CD4 effector T cell differentiation is controlled by IL-15 that is expressed and presented in trans

T cells are both producers and consumers of cytokines, and autocrine cytokine signaling plays a critical role in T cell immunity. IL-15 is a homeostatic cytokine for T cells that also controls inflammatory immune responses. An autocrine role of T cell-derived IL-15, however, remains unclear. Here we examined IL-15 expression and signaling upon effector T cell differentiation in mice, and, surprisingly, found that CD4 T cells did not express IL-15. CD4 T cells lacked Il15 gene reporter activity, did not contain IL-15 transcripts, and did not produce IL-15Rα, the proprietary IL-15 receptor required for IL-15 trans-presentation. Moreover, IL-15 failed to inhibit Th17 cell differentiation and failed to generate Foxp3⁺ Treg cells in vitro. IL-2, which utilizes the same IL-2Rβ/γc receptor complex, however, successfully did so. Exogenous IL-15 only exerted bioactivity and controlled T cell differentiation when it was trans-presented by IL-15Rα. Consequently, IL-15Rα-bound IL-15, but not free IL-15, suppressed Th17 cell differentiation and induced Treg cell generation. Collectively, these results reveal the absence of an IL-15 autocrine loop in CD4 T cells and strongly suggest that IL-15 trans-presentation by non-CD4 T cells is the primary mechanism via which IL-15 controls CD4 effector T cell differentiation.

[Oncomelania hupensis status monitoring in Changzhou City, Jiangsu Province from 2013 to 2016]

Objective To analyze the Oncomelania hupensis snail distribution and the changes of snail situation in Changzhou City from 2013 to 2016, so as to provide the evidence for formulating the schistosomiasis prevention and control interventions. Methods The data of snail monitoring in Changzhou City from 2013 to 2016 were collected and statistically analyzed. Results The total area with snails was 40.17 hm² and the newly discovered area was 30.63 hm² in Changzhou City from 2013 to 2016. In the four years, 3 454 snails were dissected, and no schistosome infected snails were found. There were totally 51 spots with snails, and the areas with snails of different types of marshland, inland and mountain were 12.13 (30.19%), 25.54 hm² (63.57%) and 2.51 hm² (6.24%), respectively. In the newly discovered snail environment, the areas of types of marshland and inland were 8.00 hm² (26.12%) and 22.63 hm² (73.88%), respectively. The main causes for snail existence were external input and adjacent diffusion. In the past four years, the total snail control area with molluscicides was 71.74 hm², the consolidated snail control area with molluscicides was 155.15 hm², and the total environmental modification areas in the current snail spots and historic snail spots were 15.90 hm² and 11.30 hm² respectively. Conclusion The diffusion of snails in inland rivers is the key of the newly discovered snail areas in Changzhou City in recent years, and the snail monitoring and control measures should be strengthened in the future.

CPT1A methylation is associated with plasma adiponectin

BACKGROUND AND AIMS

Adiponectin, an adipose-secreted protein that has been linked to insulin sensitivity, plasma lipids, and inflammatory patterns, is an established biomarker for metabolic health. Despite clinical relevance and high heritability, the determinants of plasma adiponectin levels remain poorly understood.

METHODS AND RESULTS

We conducted the first epigenome-wide cross-sectional study of adiponectin levels using methylation data on 368,051 cytosine-phosphate-guanine (CpG) sites in CD4+ T-cells from the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN, n = 991). We fit linear mixed models, adjusting for age, sex, study site, T-cell purity, and family. We have identified a positive association (regression coefficient ± SE = 0.01 ± 0.001, P = 3.4 × 10^-13) between plasma adiponectin levels and methylation of a CpG site in CPT1A, a key player in fatty acid metabolism. The association was replicated (n = 474, P = 0.0009) in whole blood samples from the Amish participants of the Heredity and Phenotype Intervention (HAPI) Heart Study as well as White (n = 592, P = 0.0005) but not Black (n = 243, P = 0.18) participants of the Bogalusa Heart Study (BHS). The association remained significant upon adjusting for BMI and smoking in GOLDN and HAPI but not BHS. We also identified associations between methylation loci in RNF145 and UFM1 and plasma adiponectin in GOLDN and White BHS participants, although the association was not robust to adjustment for BMI or smoking.

CONCLUSION

We have identified and replicated associations between several biologically plausible loci and plasma adiponectin. These findings support the importance of epigenetic processes in metabolic traits, laying the groundwork for future translational applications.

Soluble common gamma chain exacerbates COPD progress through the regulation of inflammatory T cell response in mice

Cigarette smoking (CS) is a major cause of considerable morbidity and mortality by inducing lung cancer and COPD. COPD, a smoking-related disorder, is closely related to the alteration of immune system and inflammatory processes that are specifically mediated by T cells. Soluble common gamma chain (sγc) has recently been identified as a critical regulator of the development and differentiation of T cells. We examined the effects of sγc in a cigarette smoke extract (CSE) mouse model. The sγc level in CSE mice serum is significantly downregulated, and the cellularity of lymph node (LN) is systemically reduced in the CSE group. Overexpression of sγc enhances the cellularity and IFNγ production of CD8 T cells in LN and also enhances Th1 and Th17 differentiation of CD4 T cells in the respiratory tract. Mechanistically, the downregulation of sγc expression mediated by CSE is required to prevent excessive inflammatory T cell responses. Therefore, our data suggest that sγc may be one of the target molecules for the control of immunopathogenic progresses in COPD.

Effects of Bioactive Compounds on Odontogenic Differentiation and Mineralization

Direct pulp capping involves the placement of dental materials directly onto vital pulp tissues after deep caries removal to stimulate the regeneration of reparative dentin. This physical barrier will serve as a "biological seal" between these materials and the pulp tissue. Although numerous direct pulp capping materials are available, the use of small bioactive compounds that can potently stimulate and expedite reparative dentin formation is still underexplored. Here, the authors compared and evaluated the pro-osteogenic and pro-odontogenic effects of 4 small bioactive compounds- phenamil (Phen), purmorphamine (Pur), genistein (Gen), and metformin (Met). The authors found that these compounds at noncytotoxic concentrations induced differentiation and mineralization of preosteoblastic MC3T3-E1 cells and preodontoblastic dental pulp stem cells (DPSCs) in a dose-dependent manner. Among them, Phen consistently and potently induced differentiation and mineralization in vitro. A single treatment with Phen was sufficient to enhance the mineralization potential of DPSCs in vitro. More importantly, Phen-treated DPSCs showed enhanced odontogenic differentiation and mineralization in vivo. Our study suggests that these small bioactive compounds merit further study for their potential clinical use as pulp capping materials.

Characterization of the ultrastructure in the uterovaginal junction of the hen

In poultry, the infundibulum is the place of fertilization, eggshell production, and sperm storage, while its uterovaginal junction (UVJ) is regarded as the most important site, which has abundant sperm storage tubules (SST). We examined the ultrastructure of the epithelium with relation to its unique secretory cytology in the UVJ of hens using transmission electron microscopy. The epithelium of the UVJ is lined with ciliated and secretory cells. Ciliated cells are characterized with light and dense secretory granules in supernuclear cytoplasm. Dense secretory granules in ciliated cells are larger in diameter (one μm), surrounded with a transparent rim and concentric layers, whereas the dense granules in the ciliated cells of SST are smaller (0.52 μm) in size and not surrounded by any transparent rim or layer. Ciliated cells also are involved in the shedding of exosomes and secretory vesicles in the lumen. Secretory exosomes are in close contact with cilia and directly release from the apical border into the lumen. Cell junctions are widely distributed between these cells. The secretory cells are associated with the release of secretions via apocrine blebs from microvilli and secretory vesicles, which protrude out from the surface of the epithelium. The dense secretory granules in these cells are smaller in size (0.6 μm), absent of a transparent rim or layers, and are released into the lumen through secretory vesicles. The intracellular multivesicular body (MVB) also is observed in the supernuclear cytoplasm of secretory cells, which are related to the production of exosomes. In general, the apical protrusion of the epithelium in the form of apocrine secretions, the releasing of exosomes, the identification of intracellular MVB, and the release of dense granules give the epithelium a distinct morphology in the UVJ of the hen oviduct.

Nrf2 expression is upregulated in tumor infiltrating T cells and induces T cell anergy

The transcription factor nuclear factor-erythroid 2-related-2 (Nrf2) controls cellular redox homeostasis and displays immunomodulatory properties. Hypoxic microenvironment in solid tumors generated by their outgrowth activates Nrf2 which induces the expression of anti-oxidant genes and supports continuous growth and proliferation via metabolic reprogramming. It is easy to imagine that hypoxic situation may affect function of immune cells infiltrated into tumor mass. We have thus questioned how hypoxic condition affect T cell immune response against tumor and the role of Nrf2 is involved. First, tumor infiltrating T cells (TILs) were sorted from tumor mass to investigate the alteration of Nrf2 expression. Interestingly, we found that mRNA levels of Nrf2 are significantly increased in TILs compared to control T cells. In order to test whether T cell responses are affected by Nrf2 levels, we stimulated T cells and measured Nrf2 expression. Nrf2 expression and their target genes are significantly downregulated by TCR activation. We further confirmed that IFN-γ production in Nrf2 deficient T cells was dramatically enhanced. Our findings offer novel insights into how immune response and oxidative stress is integrated in tumor cells, and we highlight Nrf2 as candidate of molecular target to control tumor in hypoxic condition.

Mis-acylation of tRNAs suppresses protective immune responses which control cutaneous inflammation by infection

The mouse sticky mutation which is a missense mutation in editing domain of the alanyl-tRNA synthetase gene impairs the proofreading activity during amino-acylation of tRNAs. An editing-defective tRNA synthetase induces the accumulation of mis-folded proteins in the neuron which is associated with neuro-degenerative disorder. Although the sticky mice were characterized by the rough, unkempt, sticky appearance, it is not clear whether the sticky mutation is associated with inflammatory disease. The protective role of T and B cells during cutaneous infection by a variety of pathogens has been known well. We therefore investigated how sticky mutation affects immune responses and linked to sticky phenotype. First of all, we examined immune cell numbers in sticky mice. LN cell number in sticky mice was significantly reduced compared to Sti/+ and WT mice, while LN profiles of sticky mice were not big different from control groups. Reduced cellularity by sticky mutant results from impaired proliferation, not by IL-7 signaling which is critical in T cell development and homeostasis. Interestingly, we found that mutation in tRNA processing reduced IFNγ and IL-17 production from stimulated T cells. And it also reduced Immunoglobulin production in B cells, particularly IgG1 and IgE which has an important role in resistance to bacterial and parasite infection. These findings indicate that disruption of translational fidelity induces deterioration of immune functions such as impaired cytokine and antibody production, resulting in reduction of the resistance to various infections. Furthermore, it provides a novel mechanism which the alteration of tRNA pool in inflammatory diseases affects the cellular and humoral immune responses.

Modification of soluble common gamma chain function controls collagen-induced arthritis

IL-2Rγ (γc) is an essential subunit in γc cytokine signaling which is very important in development and homeostasis of immune cells. Recently, we showed that the soluble form of γc (sγc) is generated by alternative splicing and their production is enhanced in activated T cells. Moreover, we found that sγc inhibits γc cytokine signaling and enhances Th17 differentiation, consequently exacerbates an inflammation. Since Th17 cells are known to play pivotal roles in the pathogenesis of autoimmune rheumatoid arthritis (RA) disease, we have questioned whether sγc affects RA pathogenesis. Consistent with EAE model, we found that sγc overexpressing mice with collagen induced arthritis (CIA) displayed accelerated clinical score of arthritis compared to WT with CIA. In addition, serum level of sγc was significantly increased in CIA mice compared to WT, indicating that sγc may contribute to exacerbate the pathogenesis of RA. It is conceivable that a blockade of sγc function potentially improves autoimmune diseases. Although sγc dimerization is more functional than monomer, the dimerization mechanism of sγc is not fully understood. Using a mutant sγc form which cysteine (Cys) is replaced to alanine (Ala), we confirmed that the generation of sγc homodimer is elicited by disulfide bond. This result suggests that Cys is critical to form the dimer structure. To further study, we are designing sγc inhibitor to block sγc functions and then testing inhibitory effect in RA animal model.

Abstract PD7-01: Interim analysis of multiplex gene panel testing for inherited susceptibility to breast cancer

Background: Emerging evidence demonstrates the effectiveness of targeted gene sequencing panels as a practical method for the diagnosis of inherited susceptibility to breast cancer. Sequencing of multiple high and moderate risk genes simultaneously accelerates the discovery of deleterious mutations (DM) or variants of unknown significance (VUS). However, a consequence of Multiplex Gene Panel (MGP) testing is the discovery of unexpected DMs in high or moderate risk genes other than BRCA1 or BRCA2 (BRCA1/2). The overall clinical utility and incremental gain of information conferred by MGP testing in hereditary cancer risk assessment is still unknown.

Methods: We are conducting a multicenter prospective cohort study of patients undergoing cancer-risk assessment using a 25 gene sequencing panel, which includes APC, ATM, BARD1, BMPR1A, BRCA1, BRCA2, BRIP1, CDH1, CDK4, CDKN2A, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, NBN, PALB2, PMS2, PTEN, RAD51C, RAD51D, SMAD4, STK11, and TP53. Patients were recruited from August 2014 to June 2015 at three medical centers. Patients are enrolled if they meet standard criteria for genetic testing or are predicted to have a ≥ 2.5% probability of inherited susceptibility to cancer calculated by validated risk prediction models. We present a planned interim analysis after enrolling 500 of 2000 total participants.

Results: HCP testing was performed for 332 patients referred for clinical suspicion of hereditary breast and ovarian cancer (HBOC). In this cohort, 96.7% were female (n=321) and the mean age was 50 years (standard deviation, SD=12.2); race/ethnicity was 43.1% Hispanic (n=143), 37% Non-Hispanic White (n=123), 4.2% Black (n=14), 10.5% Asian (n=35), and 1.8% other (n=6). Among this cohort, 37 tested positive for one deleterious mutation (DM) (11.1%: 95% confidence interval (CI), 8.2% to 15%) and 118 patients carried at least one variant of uncertain significance (VUS) (35.5%: 95% CI, 30.6% to 69%). Excluding BRCA1 or BRCA2, 14 patients (4.3%: 95% CI, 2.6% to 7.2%) have a DM in ATM (n=3), CHEK2 (n=2), MSH6 (n=1), MUTYH (n=3), PALB2 (n=1), PMS2 (n=1), RAD51C (n=2), and TP53 (n=2). In a patient with an unexpected PMS2 mutation, enhanced cancer surveillance based on Lynch Syndrome guidelines was recommended. Among 160 patients with a history of invasive breast cancer or breast DCIS, 19 patients carried a DM (11.8 %: 95 CI, 7.7% to 17.8%).

Conclusion: In this multicenter prospective cohort study among a diverse group of participants undergoing 25-gene MGP testing, 11.1% of participants tested positive for a DM. Among participants testing negative for BRCA1 and BRCA2, MGP testing identified DMs in 4.3% of participants prompting clinically appropriate risk reduction recommendations and enhanced cancer surveillance. Ongoing recruitment and long-term follow-up are in progress.

Citation Format: Idos GE, Kurian AW, Mcdonnell KJ, Ricker CN, Sturgeon DY, Culver JO, Lowstuter K, Hartman A-R, Allen B, Teeter C-R, Kingham KE, Koff R, Lebensohn A, Chun NM, Mills MA, Petrovchich I, Hong C, Ladabaum U, Ford JM, Gruber SB. Interim analysis of multiplex gene panel testing for inherited susceptibility to breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD7-01.

Abstract P2-09-07: The patient experience in a prospective trial of multiplex gene panel testing for cancer risk

Background: Multiplex gene sequencing panels (MGP) are increasingly used for assessment of hereditary breast cancer risk. Compared to testing for BRCA1 and BRCA2 (BRCA1/2) only, testing more genes increases the likelihood of identifying a deleterious mutation (DM) and/or a variant of uncertain significance (VUS), which might cause distress, uncertainty or regret about testing. Little is known about the patient experience of MGP testing.

Methods: We conducted a prospective study of MGP testing, using a panel of 25 genes: APC, ATM, BARD1, BMPR1A, BRCA1, BRCA2, BRIP1, CDH1, CDK4, CDKN2A, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, NBN, PALB2, PMS2, PTEN, RAD51C, RAD51D, SMAD4, STK11, and TP53. Participants were enrolled at three medical centers and were eligible if they met standard genetic testing guidelines or if they had a ≥2.5% probability of a DM in any gene on the panel, as calculated by predictive models (e.g. IBIS, Penn II, MMRPro). Participants were surveyed about their experiences with MGP testing including distress and uncertainty at baseline (before test results disclosure) and three months later. The 25-item Multidimensional Impact of Cancer Risk Assessment (MICRA) scale measured distress, uncertainty and positive experiences at three months after testing. We present a planned interim analysis after enrolling 500 of 2000 total participants.

Results: Of 500 participants, 332 (66%) were referred for suspicion of hereditary breast/ovarian cancer syndrome. Of these 332, 97% were female, 79% were white, 43% were Hispanic and 33% were Spanish-speaking only; for 25%, high school was their highest level of education. A total of 48% had breast cancer, 5% had ovarian cancer, and 7% had another cancer: 11% had a DM and 35% had VUS in one or more genes. At study entry most participants thought about cancer rarely or not at all (69%, 95% confidence interval (CI) 58%-77%), and few (7%, CI 3%-14%) had thoughts of cancer that affected their daily lives; results were unchanged three months later, after genetic results disclosure (Chi-squared test, p-value >0.1). MICRA scores at three months were low for distress (mean score 2 out of a possible 30) and uncertainty (mean score 7 out of 45), and high for positive testing experiences (mean score 9 out of 15). Most (82%, CI 72%-88%) participants wanted to know all of their MGP results even if the clinical relevance was not fully understood, and most (87%, CI 79%-93%) never regretted learning their MGP results.

Conclusions: Among diverse participants of a prospective, multi-center MGP testing trial, cancer- and genetic testing-related distress were low at entry and remained low three months later. These results provide no evidence for an increase in distress or uncertainty after MGP. Longer-term follow-up in a larger cohort is underway.

Citation Format: Kurian AW, Idos G, McDonnell K, Ricker C, Sturgeon D, Culver J, Lowstuter K, Hartman A-R, Allen B, Rowe-Teeter C, Kingham KE, Koff RB, Lebensohn A, Chun NM, Petrovchich IM, Mills MA, Hong C, Ladabaum U, Ford JM, Gruber SB. The patient experience in a prospective trial of multiplex gene panel testing for cancer risk. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-07.

Challenges in the Management of Breast Cancer in a Low Resource Setting in South East Asia

BACKGROUND

Breast cancer is the second most common cancer in women in Cambodia, a low income country in SouthEast Asia. The Sihanouk Hospital Centre of Hope (SHCH) is a charity hospital set up by an international nongovernmental organisation, HOPE Worldwide. In 2008, SHCH partnered with AmeriCares, a global health organisation to set up and deliver a breast cancer programme to provide education, diagnosis and treatment for women with breast cancer. The objective of this study is to characterise the presentation, diagnosis, treatment and outcomes of women treated under this program.

MATERIALS AND METHODS

A total of 215 women newly diagnosed with breast cancer from 1 March 2008 until 31 March 2011 were studied. Age at diagnosis, tumour size, histological type, tumour grade, ER, lymph node involvement, treatment modalities (surgery, radiotherapy, chemotherapy, hormone therapy) were recorded. Data on mortality at 3 years were obtained whenever possible.

RESULTS

The median age was 47 years old. Some 77.8% were diagnosed with stage 3 and 4 lesions, and 78.5% underwent mastectomy, of which 28.4% the intent was palliative. Of those whose ER status were known, only 48.3% were ER positive. Only 6 patients could afford chemotherapy while only 1 patient had radiotherapy. Hormone therapy was provided free for those who were ER positive. The overall survival rate at 3 years was 39.1%.

CONCLUSIONS

Breast cancer presents at a late stage, and because treatment is suboptimal, survival is poor in Cambodia. A more aggressive approach to early detection and treatment needs to be developed to improve outcome from this potentially curable disease.

New insights of common gamma chain in hematological malignancies

The common gamma chain (γc) receptor family of cytokines including interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21 has the common feature of sharing γc signaling subunit of their receptors. The γc cytokines have unique biological effects that regulate differentiation, survival and activation of multiple lymphocyte lineages and control proliferation of malignant cell by influencing tumor environment. It has been also described that different types of lymphoid leukemia and lymphoma exhibit expression of divergent γc cytokines and their receptors, as they may promote malignant transformation of lymphoid cells or on the contrary lead to tumor regression by inducing cell-cycle arrest. Therefore, cytokine-based or cytokine-directed blockade in cancer immunotherapy has currently revolutionized the development of cancer treatment. In this review, we will discuss about the role of γc cytokines and their signaling pathways in hematological malignancies and also propose a novel alternative approach that regulates γc cytokine responsiveness by γc in hematological malignancies.

The role of soluble common gamma chain in autoimmune disease

The common gamma chain (γc) is the central signaling unit for a number of cytokine receptors collectively known as the γc cytokine receptor family. γc is critical for ligand binding and signaling by γc cytokines. γc cytokine signaling had been thought to be mainly regulated by cytokine-specific receptor α chain expression levels with little or no effect by γc surface levels because γc expression was presumed to remain unchanged during T-cell activation and development. The extent of γc cytokine responses is thought to be regulated by cytokine specific receptor subunits and not by the γc receptor. In contrast to this prevailing view, we have recently reported that γc itself actively regulates γc cytokine responses. Interestingly, γc exerted its regulatory effects not only as a conventional membrane receptor protein but also as a secreted protein whose expression was upregulated upon T-cell stimulation. Here we will review how a soluble form of γc, which is generated by alternative splicing, regulates γc cytokine signaling and plays a role in controlling immune activation related to autoimmune disease.