UNASSIGNED

Increasing data has indicated an association between increased soluble B7-H3 (sB7-H3) levels and unfavorable prognosis in patients with malignancies. However, the level of sB7-H3 and its clinical significance in osteosarcoma (OS) are not well known. In this present study, we investigated whether sB7-H3 levels in serum could be as a tool for differential diagnosis of OS patients.

UNASSIGNED

Peripheral blood samples from healthy controls, benign bone tumors, and OS patients were collected. Levels of sB7-H3 in serum samples were measured by enzyme-linked immunosorbent assays. The correlation between OS-derived sB7-H3 and clinical features was analyzed, and prognostic significance of the sB7-H3 concentrations and tumor expressions of the biomarkers was then evaluated.

UNASSIGNED

sB7-H3 concentrations were significantly increased in patients with OS than in osteochondroma patients, bone fibrous dysplasia patients and healthy people (p < 0.05, respectively). Using 60.94 ng/mL as a cutoff value, the sensitivity and specificity of sB7-H3 was to differentiate between OS patients and other bone benign tumor patients were 75.7% and 83.8%, respectively. In addition, upregulated serum sB7-H3 in patients with OS associated with tumor differentiation, tumor stage, and metastasis status (p < 0.05, respectively). The area under the curve value for sB7-H3 (0.868) was markedly higher than those for ALP (0.713) and CA125 (0.789) for differentiating between OS patients and other begin bone tumor patients.

UNASSIGNED

We demonstrated that enhanced sB7-H3 levels correlated with the clinical characteristics of OS patients, and B7-H3 might be a potential biomarker and associated with the pathogenesis of OS.

For many years, the standard therapy for malignant melanoma was based mainly on surgical resection. Unfortunately, this treatment is curative only in the early localized stage of this malignancy. The metastatic stage of malignant melanoma still remains a huge therapeutic challenge. Despite the many new therapeutic options that have become available over the last years, there is a constant need for safer and more effective treatment modalities. There has been a dynamic development of various anti-cancer immunotherapies directed against new molecular targets. A number of clinical trials are currently being conducted to confirm their effectiveness and safety. In this review of the literature, we summarize the contemporary knowledge on promising new immunotherapies beyond the currently available treatment options for malignant melanoma, including oncolytic immunotherapy, selective inhibitors of indoleamine 2,3-dioxygenease, anti-PD-(L)1 (programmed death ligand 1) drugs, immune checkpoint protein LAG-3 antibodies, inhibitors of histone deacetylase (HDAC) and inhibitors of B7-H3.

The purpose of this study was to investigate the expression levels of the immune checkpoint proteins, programmed cell death-ligand 1 (PD-L1), B7-H3, B7-H4, and V-domain Ig suppressor of T cell activation (VISTA), as well as the significance thereof, in clear cell carcinoma (CCC) of the cervix (a rare histological subtype of cervical cancer). We also compared the expression statuses of these biomarkers in cervical CCCs with those in cervical squamous cell carcinomas (SCCs). We evaluated the expression of PD-L1, B7-H3, B7-H4, and VISTA in 50 cervical CCCs and 100 SCCs using immunohistochemical staining and investigated the associations between these markers, clinicopathologic features, and survival in patients with CCCs. Of the cervical CCC samples examined, 22%, 16%, 32%, and 34% were positive for PD-L1, B7-H3, B7-H4, and VISTA, respectively. Nineteen samples (38%) were negative for all 4 of these markers, whereas 31 (62%) expressed at least 1 marker. None of these markers was associated with the investigated clinicopathologic variables or patient survival. PD-L1, B7-H3, and VISTA were observed significantly more frequently in SCCs than in CCCs of the cervix. Our study confirmed the expression of immune checkpoint proteins in cervical CCCs and indicated their nonredundant and complementary roles. As such, our data suggest that monotherapeutic immune checkpoint blockade may not be sufficiently effective in patients with cervical CCC.

Although PD-1/PD-L1 immunotherapy has been used successfully in treating many cancers, metastatic colorectal cancer (CRC) patients are not as responsive. B7-H3 is a promising target for immunotherapy and we found it to have the highest expression among B7-CD28 family members in CRC. Thus, the aim of the present study was to investigate B7-H3 expression in a large CRC cohort. B7-H3, B7-H4, and PD-L1 protein levels and differential lymphocyte infiltration were evaluated in tissue microarrays from 805 primary tumors and matched metastases. The relationships between immune markers, patient characteristics, and survival outcomes were determined. B7-H3 (50.9%) was detected in more primary tumors than B7-H4 (29.1%) or PD-L1 (29.2%), and elevated B7-H3 expression was associated with advanced overall stage. Co-expression of B7-H3 only with B7-H4 or PD-L1 was infrequent in primary tumors (6.3%, 5.7%, respectively). Moreover, B7-H3 in primary tumors was positively correlated with their respective expression at metastatic sites (ρ = 0.631; p < 0.001). No significant relationships between B7-H4 and PD-L1 and survival were observed; however, B7-H3 overexpression in primary tumors was significantly related to decreased disease-free survival. A positive relationship between B7-H3 expression and high density CD45RO T cell was observed in primary tumors, whereas B7-H4 and PD-L1 overexpression were related to CD3 T-cell infiltration. In conclusion, compared with B7-H4 and PD-L1, B7-H3 expression exhibited a higher prevalence and was significantly related to aggressiveness, worse prognosis and CD45RO T-cell infiltration in primary tumors. Further exploration of this potential target of immunotherapy in CRC patients is warranted.

Immunotherapy based on γδT cells has limited efficiency in solid tumors, including colon cancer (CC). The immune evasion of tumor cells may be the main cause of the difficulties of γδT cell-based treatment. In the present study, we explored whether and how B7-H3 regulates the resistance of CC cells to the cytotoxicity of Vγ9Vδ2 (Vδ2) T cells. We observed that B7-H3 overexpression promoted, while B7-H3 knockdown inhibited, CC cell resistance to the killing effect of Vδ2 T cells in vitro and in vivo. Mechanistically, we showed that B7-H3-mediated CC cell resistance to the cytotoxicity of Vδ2 T cells involved a molecular pathway comprising STAT3 activation and decreased ULBP2 expression. ULBP2 blockade or knockdown abolished the B7-H3 silencing-induced increase in the cytotoxicity of Vδ2 T cells to CC cells. Furthermore, cryptotanshinone, a STAT3 phosphorylation inhibitor, reversed the B7-H3 overexpression-induced decrease in ULBP2 expression and attenuated the killing effect of Vδ2 T cells on CC cells. Moreover, there was a negative correlation between the expression of B7-H3 and ULBP2 in the tumor tissues of CC patients. Our results suggest that the B7-H3-mediated STAT3/ULBP2 axis may be a potential candidate target for improving the efficiency of γδT cell-based immunotherapy in CC.

Keywords: B7-H3; Colon cancer; STAT3; ULBP2; Vγ9Vδ2 T cells.

OBJECTIVE

To investigate the expression and clinical significance of B7 homolog 3 (B7-H3) and β-1,3-galactosyltransferase-4 (B3GALT4) in colorectal cancer (CRC) patients.

METHODS

Using tissue microarray, we identified the expression of B7-H3 and B3GALT4 in 223 CRC patient samples by immunohistochemistry and evaluated the possible correlation between B7-H3 and B3GALT4 and clinical outcomes. Further, the mRNA and protein expression were identified to establish the regulatory relationship of B7-H3 with B3GALT4 in vitro.

RESULTS

A significant positive correlation between B7-H3 and B3GALT4 was observed in CRC specimens (r = 0.219, P = 0.001). High expression of B7-H3 was identified as a significant independent predictor of poor overall survival (OS) [hazard ratio (HR) = 1.781; 95%CI: 1.027-3.089; P = 0.040]. Moreover, high expression of B3GALT4 was also recognized as an independent predictor of inferior OS (HR = 1.597; 95%CI: 1.007-2.533; P = 0.047). Additionally, CRC patients expressing both high B7-H3 and high B3GALT4 contributed to a significant decrease in OS (HR = 2.283; 95%CI: 1.289-4.042; P = 0.005). In CRC cell lines with stable expression of high B7-H3, the mRNA and protein expressions of B3GALT4 were significantly upregulated. Similarly, the expression of B3GALT4 was significantly reduced when expression of B7-H3 was knocked down.

CONCLUSIONS

The expression of B3GALT4 in CRC is positively correlated with B7-H3 expression in vitro. B7-H3/B3GLAT4 may be used as dual prognostic biomarkers for CRC.

Therapeutic options for end-stage organ failure are often limited to whole organ transplantation. The tolerance or rejection of the transplanted organ is driven by both early non-specific innate and specific adaptive responses. The use of mesenchymal stromal cells (MSCs) is considered a promising tool in regenerative medicine. Human umbilical cord (HUC) is an easily available source of MSCs, without relevant ethical issues. Moreover, Wharton's jelly-derived MSCs (WJ-MSCs), showed consistent immunomodulatory features that may be useful to promote immune tolerance in the host after transplantation. Few data are available on the phenotype of WJ-MSCs in situ. We investigated the expression of immune-related molecules, such as HLAs, IDO, CD276/B7-H3, and others, both in situ (HUC) and in in vitro-cultured WJ-MSCs. Morphological and biochemical techniques were used to define the expression of such molecules. In addition, we focused on the possible role of CD276/B7-H3 on T cells proliferation inhibition. We assessed CD276/B7-H3 expression by WJ-MSCs both in situ and alongside cell culture. WJ-MSCs were able to suppress T cell proliferation in mixed lymphocyte reaction (MLR). Moreover, we describe for the first time a specific role for CD276/B7-H3, since the immunomodulatory ability of WJ-MSCs was abolished upon anti-CD276/B7-H3 antibody addition to the MLR. These results further detail the immune regulation properties and tolerance induction exerted by human WJ-MSCs, in particular pointing to CD276/B7-H3 as one of the main involved factors. These data further suggest WJ-MSCs as potent tools to modulate local immune response in "support-type" regenerative medicine approaches.

In this study, we constructed bioconjugates of targeting immune checkpoint B7-H3 antibody and chlorin e6 to treat non-small cell lung cancer under the guidance of spectroscopic photoacoustic and fluorescence imaging. The B7-H3-Ce6 conjugates could display effective tumor diagnosis and therapy and provide a novel approach for immunotherapy.

The immunologic response toward chronic inflammation or bone regeneration via the accumulation of M1 or M2 macrophages after injury could determine the fate of biomaterial. Human umbilical cord mesenchymal stem cells (hUCMSCs) have a pivotal immunomodulatory property on directing macrophage behaviors. Herein, for the first time, 3D-printed poly(lactide-co-glycolide) (PLGA) scaffolds modified with hUCMSC-derived extracellular matrix (PLGA-ECM) are prepared by a facile tissue engineering technique with physical decellularization and 2.44 ± 0.29 mg cm^-3 proteins immobilized on the PLGA-ECM contain multiple soluble cytokines with a sustainable release profile. The PLGA-ECM not only attenuates the foreign body response, but also improves bone regeneration by increasing the accumulation of M2 macrophages in an improved heterotopic transplantation model of SCID mice. Furthermore, the PLGA-ECM scaffolds with the knockdown of transforming growth factor-β-induced protein (TGFβI/βig-H3) demonstrate that M2 macrophage accumulation improved by the PLGA-ECM could be attributed to increasing the migration of M2 macrophages and the repolarization of M1 macrophages to M2 phenotype, which are mediated by multiple integrin signaling pathways involving in integrin β7, integrin α9, and integrin β1 in a TGFβI-dependent manner. This study presents an effective surface modification strategy of polymeric scaffolds to initiate tissue regeneration and combat inflammatory response by increasing M2 macrophage accumulation.

Keywords: MSC-derived extracellular matrix; TGF-β-induced protein; bone regeneration; macrophage inflammation; surface modification.

Background: Patients with recurrent glioblastoma (rGB) have a poor prognosis with a median overall survival (OS) of 30-39 weeks in prospective clinical trials. Intravenous administration of programmed cell death protein 1 and cytotoxic T-lymphocyte-associated antigen 4 inhibitors has low activity in patients with rGB. In this phase I clinical trial, intracerebral (IC) administration of ipilimumab (IPI) and nivolumab (NIVO) in combination with intravenous administration of NIVO was investigated.

Methods: Within 24 hours following the intravenous administration of a fixed dose (10 mg) of NIVO, patients underwent a maximal safe resection, followed by injection of IPI (10 mg; cohort-1), or IPI (5 mg) plus NIVO (10 mg; cohort-2) in the brain tissue lining the resection cavity. Intravenous administration of NIVO (10 mg) was repeated every 2 weeks (max. five administrations). Next generation sequencing and RNA gene expression profiling was performed on resected tumor tissue.

Results: Twenty-seven patients were enrolled (cohort-1: n=3; cohort-2: n=24). All patients underwent maximal safe resection and planned IC administrations and preoperative NIVO. Thirteen patients (cohort-1: n=3; cohort-2: n=10) received all five postoperative intravenous doses of NIVO. In cohort-2, 14 patients received a median of 3 (range 1-4) intravenous doses. Subacute postoperative neurological deterioration (n=2) was reversible on steroid treatment; no other central nervous system toxicity was observed. Immune-related adverse events were infrequent and mild. GB recurrence was diagnosed in 26 patients (median progression-free survival (PFS) is 11.7 weeks (range 2-152)); 21 patients have died due to progression. Median OS is 38 weeks (95% CI: 27 to 49) with a 6-month, 1-year, and 2-year OS-rate of, respectively, 74.1% (95% CI: 57 to 90), 40.7% (95% CI: 22 to 59), and 27% (95% CI: 9 to 44). OS compares favorable against a historical cohort (descriptive Log-Rank p>0.003). No significant difference was found with respect to PFS (descriptive Log-Rank test p>0.05). A higher tumor mRNA expression level of B7-H3 was associated with a significantly worse survival (multivariate Cox logistic regression, p>0.029).

Conclusion: IC administration of NIVO and IPI following maximal safe resection of rGB was feasible, safe, and associated with encouraging OS.

Trial registration: NCT03233152.

Keywords: brain neoplasms; immunotherapy.

B7 negative costimulatory molecules are a group of molecules associated with the occurrence, development, and therapy of cancers. Here, we aimed to determine the clinical significance of PD-L1, B7-H3, and B7-H4 and their expression in CD8 and CD68 positive cells at different stages of gastric carcinogenesis.We detected PD-L1, B7-H3, B7-H4, CD8, and CD68 expression in samples by immunohistochemical staining of 62 chronic superficial gastritis (CSG) samples, 72 chronic atrophic gastritis (CAG) samples, 68 low-grade intraepithelial neoplasia (LIN) samples, 65 high-grade intraepithelial neoplasia (HIN) samples obtained from gastroscopic biopsies and 50 gastric adenocarcinoma (GA) samples obtained from surgical resections. Then we statistically analyzed the expression differences and correlations.Our results indicated that B7 and CD68 expression on infiltrating immune cells was associated with disease progression. However, infiltration of CD8+ cells decreased with disease progression. B7-H3 expression was markedly enhanced at neoplasia and GA stages. B7-H3 in tumor cells was negatively correlated with CD8-expressing cells. Conversely, B7-H3 expression in tumor-infiltrating immune cells was positively correlated with CD68-expressing cells. B7-H4 expression was found in the cell membrane at the stages of gastritis and low-grade neoplasia and was gradually expressed in the cytoplasm at high-grade neoplasia and GA stages. High B7-H4 expression in infiltrating immune cells was also significantly associated with lower CD8-positive and higher CD68-positive cell densities.Increased B7 protein expression by infiltrating immune cells was associated with disease progression, and specifically, the level of B7-H3 expression and localization of B7-H4 expression differed significantly among different stages of gastric carcinogenesis.

CD276 (also known as B7-H3, an immune checkpoint molecule) is aberrantly overexpressed in many cancers. However, the upregulation mechanism and in particular, whether oncogenic signaling has a role, is unclear. Here we demonstrate that a pro-oncogenic kinase PBK, the expression of which is associated with immune infiltration in nasopharyngeal carcinoma (NPC), stimulates the expression of CD276 epigenetically. Mechanistically, PBK phosphorylates MSL1 and enhances the interaction between MSL1 and MSL2, MSL3, and KAT8, the components of the MSL complex. As a consequence, PBK promotes the enrichment of MSL complex on CD276 promoter, leading to the increased histone H4 K16 acetylation and the activation of CD276 transcription. In addition, we show that CD276 is highly upregulated and associated with immune infiltrating levels in NPC. Collectively, our findings describe a novel PBK/MSL1/CD276 signaling axis, which may play an important role in immune evasion of NPC and may be targeted for cancer immunotherapy.

B7-H3, a recently discovered B7 family member, is documented as a regulator in the inflammatory response as well as T cell-mediated immune responses. In this paper, we find that patients with acute pancreatitis revealed overwhelming levels of serum soluble B7-H3 (sB7-H3) associated with the clinical outcomes. Furthermore, B7-H3 protein was marked increased in l-arginine-induced acute experimental pancreatitis. Anti-B7-H3 monoclonal antibody treatment attenuated the proinflammatory cytokine production, downregulated the activation of the NF-κB signaling pathway, and ameliorated the pancreas disruption in l-arginine-induced pancreatitis. In addition, although l-arginine alone failed to induce the production of proinflammatory cytokine and anti-B7-H3 mAb had no effect on the proinflammatory cytokine production of acinar cells, administration of anti-B7-H3 mAb in the coculture model of acinar cells and macrophages stimulated by l-arginine displayed the similar effects. On the whole, B7-H3 participates in the development of acute pancreatitis, and anti-B7-H3 monoclonal antibody ameliorates severity of acute experimental pancreatitis via attenuation of the inflammatory response.

Influenza A viruses display T cell-independent polyclonal B cell-activating properties which are mediated by the B cell-superstimulatory envelope glycoprotein hemagglutinin (HA). In this report, the receptor-binding requirements for B cell activation by influenza viruses were expected. Neuraminidase treatment of resting mature B cells from BALB/c mice abrogated late (proliferation/immunoglobulin synthesis), early (up-regulation of cell surface markers, including CD25, B220, and B7-1) and very-early events (homotypic adhesion) in virus-responding B lymphocytes. Similarly, pretreatment of murine responder cells with different inhibitors of N-glycosylation (tunicamycin, deoxymannojirimycin) significantly suppressed subsequent B lymphocyte activation by HA, but not control responses to lipopolysaccharide or anti-mu. Assays with chimeric HA transfectants, expressing the loop region of epitope B (amino acids 155-160) of the globular head of H2 (high B cell-stimulatory subtype) or H3 (medium-stimulatory subtype) on the protein backbone of a low-stimulatory subtype (H1) failed to alter the B cell-stimulatory activity of the virus, suggesting that the hypervariable loop region is not crucial in determining the B cell-activating properties of the protein. Collectively, our results imply that the B cell-superstimulatory function of influenza virus HA is not mediated by a direct protein/protein interaction, but via binding of HA to terminal sialic acid residues on cell surface receptor glycoproteins. These findings identify the influenza virus HA glycoprotein as the first viral lectin with lymphocyte-activating properties.

OBJECTIVE

To investigate the relationship between B7-H3 expression and the number of CD8(+) T cell infiltration in primary hepatocellular carcinoma (HCC) tissues.

METHODS

The level of B7-H3 expression and the number of CD8(+) T cell infiltration in primary HCC were determined using immunohistochemical staining, and then the correlation between them was analyzed statistically.

RESULTS

The immunohistochemical staining showed that the high expression of B7-H3 was found in 26 cases (41.3%), and the low expression in 37 cases (58.7%) of the 63 primary HCC. Fifty-seven cases (90.5%) were positive for B7-H3 expression in HCC tissues, and normal hepatocellular tissues hardly expressed B7-H3 molecules. The number of infiltrating CD8(+) T cells in B7-H3 high expression group was less than that in B7-H3 low expression group. B7-H3 expression was negatively correlated with the number of infiltrating CD8(+) T cells in HCC tissues. Moreover, both B7-H3 expression and CD8(+)T cell infiltration were related with clinical stage, local lymph node metastasis and distant metastasis in HCC patients.

CONCLUSIONS

B7-H3 molecules were highly expressed and negatively correlated with CD8(+) T cell infiltration in primary HCC tissues.

The costimulatory protein B7-H3 has been shown to play a contributory role in the development and progression of experimental pneumococcal meningitis by augmentation of the innate immunity-associated inflammatory response via a TLR2-dependent manner. This study aimed to clarify the component(s) of TLR2-mediated signal transduction pathways responsible for B7-H3-augmented inflammatory response and subsequent brain damage during experimental pneumococcal meningitis. Administration of B7-H3 did not augment expression of TLR2 and other TLR2 upstream components, but led to an enhanced formation of MyD88-IRAK immunocomplex in the brain of S. pneumoniae-infected mice. Furthermore, B7-H3 substantially augmented S. pneumoniae-induced activation of TLR2 downstream NF-κB p65 and MAPK p38 pathways in the brain of S. pneumoniae-infected mice. Notably, blockage of NF-κB p65 and/or MAPK p38 with their specific inhibitors strongly attenuated B7-H3-amplified inflammatory response with significantly reduced proinflammatory cytokine and chemokine production, and markedly ameliorated B7-H3-exacerbated disruption of blood-brain barrier and severity of disease status in S. pneumoniae-infected mice. These results indicate that targeting NF-κB p65 and/or MAPK p38 may represent a promising therapeutic option for amelioration of overwhelming inflammatory response-associated brain injury frequently observed during pneumococcal meningitis.

T-cell costimulatory molecules deliver positive or negative signals to govern the ultimate fate of immune responses. These ligands and receptors that negatively costimulate T cells (including cytotoxic T-lymphocyte antigen [CTLA]-4, B7-H1, programmed death [PD]-1, B7-H3 and B7x) have received significant interest recently owing to their proposed ability to form a molecular shield for tumor cells. CTLA-4 represents the most extensively studied receptor in the costimulatory pathway and functions as a potent inhibitor of T-cell-mediated immunity. Clinical trials with anti-CTLA-4 are ongoing, although numerous objective responses have been observed in heavily pretreated patients, albeit with autoimmune side effects. In renal cell carcinoma, B7-H1, PD-1 and B7x have been observed to be expressed on tumor cells or infiltrating lymphocytes and are individually associated with adverse pathologic features and poor clinical outcome. In prostate cancer, B7-H3 and B7x immunostaining intensity correlate with disease spread, clinical cancer recurrence and cancer-specific death. External validation and prospective studies are now needed to confirm these findings, while further development of humanized monoclonal antibodies, similar to the experience with anti-CTLA-4, are underway. Herein, we review the B7-CD28 family as it applies to urologic malignancies.

Hepatitis B virus (HBV) is a major public health problem, and HBV-related acute-on-chronic liver failure (HBV-ACLF) has an extremely poor prognosis due to a lack of effective treatments. B7-H3 and B7-H4 are two novel members of the B7 superfamily that are actively involved in regulating the pathogenesis of infectious diseases. However, the intrahepatic expression of both members in HBV-ACLF patients has yet to be described. In this study, we analyzed the expression of B7-H3 and B7-H4 in HBV-ACLF biopsies by immunohistochemistry. Our results showed that both members were observed in all HBV-ACLF samples, and their expression was chiefly observed on infiltrating inflammatory cells and the damaged bile ducts. Immunofluorescence double staining showed that B7-H4 was expressed chiefly on CD3(+) T cells, CD68(+) macrophages, CK-18(+) bile ducts, and CD31(+) endothelial cells, while B7-H3 was found on all cell types detected. The expression of the programmed death (PD)-1 ligands, PD-L1 and PD-L2, was also detected in these liver tissues and they were found to be co-expressed with B7-H3 and B7-H4. These results suggest that the B7-family signaling is most likely to affect the pathogenesis of this disease, and a clear understanding of their functional roles may further elucidate the disease process.

Induction of the B7 family molecules by 12-O-tetradecanoyl phorbol 13-acetate (TPA) has been reported, however, the mechanism by which TPA up-regulates these molecules remains poorly understood. In this study, the expression of B7-DC, -H1, -H2, and -H3 in response to TPA was markedly induced in K562 cells. TPA also induced activation of ERK, p38 mitogen-activated protein kinase (MAPK), JNK, phosphatidylinositol-3-kinase (PI-3K), or nuclear factor (NF)-kappaB. Pre-treatments with protein kinase C (PKC) inhibitors significantly inhibited TPA-induced expression of B7-DC, -H1, -H2, and -H3 mRNA as well as TPA-induced phosphorylation of ERK, p38 MAPK, JNK, and PI-3K. TPA-induced expression of B7-DC, -H1, -H2, and -H3 mRNA was abrogated by pre-treatments with inhibitors of ERK and p38 MAPK. However, inhibition of PI-3K and JNK only caused decrease of TPA-induced B7-DC mRNA and B7-H3 mRNA, respectively. TPA-induced degradation of IkappaB-alpha was markedly abrogated by treatments with PKC inhibitors, but not by treatments with inhibitors of ERK, p38 MAPK, JNK, or PI-3K. NF-kappaB inhibitors significantly attenuated the expression of B7-DC, -H1, -H2, and -H3 mRNA in response to TPA. These results suggest that TPA induces the expression of B7-DC, -H1, -H2, and -H3 mRNA in K562 cells via activation of PKC, ERK, p38 MAPK, and NF-kappaB. Distinctly, the expression of B7-DC mRNA and -H3 mRNA in response to TPA is also PI-3K- and JNK-dependent, respectively.

Targeted therapy using monoclonal antibodies (mAbs) has emerged as a widely used form of immunotherapy in head and neck squamous cell carcinoma (HNSCC). Membrane-associated glycoprotein CD317 has been preferentially overexpressed by multiple myeloma cells, and its humanized mAb has been previously used in clinical trials. However, overexpression of CD317 in HNSCC and its correlation with tumor immunity is still uncertain. Here, the immunoreactivity of CD317 was detected in human HNSCC tissue microarrays, which contained 43 oral mucosa samples, 48 dysplasia samples, and 165 primary HNSCC. We found that CD317 expression was up-regulated in HNSCC tumor cells, and the CD317 expression level was independent of the histological grade, tumor size, and lymph node metastasis. Moreover, Kaplan-Meier survival curve analysis showed that patients with high expression of CD317 had a poor prognosis compared with patients with low expression. Furthermore, CD317 overexpression in HNSCC was correlated with immune checkpoint molecules PD-L1, B7-H3, and B7-H4 and tumor-associated macrophage markers (CD68 and CD163). We also observed that CD317 was overexpressed in immunocompetent mouse HNSCC tissue compared with normal tissue. Taken together, our findings demonstrate that CD317 overexpression indicates poor prognosis and is correlated with immune-related components in this patient cohort. CD317 may serve as a potential target for effective immunotherapy of HNSCC.

In the present study, we report an extremely rare case of a 31-year-old woman with neuroblastoma arising in an ovarian cystic teratoma. We analyzed the expression of activating receptors on natural killer (NK) cells derived from the patient's peripheral blood and peritoneal fluid. In addition, we investigated the presence of specific ligands recognized by different NK cell receptors on tumor cells. We show that NK cells isolated from peritoneal fluid expressed certain triggering receptors including DNAM-1 (CD226) and CD16 with lower intensity as compared to peripheral blood NK cells. Remarkably, at variance with most cases of childhood neuroblastoma, the tumor cells from this patient expressed substantial amounts of HLA class-I molecules. These molecules are known to be protective against NK cell-mediated lysis. In addition, neuroblastoma cells expressed B7-H3 (CD276), another surface molecule that inhibits NK cell function. Finally, this tumor did not express the PVR (CD155) and nectin-2 (CD112) ligands for the DNAM-1 activating NK receptor, which plays a crucial role in NK/neuroblastoma interactions. Altogether, these findings indicate that the neuroblastoma cells of this patient express an NK-resistant surface phenotype, which is at least in part similar to that previously described in a fraction of childhood neuroblastoma.

Endothelial progenitor cells (EPCs) provide an important source of recovery from blood vessel dysfunction. Late EPCs (LEPCs) are circulating blood cells that are capable of promoting vascular repair. Using transcriptome analysis, we identified distinctive LEPC profiles and found that CD276 (B7-H3) mRNA is strongly expressed in LEPCs. CD276 protein is present abundantly on the cell surface of LEPC when analyzed by fluorescence-activated cell sorter and immunocytochemistry. CD276, a B7 family member, is a type I transmembrane glycoprotein. The role of CD276 in LEPCs remains unknown. CD276 knockdown by lentivirus transduction in LEPCs significantly decreased proliferation and increased apoptosis of LEPCs in vitro. After CD276 silencing, the cell cycle of LEPCs was prone to remain at the G0/G1 phase, and the cell migration rates as well as transwell and wound-healing migration were decreased. CD276 knockdown in LEPCs increased the G1 phase regulators cyclin D2/D3/E1-cyclin-dependent kinases (CDK2/4/6), but decreased the S-G2-M phase regulators cyclin A/B-CDK1. However, LEPCs with CD276 knockdown resulted in increased tube formation in vitro and angiogenesis in a Matrigel plug assay in vivo. FoxC1/C2, an upstream signal of Notch in arterial cell proliferation, and Hey1/2, which is known to promote arterial differentiation in the vasculature, were upregulated in CD276 knockdown LEPCs. In LEPCS, CD276 has a positive effect on proliferation and migration of endothelial cells, but negative effects on angiogenesis, particularly endothelial cell differentiation. Our data indicate, for therapeutic purpose, that CD276 can be used to acquire and maintain cell populations of LEPCs and blocking CD276 will promote angiogenetic differentiation. We found that CD276 (B7-H3) is enriched on the cell membrane of LEPCs. CD276 knockdown reduced proliferation and migration of LEPCs by increasing cell cycle inhibitors such as p21cip1 and pRb and decreasing pErk1/2 and pAkt but promoted angiogenesis and endothelial cell differentiation by elevating vascular endothelial growth factor-vascular endothelial growth factor receptor 1 and p-p38. Stem Cells 2018.

Tumor cells may express on their surface various characteristic antigens that can induce antitumor immunity. However, cancer in human body may induce an immunosuppressive microenvironment that limits immune response to its antigens. For many years scientists have tried to develop an immunotherapy which would induce a potent antitumor immune response and lead to an elimination of the disease. One of the most promising immunotherapies is blockade of immune checkpoints, i.e. a group of costimulatory molecules negatively regulating the immune system. Their blockade would overcome immune tolerance in the tumor microenvironment and amplify antitumor immunity. What's more, immune checkpoint blockade may turn out even more profitable, as some of immune checkpoints and their ligands are expressed on tumor surface and on tumor infiltrating lymphocytes, contributing to the immunosuppressive cancer microenvironment. Phase III clinical trials have confirmed efficacy of an anti‑CTLA‑4 antibody ipilimumab, thereby leading to its acceptance for the treatment of advanced melanoma. Thanks to promising results of the phase I clinical trials, a breakthrough therapy designation and an early approval for the treatment have been granted to anti‑PD‑1 antibodies ‑ nivolumab (for the treatment of advanced melanoma and advanced non‑small cell lung cancer) and pembrolizumab (for the treatment of advanced melanoma) and, in the treatment of advanced bladder cancer, an anti‑PD‑L1 antibody ‑ MPDL3280A as well. Other immune checkpoints, such as LAG‑3, TIM‑3, BTLA, B7‑H3 and B7‑H4, are also under early evaluation.

The role of the type 1 transmembrane glycoprotein B7-H3 is controversial in tumorigenesis; thus, a better clarification of its involvement in cancer is crucial. In the present study, 79.3% of cervical cancer samples were found to be B7-H3 positive and the expression of B7-H3 was positively correlated with the clinical features of the samples. Silencing B7-H3 using small interfering RNA or blocking it with intracellular ScFv attenuated the malignancy of HeLa cells. By pull-down assay and liquid chromatography-mass spectrometry in HeLa cells, the glycolytic enzyme ENO1 was found to interact with B7-H3. Subsequently, the involvement of B7-H3 in glycolysis was investigated. We observed decreases in the levels of ATP and lactate, as well as c-Myc and lactate dehydrogenase A, upon B7-H3 downregulation in HeLa cells. The results of the present study provide evidence for B7-H3 mediating tumor glycolysis.