remains promising. To date, most studies have been performed with B cell maturation antigen (BCMA)-targeted CARs, for which high response rates have been obtained in early-phase clinical trials. However, responses are usually temporary, and relapses have frequently been observed. One of the major reasons for relapse is the loss or downregulation of BCMA expression following CAR-T therapy. This has fostered a search for alternative target antigens that are expressed on the MM cell surface. In this review, we provide an overview of myeloma target antigens other than BCMA that are currently being evaluated in pre-clinical and clinical studies.