The phosphatidylserine receptors, T cell immunoglobulin mucin proteins 3 and 4, are markers of histiocytic sarcoma and other histiocytic and dendritic cell neoplasms

Identification of Hub Genes in Liver Hepatocellular Carcinoma Based on Weighted Gene Co-expression Network Analysis

Liver hepatocellular carcinoma (LIHC) is a malignant cancer with high incidence and poor prognosis. To investigate the correlation between hub genes and progression of LIHC and to provided potential prognostic markers and therapy targets for LIHC. Our study mainly used The Cancer Genome Atlas (TCGA) LIHC database and the gene expression profiles of GSE54236 from the Gene Expression Omnibus (GEO) to explore the differential co-expression genes between LIHC and normal tissues. The differential co-expression genes were extracted by Weighted Gene Co-expression Network Analysis (WGCNA) and differential gene expression analysis methods. The Genetic Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were carried out to annotate the function of differential genes. Then the hub genes were validated using protein-protein interaction (PPI) network. And the expression level and prognostic analysis were performed. The probable associations between the expression of hub genes and both tumor purity and infiltration of immune cells were explored by TIMER. A total of 68 differential co-expression genes were extracted. These genes were mainly enriched in complement activation (biological process), collagen trimer (cellular component), carbohydrate binding and receptor ligand activity (molecular function) and cytokine - cytokine receptor interaction. Then we demonstrated that the 10 hub genes (CFP, CLEC1B, CLEC4G, CLEC4M, FCN2, FCN3, PAMR1 and TIMD4) were weakly expressed in LIHC tissues, the qRT-PCR results of clinical samples showed that six genes were significantly downregulated in LIHC patients compared with adjacent tissues. Worse overall survival (OS) and disease-free survival (DFS) in LIHC patients were associated with the lower expression of CFP, CLEC1B, FCN3 and TIMD4. Ten hub genes had positive association with tumor purity. CFP, CLEC1B, FCN3 and TIMD4 could serve as novel potential molecular targets for prognosis prediction in LIHC.

Gene expression prognostic of early relapse risk in low-risk B-cell acute lymphoblastic leukaemia in children

ETV6::RUNX1 is the most common fusion gene in childhood acute lymphoblastic leukaemia (ALL) and is associated with favorable outcomes, especially in low-risk children. However, as many as 10% of children relapse within 3 years, and such early relapses have poor survival. Identifying children at risk for early relapse is an important challenge. We interrogated data from 87 children with low-risk ETV6::RUNX1-positive B-cell ALL and with available preserved bone marrow samples (discovery cohort). We profiled somatic point mutations in a panel of 559 genes and genome-wide transcriptome and single-nucleotide variants. We found high TIMD4 expression (> 85th-percentile value) at diagnosis was the most important independent prognostic factor of early relapse (hazard ratio [HR] = 5.07 [1.76, 14.62]; p = 0.03). In an independent validation cohort of low-risk ETV6::RUNX1-positive B-cell ALL (N = 68) high TIMD4 expression at diagnosis had an HR = 4.78 [1.07, 21.36] (p = 0.04) for early relapse. In another validation cohort including 78 children with low-risk ETV6::RUNX1-negative B-cell ALL, high TIMD4 expression at diagnosis had an HR = 3.93 [1.31, 11.79] (p = 0.01). Our results suggest high TIMD4 expression at diagnosis in low-risk B-cell ALL in children might be associated with high risk for early relapse.

Use of bioinformatic database analysis and specimen verification to identify novel biomarkers predicting gastric cancer metastasis

Background: Gastric cancer (GC) is a common gastrointestinal tumor, and its metastasis has led to a significant increase in the death rate. The mechanisms of GC metastasis remain unclear.

Methods: The differentially expressed genes (DmRs) and lncRNAs (DlncRs) of GC were selected from The Cancer Genome Atlas (TCGA) database. We applied the weighted gene co-expression network analysis (WGCNA) to construct co-expression modules related with GC metastasis. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) method analyzed the functional regions and signal pathways of genes in vital modules. DmRs-DlncRs co-expression network were drawn for finding out hub nodes. Survival analyses of significant biomarkers were analyzed by Kaplan-Meier (KM) method. Finally, the expressions of selected biomarkers were validated in cell lines and caner tissues by quantitative real-time PCR (qRT-PCR), in GC tissue microarray by Fluorescence in situ hybridization (FISH).

Results: 4776 DmRs and 213 DlncRs were involved the construction of WGCNA network, and MEyellow module was identified to have more significant correlation with GC metastasis. DmRs and DlncRs of MEyellow module were proved to be involved in the processes of cancer pathogenesis by GO and KEGG pathway analysis. Through the DmRs-DlncRs co-expression network, 7 DmRs and 1 DlncRs were considered as hub nodes. Besides, the high expression of TIMD4, CETP, KRT27, PTGDS, FAM30A was worse than low expression in GC patients survival, respectively; However, LRRC26 was opposite trend. FAM30A and TIMD4 were all significant biomarkers of GC survival and hub genes. Simultaneously, TIMD4, CETP, KRT27, PTGDS, FAM30A were increased in GC cell lines and tissues compared with GES-1 and normal tissues, respectively; the expression of LRRC26 was reduced in GC cell lines and tissues.

Conclusion: This study identified 6 genes as new biomarkers affecting the metastasis of GC. Especially, FAM30A and TIMD4 might be an effective marker for predicting the prognosis and a potential-therapeutic target in GC.

Immune Checkpoints in Pediatric Solid Tumors: Targetable Pathways for Advanced Therapeutic Purposes

The tumor microenvironment (TME) represents a complex network between tumor cells and a variety of components including immune, stromal and vascular endothelial cells as well as the extracellular matrix. A wide panel of signals and interactions here take place, resulting in a bi-directional modulation of cellular functions. Many stimuli, on one hand, induce tumor growth and the spread of metastatic cells and, on the other hand, contribute to the establishment of an immunosuppressive environment. The latter feature is achieved by soothing immune effector cells, mainly cytotoxic T lymphocytes and B and NK cells, and/or through expansion of regulatory cell populations, including regulatory T and B cells, tumor-associated macrophages and myeloid-derived suppressor cells. In this context, immune checkpoints (IC) are key players in the control of T cell activation and anti-cancer activities, leading to the inhibition of tumor cell lysis and of pro-inflammatory cytokine production. Thus, these pathways represent promising targets for the development of effective and innovative therapies both in adults and children. Here, we address the role of different cell populations homing the TME and of well-known and recently characterized IC in the context of pediatric solid tumors. We also discuss preclinical and clinical data available using IC inhibitors alone, in combination with each other or administered with standard therapies.

Immunological status of peripheral blood is associated with prognosis in patients with bone and soft-tissue sarcoma

Immune-checkpoint inhibitors have shown promising antitumor effects against certain types of cancer. However, specific immune-checkpoint inhibitors for patients with sarcoma have yet to be identified, whereas the immunological status of peripheral blood in patients with bone sarcoma and soft-tissue sarcoma (STS) remains unknown. In addition, it is unclear whether the immunological status from the peripheral blood could be used as a prognostic indicator. Therefore, the present study aimed to clarify the immunological status of peripheral blood samples derived from patients with bone sarcoma and STS. Immune monitoring was performed using the peripheral blood samples of 61 patients with no metastasis of high-grade sarcoma. A total of 25 patients with metastatic sarcoma were used for comparison. A total of 41 immune cell subsets were analyzed using multicolor-flow cytometry. The patients that did not have metastasis demonstrated higher quantities of monocytic myeloid-derived suppressor cells (M-MDSCs) and T cell immunoglobulin and mucin domain-3 (Tim-3)⁺ CD8⁺ T cells, which were significantly associated with poor disease-free survival (DFS) time, while higher quantities of NKG2D⁺ CD8⁺ T cells were significantly associated with improved DFS time. Multivariate Cox regression analysis demonstrated that the number of Tim-3⁺ CD8⁺ T cells was associated with lower DFS time. A significant association was also found between the number of M-MDSCs and progression-free survival (PFS) time in patients with metastasis. The results suggested the occurrence of immune surveillance, which indicated that the host immune reaction against cancer existed in patients with bone sarcoma and STS. Notably, a high number of M-MDSCs was associated with both DFS and PFS time, suggesting a strong prognostic value. The data suggested that the immune status of peripheral blood was associated with the prognosis in patients with sarcoma, as previously reported in patients with other cancer types. In summary, the results may assist with the development of novel strategies for sarcoma treatment, based on the use of biomarkers or immunotherapy.

Tim-4 in Health and Disease: Friend or Foe?

T-cell immunoglobulin and mucin domain containing 4 (Tim-4) is a phosphatidylserine receptor and is selectively expressed on antigen presenting cells. Recently, Tim-4 was reported to be expressed on iNKT cells, B1 cells, and tumor cells, suggesting it has multiple biological functions. In this review, we mainly summarize the expression and regulation of Tim-4 in immune cells including T cells, macrophages, dendritic cells, NKT cells, B cells, and mast cells. The expression of Tim-4 in these cells implies that Tim-4 might participate in immune related diseases. Emerging evidence emphasizes a substantial role for Tim-4 in maintaining homeostasis by regulating various immune responses, including viral infection, allergy, autoimmunity, and tumor immunity. Here, we collectively evaluated the role of Tim-4 in health and diseases. This summary will be extremely useful to fully understand the function of Tim-4 in the pathogenesis of immune related diseases, which would provide novel clues for the diagnosis and treatment of diseases.

The role of phosphatidylserine recognition receptors in multiple biological functions

Apoptotic cells are rapidly engulfed and degraded by phagocytes through efferocytosis. Efferocytosis is a highly regulated process. It is triggered upon the activation of caspase-dependent apoptosis, which in turn promotes the expression of "eat me" signals on the surface of dying cells and the release of soluble "find me" signals for the recruitment of phagocytes. To date, many "eat me" signals have been recognized, including phosphatidylserine (PS), intercellular adhesion molecule-3, carbohydrates (e.g., amino sugars, mannose) and calreticulin. Among them, PS is the most studied one. PS recognition receptors are different functionally active receptors expressed by phagocytes. Various PS recognition receptors with different structure, cell type expression, and ability to bind to PS have been recognized. Although PS recognition receptors do not fall into a single classification or family of proteins due to their structural differences, they all share the common ability to activate downstream signaling pathways leading to the production of anti-inflammatory mediators. In this review, available evidence regarding molecular mechanisms underlying PS recognition receptor-regulated clearance of apoptotic cells is discussed. In addition, some efferocytosis-independent biological functions of PS recognition receptors are reviewed.

IL-6 promotes metastasis of non-small-cell lung cancer by up-regulating TIM-4 via NF-κB

OBJECTIVES

Interleukin-6 (IL-6) is critical for the development of non-small-cell lung cancer (NSCLC). Recently, we identified T-cell immunoglobulin domain and mucin domain 4 (TIM-4) as a new pro-growth player in NSCLC progression. However, the role of TIM-4 in IL-6-promoted NSCLC migration, invasion and epithelial-to-mesenchymal transition (EMT) remains unclear.

MATERIALS AND METHODS

Expressions of TIM-4 and IL-6 were both evaluated by immunohistochemical staining in NSCLC tissues. Real-time quantitative PCR (qPCR), Western blot, flow cytometry and RT-PCR were performed to detect TIM-4 expression in NSCLC cells with IL-6 stimulation. The roles of TIM-4 in IL-6 promoting migration and invasion of NSCLC were detected by transwell assay. EMT-related markers were analysed by qPCR and Western blot in vitro, and metastasis was evaluated in BALB/c nude mice using lung cancer metastasis mouse model in vivo.

RESULTS

High IL-6 expression was identified as an independent predictive factor for TIM-4 expression in NSCLC tissues. NSCLC patients with TIM-4 and IL-6 double high expression showed the worst prognosis. IL-6 promoted TIM-4 expression in NSCLC cells depending on NF-κB signal pathway. Both TIM-4 and IL-6 promoted migration, invasion and EMT of NSCLC cells. Interestingly, TIM-4 knockdown reversed the role of IL-6 in NSCLC and IL-6 promoted metastasis of NSCLC by up-regulating TIM-4 via NF-κB.

CONCLUSIONS

TIM-4 involves in IL-6 promoted migration, invasion and EMT of NSCLC.

Immunological Targets for Immunotherapy: Inhibitory T Cell Receptors

Tumor development is characterized by the accumulation of mutational and epigenetic changes that transform normal cells and survival pathways into self-sustaining cells capable of untrammeled growth. Although multiple modalities including surgery, radiation, and chemotherapy are available for the treatment of cancer, the benefits conferred are often limited. The immune system is capable of specific, durable, and adaptable responses. However, cancers hijack immune mechanisms such as negative regulatory checkpoints that have evolved to limit inflammatory and immune responses to thwart effective antitumor immunity. The development of monoclonal antibodies against inhibitory receptors expressed by immune cells has produced durable responses in a broad array of advanced malignancies and heralded a new dawn in the cancer armamentarium. However, these remarkable responses are limited to a minority of patients and indications, highlighting the need for more effective and novel approaches. Preclinical and clinical studies with immune checkpoint blockade are exploring the therapeutic potential antibody-based therapy targeting multiple inhibitory receptors. In this chapter, we discuss the current understanding of the structure, ligand specificities, function, and signaling activities of various inhibitory receptors. Additionally, we discuss the current development status of various immune checkpoint inhibitors targeting these negative immune receptors and highlight conceptual gaps in knowledge.

MERTK tyrosine kinase receptor together with TIM4 phosphatidylserine receptor mediates distinct signal transduction pathways for efferocytosis and cell proliferation

Apoptotic cells expose phosphatidylserine (PtdSer) on their surface, leading to efferocytosis, i.e. their engulfment by resident macrophages that express the PtdSer receptor T cell immunoglobulin mucin receptor 4 (TIM4) and TAM family receptor tyrosine kinase receptors (MERTK, AXL, and TYRO3). TAM family receptors stimulate cell proliferation, and the many aspects of the growth signaling pathway downstream of TAM family receptors have been elucidated previously. However, the signaling cascade for TAM receptor-mediated efferocytosis has been elusive. Here we observed that efferocytosis by mouse-resident peritoneal macrophages was blocked by inhibitors against the MERTK, mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK), AKT Ser/Thr kinase (AKT), focal adhesion kinase (FAK), or STAT6 pathway. Accordingly, apoptotic cells stimulated the phosphorylation of MERTK, ERK, AKT, FAK, and STAT6, but not of IκB or STAT5. A reconstituted efferocytosis system using MERTK- and TIM4-expressing NIH3T3-derived cells revealed that the juxtamembrane and C-terminal regions of MERTK have redundant roles in efferocytosis. The transformation of murine IL-3-dependent Ba/F3 cells (a pro-B cell line) with MERTK and TIM4 enabled them to proliferate in response to apoptotic cells in a PtdSer-dependent manner. This apoptotic cell-induced MERTK-mediated proliferation required both MERTK's juxtamembrane and C-terminal regions and was blocked by inhibitors of not only ERK, AKT, FAK, and STAT6 but also of NF-κB and STAT5 signaling. These results suggest that apoptotic cells stimulate distinct sets of signal transduction pathways via MERTK to induce either efferocytosis or proliferation.

Diverse roles of TIM4 in immune activation: implications for alloimmunity

PURPOSE OF REVIEW

T-cell immunoglobulin and mucin domain-containing molecule (TIM)4 is a costimulatory molecule and phosphatidylserine receptor. Its dominant function varies according to the expressing cell and site of activation. In recent years, studies have identified its role in diverse disease processes and increasingly in alloimmunity. Herein, we will comprehensively review the literature on TIM4 and outline its function in shaping the alloimmune response.

RECENT FINDINGS

TIM4 expression on dendritic cells increases following transplantation. Blockade of TIM4 in vivo leads to increased differentiation of regulatory T cells and improved allograft survival. TIM4 binds phosphatidylserine-expressing apoptotic cells. Previously thought of as a tethering molecule, recent studies have demonstrated that TIM4 interacts with integrins to mediate uptake of apoptotic cells. TIM4 B cells have recently been identified, which produce high levels of IFNγ and promote allograft rejection. Targeting these B cells improved allograft survival and promoted the development of TIM1 regulatory B cells.

SUMMARY

TIM4 is expressed in niche compartments and has many immunological effects. However, inhibition of TIM4 has been demonstrated to prolong allograft survival, through varied mechanisms. A unifying explanation for the role of TIM4 in alloimmunity remains to be found, but this pathway appears to hold considerable promise in transplantation.

Spindle Cell Melanoma and Interdigitating Dendritic Cell Sarcoma: Do They Represent the Same Process?

Intranodal spindle cell lesions on biopsy are problematic for a surgical pathologist, often requiring an extensive immunohistochemical evaluation with variable and frequently unsatisfactory results. In the absence of a history of malignancy, the differential diagnosis of a spindle cell tumor must include both a primary nodal proliferation and a metastatic process. Particularly challenging are those lesions that share morphologic and immunohistochemical features; spindle cell melanomas (SCM) and interdigitating dendritic cell sarcomas (IDCS) belong to this category. At present, electron microscopy is the only method proposed to distinguish between the 2 entities; however, this method is often unavailable and impractical. In this study, we assessed the comparative immunophenotypes of 18 cases of SCM and 8 cases of IDCS, with particular emphasis on the expression of MUM-1, β-catenin, SOX-10, MiTF, and p75. Our results showed nearly equivalent staining patterns and profiles; 12% and 17% of IDCS and SCM were labeled for MUM-1, 75% and 83% stained for β-catenin, 0% and 24% expressed MiTF, and 100% and 94% labeled for p75, respectively. All cases of IDCS and SCM displayed strong nuclear reactivity for SOX-10. On the basis of our study and pertinent literature, the morphologic and immmunophenotypic features of SCM and IDCS appear to be virtually indistinguishable from one another, raising the question as to whether these 2 entities represent a pathobiologically similar or even identical process.

Modulation of Tim-3 Expression by Antigen-Dependent and -Independent Factors on T Cells from Patients with Chronic Hepatitis B Virus Infection

T-cell immunoglobulin domain and mucin domain-containing molecule-3 (Tim-3) was up-regulated on viral specific T cells and contributed to T cells exhaustion during chronic hepatitis B virus (HBV) infection. However, modulation of Tim-3 expression was still not fully elucidated. To evaluate the potential viral and inflammatory factors involved in the inductor of Tim-3 expression on T cells, 76 patients with chronic HBV infection (including 40 chronic hepatitis B [CHB] and 36 asymptomatic HBV carriers [AsC]) and 40 of normal controls (NCs) were enrolled in this study. Tim-3 expressions on CD4⁺ and CD8⁺ T cells were assessed in response to HBV-encoding antigens, HBV peptide pools, and common γ-chain (γc) cytokines stimulation by flow cytometry. HBV peptides and anti-CD3/CD28 directly induced Tim-3 expression on T cells. γc cytokines also drive Tim-3 up-regulations on both CD4⁺ and CD8⁺ T cells in patients with chronic HBV infection. However, γc cytokines did not enhance the Tim-3 inductions by either anti-CD3/CD28 or HBV peptides stimulation. Furthermore, γc cytokines-mediated Tim-3 induction could not be abrogated by γc cytokine receptor-neutralizing antibodies. The current results suggested that elevation of Tim-3 expression on T cells could be regulated by both antigen-dependent and -independent manner in patients with chronic HBV infection. The role of γc cytokines in modulation of inhibitory pathway might be evaluated as immunotherapies in humans.

Braf mutation in interdigitating dendritic cell sarcoma: a case report and review of the literature

Interdigitating dendritic cell sarcoma is an extremely rare tumor. The diagnosis is difficult and is based on clinical, pathological and immunohistochemical evaluation. Differential diagnosis includes melanoma, mesenchymal and hematological malignancies. The mainstay of treatment is surgery for limited disease and different chemotherapy combinations have been tested for advanced disease. No evidence from prospective trials is currently available. We report the case of a 59 year-old male patient who experienced axillary lymphadenopathy with initial diagnosis of large-cell lung cancer on tumor biopsy. He underwent surgical resection with radical intent. Pathological diagnosis of interdigitating dendritic cell sarcoma was obtained on surgical samples. Nine months after radical surgery, he experienced systemic recurrence of disease and underwent chemotherapy with epirubicin and ifosfamide for 4 courses. During chemotherapy, he developed brain disease progression and underwent whole-brain radiotherapy. Systemic progression was then observed and molecular characterization was performed. B-RAF evaluation resulted positive for V600E mutation and the patient was treated with Vemurafenib according to molecular findings. He thus obtained initial clinical benefit but eventually died of brain hemorrhage. In conclusion, we report a case of B-RAF mutation detected in an interdigitating dendritic cell sarcoma patient treated with targeted therapy. B-RAF pathway could have a role in pathogenesis and evolution of this rare disease and could open new perspectives of treatment.

Coinhibitory Pathways in Immunotherapy for Cancer

The immune system is capable of recognizing tumors and eliminates many early malignant cells. However, tumors evolve to evade immune attack, and the tumor microenvironment is immunosuppressive. Immune responses are regulated by a number of immunological checkpoints that promote protective immunity and maintain tolerance. T cell coinhibitory pathways restrict the strength and duration of immune responses, thereby limiting immune-mediated tissue damage, controlling resolution of inflammation, and maintaining tolerance to prevent autoimmunity. Tumors exploit these coinhibitory pathways to evade immune eradication. Blockade of the PD-1 and CTLA-4 checkpoints is proving to be an effective and durable cancer immunotherapy in a subset of patients with a variety of tumor types, and additional combinations are further improving response rates. In this review we discuss the immunoregulatory functions of coinhibitory pathways and their translation to effective immunotherapies for cancer.

TIM-4 promotes the growth of non-small-cell lung cancer in a RGD motif-dependent manner

BACKGROUND

T-cell immunoglobulin domain and mucin domain 4 (TIM-4) is exclusively expressed in antigen-presenting cells and involved in immune regulation. However, the role of TIM-4 expressed in tumour cells remains completely unknown.

METHODS

Immunohistochemistry staining was used to examine TIM-4 or Ki-67 expression in tumour tissues. Real-time PCR or RT-PCR was performed to detect TIM-4 mRNA expression. Lung cancer cell growth and proliferation were conducted by CCK-8 assay and EdU staining. Cell cycle progression was analysed by flow cytometry. The PCNA and cell cycle-related proteins were verified by western blot. Co-IP assay was used to identify the interaction of TIM-4 and integrin αvβ3. The efficacy of TIM-4 in vivo was evaluated using xenograft tumour model.

RESULTS

The expression of TIM-4 in non-small-cell lung cancer (NSCLC) tissues was significantly higher than that of the adjacent tissues. Enhanced TIM-4 expression was negatively correlated with histological differentiation of lung carcinoma and lifespan of patients. Overexpression of TIM-4 promoted lung cancer cell growth and proliferation, and upregulated the expression of PCNA, cyclin A, cyclin B1 and cyclin D1, accompanied by accumulation of lung cancer cells in S phase. Interestingly, Arg-Gly-Asp (RGD) motif mutation abolished the effect of TIM-4 on lung cancer cells, which was further verified by tumour xenografts in mice. Furthermore, we found that TIM-4 interacted with αvβ3 integrin through RGD motif.

CONCLUSIONS

This finding suggests that TIM-4 might be a potential biomarker for NSCLC that promotes lung cancer progression by RGD motif.

Phosphatidylserine receptors: enhancers of enveloped virus entry and infection

A variety of both RNA and DNA viruses envelop their capsids in a lipid bilayer. One of the more recently appreciated benefits this envelope is incorporation of phosphatidylserine (PtdSer). Surface exposure of PtdSer disguises viruses as apoptotic bodies; tricking cells into engulfing virions. This mechanism is termed apoptotic mimicry. Several PtdSer receptors have been identified to enhance virus entry and we have termed this group of proteins PtdSer-mediated virus entry enhancing receptors or PVEERs. These receptors enhance entry of a range of enveloped viruses. Internalization of virions by PVEERs provides a broad mechanism of entry with little investment by the virus itself. PVEERs may allow some viruses to attach to cells, thereby making viral glycoprotein/cellular receptor interactions more probable. Alternatively, other viruses may rely entirely on PVEERs for internalization into endosomes. This review provides an overview of PtdSer receptors that serve as PVEERs and the biology behind virion/PVEER interaction.

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Phosphatidylserine (PtdSer) receptors can mediate entry of enveloped viruses.

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PtdSer is present on the outer leaflet of the virion envelope.

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PtdSer receptors are expressed on a variety of primary cells and cell lines.

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Characteristics of PtdSer receptors that mediate virus entry are defined.

TIM-3 expression in human osteosarcoma: Correlation with the expression of epithelial-mesenchymal transition-specific biomarkers

Signals from the T cell Ig- and mucin-domain-containing molecules (TIMs) have been demonstrated to be actively involved in regulating the progression of carcinomas. However, the expression and distribution of these molecules in osteosarcoma, the most common primary bone malignancy with poor prognosis, have not been investigated. In this study, the expression of TIMs was examined in nine invasive human osteosarcomas using immunohistochemistry, and the phenotypes were detected by dual immunofluorescence staining. Using immunohistochemistry, it was observed that only TIM-3, rather than TIM-1 or TIM-4, was expressed in these tumor specimens, where it was localized in the cytoplasm and plasma membrane of tumor cells. Dual immunofluorescence staining revealed that the expression of TIM-3 was observed in all cell types investigated, including CD68⁺ macrophages, CD31⁺ endothelial cells, CK-18⁺ epithelial cells and PCNA⁺ tumor cells. Notably, in sarcoma cells, TIM-3 was co-expressed with certain biomarkers of epithelial-mesenchymal transition (EMT), including vimentin, Slug, Snail and Smad. These combined results suggest that TIM-3 triggers tumor cells to acquire features of aggressive EMT and may be involved in the pathogenesis of this malignancy.

Staphylococcal enterotoxin B-derived haptens promote sensitization

T helper 2 (Th2) polarization is a major pathological feature in allergic diseases; its etiology is not fully understood. This study aims to elucidate the adjuvant effect of the microbial product-derived small peptides in the initiation of antigen-specific Th2 polarization. In this study, a clinical survey of patients with chronic rhinosinusitis (CRS) and food allergy (FA) was carried out. The Staphylococcal enterotoxin B (SEB)-derived small peptides (Ssps) were examined in the human stool extracts. The formation of Ssp/antigen adducts was tested in a protein-protein combination assay. The bone marrow-derived dendritic cells (BMDCs) were employed to test the role of Ssp/ovalbumin (OVA) adducts in the dendritic cell (DC) maturation. A mouse model was developed to test the role of Ssp/OVA adducts in the initiation of Th2 polarization in the intestine. The results showed that 54 (18.2%) patients with FA were diagnosed among 296 patients with SEB(+) CRS; only eight (2.9%) FA patients were identified among 272 patients with SEB(-) CRS. Ssps were detected in the stool protein extracts from FA patients with SEB(+) CRS, but not in those with SEB(-) CRS. Ssp/OVA adducts induced DC maturation, speeded up DC migration, activated CD4(+) T cells in the regional lymph nodes and induced skewed Th2 polarization in the local tissue. We conclude that patients with SEB(+) CRS are prone to suffering from FA. SEB can be degraded to Ssps in the gastrointestinal tract. The Ssps can bind macromolecular antigens to form adducts to promote the antigenicity of the antigens and induction of the antigen-specific Th2 polarization and inflammation in the local tissue.

T cell immunoglobulin- and mucin-domain-containing molecule 3 gene polymorphisms and susceptibility to pancreatic cancer

T cell immunoglobulin- and mucin-domain-containing molecule 3 (TIM-3) is a novel transmembrane protein that is involved in the regulation of T-helper 1 cell-mediated immunity. Studies have shown that polymorphisms in TIM-3 gene can be associated with various diseases. Here, we investigated the correlation of TIM-3 polymorphisms with susceptibility to pancreatic cancer in the Chinese population. Three polymorphisms in TIM-3 gene (-1516G/T, -574G/T, and +4259T/G) were identified by polymerase chain reaction-restriction fragment length polymorphism in 306 pancreatic patients and 408 healthy controls. Results showed that the prevalence of +4259TG genotype and +4259G allele were significantly increased in the pancreatic cancer cases than in controls [odds ratio (OR) = 2.82, 95 % confidence interval (CI), 1.45-5.48, p = 0.0015, and OR = 2.74, 95 % CI, 1.42-2.94, p = 0.0017]. In addition, when analyzing the TIM-3 polymorphisms with different clinical parameters in pancreatic cancer patients, the cases with vascular infiltration had higher numbers of +4259T/G polymorphism than those without vascular infiltration (OR = 3.07, 95 % CI, 1.41-6.68, p = 0.003). These results suggested polymorphisms in TIM-3 gene could be new risk factors for the development of pancreatic cancer.

Antigen-independent induction of Tim-3 expression on human T cells by the common γ-chain cytokines IL-2, IL-7, IL-15, and IL-21 is associated with proliferation and is dependent on the phosphoinositide 3-kinase pathway

T cell Ig mucin domain-containing molecule 3 (Tim-3) is a glycoprotein found on the surface of a subset of CD8(+) and Th1 CD4(+) T cells. Elevated expression of Tim-3 on virus-specific T cells during chronic viral infections, such as HIV-1, hepatitis B virus, and hepatitis C virus, positively correlates with viral load. Tim-3(+) cytotoxic T cells are dysfunctional and are unable to secrete effector cytokines, such as IFN-γ and TNF-α. In this study, we examined potential inducers of Tim-3 on primary human T cells. Direct HIV-1 infection of CD4(+) T cells, or LPS, found to be elevated in HIV-1 infection, did not induce Tim-3 on T cells. Tim-3 was induced by the common γ-chain (γc) cytokines IL-2, IL-7, IL-15, and IL-21 but not IL-4, in an Ag-independent manner and was upregulated on primary T cells in response to TCR/CD28 costimulation, as well as γc cytokine stimulation with successive divisions. γc cytokine-induced Tim-3 was found on naive, effector, and memory subsets of T cells. Tim-3(+) primary T cells were more prone to apoptosis, particularly upon treatment with galectin-9, a Tim-3 ligand, after cytokine withdrawal. The upregulation of Tim-3 could be blocked by the addition of a PI3K inhibitor, LY 294002. Thus, Tim-3 can be induced via TCR/CD28 costimulation and/or γc cytokines, likely through the PI3K pathway.

Glioma-derived T cell immunoglobulin- and mucin domain-containing molecule-4 (TIM4) contributes to tumor tolerance

Tumor tolerance plays a critical role in tumor growth and escape from immune surveillance. The mechanism of tumor tolerance development is not fully understood. Regulatory T cells (Tregs) play a critical role in tumor tolerance. TIM4 (T cell immunoglobulin- and mucin domain-containing molecule-4) is involved in immune regulation. We investigated the role of TIM4 in the induction of Tregs in tumors. Surgically removed glioma tissue and peripheral blood samples were obtained from 25 glioma patients. Immune cells were isolated from the tissue and blood samples. Confocal microscopy was employed to detect macrophages phagocytosing apoptotic T cells. The generation of tumor-specific Tregs and the immune suppression function of Tregs were observed in cell culture models. High levels of TIM4 were detected in glioma-derived macrophages. Phosphatidylserine (PS) was detected in glioma-derived T cells; naïve T cells expressed low levels of PS that could be up-regulated by hypoxia. Glioma-derived macrophages phagocytosed PS-expressing T cells, gaining the tolerogenic properties, which could induce tumor-specific Tregs; the latter could suppress tumor-specific CD8(+) T cells. We conclude that macrophage-derived TIM4 plays an important role in the induction of Tregs in gliomas, which may play an important role in tumor tolerance.