CD177 plays an important role in the proliferation and differentiation of myeloid lineage cells including neutrophils, myelocytes, promyelocytes, megakaryocytes, and early erythroblasts in bone marrow. CD177 deficiency is a common phenotype in humans. Our previous studies revealed genetic mechanisms of human CD177 deficiency and expression variations. Up to now, immune functions of CD177 remain undefined. In the current study, we revealed human IgG as a ligand for CD177 by using flow cytometry, bead-rosette formation, and surface plasmon resonance (SPR) assays. In addition, we show that CD177 variants affect the binding capacity of CD177 for human IgG. Furthermore, we show that the CD177 genetic variants significantly affect antibody-dependent cell-mediated cytotoxicity (ADCC) function. The demonstration of CD177 as a functional IgG Fc-receptor may provide new insights into CD177 immune function and genetic mechanism underlying CD177 as biomarkers for human diseases.

Prostate stem cell antigen (PSCA) is expressed in all stages of prostate cancer, including in advanced androgen-independent tumors and bone metastasis. PSCA may associate with prostate carcinogenesis and lineage plasticity in prostate cancer. PSCA is also a promising theranostic marker for a variety of other solid tumors, including pancreatic adenocarcinoma and renal cell carcinoma. Here, we identified a novel fully human PSCA antibody using phage display methodology. The structure-based affinity maturation yielded a high-affinity binder, F12, which is highly specific and does not bind to 6,000 human membrane proteins based on a membrane proteome array assay. F12 targets PSCA amino acids 63-69 as tested by the peptide scanning microarray, and it cross-reacts with the murine PSCA. IgG1 F12 efficiently internalizes into PSCA-expressing tumor cells. The antimitotic reagent monomethyl auristatin E (MMAE)-conjugated IgG1 F12 (ADC, F12-MMAE) exhibits dose-dependent efficacy and specificity in a human prostate cancer PC-3-PSCA xenograft NSG mouse model. This is a first reported ADC based on a fully human PSCA antibody and MMAE that is characterized in a xenograft murine model, which warrants further optimizations and investigations in additional preclinical tumor models, including prostate and other solid tumors.

BACKGROUND: Cancer stem-like cells (CSCs) play an important role in initiation and progression of aggressive cancers, including esophageal cancer. Natural killer (NK) cells are key effector lymphocytes of innate immunity that directly attack a wide variety of cancer cells. NK cell-based therapy may provide a new treatment option for targeting CSCs. In this study, we aimed to investigate the sensitivity of human esophageal CSCs to NK cell-mediated cytotoxicity.
METHODS: CSCs were enriched from human esophageal squamous cell carcinoma cell lines via sphere formation culture. Human NK cells were selectively expanded from the peripheral blood of healthy donors. qRT-PCR, flow cytometry and ELISA assays were performed to examine RNA expression and protein levels, respectively. CFSE-labeled target cells were co-cultured with human activated NK cells to detect the cytotoxicity of NK cells by flow cytometry.
RESULTS: We observed that esophageal CSCs were more resistant to NK cell-mediated cytotoxicity compared with adherent counterparts. Consistently, esophageal CSCs showed down-regulated expression of ULBP-1, a ligand for NK cells stimulatory receptor NKG2D. Knockdown of ULBP-1 resulted in significant inhibition of NK cell cytotoxicity against esophageal CSCs, whereas ULBP-1 overexpression led to the opposite effect. Finally, the pro-differentiation agent all-trans retinoic acid was found to enhance the sensitivity of esophageal CSCs to NK cell cytotoxicity.
CONCLUSIONS: This study reveals that esophageal CSCs are more resistant to NK cells through down-regulation of ULBP-1 and provides a promising approach to promote the activity of NK cells targeting esophageal CSCs.

CD73 is a cell-surface ectoenzyme that hydrolyzes the conversion of extracellular adenosine monophosphate to adenosine, which in turn can promote resistance to immune checkpoint blockade therapy. Immune response may therefore be improved by targeting tumor CD73, and this possibility underlines the need to non-invasively assess tumor CD73 level. In this study, we developed a cysteine site-specific 89Zr-labeled anti-CD73 (89Zr-CD73) IgG immuno-PET technique that can image tumor CD73 expression in living bodies. Anti-CD73 IgG was reduced with tris(2-carboxyethyl)phosphine, underwent sulfohydryl moiety-specific conjugation with deferoxamine-maleimide, and was radiolabeled with 89Zr. CT26 mouse colon cancer cells, CT26/CD73 cells engineered to constitutively overexpress CD73, and 4T1.2 mouse breast cancer cells underwent cell binding assays and western blotting. Balb/c nude mice bearing tumors underwent 89Zr-CD73 IgG PET imaging and biodistribution studies. 89Zr-CD73 IgG showed 20-fold higher binding to overexpressing CT26/CD73 cells compared to low-expressing CT26 cells, and moderate expressing 4T1.2 cells showed uptake that was 38.9 ± 1.51% of CT26/CD73 cells. Uptake was dramatically suppressed by excess unlabeled antibody. CD73 content proportionately increased in CT26 and CT26/CD73 cell mixtures was associated with linear increases in 89Zr-CD73 IgG uptake. 89Zr-CD73 IgG PET/CT displayed clear accumulation in CT26/CD73 tumors with greater uptake compared to CT26 tumors (3.13 ± 1.70%ID/g vs. 1.27 ± 0.31%ID/g at 8 days; P = 0.04). Specificity was further supported by low CT26/CD73 tumor-to-blood ratio of 89Zr-isotype-IgG compared to 89Zr-CD73 IgG (0.48 ± 0.08 vs. 2.68 ± 0.52 at 4 days and 0.53 ± 0.07 vs. 4.81 ± 1.02 at 8 days; both P < 0.001). Immunoblotting and immunohistochemistry confirmed strong CD73 expression in CT26/CD73 tumors and low expression in CT26 tumors. 4T1.2 tumor mice also showed clear 89Zr-CD73 IgG accumulation at 8 days (3.75 ± 0.70%ID/g) with high tumor-to-blood ratio compared to 89Zr-isotype-IgG (4.91 ± 1.74 vs. 1.20 ± 0.28; P < 0.005). 89Zr-CD73 IgG specifically targeted CD73 on high expressing cancer cells in vitro and tumors in vivo. Thus, 89Zr-CD73 IgG immuno-PET may be useful for the non-invasive monitoring of CD73 expression in tumors of living subjects.

CD73, a cell surface-bound nucleotidase, serves as a crucial metabolic and immune checkpoint. Several studies have shown that CD73 is widely expressed on immune cells and plays a critical role in immune escape, cell adhesion and migration as a costimulatory molecule for T cells and a factor in adenosine production. However, recent studies have revealed that the protumour effects of CD73 are not limited to merely inhibiting the antitumour immune response. Nicotinamide adenine dinucleotide (NAD+) is a vital bioactive molecule in organisms that plays essential regulatory roles in diverse biological processes within tumours. Accumulating evidence has demonstrated that CD73 is involved in the transport and metabolism of NAD, thereby regulating tumour biological processes to promote growth and proliferation. This review provides a holistic view of CD73-regulated NAD + metabolism as a complex network and further highlights the emerging roles of CD73 as a novel target for cancer therapies.

UNASSIGNED: Myocardial inflammation and apoptosis induced by cirrhosis are among the primary mechanisms of cirrhotic cardiomyopathy. CD73, a common extracellular nucleotidase also known as 5\'-nucleotidase, is associated with the progression of inflammation and immunity in multiple organs. However, the mechanism by which CD73 contributes to myocardial inflammation and apoptosis in cirrhosis remains unclear.
UNASSIGNED: In this study, a cirrhotic cardiomyopathy model in mice was established by bile duct ligation. Myocardial-specific overexpression of CD73 was achieved by tail vein injection of AAV9 (adeno-associated virus)-cTNT-NT5E-mCherry, and cardiac function in mice was assessed using echocardiography. Myocardial inflammation infiltration and apoptosis were evaluated through pathological observation and ELISA assays. The expression of CD73, A2AR, apoptotic markers, and proteins related to the NF-κB pathway in myocardial tissue were measured.
UNASSIGNED: In the myocardial tissue of the cirrhotic cardiomyopathy mouse model, the expression of CD73 and A2AR increased. Overexpression of CD73 in the myocardium via AAV9 injection and stimulation of A2AR with CGS 21680 inhibited myocardial inflammation and cardiomyocyte apoptosis induced by cirrhosis. Additionally, overexpression of CD73 suppressed the activation of the NF-κB pathway by upregulating the expression of the adenosine receptor A2A.
UNASSIGNED: Our study reveals that the CD73/A2AR signaling axis mitigates myocardial inflammation and apoptosis induced by cirrhosis through negative feedback regulation of the NF-κB pathway.

Birdshot chorioretinopathy is an inflammatory eye condition strongly associated with MHC-I allele HLA-A29. The striking association with MHC-I suggests involvement of T cells, whereas natural killer (NK) cell involvement remains largely unstudied. Here we show that HLA-A29-positive birdshot chorioretinopathy patients have a skewed NK cell pool containing expanded CD16 positive NK cells which produce more proinflammatory cytokines. These NK cells contain populations that express CD8A which is involved in MHC-I recognition on target cells, display gene signatures indicative of high cytotoxic activity (GZMB, PRF1 and ISG15), and signaling through NK cell receptor CD244 (SH2D1B). Long-term monitoring of a cohort of birdshot chorioretinopathy patients with active disease identifies a population of CD8bright CD244bright NK cells, which rapidly declines to normal levels upon clinical remission following successful treatment. Collectively, these studies implicate CD8bright CD244bright NK cells in birdshot chorioretinopathy.

UNASSIGNED: Esophageal cancer (ESCA) is one of the most common tumors in the world, and treatment using neoadjuvant therapy (NT) based on radiotherapy and/or chemotherapy has still unsatisfactory results. Neoadjuvant immunochemotherapy (NICT) has also become an effective treatment strategy nowadays. However, its impact on the tumor microenvironment (TME) and regulatory mechanisms on T cells and NK cells needs to be further elucidated.
UNASSIGNED: A total of 279 cases of ESCA who underwent surgery alone [non-neoadjuvant therapy (NONE)], neoadjuvant chemotherapy (NCT), and NICT were collected, and their therapeutic effect and survival period were compared. Further, RNA sequencing combined with biological information was used to analyze the expression of immune-related genes. Immunohistochemistry, immunofluorescence, and quantitative real-time PCR (qRT-PCR) were used to verify the activation and infiltration status of CD8+ T and CD16+ NK cells, as well as the function and regulatory pathway of killing tumor cells.
UNASSIGNED: Patients with ESCA in the NICT group showed better clinical response, median survival, and 2-year survival rates (p < 0.05) compared with the NCT group. Our RNA sequencing data revealed that NICT could promote the expression of immune-related genes. The infiltration and activation of immune cells centered with CD8+ T cells were significantly enhanced. CD8+ T cells activated by PD-1 inhibitors secreted more IFN-γ and cytotoxic effector factor cells through the transcription factor of EOMES and TBX21. At the same time, activated CD8+ T cells mediated the CD16+ NK cell activation and secreted more IFN-γ to kill ESCA cells. In addition, the immunofluorescence co-staining results showed that more CD276+ tumor cells and CD16+ NK cells were existed in pre-NCT and pre-NICT group. However, CD276+ tumor cells were reduced significantly in the post-NICT group, while they still appeared in the post-NCT group, which means that CD16+ NK cells can recognize and kill CD276+ tumor cells after immune checkpoint blocker (ICB) treatment.
UNASSIGNED: NICT can improve the therapeutic effect and survival period of resectable ESCA patients. NICT could promote the expression of immune-related genes and activate CD8+ T and CD16+ NK cells to secrete more IFN-γ to kill ESCA cells. It provides a theoretical basis and clinical evidence for its potential as an NT strategy in ESCA.

Gymnema sylvestre (GS) and berberine (BBR) are natural products that have demonstrated therapeutic potential for the management of obesity and its comorbidities, as effective and safe alternatives to synthetic drugs. Although their anti-obesogenic and antidiabetic properties have been widely studied, comparative research on their impact on the gene expression of adipokines, such as resistin (Res), omentin (Ome), visfatin (Vis) and apelin (Ap), has not been reported.
METHODS: We performed a comparative study in 50 adult Mexican patients with obesity treated with GS or BBR for 3 months. The baseline and final biochemical parameters, body composition, blood pressure, gene expression of Res, Ome, Vis, and Ap, and safety parameters were evaluated.
RESULTS: BBR significantly decreased (p < 0.05) body weight, blood pressure and Vis and Ap gene expression and increased Ome, while GS decreased fasting glucose and Res gene expression (p < 0.05). A comparative analysis of the final measurements revealed a lower gene expression of Ap and Vis (p < 0.05) in patients treated with BBR than in those treated with GS. The most frequent adverse effects in both groups were gastrointestinal symptoms, which attenuated during the first month of treatment.
CONCLUSIONS: In patients with obesity, BBR has a better effect on body composition, blood pressure, and the gene expression of adipokines related to metabolic risk, while GS has a better effect on fasting glucose and adipokines related to insulin resistance, with minimal side effects.

OBJECTIVE: Invasive ductal carcinoma (IDC) is classified into distinct subtypes with varying prognoses and treatment sensitivities. For instance, triple-negative breast cancer (TNBC) is associated with poorer outcomes than other subtypes. We have previously reported the role of interstitial CD73 in tumor invasion and its correlation with prognosis in other cancers. This study aimed to investigate the expression of stromal CD73 (sCD73) in IDC and its potential prognostic significance.
METHODS: We analyzed 61 cases of human epidermal growth factor receptor 2-negative IDC, including TNBC and hormone receptor-positive (luminal-type) cases, treated surgically at our institution from 2005 to 2010. Cases that received preoperative drug therapy were excluded. CD73 expression was evaluated by immunostaining of the tumor stroma.
RESULTS: sCD73 expression was observed in 70% of all cases, with a significantly higher rate in TNBC (93%) compared with luminal breast cancer (48%). High sCD73 expression was associated with poor prognosis in terms of overall survival (OS) and disease-free survival (DFS) across all cases. In patients with luminal breast cancer, high sCD73 expression was also indicative of poor prognosis with respect to both OS and DFS.
CONCLUSIONS: High expression of sCD73 is associated with poor prognosis in IDC, particularly in luminal breast cancer. Further research is needed to establish sCD73 as an independent prognostic factor.