A high-density microfluidic bioreactor for the automated manufacturing of CAR T cells.

The manufacturing of autologous chimaeric antigen receptor (CAR) T cells largely relies either on fed-batch and manual processes that often lack environmental monitoring and control or on bioreactors that cannot be easily scaled out to meet patient demands. Here we show that human primary T cells can be activated, transduced and expanded to high densities in a 2 ml automated closed-system microfluidic bioreactor to produce viable anti-CD19 CAR T cells (specifically, more than 60 million CAR T cells from donor cells derived from patients with lymphoma and more than 200 million CAR T cells from healthy donors). The in vitro secretion of cytokines, the short-term cytotoxic activity and the long-term persistence and proliferation of the cell products, as well as their in vivo anti-leukaemic activity, were comparable to those of T cells produced in a gas-permeable well. The manufacturing-process intensification enabled by the miniaturized perfusable bioreactor may facilitate the analysis of the growth and metabolic states of CAR T cells during ex vivo culture, the high-throughput optimization of cell-manufacturing processes and the scale out of cell-therapy manufacturing.

Impact of weight loss on treatment interruption and unplanned hospital admission in head and neck cancer patients undergoing curative (chemo)-radiotherapy in Hong Kong.

PURPOSE: Malnutrition is highly prevalent in head and neck cancer (HNC) patients, with weight loss being one of the major nutritional indicators. The objective of this study was to investigate the impact of weight loss on treatment interruptions and unplanned hospital admissions in HNC patients undergoing radiotherapy (RT) with or without chemotherapy. METHODS: In this retrospective cohort study, consecutive HNC patients who started RT between January 2011 and December 2019 were included. Data from a total of 1086 subjects with 747 (68.8%) nasopharyngeal carcinomas (NPCs) and 31.2% (N=339) non-NPC patients were analysed. Body weight (BW) was measured before, during, and after RT treatment. Factors associated with ≥10% weight loss, treatment interruption, and unplanned admissions were analysed using multivariate logistic regression. RESULTS: The prevalence of ≥10% weight loss was 26.8% (N=288), with 32.7% (N=243) in NPC and 13.5% (N=45) in non-NPC patients. The prevalence of RT delay in patients with ≥10% vs. <10% weight loss was 6.2% vs. 7.0% (p=0.668) in NPC patients and 42.2% vs. 50.5% (p=0.300) in non-NPC patients. The prevalence of unplanned admissions in patients with ≥10% vs. <10% weight loss was 51.9% vs. 25.3% (p<0.001) in NPC patients and 68.9% vs. 27.0% (p<0.001) in non-NPC patients. CONCLUSION: In our study, ≥10% weight loss was found to be associated with a higher rate of unplanned admissions but not with RT delay or chemotherapy interruption. CLINICAL IMPLICATIONS: With the knowledge of the impact of weight loss on hospital admissions and the characteristics of patients with weight loss, nutritional intervention can be effectively focused on the stratification of patients for intensive nutritional support to reduce weight loss.

Ninety-Day Stroke or Transient Ischemic Attack Recurrence in Patients Prescribed Anticoagulation in the Emergency Department With Atrial Fibrillation and a New Transient Ischemic Attack or Minor Stroke.

Background For patients with atrial fibrillation seen in the emergency department (ED) following a transient ischemic attack (TIA) or minor stroke, the impact of initiating oral anticoagulation immediately rather than deferring the decision to outpatient follow-up is unknown. Methods and Results We conducted a planned secondary data analysis of a prospective cohort of 11 507 adults in 13 Canadian EDs between 2006 and 2018. Patients were eligible if they were aged 18 years or older, with a final diagnosis of TIA or minor stroke with previously documented or newly diagnosed atrial fibrillation. The primary outcome was subsequent stroke, recurrent TIA, or all-cause mortality within 90 days of the index TIA diagnosis. Secondary outcomes included stroke, recurrent TIA, or death and rates of major bleeding. Of 11 507 subjects with TIA/minor stroke, atrial fibrillation was identified in 11.2% (1286, mean age, 77.3 [SD 11.1] years, 52.4% male). Over half (699; 54.4%) were already taking anticoagulation, 89 (6.9%) were newly prescribed anticoagulation in the ED. By 90 days, 4.0% of the atrial fibrillation cohort had experienced a subsequent stroke, 6.5% subsequent TIA, and 2.6% died. Results of a multivariable logistic regression indicate no association between prescribed anticoagulation in the ED and these 90-day outcomes (composite odds ratio, 1.37 [95% CI, 0.74-2.52]). Major bleeding was found in 5 patients, none of whom were in the ED-initiated anticoagulation group. Conclusions Initiating oral anticoagulation in the ED following new TIA was not associated with lower recurrence rates of neurovascular events or all-cause mortality in patients with atrial fibrillation.

Prospective Validation of Computed Tomography to Identify Patients at High Risk for Stroke After Transient Ischemic Attack or Minor Stroke.

BACKGROUND: Computed tomography (CT) findings of acute and chronic ischemia are associated with subsequent stroke risk in patients with transient ischemic attack. We sought to validate these associations in a large prospective cohort of patients with transient ischemic attack or minor stroke. METHODS: This prospective cohort study enrolled emergency department patients from 13 hospitals with transient ischemic attack who had CT imaging. Primary outcome was stroke within 90 days. Secondary outcomes were stroke within 2 or 7 days. CT findings were abstracted from radiology reports and classified for the presence of acute ischemia, chronic ischemia, or microangiopathy. Multivariable logistic regression was used to test associations with primary and secondary end points. RESULTS: From 8670 prospectively enrolled patients between May 2010 and May 2017, 8382 had a CT within 24 hours. From this total population, 4547 (54%) patients had evidence of acute ischemia, chronic ischemia, or microangiopathy on CT, of whom 175 had a subsequent stroke within 90 days (3.8% subsequent stroke rate; adjusted odds ratio [aOR], 2.33 [95% CI, 1.62-3.36]). This was in comparison to those with CT imaging without ischemia. Findings associated with an increased risk of stroke at 90 days were isolated acute ischemia (6.0%; aOR, 2.42 [95% CI, 1.03-5.66]), acute ischemia with microangiopathy (10.7%; aOR, 3.34 [95% CI, 1.57-7.14]), chronic ischemia with microangiopathy (5.2%; aOR, 1.83 [95% CI, 1.34-2.50]), and acute ischemia with chronic ischemia and microangiopathy (10.9%; aOR, 3.49 [95% CI, 1.54-7.91]). Acute ischemia with chronic ischemia and microangiopathy were most strongly associated with subsequent stroke within 2 days (aOR, 4.36 [95% CI, 1.31-14.54]) and 7 days (aOR, 4.50 [95% CI, 1.73-11.69]). CONCLUSIONS: In patients with transient ischemic attack or minor stroke, CT evidence of acute ischemia with chronic ischemia or microangiopathy significantly increases the risk of subsequent stroke within 90 days of index visit. The combination of all 3 findings results in the greatest early risk.

External Validation of a Nomogram to Predict Survival and Benefit of Concurrent Chemoradiation for Stage II Nasopharyngeal Carcinoma.

A nomogram was recently published by Sun et al. to predict overall survival (OS) and the additional benefit of concurrent chemoradiation (CCRT) vs. radiotherapy (RT) alone, in stage II NPC treated with conventional RT. We aimed to assess the predictors of OS and to externally validate the nomogram in the IMRT era. We analyzed stage II NPC patients treated with definitive RT alone or CCRT between 2001 and 2011 under the territory-wide Hong Kong NPC Study Group 1301 study. Clinical parameters were studied using the Cox proportional hazards model to estimate OS. The nomogram by Sun et al. was applied with 1000 times bootstrap resampling to calculate the concordance index, and we compared the nomogram predicted and observed 5-year OS. There were 482 patients included. The 5-year OS was 89.0%. In the multivariable analysis, an age > 45 years was the only significant predictor of OS (HR, 1.98; 95%CI, 1.15-3.44). Other clinical parameters were insignificant, including the use of CCRT (HR, 0.99; 95%CI, 0.62-1.58). The nomogram yielded a concordance index of 0.55 (95% CI, 0.49-0.62) which lacked clinically meaningful discriminative power. The nomogram proposed by Sun et al. should be interpreted with caution when applied to stage II NPC patients in the IMRT era. The benefit of CCRT remained controversial.

Predictors of neurologists confirming or overturning emergency physicians' diagnosis of TIA or stroke.

BACKGROUND: Transient ischemic attack (TIA) and non-disabling stroke are common emergency department (ED) presentations. Currently, there are no prospective multicenter studies determining predictors of neurologists confirming a diagnosis of cerebral ischemia in patients discharged with a diagnosis of TIA or stroke. The objectives were to (1) calculate the concordance between emergency physicians and neurologists for the outcome of diagnosing TIA or stroke, and (2) identify characteristics associated with neurologists diagnosing a stroke mimic. METHODS: This was a planned sub-study of a prospective cohort study at 14 Canadian EDs enrolling patients diagnosed with TIA or non-disabling stroke from 2006 to 2017. Logistic regression was used to identify factors associated with neurologists' diagnosis of cerebral ischemia. Our primary outcome was the composite outcome of cerebral ischemia (TIA or non-disabling stroke) based on the neurologists' assessment. RESULTS: The diagnosis of cerebral ischemia was confirmed by neurologists in 5794 patients (55.4%). The most common identified stroke mimics were migraine (18%), peripheral vertigo (7%), syncope (4%), and seizure (3%). Over a third of patients (38.4%) ultimately had an undetermined aetiology for their symptoms. The strongest predictors of cerebral ischemia confirmation were infarct on CT (OR 1.83, 95% CI 1.65-2.02), advanced age (OR comparing 75th-25th percentiles 1.67, 1.55-1.80), language disturbance (OR 1.92, 1.75-2.10), and smoking (OR 1.67, 1.46-1.91). The strongest predictors of stroke mimics were syncope (OR 0.59, 0.48-0.72), vertigo (OR 0.52, 0.45-0.59), bilateral symptoms (OR 0.60, 0.50-0.72), and confusion (OR 0.50, 0.44-0.57). CONCLUSION: Physicians should have a high index of suspicion of cerebral ischemia in patients with advanced age, smoking history, language disturbance, or infarcts on CT. Physicians should discriminate in which patients to pursue stroke investigations on when deemed at minimal risk of cerebral ischemia, including those with isolated vertigo, syncope, or bilateral symptoms.

RéSUMé: CONTEXTE: L'accident ischémique transitoire (AIT) et l'accident vasculaire cérébral (AVC) non invalidant sont des présentations courantes dans les services d'urgence. Actuellement, il n'existe pas d'études prospectives multicentriques déterminant les facteurs prédictifs de la confirmation par les neurologues d'un diagnostic d'ischémie cérébrale chez les patients sortis de l'hôpital avec un diagnostic d'AIT ou d'AVC. Les objectifs étaient de (1) calculer la concordance entre les urgentistes et les neurologues pour le résultat du diagnostic de l'AIT ou de l'AVC, et (2) identifier les caractéristiques associées au diagnostic par les neurologues d'une imitation d'AVC. MéTHODES: Il s'agissait d'une sous-étude planifiée d'une étude de cohorte prospective dans 14 services d'urgence canadiens recrutant des patients diagnostiqués avec un AIT ou un AVC non invalidant de 2006 à 2017. Une régression logistique a été utilisée pour identifier les facteurs associés au diagnostic d'ischémie cérébrale par les neurologues. Notre résultat principal était le résultat composite de l'ischémie cérébrale (AIT ou accident vasculaire cérébral non invalidant) selon l'évaluation des neurologues. RéSULTATS: Le diagnostic d'ischémie cérébrale a été confirmé par des neurologues chez 5 794 patients (55,4 %). Les imitateurs d'AVC identifiés les plus courants étaient la migraine (18 %), le vertige périphérique (7 %), la syncope (4 %) et les convulsions (3 %). Plus d'un tiers des patients (38,4 %) avaient finalement une étiologie indéterminée pour leurs symptômes. Les prédicteurs les plus forts de la confirmation de l'ischémie cérébrale étaient l'infarctus au scanner (OR 1.83, IC 95 % 1.65­2.02), l'âge avancé (OR comparant les 75e et 25e percentiles 1.67, 1.55­1.80), les troubles du langage (OR 1.92, 1.75­2.10) et le tabagisme (OR 1.67, 1.46­1.91). Les prédicteurs les plus forts d'imitateurs d'AVC étaient la syncope (OR 0.59, 0.48­0.72), le vertige (OR 0.52, 0.45­0.59), les symptômes bilatéraux (OR 0.60, 0.50­0.72) et la confusion (OR 0.50, 0.44­0.57). CONCLUSION: Les médecins devraient avoir un indice élevé de suspicion d'ischémie cérébrale chez les patients ayant un âge avancé, des antécédents de tabagisme, des troubles du langage ou des infarctus au scanner. Les médecins doivent distinguer les patients sur lesquels poursuivre des investigations sur un AVC lorsqu'ils sont jugés à risque minimal d'ischémie cérébrale, y compris ceux présentant des vertiges isolés, une syncope ou des symptômes bilatéraux.

The use of ketamine in the management of refractory cancer pain in a palliative care unit.

BACKGROUND: Ketamine has been used as an adjuvant to opioid therapy for the management of refractory cancer pain but the current evidence is insufficient to draw any conclusions regarding its efficacy. We aimed to assess the response to ketamine in patients with refractory cancer pain treated in an oncology palliative care unit. METHODS: Patients with refractory cancer pain despite opioid dose escalation were selected for a trial of parenteral ketamine infusion according to a local protocol. The medical records of those patients treated between January 2004 and December 2018 were retrospectively reviewed. The primary endpoint of the study was a favorable response to ketamine, defined as a reduction in regular opioid dose with no increase in pain intensity or a reduction in pain intensity by ≥2 points on the numerical rating scale (NRS) with a stable regular opioid dose. The secondary endpoint was adverse events associated with ketamine. RESULTS: Among the 70 patients, mean pain score on NRS improved from 7.0 to 4.0 after ketamine (P<0.001). Forty-nine patients had a reduction of pain score by ≥2 points on NRS, 33 had ≥50% reduction in pain intensity. The median decrease in regular opioid dose was 25.5%, and the mean difference was -133.2 mg (P=0.002). A favorable response to ketamine was observed in 52 patients (74.3%). The use of more than one coanalgesic (odds ratio 3.451; 95% CI: 1.087-10.960; P=0.036) was associated with a favorable response to ketamine on multivariate analysis. Adverse events were mostly mild, with the commonest being drowsiness (45.7%), hypertension (34.3%) and nightmares (25.7%). Only five and three patients required temporary suspension and early termination of ketamine infusion respectively. CONCLUSIONS: These data demonstrated the efficacy and safety of ketamine in a population of patients with refractory cancer pain. The use of more than one coanalgesic was associated with a favorable response to ketamine. Further large and multicentered studies are warranted to confirm these data.

Patterns and infection outcomes of bacterial colonization in patients with indwelling abdominal drains for malignant ascites.

BACKGROUND: Indwelling abdominal drains for intermittent drainage is an effective treatment for refractory malignant ascites, bacterial colonization and subsequent drain-related infection is however a common concern. This study aimed to investigate the patterns of bacterial colonization and the subsequent infection outcomes in patients with indwelling abdominal drains. METHODS: All consecutive advanced cancer patients with newly inserted indwelling abdominal drains and who were under the service of the ascites clinic of our institution for intermittent drainage between January 2011 and March 2018 were screened for study eligibility. Patients with positive surveillance ascitic fluid culture without immediate drain-related infection were included in the final analysis. Clinical information during the drainage period was prospectively collected using standardized clinical assessment forms. These assessment forms and other medical records were retrospectively reviewed. RESULTS: Sixty nine patients developed bacterial colonization without immediate infection during the study period. The most common cancer diagnosis was hepatocellular carcinoma (HCC), which comprise 30.4% of the population. Central venous catheters (CVCs) were inserted in 76.8% of patients and pigtail drains in 23.2% as the indwelling abdominal drain. The median duration from drain insertion to the development of bacterial colonization was 18.0 days. Staphylococci, Diphtheroid bacilliand Enterococci were the most common types of bacteria isolated during colonization. Thirty patients (43.5%) developed drain-related infection subsequently and the median time from bacterial colonization to development of infection was 14.5 days. The incidence rate of drain-related infection after bacterial colonization was 1.78 per 100-catheter days and the 1-month infection-free survival was 54.4%. Five patients (7.2%) developed peritonitis and 4 of them died from the infection episode. Decrease in body mass index (BMI) (P=0.03), having 3 or more episodes of drainage in the ascites clinic before bacterial colonization (P=0.03), presence of Escherichia coli (P=0.04) and Bacillus species (P=0.04) in surveillance ascitic fluid culture were significantly correlating with infection outcomes in univariate analyses. HCC as cancer diagnosis (OR 8.85, 95% CI: 1.86-42.07, P=0.006) and decrease in body weight (OR 1.20, 95% CI: 1.02-1.42, P=0.03) were significant factors that correlated with infection outcomes in multivariate analysis. CONCLUSIONS: Bacterial colonization and subsequent progression into drain-related infection are common in patients on indwelling abdominal drains for malignant ascites. Staphylococci is the most common type of bacteria causing both colonization and subsequent drain-related infection. HCC and decrease in body weight are significant factors that correlate with infection outcomes after bacterial colonization.

Virotherapy-recruited PMN-MDSC infiltration of mesothelioma blocks antitumor CTL by IL-10-mediated dendritic cell suppression.

Antitumor cytotoxic T lymphocytes (CTLs) are essential for immune surveillance, yet the blockade of eliciting such CTLs during oncolytic virotherapy remains incompletely understood. Here, we show that oncolysis of mesothelioma by modified vaccinia Tiantan (MVTT) induces damage-associated molecular patterns exposure. Although MVTT leads to regression of established mesothelioma dose-dependently, antitumor CTLs are rarely induced. Mechanistically, MVTT virotherapy generates C-X-C chemokines that recruit CXCR2-expressing polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) into tumor microenvironment, where they suppress dendritic cells (DCs) by producing IL-10 and halt CTL responses. During the virotherapy, however, depletion of PMN-MDSCs but not of monocytic (M)-MDSCs results in the induction of potent antitumor CTLs that not only eradicate established mesothelioma but also prevent the second tumor challenge. Our findings suggest that vaccinia virotherapy may combine strategies that prevent the chemotactic recruitment of PMN-MDSCs, block their suppression on DCs or deplete PMN-MDSCs in order to induce potent CTLs for tumor eradication.

Randomized controlled trial of emergency department initiated smoking cessation counselling and referral to a community counselling service.

OBJECTIVE: Worldwide, tobacco smoke is still the leading cause of preventable morbidity and mortality. Many smokers develop chronic smoking-related conditions that require emergency department (ED) visits. However, best practices for ED smoking cessation counselling are still unclear. METHODS: A randomized controlled trial was conducted to determine whether an "ask, advise, and refer" approach increases 12-month, 30-day quit rates in the stable adult ED smoking population compared to usual care. Patients in the intervention group were referred to a community counselling service that offers a quitline, a text-based program, and a Web-based program. Longitudinal intention-to-treat analyses were performed. RESULTS: From November 2011 to March 2013, 1,295 patients were enrolled from one academic tertiary care ED. Six hundred thirty-five were allocated to usual care, and 660 were allocated to intervention. Follow-up data were available for 70% of all patients at 12 months. There was no statistically significant difference in 12-month, 30-day quit rates between the two groups. However, there was a trend towards higher 7-day quit attempts, 7-day quit rates, and 30-day quit rates at 3, 6, and 12 months in the intervention group. CONCLUSION: In this study, there was a trend towards increased smoking cessation following referral to a community counselling service. There was no statistically significant difference. However, if ED smoking cessation efforts were to provide even a small positive effect, such an intervention may have a significant public health impact given the extensive reach of emergency physicians.

Emergency Department-Initiated Tobacco Control: Update of a Systematic Review and Meta-Analysis of Randomized Controlled Trials.

INTRODUCTION: A 2012 systematic review and meta-analysis of randomized controlled trials on emergency department-initiated tobacco control (ETC) showed only short-term efficacy. The aim of this study was to update data through May 2015. METHODS: After registering the study protocol on the international prospective register of systematic reviews (PROSPERO) in May 2015, we searched 7 databases and the gray literature. Our outcome of interest was the point prevalence of tobacco-use abstinence at 1-month, 3-month, 6-month, or 12-month follow-up. We calculated the relative risk (RR) of tobacco-use abstinence after ETC at each follow-up time separately for each study and then pooled Mantel-Haenszel RRs by follow-up time. These results were pooled with results of the 7 studies included in the previous review. We calculated the effect of ETC on the combined point prevalence of tobacco-use abstinence across all follow-up times by using generalized linear mixed models. RESULTS: We retrieved 4 additional studies, one published as an abstract, comprising 1,392 participants overall. The 1-month follow-up point prevalence of tobacco-use abstinence after ETC resulted in an RR of 1.49 (95% confidence interval [CI], 1.08-2.05) across 3 studies; 3-month follow-up, an RR of 1.38 (95% CI, 1.12-1.71) across 9 studies; 6-month follow-up, an RR of 1.09 (95% CI, 0.84-1.41) across 6 studies; and 12-month follow-up, an RR of 1.26 (95% CI, 1.00-1.59) across 3 studies. The effect on the combined point prevalence of abstinence was an RR of 1.40 (95% CI, 1.06-1.86) (P = .02). CONCLUSION: ETC is effective in promoting continual tobacco-use abstinence up to 12 months after intervention. ETC may be a critically important public health strategy for engaging hard-to-reach smokers in tobacco-use cessation.

Prevalence of potential smoking-related conditions among tobacco users in the emergency department and their perception that their visit may be smoking-related.

OBJECTIVES: Patients who are tobacco users present to the emergency department (ED) with many medical conditions that are causally or potentially causally related to smoking. Previous studies have shown increased cessation rates for patients who accurately perceive that their ED visit is smoking-related. Our study goals were 1) to determine the prevalence of potential smoking-related conditions among tobacco users at a tertiary care academic ED, and 2) to determine which medical conditions are more or less likely to be perceived by patients as smoking-related. METHODS: We included adults≥19 years of age who reported smoking within 30 days of their ED visit, and were enrolled in a randomized controlled trial (ClinicalTrials.gov, NCT01454375) from December 1, 2011 to August 31, 2012. Patients were asked whether they perceived their ED visit to be related to smoking. ED discharge diagnoses were coded as smoking-related or not smoking-related based on the 2004 U.S. Surgeon General's Report. RESULTS: We included 893 patients (62% male; mean age=40±15), of which 120 (13%) had a visit for a potential smoking-related condition: 6 (5%) of neoplasm, 18 (15%) of cardiovascular disease, 67 (56%) of respiratory disease, 3 (3%) of reproductive complication, 7 (6%) of postoperative complication, 9 (8%) of dental disease, 9 (8%) of peptic ulcer disease, 0 (0%) of eye condition, and 1 (1%) of bony condition. Of the potential smoking-related conditions, 46 (38%) were perceived by patients to be possibly smoking-related: 61% of cardiovascular disease, 33% of neoplasm, 43% of respiratory disease, 22% of dental disease, 14% of postoperative complication, 11% of peptic ulcer disease, and 0% of the remaining conditions. CONCLUSION: In this study, 13% of all ED visits among smokers were for a potential smoking-related condition, of which 38% were perceived by patients to be smoking-related. Education to increase awareness of smoking-related conditions may increase cessation rates.

Choice of smoking cessation counselling via phone, text, or email in emergency department patients.

Globally, tobacco smoke is the leading cause of preventable deaths. Smoking cessation counselling services are widely available in Canada. In British Columbia, our government-funded smoking cessation service offers counselling via phone, text, or email. In this study, we sought to determine whether age, gender, or motivation to quit affect a patient's choice of service modality. We included all adults ≥ 18 years who had used tobacco within 30 days prior to their Emergency Department (ED) visit and who chose to receive phone, text, or email counselling services from November 2011-February 2013 at Vancouver General Hospital as part of a randomized-controlled trial (ClinicalTrials.gov, NCT0145437). A one-way ANOVA was used to compare the mean age of patients in each group. Chi-squared tests of independence were used to determine if gender or motivation to quit were associated with modality selection. In total, 368 patients were included. The average age was 41.7 years and 67% were female. In our study, 44% chose phone, 17% chose text, and 40% chose email services. The average age for patients preferring text services (mean = 33.6 years) was significantly lower than both the email (mean = 41.3 years) and phone (mean = 45.1 years) groups (p < 0.001). Gender and motivation to quit were not associated with service modality choice. Over 80% of ED smokers who accepted a referral to counselling services chose the phone or email modality. The lesser chosen text modality was more popular with younger patients. With further research, smoking cessation counselling services can refine their programs to meet the needs of the population they serve.

Antigen spreading-induced CD8+T cells confer protection against the lethal challenge of wild-type malignant mesothelioma by eliminating myeloid-derived suppressor cells.

A key focus in cancer immunotherapy is to investigate the mechanism of efficacious vaccine responses. Using HIV-1 GAG-p24 in a model PD1-based DNA vaccine, we recently reported that vaccine-elicited CD8+ T cells conferred complete prevention and therapeutic cure of AB1-GAG malignant mesothelioma in immunocompetent BALB/c mice. Here, we further investigated the efficacy and correlation of protection on the model vaccine-mediated antigen spreading against wild-type AB1 (WT-AB1) mesothelioma. We found that this vaccine was able to protect mice completely from three consecutive lethal challenges of AB1-GAG mesothelioma. Through antigen spreading these animals also developed tumor-specific cytotoxic CD8+ T cells, but neither CD4+ T cells nor antibodies, rejecting WT-AB1 mesothelioma. A majority of these protected mice (90%) were also completely protected against the lethal WT-AB1 challenge. Adoptive cell transfer experiments further demonstrated that antigen spreading-induced CD8+ T cells conferred efficacious therapeutic effects against established WT-AB1 mesothelioma and prevented the increase of exhausted PD-1+ and Tim-3+ CD8+ T cells. A significant inverse correlation was found between the frequency of functional PD1-Tim3- CD8+ T cells and that of MDSCs or tumor mass in vivo. Mechanistically, we found that WT-AB1 mesothelioma induced predominantly polymorphonuclear (PMN) MDSCs in vivo. In co-cultures with efficacious CD8+ T cells, a significant number of PMN-MDSCs underwent apoptosis in a dose-dependent way. Our findings indicate that efficacious CD8+ T cells capable of eliminating both tumor cells and MDSCs are likely necessary for fighting wild-type malignant mesothelioma.

Monoclonal antibodies specific to human Δ42PD1: A novel immunoregulator potentially involved in HIV-1 and tumor pathogenesis.

We recently reported the identification of Δ42PD1, a novel alternatively spliced isoform of human PD1 that induces the production of pro-inflammatory cytokines from human peripheral blood mononuclear cells and enhances HIV-specific CD8(+) T cell immunity in mice when engineered in a fusion DNA vaccine. The detailed functional study of Δ42PD1, however, has been hampered due to the lack of a specific monoclonal antibody (mAb). In this study, we generated 2 high-affinity mAbs, clones CH34 (IgG2b) and CH101 (IgG1), from Δ42PD1-immunized mice. They recognize distinct domains of Δ42PD1 as determined by a yeast surface-displaying assay and ELISA. Moreover, they recognize native Δ42PD1 specifically, but not PD1, on cell surfaces by both flow cytometry and immunohistochemical assays. Δ42PD1 appeared to be expressed constitutively on healthy human CD14(+) monocytes, but its level of expression was down-regulated significantly during chronic HIV-1 infection. Since the level of Δ42PD1 expression on CD14(+) monocytes was negatively correlated with the CD4 count of untreated patients in a cross-sectional study, Δ42PD1 may play a role in HIV-1 pathogenesis. Lastly, when examining Δ42PD1 expression in human esophageal squamous-cell carcinoma tissues, we found high-level expression of Δ42PD1 on a subset of tumor-infiltrating T cells. Our study, therefore, resulted in 2 Δ42PD1-specific mAbs that can be used to further investigate Δ42PD1, a novel immune regulatory protein implicated in HIV-1 and tumor pathogenesis as well as other immune diseases.

Vaccine-elicited CD8+ T cells cure mesothelioma by overcoming tumor-induced immunosuppressive environment.

Eradicating malignant tumors by vaccine-elicited host immunity remains a major medical challenge. To date, correlates of immune protection remain unknown for malignant mesothelioma. In this study, we demonstrated that antigen-specific CD8(+) T-cell immune response correlates with the elimination of malignant mesothelioma by a model PD-1-based DNA vaccine. Unlike the nonprotective tumor antigen WT1-based DNA vaccines, the model vaccine showed complete and long-lasting protection against lethal mesothelioma challenge in immunocompetent BALB/c mice. Furthermore, it remained highly immunogenic in tumor-bearing animals and led to therapeutic cure of preexisting mesothelioma. T-cell depletion and adoptive transfer experiments revealed that vaccine-elicited CD8(+) T cells conferred to the protective efficacy in a dose-dependent way. Also, these CD8(+) T cells functioned by releasing inflammatory IFNγ and TNFα in the vicinity of target cells as well as by initiating TRAIL-directed tumor cell apoptosis. Importantly, repeated DNA vaccinations, a major advantage over live-vectored vaccines with issues of preexisting immunity, achieve an active functional state, not only preventing the rise of exhausted PD-1(+) and Tim-3(+) CD8(+) T cells but also suppressing tumor-induced myeloid-derived suppressive cells and Treg cells, with the frequency of antigen-specific CD8(+) T cells inversely correlating with tumor mass. Our results provide new insights into quantitative and qualitative requirements of vaccine-elicited functional CD8(+) T cells in cancer prevention and immunotherapy.

The immunomodulatory and anticancer properties of propolis.

Propolis, a waxy substance produced by the honeybee, has been adopted as a form of folk medicine since ancient times. It has a wide spectrum of alleged applications including potential anti-infection and anticancer effects. Many of the therapeutic effects can be attributed to its immunomodulatory functions. The composition of propolis can vary according to the geographic locations from where the bees obtained the ingredients. Two main immunopotent chemicals have been identified as caffeic acid phenethyl ester (CAPE) and artepillin C. Propolis, CAPE, and artepillin C have been shown to exert summative immunosuppressive function on T lymphocyte subsets but paradoxically activate macrophage function. On the other hand, they also have potential antitumor properties by different postulated mechanisms such as suppressing cancer cells proliferation via its anti-inflammatory effects; decreasing the cancer stem cell populations; blocking specific oncogene signaling pathways; exerting antiangiogenic effects; and modulating the tumor microenvironment. The good bioavailability by the oral route and good historical safety profile makes propolis an ideal adjuvant agent for future immunomodulatory or anticancer regimens. However, standardized quality controls and good design clinical trials are essential before either propolis or its active ingredients can be adopted routinely in our future therapeutic armamentarium.

Genome-wide association study of hepatocellular carcinoma in Southern Chinese patients with chronic hepatitis B virus infection.

One of the most relevant risk factors for hepatocellular carcinoma (HCC) development is chronic hepatitis B virus (HBV) infection, but only a fraction of chronic HBV carriers develop HCC, indicating that complex interactions among viral, environmental and genetic factors lead to HCC in HBV-infected patients. So far, host genetic factors have incompletely been characterized. Therefore, we performed a genome-wide association (GWA) study in a Southern Chinese cohort consisting of 95 HBV-infected HCC patients (cases) and 97 HBV-infected patients without HCC (controls) using the Illumina Human610-Quad BeadChips. The top single nucleotide polymorphisms (SNPs) were then validated in an independent cohort of 500 cases and 728 controls. 4 SNPs (rs12682266, rs7821974, rs2275959, rs1573266) at chromosome 8p12 showed consistent association in both the GWA and replication phases (OR(combined) = 1.31-1.39; p(combined) = 2.71 × 10(-5)-5.19 × 10(-4); PAR(combined) = 26-31%). We found a 2.3-kb expressed sequence tag (EST) in the region using in-silico data mining and verified the existence of the full-length EST experimentally. The expression level of the EST was significantly reduced in human HCC tumors in comparison to the corresponding non-tumorous liver tissues (P<0.001). Results from sequence analysis and in-vitro protein translation study suggest that the transcript might function as a long non-coding RNA. In summary, our study suggests that variations at chromosome 8p12 may promote HCC in patients with HBV. Further functional studies of this region may help understand HBV-associated hepatocarcinogenesis.

Brazilian green propolis and its constituent, Artepillin C inhibits allogeneic activated human CD4 T cells expansion and activation.

ETHNOPHARMACOLOGICAL RELEVANCE: Propolis has long been used as a popular folk medicine by various ethnic groups due to its wide spectrum of alleged biological and pharmaceutical properties including anti-microbial, anti-cancer and anti-inflammatory functions. All these can be linked to the modulation of immune function. Therefore, it will be relevant for us to find out whether there is any novel compound that can account for such action and the mechanism involved. AIM OF THE STUDY: We investigated the immune modulating effect of Brazilian green propolis (PBrazil) and its constituent Artepillin C (Art-C) by using mixed leukocytes reaction. MATERIALS AND METHODS: The cytotoxic effect of Art-C on non-tumorigenic human liver cell line miHA and non-tumorigenic human kidney cell line HK-2 as well as human peripheral blood mononuclear cells (PBMCs) were measured by XTT cell proliferation assay. The effect of PBrazil and Art-C on T cell proliferation and activation were determined by using carboxyfluorescein succinimidyl ester (CFSE) and by CD25 expression, respectively. Cytokines including tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-γ), interleukins such as IL-2, IL-17 were measured by intracellular cytokine staining and IL-10 was measured by ELISA. The effect of PBrazil and Art-C on regulatory T cells (Treg) induction was determined by the Foxp3 expression. The apoptotic effect of these compounds on CFSE labeled alloreactive T cells was measured by using Annexin V. RESULTS: Using mixed leukocytes reaction we demonstrated for the first time that both Art-C and PBrazil significantly inhibited the alloreactive CD4 T cell proliferation, activation, and suppressed the expressions of IL-2, IFN-γ and IL-17 in these alloreactive CD4 T cells. The inhibitions of Art-C and PBrazil on CD4 T cells were not due to direct cytotoxic effect on PBMC or inducing regulatory T cells differentiation. Both Art-C and PBrazil were found to selectively induce apoptosis in proliferating T cells. The anti-proliferative effect of Art-C and PBrazil were reversible and were also applied to the activated T cells. CONCLUSIONS: In conclusion, our results indicated that Art-C and PBrazil can suppress alloreactive CD4 T cell responses in vitro, suggesting that Art-C could be used as a potential immunosuppressant, either solely or as adjunct agent in treating graft versus host disease.