Description: Hepatic injury undergoes significant increases in endocannabinoidsand infiltrations of macrophages, yet the concrete mechanisms of changes in endocannabinoids and the functions of macrophage-expressed cannabinoid receptors (CBs) are unclear. Biosynthetic and degradative enzymes of endocannabinoids revealed a significant change in human fibrotic liver. Meanwhile, we showed dynamic changes of these enzymes and CBs (CB1 and CB2) from 1 to 56 d in carbon tetrachloride–induced murine liver injury. Biosynthetic enzymes ( N -acylphosphatidyl-ethanolamine selective phospholipase D and diacylglycerol lipase-α) and CBs were markedly increased, whereas degradative enzymes (fatty acid amidohydrolase and monoacylglycerol lipase) were downregulated. Moreover, these enzymes intimately correlated with the fibrosis parameter [procollagen α1(III)]. Bone marrow–derived monocytes/macrophages (BMM) expressed CBs. Interestingly, CB1 but not CB2 mediated BMM migration through a Boyden chambers assay, and the effect depended on the G (α)i/o /RhoA/ROCK signaling pathway. ICR mice were lethally irradiated and received BM transplants from enhanced GFP transgenic mice. Four weeks later, mice of BM reconstruction were subjected to carbon tetrachloride–induced liver injury. In the chimeric murine model, we found that blockade of CB1 by administration of a CB1 antagonist inhibited the recruitment of BMM into injured liver using immunofluorescence staining and FACS, but it did not have effects on migration of T cells and dendritic cells without CB1 expression. Furthermore, activation of CB1 enhanced cytokine expression of BMM. In vivo, inhibition of CB1 attenuated the inflammatory cytokine level through real-time RT-PCR and cytometric bead array, ameliorating hepatic inflammation and fibrosis. In this study, we identify inactivation of BMM-expressed CB1 as a therapeutic strategy for reducing hepatic inflammation and fibrosis.

Description: Acute tubulointerstitial nephritis (ATIN) is a common cause of acute kidney injury with various origins. HLA-DQA1 , -DQB1 , and -DRB1 have been associated with development of tubulointerstitial nephritis and uveitis (TINU) syndrome in case reports and small case series, but information about HLA genetic susceptibility to drug hypersensitivity–related ATIN (D-ATIN) or other types of ATIN is limited. In this article, we genotyped 154 patients with ATIN of different causes and 200 healthy controls at HLA-DQA1 , -DQB1 , and - DRB1 loci. We found that there was no difference between patients with D-ATIN and TINU in the carrier’s frequency of HLA-DQA1 , -DQB1 , or -DRB1 . Patients with Sjogren’s syndrome–ATIN and IgG4-related ATIN presented a different pattern of tested HLA alleles. HLA-DQA1*0104 ( p value corrected by false discovery rate method [ Pc ] = 4.72 x 10 –22 , odds ratio [OR] = 13.81), -DQB1*0503 ( Pc = 1.95 x 10 –14 , OR = 9.51), and -DRB1*1405 ( Pc = 8.06 x 10 –19 , OR = 12.80) were significant risk alleles for the occurrence of D-ATIN and TINU. There were no significant associations between tested HLA alleles and ATIN induced by other causes. Patients with D-ATIN/TINU carrying HLA-DQA1*0104 / DQB1*0503 / DRB1*1405 had higher peak serum creatinine and more severe renal tubulointerstitial inflammatory impairment. They also had significantly higher levels of tubular HLA-DR and HLA-DQ expression, which were correlated with the numbers of interstitial CD4 + T lymphocytes ( r = 0.975, p 〈 0.001 and r = 0.832, p = 0.005, respectively) and monocytes/macrophages ( r = 0.721, p = 0.004 and r = 0.615, p = 0.02, respectively). In conclusion, patients with D-ATIN or TINU have genetic susceptibility in HLA - DQA1 , - DQB1 , and - DRB1 alleles. HLA-DQA1*0104/DQB1*0503/DRB1*1405 serves as a significant risk haplotype for development of D-ATIN and TINU, which might facilitate renal tubulointerstitial inflammation by enhancing Ag-presenting capacity of renal tubular cells.

Description: Ammonia levels are often elevated in patients with cirrhosis or tumors. Patients with these diseases are immunocompromised. In this study, we investigated the effects of ammonia on a member of the immune cell family, the dendritic cells (DCs). Our results demonstrated that ammonia diminished cell count, phagocytosis, and lymphocyte stimulation of DCs. Ammonia also induced DC swelling, excessive reactive oxygen species production, and mitochondrial damage, which may constitute the underlying mechanism of ammonia-induced DC dysfunction. In ammonium chloride (NH 4 Cl)–loaded mice, DCs exhibited lowered phagocytosis and a weakened immune response to the chicken OVA vaccine. DCs from patients with cirrhosis or ammonia-treated healthy human blood both exhibited diminished phagocytosis. Moreover, tumor cell conditioned medium drove DCs into dysfunction, which could be reversed by ammonia elimination. In a murine colon carcinoma model, we found that ammonia could regulate tumor growth involving DCs and their related immune response. These findings reveal that ammonia could drive DCs into dysfunction, which contributes to the immunocompromised state of patients with cirrhosis or tumors.

Description: More than 350 million people are chronically infected with hepatitis B virus, and dysfunctional T cell responses contribute to persistent viral infection and immunopathogenesis in chronic hepatitis B (CHB). However, the underlying mechanisms of T cell hyporesponsiveness remain largely undefined. Given the important role of microRNA-146a (miR-146a) in diverse aspects of lymphocyte function, we investigated the potential role and mechanism of miR-146a in regulating T cell immune responses in CHB. We found that miR-146a expression in T cells is significantly upregulated in CHB compared with healthy controls, and miR-146a levels were correlated with serum alanine aminotransaminase levels. Both inflammatory cytokines and viral factors led to miR-146a upregulation in T cells. Stat1 was identified as a miR-146a target that is involved in antiviral cytokine production and the cytotoxicity of CD4 + and CD8 + T cells. In vitro blockage of miR-146a in T cells in CHB greatly enhanced virus-specific T cell activity. Therefore, our work demonstrates that miR-146a upregulation in CHB causes impaired T cell function, which may contribute to immune defects and immunopathogenesis during chronic viral infection.

Description: Several recent studies have demonstrated that innate immune NK cells exhibit memory-like properties with enhanced nonspecific and specific recall responses. Cytokine activation alone of murine NK cells induces the differentiation of memory-like cells that are more likely to produce IFN-, a key NK cell cytokine important for activation of the immune response. Using an adoptive cotransfer system, we first show that cytokine-induced memory-like responses are NK intrinsic. However, engraftment of donor NK cells in NK-competent hosts is poor because of homeostatic control mechanisms. Therefore, we used alymphoid Rag- and common -chain–deficient mice as recipients and observed homeostatic expansion of cotransferred cytokine-activated and control donor NK cells. Despite proliferation of all cells, NK cells derived from those cells originally activated by cytokines retained an intrinsic enhanced capacity to produce IFN- when restimulated in vitro with cytokines or target cells. These NK cell memory-like responses persisted for at least 4 wk in alymphoid hosts and 12 wk in NK-competent hosts. These findings indicate that memory-like NK cells can readily self-renew and maintain enhanced function in a lymphopenic host for at least a month.

Description: Purpose: The early detection of colorectal cancer (CRC) is crucial for successful treatment and patient survival. However, compliance with current screening methods remains poor. This study aimed to identify an accurate blood-based gene expression signature for CRC detection. Experimental Design: Gene expression in peripheral blood samples from 216 patients with CRC tumors and 187 controls was investigated in the study. We first conducted a microarray analysis to select candidate genes that were significantly differentially expressed between patients with cancer and controls. A quantitative reverse transcription PCR assay was then used to evaluate the expression of selected genes. A gene expression signature was identified using a training set ( n = 200) and then validated using an independent test set ( n = 160). Results: We identified an 18-gene signature that discriminated the patients with CRC from controls with 92% accuracy, 91% sensitivity, and 92% specificity. The signature performance was further validated in the independent test set with 86% accuracy, 84% sensitivity, and 88% specificity. The area under the receiver operating characteristics curve was 0.94. The signature was shown to be enriched in genes related to immune functions. Conclusions: This study identified an 18-gene signature that accurately discriminated patients with CRC from controls in peripheral blood samples. Our results prompt the further development of blood-based gene expression biomarkers for the diagnosis and early detection of CRC. Clin Cancer Res; 19(11); 3039–49. ©2013 AACR .

Description: βIII-tubulin (encoded by TUBB3) expression is associated with therapeutic resistance and aggressive disease in non–small cell lung cancer (NSCLC), but the basis for its pathogenic influence is not understood. Functional and differential proteomics revealed that βIII-tubulin regulates expression of proteins associated with malignant growth and metastases. In particular, the adhesion-associated tumor suppressor maspin was differentially regulated by βIII-tubulin. Functionally, βIII-tubulin suppression altered cell morphology, reduced tumor spheroid outgrowth, and increased sensitivity to anoikis. Mechanistically, the PTEN/AKT signaling axis was defined as a critical pathway regulated by βIII-tubulin in NSCLC cells. βIII-Tubulin blockage in vivo reduced tumor incidence and growth. Overall, our findings revealed how βIII-tubulin influences tumor growth in NSCLC, defining new biologic functions and mechanism of action of βIII-tubulin in tumorigenesis. Cancer Res; 75(2); 415–25. ©2014 AACR.

Description: Purpose: This study was implemented to investigate the associations between SNP in mature microRNA (miRNA) sequence and lung cancer prognosis and to verify the function of those SNP. Experimental Design: Eight SNPs (rs3746444T〉C in hsa-mir-499, rs4919510C〉G in hsa-mir-608, rs13299349G〉A in hsa-mir-3152, rs12220909G〉C in hsa-mir-4293, rs2168518G〉A in hsa-mir-4513, rs8078913T〉C in hsa-mir-4520a, rs11237828T〉C in hsa-mir-5579, and rs9295535T〉C in hsa-mir-5689) were analyzed in a southern Chinese population with 576 patients with lung cancer, and the significant results were validated in two additional cohorts of 346 and 368 patients, respectively. A series of experiments were performed to evaluate the relevancies of those potentially functional SNPs. Results: We found that the microRNA-499 rs3746444T〉C polymorphism exhibited a consistently poor prognosis for patients with lung cancer in the discovery set [HR, 1.24; 95% confidence interval (CI), 1.02–1.49; P = 0.028], in the validation set I (HR, 1.31; 95% CI, 1.01–1.71; P = 0.048) and in the validation set II (HR, 1.45; 95% CI, 1.12–1.86; P = 0.004). The adverse effect of CT/CC variants was more remarkable in patients receiving platinum-based chemotherapy. Further functional assays demonstrated that the rs3746444C variant allele influences the expression of several cancer-related genes and affects lung cancer cells' proliferation and tumor growth in vivo and in vitro via the cisplatinum resistance. Conclusion: Our findings suggested that the rs3746444T〉C polymorphism in mature miR-499 sequence could contribute to poor prognosis by modulating cancer-related genes' expression and thus involve tumorigenesis and anti-chemotherapy, which may be a useful biomarker to predict lung cancer patients' prognosis. Clin Cancer Res; 21(7); 1602–13. ©2015 AACR .

Description: The anionic antimicrobial peptide SP-B N , derived from the N-terminal saposin-like domain of the surfactant protein (SP)-B proprotein, and SP-A are lung anti-infective proteins. SP-A–deficient mice are more susceptible than wild-type mice to lung infections, and bacterial killing is enhanced in transgenic mice overexpressing SP-B N . Despite their potential anti-infective action, in vitro studies indicate that several microorganisms are resistant to SP-A and SP-B N . In this study, we test the hypothesis that these proteins act synergistically or cooperatively to strengthen each other’s microbicidal activity. The results indicate that the proteins acted synergistically in vitro against SP-A– and SP-B N –resistant capsulated Klebsiella pneumoniae (serotype K2) at neutral pH. SP-A and SP-B N were able to interact in solution ( K d = 0.4 μM), which enabled their binding to bacteria with which SP-A or SP-B N alone could not interact. In vivo, we found that treatment of K. pneumoniae– infected mice with SP-A and SP-B N conferred more protection against K. pneumoniae infection than each protein individually. SP-A/SP-B N –treated infected mice showed significant reduction of bacterial burden, enhanced neutrophil recruitment, and ameliorated lung histopathology with respect to untreated infected mice. In addition, the concentrations of inflammatory mediators in lung homogenates increased early in infection in contrast with the weak inflammatory response of untreated K. pneumoniae –infected mice. Finally, we found that therapeutic treatment with SP-A and SP-B N 6 or 24 h after bacterial challenge conferred significant protection against K. pneumoniae infection. These studies show novel anti-infective pathways that could drive development of new strategies against pulmonary infections.

Description: Myeloid-derived suppressive cells (MDSC) have been reported to promote metastasis, but the loss of cancer-induced B cells/B regulatory cells (tBreg) can block metastasis despite MDSC expansion in cancer. Here, using multiple murine tumor models and human MDSC, we show that MDSC populations that expand in cancer have only partially primed regulatory function and limited prometastatic activity unless they are fully educated by tBregs. Cancer-induced tBregs directly activate the regulatory function of both the monocyte and granulocyte subpopulations of MDSC, relying, in part, on TgfβR1/TgfβR2 signaling. MDSC fully educated in this manner exhibit an increased production of reactive oxygen species and NO and more efficiently suppress CD4+ and CD8+ T cells, thereby promoting tumor growth and metastasis. Thus, loss of tBregs or TgfβR deficiency in MDSC is sufficient to disable their suppressive function and to block metastasis. Overall, our data indicate that cancer-induced B cells/B regulatory cells are important regulators of the immunosuppressive and prometastatic functions of MDSC. Cancer Res; 75(17); 3456–65. ©2015 AACR.