CD39 delineates chimeric antigen receptor regulatory T cell subsets with distinct cytotoxic & regulatory functions against human islets.

Human regulatory T cells (Treg) suppress other immune cells. Their dysfunction contributes to the pathophysiology of autoimmune diseases, including type 1 diabetes (T1D). Infusion of Tregs is being clinically evaluated as a novel way to prevent or treat T1D. Genetic modification of Tregs, most notably through the introduction of a chimeric antigen receptor (CAR) targeting Tregs to pancreatic islets, may improve their efficacy. We evaluated CAR targeting of human Tregs to monocytes, a human ß cell line and human islet ß cells in vitro. Targeting of HLA-A2-CAR (A2-CAR) bulk Tregs to HLA-A2+ cells resulted in dichotomous cytotoxic killing of human monocytes and islet ß cells. In exploring subsets and mechanisms that may explain this pattern, we found that CD39 expression segregated CAR Treg cytotoxicity. CAR Tregs from individuals with more CD39low/- Tregs and from individuals with genetic polymorphism associated with lower CD39 expression (rs10748643) had more cytotoxicity. Isolated CD39- CAR Tregs had elevated granzyme B expression and cytotoxicity compared to the CD39+ CAR Treg subset. Genetic overexpression of CD39 in CD39low CAR Tregs reduced their cytotoxicity. Importantly, ß cells upregulated protein surface expression of PD-L1 and PD-L2 in response to A2-CAR Tregs. Blockade of PD-L1/PD-L2 increased ß cell death in A2-CAR Treg co-cultures suggesting that the PD-1/PD-L1 pathway is important in protecting islet ß cells in the setting of CAR immunotherapy. In summary, introduction of CAR can enhance biological differences in subsets of Tregs. CD39+ Tregs represent a safer choice for CAR Treg therapies targeting tissues for tolerance induction.

Contribution and underlying mechanisms of CXCR4 overexpression in patients with systemic lupus erythematosus.

Aberrant expression of CXCR4 has been indicated to play a role in the pathogenesis of systemic lupus erythematosus (SLE), but the mechanism of CXCR4 dysregulation in SLE is unclear. This study is aimed to explore the clinical significance and possible mechanisms of abnormal CXCR4 expression on B cells from patients with untreated SLE. Expression of CXCR4 on peripheral B cells was determined by flow cytometry and western blotting. Freshly isolated B cells were cultured with exogenous interleukin 21(IL-21) in the presence or absence of CD40 ligand (CD40L) plus anti-IgM antibody (aIgM), and changes in CXCR4 expression were detected. Involvement of phosphatidylinositol 3 kinase (PI3K)/Akt and Janus kinase/Signal transducer and activator of transcription (JAK/STAT) signaling pathways was assessed by adding blocking agents Ly294002 and AG490. Since CD63 is reported to mediate endosomal recruitment of CXCR4 and BCL6 is capable of silencing CD63 gene transcription, we also measured BCL6 and CD63 gene transcription with real-time PCR. It was shown that CXCR4 expression on B cells was significantly upregulated in SLE patients, especially in those with lupus nephritis, and was positively correlated with SLE Disease Activity Index scores and negatively with the serum complement 3 levels (P<0.05). Downregulation of CXCR4 by IL-21 was intact. In contrast, a similar effect of aIgM plus CD40L in downregulating CXCR4 expression was defective in SLE patients but was restored by co-stimulation with IL-21 in vitro. Both Ly294002 and AG490 promoted downregulation of surface CXCR4 expression on B cells from SLE patients (P=0.078 and P=0.064). Furthermore, B cells from SLE patients exhibited diminished CD63 mRNA and enhanced BCL6 mRNA expression (both P<0.05). To sum up, CXCR4 was overexpressed on SLE B cells, positively correlating with disease activity and kidney involvement. Overactivation of the PI3K/Akt and JAK/STAT pathways as well as defective CD63 synthesis may contribute to CXCR4 dysregulation in SLE.

Defective PTEN regulation contributes to B cell hyperresponsiveness in systemic lupus erythematosus.

PTEN regulates normal signaling through the B cell receptor (BCR). In systemic lupus erythematosus (SLE), enhanced BCR signaling contributes to increased B cell activity, but the role of PTEN in human SLE has remained unclear. We performed fluorescence-activated cell sorting analysis in B cells from SLE patients and found that all SLE B cell subsets, except for memory B cells, showed decreased expression of PTEN compared with B cells from healthy controls. Moreover, the level of PTEN expression was inversely correlated with disease activity. We then explored the mechanisms governing PTEN regulation in SLE B cells. Notably, in normal but not SLE B cells, interleukin-21 (IL-21) induced PTEN expression and suppressed Akt phosphorylation induced by anti-immunoglobulin M and CD40L stimulation. However, this deficit was not primarily at the signaling or the transcriptional level, because IL-21-induced STAT3 (signal transducer and activator of transcription 3) phosphorylation was intact and IL-21 up-regulated PTEN mRNA in SLE B cells. Therefore, we examined the expression of candidate microRNAs (miRs) that could regulate PTEN: SLE B cells were found to express increased levels of miR-7, miR-21, and miR-22. These miRs down-regulated the expression of PTEN, and IL-21 stimulation increased the expression of miR-7 and miR-22 in both normal and SLE B cells. Indeed, a miR-7 antagomir corrected PTEN-related abnormalities in SLE B cells in a manner dependent on PTEN. Therefore, defective miR-7 regulation of PTEN contributes to B cell hyperresponsiveness in SLE and could be a new target of therapeutic intervention.

Incidence and predictive factors for malignancies with dermatomyositis: a cohort from southern China.

OBJECTIVES: We aimed to explore the incidence of malignancy in dermatomyositis and assess the potential risk factors of occurrence of malignancy in DM from southern China. METHODS: A retrospective cohort study of patients admitted in the 1st affiliated university hospital between 2003 and 2012 was performed. Demographic information, clinical symptoms, laboratory findings, medications were documented. The endpoint of the study was defined as occurrence of malignancy or death. RESULTS: For this approximately 10-year retrospective study, 60 out of 246 dermatomyositis patients developed malignancies with the overall incidence of 24.4%. Nasopharyngeal carcinoma (NPC) and ovarian carcinoma were the most common malignant disease, accounting for 35% (21/60) and 15% (9/60) of malignancies, respectively. Lung and colon were followed as the third most common carcinoma (5 out of 60, 8.3%). Among these 60 patients with malignancies, 39 (65.0%, 39/60) cases occurred within 1 year after DM diagnosis. Subsequently, malignancies were detected in 13 (21.7%, 13/60) patients during the second year and 8 (13.3%, 8/60) during the third year. One patient developed cancer at the 35th month after DM as the latest. The logistic regression multivariate analysis indicated that male gender [odds ratio (OR) = 3.76, 95% confidence interval (CI ) 1.86~7.61, p<0.01], dysphagia (OR= 2.21, 95%CI 1.10~4.48, p=0.03) and elevated erythrocyte sedimentation rate (ESR) (OR= 2.37, 95% CI 1.18~4.75, p=0.02) were risk factors for the occurrence of malignancies, while interstitial lung disease (ILD) acted as a protective factor (OR=0.13, 95%CI 0.06~0.28, p<0.01). CONCLUSIONS: It was necessary to carry out routine malignancy screening for Chinese DM patients due to its high incidence. Nasopharyngeal carcinoma and ovarian cancer were the most common malignant disease. The risk of malignancy was highest in the first year after DM diagnosis and reduced thereafter. Extensive work-ups for malignancy screening should be carried out at the first year. Male gender, dysphagia and elevated ESR were risk factors for occurrence of malignancy. The presence of ILD could diminish the risk of coexisting of malignancy.

The status of rheumatoid factor and anti-cyclic citrullinated peptide antibody are not associated with the effect of anti-TNFα agent treatment in patients with rheumatoid arthritis: a meta-analysis.

OBJECTIVES: This meta-analysis was conducted to investigate whether the status of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody are associated with the clinical response to anti-tumor necrosis factor (TNF) alpha treatment in rheumatoid arthritis (RA). METHODS: A systemic literature review was performed using the MEDLINE, SCOPUS, Cochrane Library, ISI Web of Knowledge, and Clinical Trials Register databases, and Hayden's criteria of quality assessment for prognostic studies were used to evaluate all of the studies. The correlation between the RF and anti-CCP antibody status with the treatment effect of anti-TNFα agents was analyzed separately using the Mantel Haenszel method. A fixed-effects model was used when there was no significant heterogeneity; otherwise, a random-effects model was applied. Publication bias was assessed using Egger's linear regression and a funnel plot. RESULTS: A total of 14 studies involving 5561 RA patients meeting the inclusion criteria were included. The overall analysis showed that the pooled relative risk for the predictive effects of the RF and anti-CCP antibody status on patient response to anti-TNFα agents was 0.98 (95% CI: 0.91-1.05, p=0.54) and 0.88 (95% CI: 0.76-1.03, p=0.11), respectively, with I(2) values of 43% (p=0.05) and 67% (p<0.01), respectively. Subgroup analyses of different anti-TNFα treatments (infliximab vs. etanercept vs. adalimumab vs. golimumab), response criteria (DAS28 vs. ACR20 vs. EULAR response), follow-up period (≥ 6 vs. <6 months), and ethnic group did not reveal a significant association for the status of RF and anti-CCP. CONCLUSIONS: Neither the RF nor anti-CCP antibody status in RA patients is associated with a clinical response to anti-TNFα treatment.