Immune checkpoint inhibitors (ICIs) have shown unprecedented benefits in various adult cancers, and this success has prompted the exploration of ICI therapy even in childhood malignances. Although the use of ICIs as individual agents has achieved disappointing response rates, combinational therapies are likely to promise better results. However, only a subset of patients experienced prolonged clinical effects, thus suggesting the need to identify robust bio-markers that predict individual clinical response or resistance to ICI therapy as the main challenge. In this review, we focus on how the use of ICIs in adult cancers can be translated into pediatric malignances. We discuss the physiological mechanism of action of each IC, including PD-1, PD-L1 and CTLA-4 and the new emerging ones, LAG-3, TIM-3, TIGIT, B7-H3, BTLA and IDO-1, and evaluate their prognostic value in both adult and childhood tumors. Furthermore, we offer an overview of preclinical models and clinical trials currently under investigation to improve the effectiveness of cancer immunotherapies in these patients. Finally, we outline the main predictive factors that influence the efficacy of ICIs, in order to lay the basis for the development of a pan-cancer immunogenomic model, able to direct young patients towards more specific immunotherapy.

Keywords: adult cancers; clinical trials; immune checkpoint inhibitors; immunotherapy; pediatric cancers.

We aimed to investigate the involvement of macroautophagy/autophagy in autoimmunity in rheumatoid arthritis (RA) through citrullination of VIM (vimentin) and its interaction with MHC class II in synovial fibroblasts (SFs). The cell surface expression of MHC class II and B7 costimulatory molecules on SFs was analyzed by flow cytometry after treatment with IFNG/IFN-γ (interferon gamma). Intracellular citrullinated autoantigens in SFs were analyzed by immunoblotting using serum from anti-citrullinated peptide antibodies (ACPA)-positive patient as a primary antibody. SFs were incubated in serum-free medium or treated with proteasome inhibitor MG132 to induce autophagy. An autophagy inhibitor 3-methyladenin (3-MA) was used. Intracellular citrullinated VIM (cVIM) was evaluated by immunoblotting and immunocytochemistry. The interaction between MHC class II and cVIM was evaluated with co-immunoprecipitation and proximity ligation assay (PLA). We demonstrated that MHC class II, CD274/B7-H1 and PDCD1LG2/B7-DC were expressed on SFs following treatment with IFNG whereas CD276/B7-H3 was detected on SFs regardless of the presence of IFNG. ACPA-positive sera recognized a 54 kDa protein in SFs. By immunoprecipitation, the 54 kDa protein recognized by RA sera was revealed to be cVIM. Following induction of autophagy, intracellular cVIM was increased in SFs but the effect was canceled by 3-MA. The interaction between MHC class II and cVIM was demonstrated by co-immunoprecipitation. Furthermore, PLA revealed the significant increase of MHC class II-cVIM interaction following induction of autophagy. Our findings suggest that SFs may contribute to the autoimmunity in RA through citrullination of VIM and its interaction with MHC class II promoted by autophagy. Abbreviations: 3-MA: 3-methyladenine; ACPA: anti-citrullinated peptide antibodies; anti-CCP: anti-cyclic citrullinated peptide antibody; cVIM: citrullinated VIM; BECN1: beclin1; DAPI: 4',6-diamidino-2-phenylindole; FBS: fetal bovine serum; HLA: human leukocyte antigen; IFNG/IFN-γ: interferon gamma; IL6: interleukin 6; IP: immunoprecipitation; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MFI: mean fluorescence index; MHC: major histocompatibility complex; OA: osteoarthritis; PADI: peptidyl arginine deiminase; PepA: pepstatin A; PBS: phosphate-buffered saline; PtdIns3K: phosphatidylinositol 3-kinase; RA: rheumatoid arthritis; SFs: synovial fibroblasts; siRNA: small interfering RNA; VIM: vimentin.

B7-H3 is a member of the B7 superfamily of immune checkpoint molecules. B7-H3 up regulation has been linked to cancer development and progression in many tumors including prostate cancer. To clarify the potential utility of B7-H3 as a prognostic biomarker, B7-H3 expression was analyzed by immunohistochemistry in more than 17 000 prostate cancers. Normal prostatic glands were largely B7-H3 negative, while membranous B7-H3 immunostaining was seen in 47.0% of analyzed cancers. B7-H3 immunostaining was weak in 12.3%, moderate in 21.1% and strong in 13.5% of cases. High B7-H3 expression was associated with pT, Gleason score, lymph node metastasis, high Ki67 labeling index and early prostate-specific antigen recurrence (P < 0.0001 each). High B7-H3 expression was also linked to high androgen receptor expression and TMPRSS2:V-ets avian erythroblastosis virus E26 oncogene homolog (ERG) fusions (P < 0.0001 each). Multivariate analyses showed a strong independent prognostic impact of high B7-H3 expression in all cancers and in the ERG negative subgroup. Comparison with previously analyzed frequent chromosomal deletions revealed a close association with Phosphatase and Tensin Homolog deletions. Analysis of B7-H3, alone or in combination with other markers, might be of clinical utility, especially in the subgroup of ERG negative prostate cancers.

Keywords: B7-H3; CD276; TMA; prognosis; prostate cancer.

Phyllodes tumors are rare biphasic breast tumors with the potential for both local recurrence and distant metastasis. The aberrant expression of B7-H3 and B7-H4 B7 molecules could be potential targets for future development of immunotherapeutic approaches. This work was undertaken to evaluate the expression of B7-H3 and B7-H4 in phyllodes tumors and assess the association with the grade and clinical behavior of phyllodes tumors. In addition, the roles of B7-H3 and B7-H4 in the regulation of tumor immune surveillance were evaluated by assessing the relationship between B7-H3/B7-H4 expression and T-cell infiltration. The messenger RNA and protein expression of B7-H3/B7-H4 were determined by RNAscope in situ hybridization and immunohistochemistry, respectively, in 101 phyllodes tumors (60 benign, 26 borderline, and 15 malignant) using a tissue microarray. Immunohistochemistry for CD3 and CD8 was also performed. B7-H3 messenger RNA and protein appeared to be concentrated mainly in the stromal compartment of phyllodes tumors. However, B7-H4 messenger RNA and protein were undetectable in the stromal compartment of phyllodes tumors. Stromal B7-H3 messenger RNA and protein expression were noted in 10 (16.7%) and 31 (51.7%) of 60 benign phyllodes tumors, 12 (46.1%) and 20 (76.9%) of 26 borderline phyllodes tumors, and 10 (66.7%) and 13 (86.7%) of 15 malignant phyllodes tumors, respectively. Stromal B7-H3 messenger RNA and protein expression increased as phyllodes tumors progressed from benign to borderline and finally to the malignant grade (Pearson's R = 0.411, p < 0.001 and Pearson's R = 0.293, p = 0.003, respectively). The recurrence rate was higher in the stromal B7-H3 messenger RNA or protein-positive group than in the negative group, but this difference was not significant. Stromal B7-H3 protein expression inversely correlated with the densities of CD3+ and CD8+ T-cell infiltrates ( p = 0.001 and p = 0.027, respectively). These results suggest that B7-H3 is involved in the progression of phyllodes tumors and may contribute to their immune surveillance.

Head and neck cancers (HNCs) are the sixth most common type of cancer in the world. Despite the development of refined surgical techniques and precise targeted radiation, patients with HNCs have a dismal prognosis. Here, we examine the expression profile of B7-H3 in HNCs and verify whether B7-H3 can serve as a novel therapeutic target for HNCs via anti-B7-H3×CD3 bispecific antibodies (biAbs). We analyzed the expression level of B7-H3 in 274 HNC samples and evaluated the association between B7-H3 expression and clinicopathological parameters. Anti-B7-H3×CD3 biAbs were constructed, and the efficacy of these biAbs in targeting HNCs was assessed in vitro and in vivo. As a result, high expression of B7-H3 was detected in 66.1% of clinical HNC samples and was correlated with poor survival. Specific antitumor effects of anti-B7-H3×CD3 biAbs were confirmed in vitro using HNC cell lines. In xenograft HNC mouse model, anti-B7-H3×CD3 biAbs delayed tumor growth and prolonged survival. In conclusion, B7-H3 is frequently overexpressed in HNCs and could be a promising therapeutic target for biAb therapy.

BACKGROUND

The B7 family member B7-H3 (CD276) is involved in tumor immunity including Non-small-cell lung cancer (NSCLC). We have previously demonstrated an elevated circulating level of the soluble form of B7-H3 (sB7-H3) in NSCLC patients. However, the expression of sB7-H3 in NSCLC-derived malignant pleural effusions (MPEs) and its clinical significance remain elusive.

METHODS

We measured and compared sB7-H3 levels in NSCLC-derived MPEs (n=52) and nonneoplastic pleural effusions (NPEs) (n=47), and then evaluated the diagnostic performance for sB7-H3 in NSCLC-derived MPEs. The correlation between MPE-derived sB7-H3 and clinical characteristics including TNM staging system was also analyzed.

RESULTS

The median value of sB7-H3 in 52 MPEs and 47 NPEs were 41.60ng/ml (interquartile range: 36.76-51.30ng/ml) and 31.55ng/ml (interquartile range: 26.97-36.63ng/ml) (P<0.0001), respectively. At the proposed cut-off value at 38.41ng/ml, sB7-H3 was capable of discriminating NSCLC-derived MPEs from NPEs with a sensitivity of 67.3% and a specificity of 91.5% respectively. Furthermore, MPEs-derived sB7-H3 was correlated with smoking status (P=0.005), primary tumor size (T factor, P=0.03), regional lymph node dissemination (N factor, P=0.019) and distant metastasis (M factor, P=0.009) of NSCLC patients.

CONCLUSIONS

Upregulated sB7-H3 expression in MPEs is correlated with TNM stage of NSCLC and may serve as a potential biomarker for NSCLC-derived MPEs.

B7-H3 is an immune co-stimulatory molecule of the B7 family that contains a set of immunoglobulin-V (IgV) and immunoglobulin-C (IgC) domains. To explore the evolutionary process of B7-H3 gene, we conducted a genome-wide structure and phylogenetic analysis of B7-H3 genes in currently sequenced genomes. On the basis of the available data, 17 mammalian B7-H3 genes were predicted to have tandemly duplicated 4Ig domains. The analysis of gene structure and phylogenesis reveal that these 4IgB7-H3 genes resulted from domain duplication. Nevertheless, no difference in function has been observed between the two isoforms. It is more likely that domain duplication in 4IgB7-H3 leads to functional redundancy.

The objective of the present study was to investigate the association of B7-H3 expression and cluster of differentiation (CD)163+ tumor-associated macrophage (TAM) infiltration with clinicopathological parameters in urothelial cell carcinoma of the bladder (UCB), and to investigate their potential conjoint effects on progression of UCB. B7-H3 expression and CD163+ TAM infiltration in tumor specimens from 134 consecutive patients that underwent radical cystectomy for UCB were tested using immunohistochemistry, followed by statistical analysis. In these 134 patients, B7-H3 expression and CD163+ TAM infiltration in the bladder carcinoma tissues were significantly associated with an increased ratio of vascular invasion (P=0.009; P=0.012) and distant metastasis (P=0.015; P=0.038); however, they were not associated with gender, age, pathologic grade, tumor stage, recurrence or lymphatic metastasis. The results of χ2 test analysis indicated that CD163+ TAM infiltration and B7-H3 expression were positively correlated (χ2=20.714; P<0.001). Overall survival (OS) and progression-free survival (PFS) rates were significantly worsened by high B7-H3 expression (P=0.002; P=0.020). However, CD163+ TAM infiltration was not associated with OS or PFS rate. Notably, the OS and PFS rates in patients with high B7-H3 expression or high CD163+ TAM infiltration were significantly poorer than the patients with low B7-H3 expression (P<0.001; P<0.001) or low CD163+ TAM infiltration (P=0.022; P=0.017) in the subgroup of 115 patients with muscle-invasive bladder cancer. The results of the present study indicate that B7-H3 expression level could be used as an independent prognostic indicator following radical cystectomy for UCB and patients with high B7-H3 expression and high CD163+ TAM infiltration experience a poorer prognosis.

The co-stimulatory ligands of B7-family have been confirmed to play an important role in negatively regulating the T-cell mediated anti-tumor immunity. In addition, these inhibitory molecules are also aberrantly expressed on various human cancers tissues, and significantly associated with cancer progression and patients' poor prognoses. We have previously reported that B7-H3 and B7-H4 ligands are highly expressed in human esophageal cancer tissues. Herein, we tried to further analyze the value of their combined expression on prognostic prediction for esophageal cancer patients. We found that the combined expression of both B7-H3 and B7-H4 could be used as a valuable risk factor for predicting the prognosis of esophageal cancer patients (P=0.003). Moreover the status of these patients with high expression of both B7-H3 and B7-H4, was positively and significantly associated with the tumor invasion depth (P=0.0414) and TNM stage (P=0.0414). The Cox multivariate proportional hazards regression analysis revealed that the tumor size (P=0.007), the TNM stage (P=0.024) and the status of both B7-H3 and B7-H4 high expression (P=0.011), could be used as an independent risk factor for predicting patients' postoperative prognosis, respectively. In conclusion, our data indicated that the combined application of B7-H3 and B7-H4 expression can be effectively used as a prognostic marker in esophageal cancer patients.

OBJECTIVE

The co-stimulatory molecule B7-H3 plays an important role in prognosis of several malignancies. However, its prognostic value in clinic in patient with colorectal cancer (CRC) is still controversial. This meta-analysis evaluated the relationship between B7-H3 expression and the outcomes of CRC patients.

METHODS

PubMed, Google Scholar, Embase, CNKI and Wanfang database were searched for the studies on the relationship between the expression of B7-H3 and prognosis of CRC patients. Pooled odds ratios (ORs) analysis with 95% confidence interval (95% CIs) for lymph node metastasis, 24-month overall survival and 72-month overall survival were performed mainly using Review Manager 5.0.

RESULTS

Six articles including 1,202 total CRC cases were included for the meta-analysis. Pooled analysis with fixed-effects model showed that B7-H3 expression had no relationship with lymphatic metastasis in CRC patients (Fixed-effects, OR= 1.18; 95 % CI:0.87-1.61, P=0.28). However, B7-H3 expression was associated with 24-month overall survival (Fixed-effects, OR=0.48, 95% CI:0.32-0.74, P<0.001) and 72-month overall survival (Fixed-effects, OR = 0.61, 95% CI: 0.43-0.85, P< 0.01) in CRC patients.

CONCLUSIONS

The co-stimulatory molecule B7-H3 expression is negatively associated with lymph node metastasis in CRC. However, B7-H3 detection might be a feasible and effective means to predict the prognosis in CRC patients.

The immunoregulatory protein B7-H3, a member of the B7 family, has been confirmed to be highly expressed in colon cancer. However, the exact influence of B7-H3 on the features and antitumor ability of γδT cells in colon cancer remains unknown. In the present study, we investigated that the proportions of B7-H3⁺ γδT cells were distinctly increased in the peripheral blood and tumor tissues of colon cancer patients. B7-H3 blockade or knockdown promoted proliferation, inhibited cell apoptosis and induced the expression of activation markers (CD25 and CD69) on Vδ2 T cells. In contrast, treatment with the B7-H3 agonist 4H7 had the opposite effect. Furthermore, B7-H3 suppressed IFN-γ expression by inhibiting T-bet in Vδ2 T cells. Moreover, B7-H3 mediated the inhibition of Vδ2 T cell cytotoxicity via the downregulation of IFN-γ and perforin/granzyme B expression. More importantly, blocking the B7-H3 function significantly enhanced the cytotoxicity of Vδ2 T cells against colon cancer cells in vivo. Therefore, the inhibition or blockade of B7-H3 is a potential immunotherapeutic approach for colon cancer.

Of the four primary subgroups of medulloblastoma, the most frequent cytogenetic abnormality, i17q, distinguishes Groups 3 and 4 which carry the highest mortality; haploinsufficiency of 17p13.3 is a marker for particularly poor prognosis. At the terminal end of this locus lies miR-1253, a brain-enriched microRNA that regulates bone morphogenic proteins during cerebellar development. We hypothesized miR-1253 confers novel tumor-suppressive properties in medulloblastoma. Using two different cohorts of medulloblastoma samples, we first studied the expression and methylation profiles of miR-1253. We then explored the anti-tumorigenic properties of miR-1253 in parallel with a biochemical analysis of apoptosis and proliferation, and isolation of oncogenic targets using high-throughput screening. Deregulation of miR-1253 expression was noted, both in medulloblastoma clinical samples and cell lines, by epigenetic silencing via hypermethylation; specific de-methylation of miR-1253 not only resulted in rapid recovery of expression but also a sharp decline in tumor cell proliferation and target gene expression. Expression restoration also led to a reduction in tumor cell virulence, concomitant with activation of apoptotic pathways, cell cycle arrest, and reduction of markers of proliferation. We identified two oncogenic targets of miR-1253, CDK6 and CD276, whose silencing replicated the negative trophic effects of miR-1253. These data reveal novel tumor-suppressive properties for miR-1253, i.e. 1) loss of expression via epigenetic silencing, 2) negative trophic effects on tumor aggressiveness, and 3) downregulation of oncogenic targets.

Background: Craniopharyngioma (CP) is a common refractory tumor of the central nervous system. However, little is known about the expression and clinical significance of B7 family ligands/receptors in CP patients. Thus, we conducted the present study to address this issue in a cohort of 132 CP cases.

Methods: We mapped and quantified the expression of B7 family ligands/receptors molecules programmed cell death ligand 1 (PD-L1), B7-H3, B7-H4 and V-domain Ig-containing suppressor of T cell activation (VISTA) in 89 adamantinomatous-type CP and 43 papillary-type CP samples using immunohistochemistry and immunofluorescence. Associations between the marker levels, clinicopathological variables and survival were evaluated.

Results: The positive rates of PD-L1, B7-H3, B7-H4 and VISTA in the cohort of 132 CP cases were 76.5%, 100%, 40.2% and 80.3%, respectively. The cut-off values of PD-L1, B7-H3, B7-H4 and PD-L1 expression were determined by survival receiver operating characteristic (ROC) package, which was 70, 182, 0 and 20, respectively. Elevated expressions of PD-L1, B7-H3, B7-H4 and VISTA were significantly associated with some clinicopathological characteristics. Kaplan-Meier analysis indicated that higher VISTA expressions correlated with better overall survival (OS) and progression-free survival (PFS) (p=0.0053 and p=0.0066, respectively). Multivariate Cox regression analysis indicated that VISTA was an independent prognostic factor for OS (p=0.018) but not for PFS (p=0.898).

Conclusions: We found variable expression of PD-L1, B7-H3, B7-H4 and VISTA proteins in CPs. The results suggest that the expression level of VISTA may be used as an important indicator to predict the OS and PFS of CPs. B7 family ligands/receptors could be potential immunotherapeutic targets when treating CPs.

Keywords: pathology; tumours.

Background: High-risk neuroblastomas (HR-NBs) are rare, aggressive pediatric cancers characterized by resistance to therapy and relapse in more than 30% of cases, despite using an aggressive therapeutic protocol including targeting of GD2. The mechanisms responsible for therapy resistance are unclear and might include the presence of GD2neg/low NB variants and/or the expression of immune checkpoint ligands such as B7-H3.

Method: Here, we describe a multiparametric flow cytometry (MFC) combining the acquisition of 10⁶ nucleated singlets, Syto16pos CD45neg CD56pos cells, and the analysis of GD2 and B7-H3 surface expression. 41 bone marrow (BM) aspirates from 25 patients with NB, at the onset or relapse, are analyzed, comparing results with cytomorphological analysis (CA) and/or immunohistochemistry (IHC). Spike in experiments assesses the sensitivity of MFC. Kaplan-Meier analysis on 498 primary NBs selects novel prognostic markers possibly integrating the MFC panel.

Results: No false positive are detected, and MFC shows high sensitivity (0.0005%). Optimized MFC identifies CD45negCD56pos NB cells in 11 out of 12 (91.6%) of BM indicated as infiltrated by CA, 7 of which coexpress high levels of GD2 and B7-H3. MFC detects CD45negCD56posGD2neg/low NB variants expressing high surface levels of B7-H3 in two patients with HR-NB (stage M) diagnosed at 53 and 139 months of age. One of them has a non-MYCN amplified tumor with unusual THpos PHOX2Bneg phenotype, which relapsed 141 months post-diagnosis with BM infiltration and a humerus lesion. All GD2neg/low NB variants are detected in patients at relapse. Kaplan-Meier analysis highlights an interesting dichotomous prognostic value of MML5, ULBPs, PVR, B7-H6, and CD47, ligands involved in NB recognition by the immune system.

Conclusions: Our study validates a sensitive MFC analysis providing information on GD2 and B7-H3 surface expression and allowing fast, specific and sensitive evaluation of BM tumor burden. With other routinely used diagnostic and prognostic tools, MFC can improve diagnosis, prognosis, orienting novel personalized treatments in patients with GD2low/neg NB, who might benefit from innovative therapies combining B7-H3 targeting.

Keywords: antigens; immune evation; immunotherapy; neoplasm; neuroblastoma; tumor biomarkers.

Immune cells might participate in the ontogenesis of osteosarcoma. B7-H3 is a new discovered T cell co-stimulatory molecule that was found to be overexpressed in malignant tumors. We aimed to investigate the dynamic expression level of B7-H3 in nude mice with osteosarcoma. A nude mouse osteosarcoma model was successfully established. B7-H3 expression and distribution changes in the early, middle, and late phases of osteosarcoma formation after tumor implantation were observed. Reverse transcription-polymerase chain reaction and western blot analyses were applied to measure the B7-H3 mRNA and protein dynamic changes. Confocal microscopy and immunohistochemistry were used to determine B7-H3 localization and CD3+ T cell expression, respectively, in osteosarcoma tissue. B7-H3 mRNA and protein levels fluctuated during the process of osteosarcoma formation in the nude mouse model. Expression levels were lower in the early and middle phases, while B7-H3 mRNA and protein were overexpressed in the late stage. Accordingly, CD3+ T cell numbers in the early, middle, and late phases in osteosarcoma tissue were 93 ± 13, 92 ± 12, and 46 ± 15, respectively; they can be seen to have decreased significantly in the late stage (P < 0.05). Overall, our results indicated that the B7-H3 expression level is correlated with tumor volume and severity; therefore, it might serve as a tumor biomarker for osteosarcoma.

Spectroscopic photoacoustic (sPA) molecular imaging has high potential for identification of exogenous contrast agents targeted to specific markers. Antibody-dye conjugates have recently been used extensively for preclinical sPA and other optical imaging modalities for highly specific molecular imaging of breast cancer. However, antibody-based agents suffer from long circulation times that limit image specificity. Here, the efficacy of a small protein scaffold, the affibody (ABY), conjugated to indocyanine green (ICG), a near-infrared fluorescence dye, as a targeted molecular imaging probe is demonstrated. In particular, B7-H3 (CD276), a cellular receptor expressed in breast cancer, was imaged via sPA and fluorescence molecular imaging to differentiate invasive tumors from normal glands in mice. Administration of ICG conjugated to an ABY specific to B7-H3 (ABY_B7-H3-ICG) showed significantly higher signal in mammary tumors compared to normal glands of mice. ABY_B7-H3-ICG is a compelling scaffold for molecular sPA imaging for breast cancer detection.

Targeting cancer antigens by T cell-engaging bispecific antibody (BiAb) or chimeric antigen receptor T cell therapy has achieved successes in hematological cancers, but attempts to use it to fight solid cancers have been disappointing, in part due to antigen escape. MEK inhibitor had limited activity as a single agent, but enhanced antitumor activity when combined with other therapies, such as targeted drugs or immunotherapy agents. This study aimed to analyze the expression of B7-H3 in non-small-cell lung cancer (NSCLC) and bladder cancer (BC) and to evaluate the combinatorial antitumor effect of B7-H3 × CD3 BiAb with MEK inhibitor trametinib. We found B7-H3 was highly expressed in NSCLC and BC compared with normal samples and its increased expression was associated with poor prognosis. Treatment with trametinib alone could induce apoptosis in tumor cell, while has no effect on T cell proliferation, and a noticeable elevation of B7-H3 expression in tumor cells was also observed following treatment. B7-H3 × CD3 BiAb specifically and efficiently redirected their cytotoxicity against B7-H3 overexpressing tumor cells both in vitro and in xenograft mouse models. While trametinib treatment alone affected tumor growth, the combined therapy increased T cell infiltration and significantly suppressed tumor growth. Together, these data suggest that combination therapy with B7-H3 × CD3 BiAb and MEK inhibitor may serve as a new therapeutic strategy in the future clinical practice for the treatment of NSCLC and BC.

Keywords: B7-H3; bispecific antibody; bladder cancer; immunotherapy; non-small-cell lung cancer; trametinib.

BACKGROUND

MicroRNAs play roles in the pathogenesis of bronchial asthma. However, the mechanism of miR-29c in allergic asthma remains unclear. This study is to elucidate the regulation of Th cell differentiation by miR-29c in mononuclear macrophages.

METHODS

A total of 52 children with asthma exacerbation and 26 children as controls were enrolled in the study. CD14+ monocytes were isolated from the peripheral blood. Differential expressions of microRNAs were evaluated using microarray analysis and miR-29c expression in monocytes was determined by qRT-PCR. The plasma B7-H3 was determined by ELISA. Transfection studies and luciferase reporter assay were performed to confirm target gene of miR-29c and its function.

RESULTS

Compared to controls, 88 miRNAs in blood monocytes were up-regulated and 41 miRNAs down-regulated including miR-29c in asthma children. Children with asthma exacerbation had significantly lower level of miR-29c and higher level of plasma B7-H3 compared to controls (both P < 0.05). Functional studies based on luciferase reporter assay and immunofluorescence staining suggest that B7-H3 is the direct target of miR-29c and transfection anti-miR-29c into macrophages could enhance ROR-γt and GATA-3 expression in co-cultured CD4+ T cells and increase levels of IL-4 and IL-17 in supernatants.

CONCLUSIONS

The axis of miR-29c/B7-H3 plays an important role in children with asthma through regulating Th2/Th17 cell differentiation and may provide new targets for treatment of asthma.

Background: In order to find new immune targets for lung cancer with different EGFR mutant status, we describe differential expression profiles of checkpoint molecules of the new discovery B7 family member to find new immune targets for lung cancer with different EGFR statuses.

Methods: We performed immunohistochemistry with antibodies of B7-H3, B7-H4, VISTA, B7-H6, HHLA2, IDO-1, PD-L1 and CD8 in lung adenocarcinoma tissues constructed from 372 cases in the discovery cohort and 231 cases in the validation set. The differential expression profiles of these indices in EGFR mutant and wild-type lung adenocarcinoma was described and compared.

Results: In the discovery cohort, the median IHC scores of B7-H4 and HHLA2 for the EGFR mutant group were significantly higher than those in the wild-type group (median score [interquartile range], mutant vs. wild type: 3.250 [0-7.000] vs. 5.000 [1.000-7.000], P = 0.045 for B7-H4; 8.000 [6.000-10.500] vs. 7.000 [5.000-8.630] P = 0.003 for HHLA2). Meanwhile, the median IHC scores of IDO-1 and PD-L1 in the wild-type group were significantly higher than those in the mutant group (median score [interquartile range], mutant vs. wild type: 1.000 [0-5.000] vs. 3.000 [0-8.500], P = 0.000 for IDO-1; 0 [0-3.500] vs. 3.000 [0-6.000], P = 0.000 for PD-L1). Results above was confirmed in the discovery cohort. The increased CD8 and decreased HHLA2 expression levels were associated with long disease-free survival in lung adenocarcinoma (P = 0.000 for CD8 expression and P = 0.004 for HHLA2 expression).

Conclusions: B7-H4 and HHLA2 are promising immune targets for lung adenocarcinoma, especially for patients with EGFR mutation.

Keywords: B7 family; EGFR Mutation; IDO-1; Lung cancer; PD-L1.

Improving the survival of patients with osteosarcoma has long proved challenging, although the treatment of this disease is on the precipice of advancement. The increasing feasibility of molecular profiling together with the creation of both robust model systems and large, well-annotated tissue banks has led to an increased understanding of osteosarcoma biology. The historical invariability of survival outcomes and the limited number of agents known to be active in the treatment of this disease facilitate clinical trials designed to identify efficacious novel therapies using small cohorts of patients. In addition, trial designs will increasingly consider the genetic background of the tumour through biomarker-based patient selection, thereby enriching for clinical activity. Indeed, osteosarcoma cells are known to express a number of surface proteins that might be of therapeutic relevance, including B7-H3, GD2 and HER2, which can be targeted using antibody-drug conjugates and/or adoptive cell therapies. In addition, immune-checkpoint inhibition might augment the latter approach by helping to overcome the immunosuppressive tumour microenvironment. In this Review, we provide a brief overview of current osteosarcoma therapy before focusing on the biological insights from the molecular profiling and preclinical modelling studies that have opened new therapeutic opportunities in this disease.

BACKGROUND

Members of the B7 superfamily costimulate the proliferation of lymphocytes during the initiation and maintenance of antigen-specific humoral and cell-mediated immune responses. B7-H3 (CD276) is a newly identified member of the B7 superfamily. It has been shown that B7-H3 plays a significant role in regulating T cell response in humans and mice, but it is not known whether a counterpart of human or murine B7-H3 exists in porcine species.

RESULTS

We cloned the porcine 4ig-b7-h3 gene using a blast search at the NCBI database with human b7-h3, RT-PCR and 3'-terminus RACE. Protein sequence analysis showed that the protein encoded by this gene contained 4Ig-like domains and was 90.88% identical with human 4Ig-B7-H3. Results of Dot-blot hybridization and RT-PCR showed that B7-H3 was broadly distributed in porcine tissues mainly as two isoforms, 2Ig-B7-H3 and 4Ig-B7-H3, of which 4Ig-B7-H3 was dominant. We further demonstrated that porcine 4Ig-B7-H3 was able to inhibit the proliferation and cytokine production of porcine T cells activated through the TCR pathway, similar to human B7-H3.

CONCLUSIONS

We cloned the porcine 4ig-b7-h3 gene and demonstrated that the porcine 4Ig-B7-H3 serves as a negative regulator for the T-cell immune response.

To establish a novel and widely applicable payload-linker technology for antibody-drug conjugates (ADCs), we have focused our research on applying exatecan mesylate (DX-8951f), a potent topoisomerase I inhibitor, which exhibits extensive antitumor activity as well as significant myelotoxicity, as the payload part. Through this study, we discovered a promising exatecan derivative (DX-8951 derivative, DXd), that has the characteristics of low membrane permeability and shows considerably less myelotoxicity than that shown by exatecan mesylate in an in vitro human colony forming unit-granulocyte macrophage assay. DXd was further used for drug conjugation by using commercially or clinically useful monoclonal antibodies to evaluate the potency of the ADC. The result revealed that the DXd-ADCs targeting CD30, CD33, and CD70 were effective against each of their respective target-expressing tumor cell lines. Moreover, a novel DXd-ADC targeting B7-H3, which is a new target for ADCs, also showed potent antitumor efficacy both in vitro and in vivo. In conclusion, this study showed that this novel topoisomerase I inhibitor-based ADC technology is widely applicable to a diverse number of antibodies and is expected to mitigate myelotoxicity, thereby possibly resulting in better safety profiles than that of existing ADC technologies.