Integrative analyses of hub genes and their association with immune infiltration in adipose tissue, liver tissue and skeletal muscle of obese patients after bariatric surgery.

Bariatric surgery (BS) is an effective treatment for obesity. Adipose tissue, liver tissue and skeletal muscle are important metabolic tissues. This study investigated hub genes and their association with immune infiltration in these metabolic tissues of obese patients after BS by bioinformatic analysis with Gene Expression Omnibus datasets. Differentially expressed genes (DEGs) were identified, and a protein-protein interaction network was constructed to identify hub genes. As a result, 121 common DEGs were identified and mainly enriched in cytokine-cytokine receptor interactions, chemokine signaling pathway, neutrophil activation and immune responses. Immune cell infiltration analysis showed that the abundance of M1 macrophages was significantly lower in adipose and liver tissue after BS (p<0.05). Ten hub genes (TYROBP, TLR8, FGR, NCF2, HCK, CCL2, LAPTM5, MNDA and S100A9) that were all downregulated after BS were also associated with immune cells. Consistently, results in the validated dataset showed that the expression levels of these hub genes were increased in obese patients and mice, and decreased after BS. In conclusion, this study analysed the potential immune and inflammatory mechanisms of BS in three key metabolic tissues of obese patients, and revealed hub genes associated with immune cell infiltration, thus providing potential targets for obesity treatment.

Sex Differences in the Immune System Become Evident in the Perinatal Period in the Four Core Genotypes Mouse.

We have used the four core genotypes (FCG) mouse model, which allows a distinction between effects of gonadal secretions and chromosomal complement, to determine when sex differences in the immune system first appear and what influences their development. Using splenic T cell number as a measure that could be applied to neonates with as yet immature immune responses, we found no differences among the four genotypes at postnatal day 1, but by day 7, clear sex differences were observed. These sex differences were unexpectedly independent of chromosomal complement and similar in degree to gonadectomized FCG adults: both neonatal and gonadectomized adult females (XX and XY) showed 2-fold the number of CD4+ and 7-fold the number of CD8+ T cells versus their male (XX and XY) counterparts. Appearance of this long-lived sex difference between days 1 and 7 suggested a role for the male-specific perinatal surge of testicular testosterone. Interference with the testosterone surge significantly de-masculinized the male CD4+, but not CD8+ splenic profile. Treatment of neonates demonstrated elevated testosterone limited mature cell egress from the thymus, whereas estradiol reduced splenic T cell seeding in females. Neonatal male splenic epithelium/stroma expressed aromatase mRNA, suggesting capacity for splenic conversion of perinatal testosterone into estradiol in males, which, similar to administration of estradiol in females, would result in reduced splenic T cell seeding. These sex steroid effects affected both CD4+ and CD8+ cells and yet interference with the testosterone surge only significantly de-masculinized the splenic content of CD4+ cells. For CD8+ cells, male cells in the thymus were also found to express one third the density of sphingosine-1-phosphate thymic egress receptors per cell compared to female, a male characteristic most likely an indirect result of Sry expression. Interestingly, the data also support a previously unrecognized role for non-gonadal estradiol in the promotion of intra-thymic cell proliferation in neonates of both sexes. Microarray analysis suggested the thymic epithelium/stroma as the source of this hormone. We conclude that some immune sex differences appear long before puberty and more than one mechanism contributes to differential numbers and distribution of T cells.

Whole-Exome Sequencing, Proteome Landscape, and Immune Cell Migration Patterns in a Clinical Context of Menkes Disease.

Menkes disease (MD) is a rare and often lethal X-linked recessive syndrome, characterized by generalized alterations in copper transport and metabolism, linked to mutations in the ATPase copper transporting α (ATP7A) gene. Our objective was to identify genomic alterations and circulating proteomic profiles related to MD assessing their potential roles in the clinical features of the disease. We describe the case of a male patient of 8 months of age with silvery hair, tan skin color, hypotonia, alterations in neurodevelopment, presence of seizures, and low values of plasma ceruloplasmin. Trio-whole-exome sequencing (Trio-WES) analysis, plasma proteome screening, and blood cell migration assays were carried out. Trio-WES revealed a hemizygous change c.4190C > T (p.S1397F) in exon 22 of the ATP7A gene. Compared with his parents and with child controls, 11 plasma proteins were upregulated and 59 downregulated in the patient. According to their biological processes, 42 (71.2%) of downregulated proteins had a participation in cellular transport. The immune system process was represented by 35 (59.3%) downregulated proteins (p = 9.44 × 10-11). Additional studies are necessary to validate these findings as hallmarks of MD.

Immune cell infiltration landscape and immune marker molecular typing in preeclampsia.

Preeclampsia (PE) is an important topic in obstetrics. In this study, we used weighted gene co-expression network analysis (WGCNA) to screen the key modules related to immune cell infiltration and to identify the hub genes for the molecular subtyping of PE. We first downloaded a set of PE transcriptional data (GSE75010; 157 samples: 80 PE and 77 non-PE) from the GEO database. We then analyzed the PE samples and non-PE samples for immune cell infiltration and screened cells with differences in such infiltration. Next, we downloaded the immune-related genes from an immune-related database to screen the expression profile of the immune-related genes. Then, we obtained a candidate gene set by screening the immune-related genes differentially expressed between the two groups. We used WGCNA to construct a weighted co-expression network for these candidate genes, mined co-expression modules, and then calculated the correlation between each module and immune cells with differential infiltration. We screened the modules related to infiltrating immune cells, identified the key modules' hub genes, and determined the key module genes that interacted with each other. Finally, we obtained the hub genes related to the infiltrating immune cells. We classified the preeclampsia patients by unsupervised cluster molecular typing, determined the difference of immune cell infiltration among the different PE subtypes, and calculated the expression of hub genes in these different subtypes. In conclusion, we found 41 hub genes that may be closely related to the molecular typing of PE.

Long noncoding RNAs in cancer immunity: a new avenue in drug discovery.

The central role of the nonprotein-coding portion of the genome, such as long noncoding (lnc)RNAs is emerging as a hidden player manipulating the immune system in cancer. lncRNAs, in association with their interacting partners, regulate the expression of various immune system genes, which are perturbed during cancer. The tissue-specific expression of lncRNAs and their importance in cellular proliferation, the tumor microenvironment (TME), epithelial-mesenchymal transition (EMT), and modulation of the cells of the innate and adaptive immune system have novel therapeutic implications in establishing lncRNAs as biomarkers and targets to overcome cancer-associated immunosuppression. In this review, we establish and strengthen the link between lncRNAs and cancer immunity.

Overexpression of TPX2 predicts poor clinical outcome and is associated with immune infiltration in hepatic cell cancer.

Targeting protein for Xenopus kinesin-like protein 2 (TPX2) has been identified as an oncogene in multiple cancers. However, the associations among TPX2 expression, prognosis, and tumor immunity in hepatic cell cancer (HCC) have not been explored. We analyzed TPX2 expression by multiple gene expression databases, including Oncomine, TIMER, and UALCAN. The prognosis effect of TPX2 was analyzed by Kaplan--Meier plotter. The coexpressed genes with TPX2 were analyzed using Linked Omics. The association among TPX2 and immune infiltrates and immune checkpoints was determined by TIMER. It was found that TPX2 expression was notably upregulated in multiple HCC tissues. Overexpression of TPX2 has associations with race, age, weight, clinical stage and tumor grade, as well as poor prognosis in overall survival (OS), progression-free survival (PFS), disease-free survival (DFS), and disease-specific survival (DSS). In addition, TPX2 expression has a positive association with the infiltration of immune cells and the expression of immune checkpoint molecules. Coexpressed genes and functional network analysis suggested several potential mechanisms of TPX2 affecting HCC progression. The findings reveal that TPX2 has associations with prognosis and infiltration of immune cells in HCC patients, which has laid a basis for in-depth study of TPX2 role in HCC.

Immune-related gene signature in predicting prognosis of early-stage colorectal cancer patients.

AIM: Immune-related genes are associated with the prognosis of colorectal cancer (CRC) patients. The aim of this study was to evaluate the impact of an immune-related gene signature (IRGS) in predicting the prognosis of early-stage CRC patients. METHODS: In total, 309 CRC patients were selected for the identification of prognostic IRGS using the CIT/GSE39582 microarray dataset. Five independent datasets including 1587 CRC patients were divided into a training cohort (n = 566) and two validation cohorts (n = 624 in validation-1 and n = 397 in meta-validation). Prognostic analyses were performed to test the predictive value of IRGS. RESULTS: A prognostic IRGS that included 23 immune-related genes was constructed and significantly stratified patients into immune low-vs. high-risk groups in terms of disease-free survival using patients with early-stage disease (I or II) in the training cohort. Similarly, a higher IRGS was correlated with significantly worse prognosis of early-stage patients in validation-1 and meta-validation cohorts. Compared with Oncotype DX colon, we found that IRGS exhibited an improved survival correlation in the training cohort. After integration with clinical characteristics, IRGS remained as an independent prognostic factor in multivariate analysis. Furthermore, IRGS-stratified immune low-risk group patients gained less benefit from adjuvant chemotherapy in the validation-1 cohort. Several biological processes, including inflammatory response, were enriched among genes in identified the immune high-risk group. Consistent with this finding, the IRGS-identified immune high-risk group exhibited significantly increased immune and stromal cell infiltration. CONCLUSION: The proposed prognostic IRGS is a promising system for estimating DFS of colorectal cancer patients, especially those with early-stage disease.

Roles of G protein-coupled receptors in inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a complex disease with multiple pathogenic factors. Although the pathogenesis of IBD is still unclear, a current hypothesis suggests that genetic susceptibility, environmental factors, a dysfunctional immune system, the microbiome, and the interactions of these factors substantially contribute to the occurrence and development of IBD. Although existing and emerging drugs have been proven to be effective in treating IBD, none can cure IBD permanently. G protein-coupled receptors (GPCRs) are critical signaling molecules implicated in the immune response, cell proliferation, inflammation regulation and intestinal barrier maintenance. Breakthroughs in the understanding of the structures and functions of GPCRs have provided a driving force for exploring the roles of GPCRs in the pathogenesis of diseases, thereby leading to the development of GPCR-targeted medication. To date, a number of GPCRs have been shown to be associated with IBD, significantly advancing the drug discovery process for IBD. The associations between GPCRs and disease activity, disease severity, and disease phenotypes have also paved new avenues for the precise management of patients with IBD. In this review, we mainly focus on the roles of the most studied proton-sensing GPCRs, cannabinoid receptors, and estrogen-related GPCRs in the pathogenesis of IBD and their potential clinical values in IBD and some other diseases.

Prognostic Molecular Classification of Appendiceal Mucinous Neoplasms Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Appendiceal mucinous neoplasm (AMN) with peritoneal metastasis is a rare but deadly disease with few prognostic or therapy-predictive biomarkers to guide treatment decisions. Here, we investigated the prognostic and biological attributes of gene expression-based AMN molecular subtypes. METHODS: AMN specimens (n = 138) derived from a population-based subseries of patients treated at our institution with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) between 05/2000 and 05/2013 were analyzed for gene expression using a custom-designed NanoString 148-gene panel. Signed non-negative matrix factorization (sNMF) was used to define a gene signature capable of delineating robustly-classified AMN molecular subtypes. The sNMF class assignments were evaluated by topology learning, reverse-graph embedding and cross-cohort performance analysis. RESULTS: Three molecular subtypes of AMN were discerned by the expression patterns of 17 genes with roles in cancer progression or anti-tumor immunity. Tumor subtype assignments were confirmed by topology learning. AMN subtypes were termed immune-enriched (IE), oncogene-enriched (OE) and mixed (M) as evidenced by their gene expression patterns, and exhibited significantly different post-treatment survival outcomes. Genes with specialized immune functions, including markers of T-cells, natural killer cells, B-cells, and cytolytic activity showed increased expression in the low-risk IE subtype, while genes implicated in the promotion of cancer growth and progression were more highly expressed in the high-risk OE subtype. In multivariate analysis, the subtypes demonstrated independent prediction power for post-treatment survival. CONCLUSIONS: Our findings suggest a greater role for the immune system in AMN than previously recognized. AMN subtypes may have clinical utility for predicting CRS/HIPEC treatment outcomes.

Immune gene expression in head and neck squamous cell carcinoma patients.

BACKGROUND: Nivolumab and pembrolizumab targeting programmed cell death protein 1 (PD-1) have recently been approved among patients with recurrent and/or metastatic head and neck squamous cell carcinoma (HNSCC) who failed platinum therapy. We aimed to evaluate the prognostic value of selected immune gene expression in HNSCC. PATIENTS AND METHODS: We retrospectively assessed the expression of 46 immune-related genes and immune-cell subpopulation genes including immune checkpoints by real-time polymerase chain reaction among 96 patients with HNSCC who underwent primary surgery at Institut Curie between 1990 and 2006. Univariate and multivariate analyses were performed to assess the prognostic value of dysregulated genes. RESULTS: The Median age of the population was 56 years [range: 35-78]. Primary tumour location was oral cavity (45%), oropharynx (21%), larynx (18%) and hypopharynx (17%). Twelve patients (13%) had an oropharyngeal human papillomavirus-positive tumour. Most significantly overexpressed immune-related genes were TNFRSF9/4-1BB (77%), IDO1 (75%), TNFSF4/OX40L (74%) and TNFRSF18/GITR (74%), and immune-cell subpopulation gene was FOXP3 (62%). Eighty-five percent of tumours analysed overexpressed actionable immunity genes, including PD-1/PD-L1, TIGIT, OX40/OX40L and/or CTLA4. Among the immune-related genes, high OX40L mRNA level (p = 0.0009) and low PD-1 mRNA level (p = 0.004) were associated with the highest risk of recurrence. Among the immune-cell subpopulation genes, patients with high PDGFRB mRNA level (p < 0.0001) and low CD3E (p = 0.0009) or CD8A mRNA levels (p = 0.004) were also at the highest risk of recurrence. CONCLUSIONS: OX40L and PDGFRB overexpression was associated with poor outcomes, whereas PD-1 overexpression was associated with good prognosis in patients with HNSCC treated with primary surgery, suggesting their relevance as potential prognostic biomarkers and major therapeutic targets.

Spatial Heterogeneity of Lung Strain and Aeration and Regional Inflammation During Early Lung Injury Assessed with PET/CT.

INTRODUCTION: Spatial heterogeneity of lung aeration and strain (change volume/resting volume) occurs at microscopic levels and contributes to lung injury. Yet, it is mostly assessed with histograms or large regions-of-interest. Spatial heterogeneity could also influence regional gene expression. We used positron emission tomography (PET)/computed tomography (CT) to assess the contribution of different length-scales to mechanical heterogeneity and to direct lung injury biological pathway identification. MATERIALS AND METHODS: Sheep exposed to mild (n = 5, supine and n = 3, prone) and moderate (n = 6, supine) systemic endotoxemia were protectively ventilated. At baseline, 6 hours and 20 hours length-scale analysis was applied to aeration in CT (mild groups) and PET transmission (moderate group) scans; and voxel-level strain derived from image registration of end-inspiratory and end-expiratory CTs (mild). 2-deoxy-2-[(18)F]fluoro-d-glucose (18F-FDG)-PET kinetics parameters in ventral and dorsal regions were correlated with tissue microarray gene expression (moderate). RESULTS: While aeration and strain heterogeneity were highest at 5-10 mm length-scales, larger length-scales contained a higher fraction of strain than aeration heterogeneity. Contributions of length-scales >5-10 mm to aeration and strain heterogeneity increased as lung injury progressed (p < 0.001) and were higher in supine than prone animals. Genes expressed with regional correlation to 18F-FDG-PET kinetics (|r| = 0.81 [0.78-0.85]) yielded pathways associated with immune system activation and fluid clearance. CONCLUSION: Normal spatial heterogeneity of aeration and strain suggest larger anatomical and functional determinants of lung strain than aeration heterogeneity. Lung injury and supine position increase the contribution of larger length-scales. 18F-FDG-PET-based categorization of gene expression results in known and novel biological pathways relevant to lung injury.

Compositional differences between Copaxone and Glatopa are reflected in altered immunomodulation ex vivo in a mouse model.

Copaxone (glatiramer acetate, GA), a structurally and compositionally complex polypeptide nonbiological drug, is an effective treatment for multiple sclerosis, with a well-established favorable safety profile. The short antigenic polypeptide sequences comprising therapeutically active epitopes in GA cannot be deciphered with state-of-the-art methods; and GA has no measurable pharmacokinetic profile and no validated pharmacodynamic markers. The study reported herein describes the use of orthogonal standard and high-resolution physicochemical and biological tests to characterize GA and a U.S. Food and Drug Administration-approved generic version of GA, Glatopa (USA-FoGA). While similarities were observed with low-resolution or destructive tests, differences between GA and USA-FoGA were measured with high-resolution methods applied to an intact mixture, including variations in surface charge and a unique, high-molecular-weight, hydrophobic polypeptide population observed only in some USA-FoGA lots. Consistent with published reports that modifications in physicochemical attributes alter immune-related processes, genome-wide expression profiles of ex vivo activated splenocytes from mice immunized with either GA or USA-FoGA showed that 7-11% of modulated genes were differentially expressed and enriched for immune-related pathways. Thus, differences between USA-FoGA and GA may include variations in antigenic epitopes that differentially activate immune responses. We propose that the assays reported herein should be considered during the regulatory assessment process for nonbiological complex drugs such as GA.

Viruses and the origin of microbiome selection and immunity.

The last common metazoan ancestor (LCMA) emerged over half a billion years ago. These complex metazoans provided newly available niche space for viruses and microbes. Modern day contemporaries, such as cnidarians, suggest that the LCMA consisted of two cell layers: a basal endoderm and a mucus-secreting ectoderm, which formed a surface mucus layer (SML). Here we propose a model for the origin of metazoan immunity based on external and internal microbial selection mechanisms. In this model, the SML concentrated bacteria and their associated viruses (phage) through physical dynamics (that is, the slower flow fields near a diffusive boundary layer), which selected for mucin-binding capabilities. The concentration of phage within the SML provided the LCMA with an external microbial selective described by the bacteriophage adherence to mucus (BAM) model. In the BAM model, phage adhere to mucus protecting the metazoan host against invading, potentially pathogenic bacteria. The same fluid dynamics that concentrated phage and bacteria in the SML also concentrated eukaryotic viruses. As eukaryotic viruses competed for host intracellular niche space, those viruses that provided the LCMA with immune protection were maintained. If a resident virus became pathogenic or if a non-beneficial infection occurred, we propose that tumor necrosis factor (TNF)-mediated programmed cell death, as well as other apoptosis mechanisms, were utilized to remove virally infected cells. The ubiquity of the mucosal environment across metazoan phyla suggest that both BAM and TNF-induced apoptosis emerged during the Precambrian era and continue to drive the evolution of metazoan immunity.

Immune Checkpoint Modulation in Colorectal Cancer: What's New and What to Expect.

Colorectal cancer (CRC), as one of the most prevalent types of cancer worldwide, is still a leading cause of cancer related mortality. There is an urgent need for more efficient therapies in metastatic disease. Immunotherapy, a rapidly expanding field of oncology, is designed to boost the body's natural defenses to fight cancer. Of the many approaches currently under study to improve antitumor immune responses, immune checkpoint inhibition has thus far been proven to be the most effective. This review will outline the treatments that take advantage of our growing understanding of the role of the immune system in cancer, with a particular emphasis on immune checkpoint molecules, involved in CRC pathogenesis.

The perioperative immune response.

PURPOSE OF REVIEW: A host of immune modulators are now available in clinical practice. The perioperative period is characterized by profound alterations in host immunity, which can result in poor outcomes, which include infection, cancer recurrence and organ failure. Manipulation of the perioperative immune response has the potential to improve outcomes. A complete understanding of the mechanisms and clinical consequences of altered immune function in this setting is therefore imperative. RECENT FINDINGS: Recent in-vivo data have emerged which further our understanding of the interaction between tissue damage, immune modulation and clinical outcomes by utilizing novel laboratory techniques capable of monitoring single-cell immune signatures. Traditional gene expression assays have continued to demonstrate their utility and have been instrumental in defining the host response to perioperative allogeneic blood transfusion. These mechanistic studies are complemented by large clinical studies describing associations between anaesthetic modalities and immune-related outcomes. SUMMARY: Laboratory techniques are now available that can monitor the perioperative immune response and could be further developed to introduce personalized care pathways. Consideration must also be given to anaesthesia techniques and perioperative treatments that, although not immediately harmful, may be associated with poor outcomes temporally distant from the treatment, secondary to induced immunosuppression.

Quantitative dynamic imaging of immune cell signalling using lentiviral gene transfer.

Live-cell imaging of fluorescent fusion proteins has transformed our understanding of mammalian cell signalling and function. However, some cellular systems such as immune cells are unsuitable or refractory to many existing transgene delivery methods thus limiting systematic analyses. Here, a flexible lentiviral gene transfer platform for dynamic time-lapse imaging has been developed and validated with single-molecule spectroscopy, mathematical modelling and transcriptomics and used for analysis of a set of inflammation-related signalling networks. Time-lapse imaging of nuclear factor kappa B (NF-κB), signal transducer and activator of transcription (STATs) and nuclear factor of activated T-cells (NFAT) in mammalian immune cell lines provided evidence for heterogeneous temporal encoding of inflammatory signals. In particular, the absolute quantification of single-cell responses over time via fluorescent correlation spectroscopy (FCS) showed that NF-κB p65 activation in response to tumour necrosis factor α (TNFα) was differentially encoded in variable amplitude of nuclear translocation between immune and non-immune cells. The absolute number of activated molecules was dictated in part by the cell size, suggesting a morphology-dependent regulatory mechanism. The developed platform will enable further absolute quantitative analyses of the dynamic interactions between signalling networks, in and between individual cells, allowing better integration with mathematical models of signalling networks.

Multifaceted Modulation of SIRT1 in Cancer and Inflammation.

SIRT1 is a highly conserved NAD+-dependent protein deacetylase that is involved in diverse cellular processes. SIRT1 can deacetylate not only histones, but also a growing number of nonhistone substrates involved in multiple signaling pathways. Accumulating evidence has indicated that SIRT1 is a key regulator of life span extension, DNA damage, metabolism stress, inflammation, and cancer. In inflammation, SIRT1 deacetylates several transcription factors and regulates the immune cell responses. In cancer, recent discoveries revealed opposite effects of SIRT1 as an oncoprotein or a tumor suppressor under different conditions. In the tumor microenvironment, both infiltrated immune cells and cancer cells can be affected by SIRT1. Understanding the proper cancer-related functions of SIRT1 in both systems may provide potential evidence for SIRT1-based therapies. Here, we discuss the current understanding of SIRT1 in regulating immune responses and tumorigenesis.

Comparison of tamoxifen and letrozole response in mammary preneoplasia of ER and aromatase overexpressing mice defines an immune-associated gene signature linked to tamoxifen resistance.

Response to breast cancer chemoprevention can depend upon host genetic makeup and initiating events leading up to preneoplasia. Increased expression of aromatase and estrogen receptor (ER) is found in conjunction with breast cancer. To investigate response or resistance to endocrine therapy, mice with targeted overexpression of Esr1 or CYP19A1 to mammary epithelial cells were employed, representing two direct pathophysiological interventions in estrogen pathway signaling. Both Esr1 and CYP19A1 overexpressing mice responded to letrozole with reduced hyperplastic alveolar nodule prevalence and decreased mammary epithelial cell proliferation. CYP19A1 overexpressing mice were tamoxifen sensitive but Esr1 overexpressing mice were tamoxifen resistant. Increased ER expression occurred with tamoxifen resistance but no consistent changes in progesterone receptor, pSTAT3, pSTAT5, cyclin D1 or cyclin E levels in association with response or resistance were found. RNA-sequencing (RNA-seq) was employed to seek a transcriptome predictive of tamoxifen resistance using these models and a second tamoxifen-resistant model, BRCA1 deficient/Trp53 haploinsufficient mice. Sixty-eight genes associated with immune system processing were upregulated in tamoxifen-resistant Esr1- and Brca1-deficient mice, whereas genes related to aromatic compound metabolic process were upregulated in tamoxifen-sensitive CYP19A1 mice. Interferon regulatory factor 7 was identified as a key transcription factor regulating these 68 immune processing genes. Two loci encoding novel transcripts with high homology to human immunoglobulin lambda-like polypeptide 1 were uniquely upregulated in the tamoxifen-resistant models. Letrozole proved to be a successful alternative to tamoxifen. Further study of transcriptional changes associated with tamoxifen resistance including immune-related genes could expand our mechanistic understanding and lead to biomarkers predictive of escape or response to endocrine therapies.

Transcriptome profiling of zebrafish infected with Streptococcus suis.

Streptococcus suis is an important pathogen in swine, and it also represents an emerging zoonotic agent. Zebrafish as a model for the evaluation of virulence of S. suis has been demonstrated before. Here, an Affymetrix Zebrafish GeneChip was used to identify alterations in gene expression of zebrafish injected with S. suis serotype 2 strain HA9801. The results showed that 189 genes were differentially expressed, of which 125 genes were upregulated and 64 genes were downregulated. Gene Ontology category and KEGG pathway were analyzed for differentially expressed genes. Upregulated genes were involved in response to bacterium, immune response, inflammatory response, complement activation, defense response. Three genes (encoding serum amyloid protein A, matrix metalloproteinase 9 and apoptosis-related cysteine protease) and genes involved in the regulation of IL-6 biosynthetic process, which have previously been implicated in the response to S. suis infection in other organisms, were also upregulated. Downregulated genes played roles in glycolysis, carbohydrate metabolic process, amino acids metabolism, behavior and muscle. The reliability of the data obtained from the microarray was verified by performing quantitative real-time PCR on 12 representative genes. The data may provide further validation of this model, which will contribute to understanding of S. suis pathogenic mechanisms.