Antigen Expression Levels Research Articles

Docosahexaenoic acid (DHA) effects on proliferation and steroidogenesis of bovine granulosa cells

BackgroundDocosahexaenoic acid (DHA) is a n-3 polyunsaturated fatty acid (PUFA) belonging to a family of biologically active fatty acids (FA), which are known to have numerous health benefits. N-3 PUFAs affect reproduction in cattle, and notably directly affect follicular cells. In terms of reproduction in cattle, n-3 PUFA-enriched diets lead to increased follicle size or numbers.MethodsThe objective of the present study was to analyze the effects of DHA (1, 10, 20 and 50 μM) on proliferation and steroidogenesis (parametric and/or non parametric (permutational) ANOVA) of bovine granulosa cells in vitro and mechanisms of action through protein expression (Kruskal-Wallis) and signaling pathways (non parametric ANOVA) and to investigate whether DHA could exert part of its action through the free fatty acid receptor 4 (FFAR4).ResultsDHA (10 and 50 μM) increased granulosa cell proliferation and DHA 10 μM led to a corresponding increase in proliferating cell nuclear antigen (PCNA) expression level. DHA also increased progesterone secretion at 1, 20 and 50 μM, and estradiol secretion at 1, 10 and 20 μM. Consistent increases in protein levels were also reported for the steroidogenic enzymes, cytochrome P450 family 11 subfamily A member 1 (CYP11A1) and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 (HSD3B1), and of the cholesterol transporter steroidogenic acute regulatory protein (StAR), which are necessary for production of progesterone or androstenedione. FFAR4 was expressed in all cellular types of bovine ovarian follicles, and in granulosa cells it was localized close to the cellular membrane. TUG-891 treatment (1 and 50 μM), a FFAR4 agonist, increased granulosa cell proliferation and MAPK14 phosphorylation in a similar way to that observed with DHA treatment. However, TUG-891 treatment (1, 10 and 50 μM) showed no effect on progesterone or estradiol secretion.ConclusionsThese data show that DHA stimulated proliferation and steroidogenesis of bovine granulosa cells and led to MAPK14 phosphorylation. FFAR4 involvement in DHA effects requires further investigation, even if our data might suggest FFAR4 role in DHA effects on granulosa cell proliferation. Other mechanisms of DHA action should be investigated as the steroidogenic effects seemed to be independent of FFAR4 activation.

Quantification of number of CD38 sites on bone marrow plasma cells in patients with light chain amyloidosis and smoldering multiple myeloma.

Recent approaches in multiple myeloma (MM) treatment have targeted CD38. As antigen expression levels on plasma cells (PCs) were demonstrated to affect response to monoclonal antibody (mAb) treatment, a precise characterization of PC phenotype is warranted. Anti-CD38 mAb (isatuximab) was tested for antibody-dependent cellular cytotoxicity (ADCC) in MM cell lines. Quantification of the number of sites (NOS) of CD38 on bone marrow PCs and other immune cells obtained from light chain (AL) amyloidosis (n = 46) and smoldering multiple myeloma (SMM) patients (n = 19) was performed with two different quantitative flow cytometry (QFCM) applications. ADCC activity of isatuximab was observed in cell lines with >100 × 103 CD38-NOS only. The average PC CD38-NOS was 153 ± 53 × 103 in AL amyloidosis and 138.7 ± 53 × 103 in SMM patients. Eight (17%) AL amyloidosis and 4 (21%) SMM patients showed a PC CD38-NOS level <100 × 103 . In four AL amyloidosis and two SMM patients <10% of PCs had a CD38-NOS ≥100 × 103 . The CD38-NOS identified on bone marrow lymphocytes, monocytes, and granulocytes was two log units below the CD38-NOS on PCs (P < 0.001). No significant differences in CD38-NOS expression levels on any of the analyzed PC subpopulations in AL amyloidosis and SMM patients were identified. Levels of CD38 expression affect the isatuximab-mediated ADCC in vitro. As PCs of patients with AL amyloidosis and SMM do not homogenously express high CD38 our data provide a rationale for assessment of CD38-NOS in patients with PC disorders prior to anti-CD38 treatment. © 2018 International Clinical Cytometry Society.

Application of Bld-1-Embedded Elastin-Like Polypeptides in Tumor Targeting

Expression of various molecules on the surface of cancer cells compared to normal cells creates a platform for the generation of various drug vehicles for targeted therapy. Multiple interactions between ligands and their receptors mediated by targeting peptide-modified polymer could enable simultaneous delivery of a drug selectively to target tumor cells, thus limiting side effects resulting from non-specific drug delivery. In this study, we synthesized a novel tumor targeting system by using two key elements: (1) Bld-1 peptide (SNRDARRC), a recently reported bladder tumor targeting peptide identified by using a phage-displayed peptide library, and (2) ELP, a thermally responsive polypeptide. B5V60 containing five Bld-1 peptides and non-targeted ELP77 with a thermal phase-transition over 37 °C were analyzed to determine their bioactivities. Further studies confirmed the superior binding ability of B5V60 to bladder tumor cells and the cellular accumulation of B5V60 in cancer cells was dependent on the expression level of sialyl-Tn antigen (STn), a tumor-associated carbohydrate antigen. Additionally, B5V60 displayed excellent localization in bladder tumor xenograft mice after intravenous injection and was strictly confined to sialyl-Tn antigen-overexpressing tumor tissue. Thus, our newly designed B5V60 showed high potential as a novel carrier for STn-specific targeted cancer therapy or other therapeutic applications.

The Effects of the 3-OH Group of Kaempferol on Interfollicular Epidermal Stem Cell Fate.

BackgroundKaempferol (3,4′,5,7-tetrahydroxyflavone) is a flavonoid known to have a wide range of pharmacological activities. The 3-OH group in flavonoids has been reported to determine antioxidant activities.ObjectiveWe tested whether kaempferol can affect the expression of integrins and the stem cell fate of interfollicular epidermal stem cells.MethodsSkin equivalent (SE) models were constructed, and the expression levels of stem cell markers and basement membrane-related antigens were tested. The immunohistochemical staining patterns of integrins, p63, and proliferating cell nuclear antigen (PCNA) were compared between kaempferol- and apigenin-treated SE models. Reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate the mRNA expression of integrins.ResultsKaempferol increased the thickness of the epidermis when added to prepare SEs. In addition, the basal cells of kaempferol- treated SEs appeared more columnar. In the immunohistological study, the expression of integrins α6 and β1 and the numbers of p63- and PCNA-positive cells were markedly higher in the kaempferol-treated model. However, apigenin showed no effects on the formation of three-dimensional skin models. RT-PCR analysis also confirmed that kaempferol increased the expression of integrin α6 and integrin β1.ConclusionOur findings indicated that kaempferol can increase the proliferative potential of basal epidermal cells by modulating the basement membrane. In other words, kaempferol can affect the fate of interfollicular epidermal stem cells by increasing the expression of both integrins α6 and β1. These effects, in particular, might be ascribed to the 3-OH group of kaempferol.

Comparative Proteomics and Functional Analysis of Red Blood Cell Membrane Proteins in the Rare in(Lu) Blood Type

KLF1 is an essential erythroid transcription factor (EKLF) involved both in the ß-globin switch from fetal to adult and in definitive erythropoiesis. KLF1 also activates genes encoding heme biosynthetic enzymes, as well as genes involved in the cell cycle and the synthesis of membrane proteins. Heterozygosity for one or several nucleotide changes in KLF1 may be responsible for the so-called dominant Lu(a-b-) phenotype, also known as In(Lu) for “Inhibitor Lutheran” and characterized by a dramatic reduction in the expression levels of the Lutheran blood group antigens and a slight elevation in hemoglobin F (HbF). Several other blood group antigens are also under the direct control of KLF1, but their number and expression level in In(Lu) red blood cells (RBCs) remain a matter of debate. In addition, mutations in KLF1 in humans lead to anemia, acantocytosis and some of these variants, such as CDA type IV, are characterized by ineffective terminal differentiation and defects in enucleation. Given the major role of KLF1 in erythropoiesis, it would not be surprising that In(Lu) RBCs show abnormal properties. In this work, we performed proteomic studies to quantify membrane proteins in In(Lu) vs control RBCs.Results: using label-free mass spectrometry, we analyzed the expression levels of membrane proteins in 5 In(Lu) and 4 control RBCs. Hierarchical clustering allowed to identify two modulation profiles of protein expression (Figure 1). The first profile (red color) is composed of 49 proteins over-expressed in In(Lu) RBCs, with the majority of them corresponding to the “26S proteasome complex” (PSMA, PSMB, PSMD, and PSME). In addition, we confirmed the overexpression of the 26S proteasome complex in In(Lu) RBCs by western blot analyses.The second profile (green color) includes 23 membrane proteins with a lower expression level in In(Lu) RBCs; these proteins correspond to blood group antigens (e.g. Lu/BCAM, CD44), and to cytoskeletal proteins (e.g. dematin, flotillin). Five proteins carrying blood group systems show a decrease of expression in In(Lu) RBCs over 40%: Chido/Rodgers, Xg, Indian, Duffy and Lutheran: antigens. While our results indicating of decreased expression of Indian and Chido/Rodgers systems are consistent with previous reports, the Duffy expression was unexpectedly found to be decreased by 86%.Since we evidenced an important increase in the proteasome complex, and taking into account that KLF1 is involved in the regulation or erythropoiesis, we, investigated the expression profile of the 26 S proteasome expression during erythropoiesis. We observed an important decrease of all proteins of the proteasome complex during erythropoiesis.Conclusion: from our preliminary results reported in this study, we hypothesized that the increase of the 26S proteasome in the In(Lu) individuals may result from defects in organelle loss and could explain the profound dyserytropoiesis observed in the “nan” mice null for KLF1.Figure 1: Comparative proteomics of red blood cell membrane proteins in In(Lu) blood group type. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

The activity of myeloid cell-specific VHH immunotoxins is target-, epitope-, subset- and organ dependent

The central role of myeloid cells in driving autoimmune diseases and cancer has raised interest in manipulating their function or depleting them for therapeutic benefits. To achieve this, antibodies are used to antagonize differentiation, survival and polarization signals or to kill target cells, for example in the form of antibody-drug conjugates (ADC). The action of ADC in vivo can be hard to predict based on target expression pattern alone. The biology of the targeted receptor as well as its interplay with the ADC can have drastic effects on cell apoptosis versus survival. Here we investigated the efficacy of CD11b or Ly-6C/Ly-6G-specific variable fragments of camelid heavy chain-only antibodies (VHH) conjugated to Pseudomonas exotoxin A to deplete myeloid cells in vitro and in vivo. Our data highlight striking differences in cell killing in vivo, depending on the cell subset and organs targeted, but not antigen expression level or VHH affinity. We observed striking differences in depletion efficiency of monocytes versus granulocytes in mice. Despite similar binding of Ly-6C/Ly-6G-specific VHH immunotoxin to granulocytes and monocytes, granulocytes were significantly more sensitive than monocytes to immunotoxins treatment. Our results illustrate the need of early, thorough in vivo characterization of ADC candidates.

Silencing of suppressor of cytokine signaling 1 enhances the immunological effect of mucin 1-calreticulin-primed 4T1 cell-treated dendritic cells in breast cancer treatment.

In cancer immunotherapy, dendritic cell (DC)-based vaccines represent a promising, yet challenging, treatment method. In addition to overcoming the low expression levels of antigenic epitopes on cancer cells, it is also necessary to overcome the inhibitory effect of suppressor of cytokine signaling 1 (SOCS1) on DC self-antigen presentation. Our group previously demonstrated that calreticulin (CRT) translocated type I transmembrane glycoprotein mucin 1 (MUC1), a breast cancer antigen, to the surface of 4T1 cells, and that treatment with MUC1-CRT-primed 4T1 cell-treated DCs induced apoptosis in a breast cancer cell line. In the present study, cell penetrate peptide, hpp10-DRBD was successfully used to deliver siRNAs into bone marrow-derived (BM) DCs to construct SOCS1-silenced DCs, which were incubated with MUC1-CRT-primed 4T1 cells, and antigen-specific antitumor immunity was markedly enhanced in vitro and in vivo. These results demonstrated that SOCS1-silencing, combined with MUC1-CRT-primed 4T1 cell treatment, may induce increased cytokine production and T cell proliferation by DCs. Furthermore, the in vivo experimental data demonstrated that the silencing of SOCS1 combined with MUC1-CRT-primed 4T1 treatment of BMDCs may induce enhanced immunological effects. The results of the present study have implications for the development of more effective DC-based tumor vaccines, suggesting that the combination of high tumor-associated antigen expression levels on cancer cells with the silencing of a critical inhibitor of DC antigen presentation may be beneficial.

The mechanism of mesenchymal stem cells on neural function in rats with traumatic brain injury

Objective To investigate the effect of mesenchymal stem cells (MSCs) on the neurological function of rats with traumatic brain injury, and to investigate the mechanism of the effect of MSCs. Methods 60 SD rats models with brain injury established by the modified Feeney method were divided into model group, MSCs group and phosphate buffer (PBS) group by. Another 20 healthy SD rats were chosen as the control group. Rats of MSCs group were transplantated with Umbilical cord mesenchymal stem cells isolated and cultured in vitro. Neurological function of rats in each group were evaluated by improved neurological function score (mNSS) standard at 1, 3, 7, 14, 21, 28 d after transplantation. Neuronal nuclear antigen (NeuN) expression level in the brain tissue of rats was detected with immunohistochemical method. Brain-derived neurotrophic factor (BDNF) mRNA level of in the brain tissue of rats was detected with reverse transcriptase-polymerase chain reaction (RT-PCR) method. The apoptosis level of cerebral tissue cells in rats was detected by TdT-mediated dUTP nick end labeling (TUNEL) method. Results Compared with the control group, mNSS score of rats in model group, MSCs group and PBS group increased, NeuN expression decreased increased (P=0.000). Compared with the model group and PBS group, mNSS score of rats in MSCs group significantly decreased, NeuN expression significantly decreased(P=0.000). Compared with the control group BDNF mRNA level (0.31±0.12), BDNF mRNA level in model group, PBS group and MSCs Group (1.32±0.34, 1.23±0.30, 0.81±0.21) significantly increased (P=0.000). Compared with model group and PBS group, the levels of BDNF mRNA in MSCs group significantly reduced (P=0.014, P=0.019). Compared with the apoptosis level of brain tissue in control group (3.14±1.12), apoptosis level in model group, PBS group and MSCs group (27.84±4.32, 25.35±4.89, 10.33±3.32) significantly increased (P=0.000). Compared with model group and PBS group, the level of apoptosis in brain tissue of MSCs group significantly decreased (P=0.000). Conclusion Mesenchymal stem cells can decreased the apoptosis level of brain injury in rats through the mechanism of repairing damaged neurons and promoting the BDNF secretion. It can promote the repair effect on neural function of rats with traumatic brain injury. Key words: Brain injury; Mesenchymal stem cells; Nerve function

The potential association of the transcription levels of the ABO gene with the disease phases in AML patients

Patients with AML may show ABO blood typing discrepancy, and the expression levels of the ABO antigens may show some alterations with the disease progression. To better understand this phenomenon, the blood samples of 25 AML patients and 25 healthy blood donors were examined. The serological ABO blood types of the patients were determined in different AML stages, and gene sequencing was performed to identify the precise ABO genotypes. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out to detect the transcription levels of the antigens. The genotyping result showed that there were 4 patients with genotype A1O, 5 patients with B1O, and 16 patients with A1B1. RT-PCR results indicated that the transcription levels of the ABO gene in 76% (19/25) of the patients were significantly lower compared with those in controls (p <0.05). After therapy, 3/4 patients with A1O returned to normal A, 4/5 patients with B1O returned to normal B, and 10/16 patients with A1B1 returned to normal AB. The patients who achieved complete remission (CR) showed no difference of transcription levels of the ABO gene from those of controls. The data indicated that the transcription levels of the ABO gene changed with the disease progression, suggesting its potential role in the progression of AML disease.

Isolation, Detection, and Antigen‐Based Profiling of Circulating Tumor Cells Using a Size‐Dictated Immunocapture Chip

AbstractEven though the diagnostic and prognostic value of circulating tumor cells (CTCs) has been demonstrated, their clinical utility and widespread adoption have been limited. Herein, we describe a new device, size‐dictated immunocapture chip (SDI‐Chip), for efficient, sensitive, and spatially resolved capture and detection of CTCs. SDI‐Chip enables selective, frequent, and extended interaction of CTCs with hydrodynamically optimized immunocoated micropillar surfaces. CTCs with different antigen expression levels can be efficiently captured and spatially resolved around the micropillars. Capture efficiency greater than 92 % with a purity of 82 % was achieved with blood samples. CTCs were detected in non‐metastasis colorectal (CRC) patients, while none was detected from healthy volunteers. We believe that SDI‐Chip will facilitate the transition of tumor diagnosis from anatomical pathology to molecular pathology in localized CRC patients.

Isolation, Detection, and Antigen-Based Profiling of Circulating Tumor Cells Using a Size-Dictated Immunocapture Chip.

Even though the diagnostic and prognostic value of circulating tumor cells (CTCs) has been demonstrated, their clinical utility and widespread adoption have been limited. Herein, we describe a new device, size-dictated immunocapture chip (SDI-Chip), for efficient, sensitive, and spatially resolved capture and detection of CTCs. SDI-Chip enables selective, frequent, and extended interaction of CTCs with hydrodynamically optimized immunocoated micropillar surfaces. CTCs with different antigen expression levels can be efficiently captured and spatially resolved around the micropillars. Capture efficiency greater than 92 % with a purity of 82 % was achieved with blood samples. CTCs were detected in non-metastasis colorectal (CRC) patients, while none was detected from healthy volunteers. We believe that SDI-Chip will facilitate the transition of tumor diagnosis from anatomical pathology to molecular pathology in localized CRC patients.

High glucose promotes vascular smooth muscle cell proliferation by upregulating proto-oncogene serine/threonine-protein kinase Pim-1 expression.

Serine/threonine kinase proviral integration site for Moloney murine leukemia virus 1 (Pim-1) plays an essential role in arterial wall cell proliferation and associated vascular diseases, including pulmonary arterial hypertension and aortic wall neointima formation. Here we tested a role of Pim-1 in high-glucose (HG)-mediated vascular smooth muscle cell (VSMC) proliferation. Pim-1 and proliferating cell nuclear antigen (PCNA) expression levels in arterial samples from streptozotocin-induced hyperglycemia rats were increased, compared with their weak expression in normoglycemic groups. In cultured rat VSMCs, HG led to transient Pim-1 expression decline, followed by sustained expression increase at both transcriptional and translational levels. Immunoblot analysis demonstrated that HG increased the expression of the 33-kDa isoform of Pim-1, but at much less extent to its 44-kDa plasma membrane isoform. D-glucose at a concentration of 25 mmol/L showed highest activity in stimulating Pim-1 expression. Both Pim-1 inhibitor quercetagetin and STAT3 inhibitor stattic significantly attenuated HG-induced VSMC proliferation and arrested cell cycle progression at the G1 phase. Quercetagetin showed no effect on Pim-1 expression but decreased the phosphorylated-Bad (T112)/Bad ratio in HG-treated VSMCs. However, stattic decreased phosphorylated-STAT3 (Y705) levels and caused transcriptional and translational down-regulation of Pim-1 in HG-treated VSMCs. Our findings suggest HG-mediated Pim-1 expression contributes to VSMC proliferation, which may be partly due to the activation of STAT3/Pim-1 signaling.

Tyrosine kinase inhibitors as modulators of trastuzumab-mediated antibody-dependent cell-mediated cytotoxicity in breast cancer cell lines

BackgroundTrastuzumab is an anti-HER2 monoclonal antibody (mAb) therapy capable of antibody-dependent cell-mediated cytotoxicity (ADCC) and used in the treatment of HER2+ breast cancer. Through interactions with FcƴR+ immune cell subsets, trastuzumab functions as a passive immunotherapy. The EGFR/HER2-targeting tyrosine kinase inhibitor (TKI) lapatinib and the next generation TKIs afatinib and neratinib, can alter HER2 levels, potentially modulating the ADCC response to trastuzumab. Using LDH-release assays, we investigated the impact of antigen modulation, assay duration and peripheral blood mononuclear cell (PBMC) activity on trastuzumab-mediated ADCC in breast cancer models of maximal (SKBR3) and minimal (MCF-7) target antigen expression to determine if modulating the ADCC response to trastuzumab using TKIs may be a viable approach for enhancing tumor immune reactivity. MethodsHER2 levels were determined in lapatinib, afatinib and neratinib-treated SKBR3 and MCF-7 using high content analysis (HCA). Trastuzumab-mediated ADCC was assessed following treatment with TKIs utilising a colorimetric LDH release-based protocol at 4 and 12h timepoints. PBMC activity was assessed against non-MHC-restricted K562 cells. A flow cytometry-based method (CFSE/7-AAD) was also used to measure trastuzumab-mediated ADCC in medium-treated SKBR3 and MCF-7. ResultsHER2 antigen levels were significantly altered by the three TKIs in both cell line models. The TKIs significantly reduced LDH levels directly in SKBR3 cells but not MCF-7. Lapatinib and neratinib augment trastuzumab-related ADCC in SKBR3 but the effect was not consistent with antigen expression levels and was dependent on volunteer PBMC activity (vs. K562). A 12h assay timepoint produced more consistent results. Trastuzumab-mediated ADCC (PBMC:target cell ratio of 10:1) was measured at 7.6±4.7% (T12) by LDH assay and 19±3.2 % (T12) using the flow cytometry-based method in the antigen-low model MCF-7. ConclusionsIn the presence of effector cells with high cytotoxic capacity, TKIs have the ability to augment the passive immunotherapeutic potential of trastuzumab in SKBR3, a model of HER2+ breast cancer. ADCC levels detected by LDH release assays are extremely low in MCF-7; the flow cytometry-based CFSE/7-AAD method is more sensitive and consistent for the determination of ADCC in HER2-low models.

Abstract 982: Development of homogeneous dual-drug ADCs: Application to the co-delivery of auristatin payloads with complementary antitumor activities

Abstract A common theme in treating cancer is the use of combination chemotherapy, where multiple drugs with different mechanisms of action are combined to elicit synergistic activity or overcome differential drug sensitivities. Antibody-drug conjugates (ADCs) have emerged as a powerful approach for treating cancer, combining the tumor targeting specificity of monoclonal antibodies with the potent cell-killing activity of cytotoxic drugs. Like other therapies, these agents are increasingly being tested in combination with unconjugated, clinically approved anticancer agents. In addition, emerging data demonstrates that insensitivity to a particular ADC can be overcome through delivery of a different payload using the same antibody. For these reasons, the development of ADCs that can deliver two complementary payloads to a tumor would likely be a significant advancement in ADC technology. To enable dual-drug conjugation, we utilized a multiplexing drug carrier that contains cysteine residues with orthogonal protecting groups and identified novel conditions for utilization of these protecting groups on a folded protein. Sequential cysteine unmasking enables discrimination between conjugation sites to allow for site-specific drug conjugation. This strategy provides homogeneous ADCs bearing 16 total drugs per antibody, split evenly between the two drug linkers. Importantly, this strategy is flexible, as it does not require engineered antibodies or custom enzymes for drug-linker conjugation. To demonstrate the potential benefits of ADC dual drug delivery, this strategy was applied to the construction of ADCs bearing two classes of auristatin drug linkers that have different physiochemical properties and complementary anti-cancer activities. Dual-auristatin ADCs were tested in cell line and xenograft models that have differential sensitivities to the individual auristatin components, including those with heterogeneous antigen expression or high levels of drug efflux transporters. The data from these studies demonstrate that the dual-auristatin ADCs were active on cells and tumors that are refractory to treatment with either of the individual component drugs. This work highlights the potential for delivering two synergistic or complementary payloads on a single ADC and presents a flexible method for constructing dual-drug ADCs with site-specific and homogeneous drug loading. Citation Format: Matthew R. Levengood, Xinqun Zhang, Kim K. Emmerton, Joshua H. Hunter, Peter D. Senter. Development of homogeneous dual-drug ADCs: Application to the co-delivery of auristatin payloads with complementary antitumor activities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 982. doi:10.1158/1538-7445.AM2017-982

Direct and Indirect Cell-Based Enzyme-Linked Immunosorbent Assay.

The direct cell-based enzyme-linked immunosorbent assay (ELISA) has developed into a popular alternative immunoassay for the rapid detection of expressed cell-surface antigens or receptors. It is used to determine cell surface antigen expression profiles using existing reporter-labeled antibodies. The target specificity of newly developed antibodies can be determined by the indirect approach, which screens hybridoma supernatants for antibody reactivity against the target antigen of interest. The cell-based ELISA acts as a surrogate for the identification of immunohistochemistry-reactive (IHC) antibodies and aids in hybridoma-derived antibody identification, which is used for further ELISA development. Briefly, cells are adsorbed onto the microtiter plate surface and then fixed. Next, either hybridoma supernatant or reporter-labeled antibody is added and allowed to bind, followed by a washing step to remove unbound antibodies. For the indirect approach-during the screening of hybridoma supernatant-a reporter-labeled species-specific secondary antibody is added. For either approach, the next step is the addition of substrate. Substrate hydrolysis is proportional to the level of cell-surface antigen expression and can be measured using a microplate reader. Cell-based ELISAs have detection sensitivities comparable to quantitative analyses by flow cytometry and can be developed in multiplex format using different reporters for the analysis of cell populations.

Modulation of Hepatitis C Virus-Specific CD8 Effector T-Cell Function with Antiviral Effect in Infectious Hepatitis C Virus Coculture Model.

The antiviral effects of hepatitis C virus (HCV)-specific CD8 T cells have been shown in an HCV replicon system but not in an authentic infectious HCV cell culture (HCVcc) system. Here, we developed tools to examine the antigenicity of HCV-infected HLA-A2-positive Huh7.5 hepatoma cells (Huh7.5A2 cells) in activating HCV-specific CD8 T cells and the downstream antiviral effects. Infectious HCV epitope mutants encoding the well-defined genotype 1a-derived HLA-A2-restricted HCV NS3-1073 or NS5-2594 epitope were generated from a genotype 2a-derived HCV clone (Jc1Gluc2A) by site-directed mutagenesis. CD8 T-cell lines specific for NS3-1073 and NS5-2594 were expanded from HCV-seropositive persons by peptide stimulation in vitro or engineered from HCV-seronegative donor T cells by transduction of a lentiviral vector expressing HCV-specific T-cell receptors. HCV-specific CD8 T cells were cocultured with Huh7.5 cells that were pulsed with titrating doses of HCV epitope peptides or infected with HCV epitope mutants. HCV-specific CD8 T-cell activation (CD107a, gamma interferon, macrophage inflammatory protein 1β, tumor necrosis factor alpha) was dependent on the peptide concentrations and the relative percentages of HCV-infected Huh7.5A2 cells. HCV-infected Huh7.5A2 cells activated HCV-specific CD8 T cells at levels comparable to those achieved with 0.1 to 2 μM pulsed peptides, providing a novel estimate of the level at which endogenously processed HCV epitopes are presented on HCV-infected cells. While HCV-specific CD8 T-cell activation with cytolytic and antiviral effects was blunted by PD-L1 expression on HCV-infected Huh7.5A2 cells, resulting in the improved viability of Huh7.5A2 cells, PD-1 blockade reversed this effect, producing enhanced cytolytic elimination of HCV-infected Huh7.5A2 cells. Our findings, obtained using an infectious HCVcc system, show that the HCV-specific CD8 T-cell function is modulated by antigen expression levels, the percentage of HCV-infected cells, and the PD-1/PD-L1 pathways and has antiviral and cytotoxic effects.IMPORTANCE We developed several novel molecular and immunological tools to study the interactions among HCV, HCV-infected hepatocytes, and HCV-specific CD8 T cells. Using these tools, we show the level at which HCV-infected hepatoma cells present endogenously processed HCV epitopes to HCV-specific CD8 T cells with antiviral and cytotoxic effects. We also show the marked protective effect of PD-L1 expression on HCV-infected hepatoma cells against HCV-specific CD8 T cells.

Changes of systemic immune response after stereotactic ablative radiotherapy (SABR) - first results of a prospective study in early lung cancer patients

INTRODUCTION Non‑small cell lung cancer (NSCLC) is the most common lung tumor. Conventional conservative treatment in medically inoperable patients with early stage NSCLC has poor outcome. To improve treatment efficacy, stereotactic ablative radiotherapy (SABR) has been developed, which enables the delivery of high‑dose radiation to the tumor. OBJECTIVES This prospective study was conducted to test the hypothesis that a sudden death of cancer cells after SABR may lead to changes in systemic immune response. PATIENTS AND METHODS We enrolled 89 treatment‑naive patients with stage T1/2aN0 NSCLC. All patients received SABR, in accordance with treatment standards at our department. Blood samples were collected 3 times: before treatment (n = 89), and then at 2 (n = 86) and 12 weeks (n = 75) after treatment completion to assess the proportion of CD4(+) and CD8(+) T cells, and the expression of T‑lymphocyte transcription factors: T‑bet, GATA‑3, ROR‑γt, and FoxP3. Serum C‑reactive protein (CRP) levels, absolute neutrophil count (ANC), absolute lymphocyte count, and white blood cell (WBC) count were measured to exclude the impact of nonspecific inflammatory reaction. The expression levels of lymphocyte antigens were measured by flow cytometry. RESULTS Serum CRP levels, ANC, and WBC count remained stable during the study. We observed slight lymphopenia, which correlated with irradiated lung volume. After SABR, the proportion of CD8(+), CD4(+), as well as the proportion of CD4(+) T cells expressing GATA‑3(+), T‑bet(+), or ROR‑γt(+) increased, while the number of CD4(+)FoxP3(+) cells (specific for regulatory T cells) decreased. CONCLUSIONS Our findings may suggest that SABR enhances the systemic immune response by increasing the proportion of proinflammatory T‑cell subpopulations.

Regulatory role of tumor necrosis factor receptor-associated factor 6 in breast cancer by activating the protein kinase B/glycogen synthase kinase 3β signaling pathway.

Tumor necrosis factor receptor-associated factor6 (TRAF6) is an endogenous adaptor of innate and adaptive immune responses, and serves a crucial role in tumor necrosis factor receptor and toll‑like/interleukin‑1 receptor signaling. Although studies have demonstrated that TRAF6 has oncogenic activity, its potential contributions to breast cancer in human remains largely uninvestigated. The present study examined the expression levels and function of TRAF6 in breast carcinoma (n=32) and adjacent healthy (n=25) tissue samples. Compared with adjacent healthy tissues, TRAF6 protein expression levels were significantly upregulated in breast cancer tissues. Reverse transcription‑quantitative polymerase chain reaction analysis revealed a significant upregulation of the cellular proliferative marker Ki‑67 and proliferation cell nuclear antigen expression levels in breast carcinoma specimens. Furthermore, protein expression levels of the accessory molecule, transforming growth factor β‑activated kinase 1 (TAK1), were significantly increased in breast cancer patients, as detected by western blot analysis. As determined by MTT assay, TRAF6 exerted profoundly proliferative effects in the MCF‑7 breast cancer cell line; however, these detrimental effects were ameliorated by TAK1 inhibition. Notably, protein kinase B (AKT)/glycogen synthase kinase (GSK)3β phosphorylation levels were markedly upregulated in breast cancer samples, compared with adjacent healthy tissues. In conclusion, an altered TRAF6‑TAK1 axis and its corresponding downstream AKT/GSK3β signaling molecules may contribute to breast cancer progression. Therefore, TRAF6 may represent a potential therapeutic target for the treatment of breast cancer.

CD-PLLD co-delivering docetaxel and MMP-9 siRNA plasmid for nasopharyngeal carcinoma therapy invivo.

The co-delivery of a drug and a target gene has become a primary strategy in cancer therapy. Based on our previous study, a synthesized star‑shaped co‑polymer consisting of β‑cyclodextrin (CD) and a poly(L‑lysine) dendron (PLLD) was used to co-deliver docetaxel (DOC) and matrix metalloproteinase 9 (MMP‑9) small interfering RNA, via CD‑PLLD/DOC/MMP‑9 complexes, into mice implanted with HNE‑1 human nasopharyngeal carcinoma (NPC) tumor cells invivo. Unlike the commonly used amphiphilic co‑polymer micelles, the obtained CD derivative may be used directly for a combined delivery of nucleic acid and hydrophobic DOC without a complicated micellization process. Invivo assays demonstrated that CD‑PLLD/DOC/MMP‑9 inhibited HNE‑1 tumor growth and decreased proliferating cell nuclear antigen expression levels, indicating a potential strategy for NPC therapy. In addition, the distribution of DOC and MMP‑9 was investigated; CD‑PLLD/DOC/MMP‑9 complexes were phagocytized in reticuloendothelial systems, including the liver and spleen, which requires further study. Furthermore, the complexes did not cross the blood‑brain barrier due to their large molecular size, suggesting they may be relatively safe. Additionally, the complexes mediated increased DOC concentrations with prolonged blood circulation and EGFP expression in HNE‑1 tumors. These results suggest the future potential application of CD-PLLD/DOC/MMP-9 for NPC therapy.

Identification of TWIST-interacting genes in prostate cancer.

Prostate cancer is one of the most common cancers in men worldwide, and the number of diagnosed patients has dramatically increased in recent years. Currently, the clinical parameters used to diagnose prostate cancer, such as Gleason score, pathological tumor staging, and prostate-specific antigen (PSA) expression level, are considered insufficient to inform recommendation to guide clinical practice. Thus, identification of a novel biomarker is necessary. TWIST is one of the well-studied targets and is correlated with cancer invasion and metastasis in several human cancers. We have investigated two largest prostate cancer patient cohorts available in GEO database and found that TWIST expression is positive correlated with Gleason score and associated with poorer survival. By using a prostate cancer cohort and a prostate cancer cell line dataset, we have identified three potential downstream targets of TWIST, PPM1A, SRP72 and TBCB. TWIST's prognostic capacity is lost when the gene is mutated. Further investigation in the prostate cancer cohort revealed that gene expression of SERPINA, STX7, PDIA2, FMP5, GP1BB, VGLL4, KCNMA1, SHMT2, SAA4 and DIDO1 influence the prognostic significance of TWIST and vice versa. Importantly, eight out of these ten genes are prognostic indicator by itself. In conclusion, our study has further confirmed that TWIST is a prognostic marker in prostate cancer, identified its potential downstream targets and genes that could possibly give additional prognostic value to predict TWIST-mediated prostate cancer progression.