Mouse Anti-human Monoclonal Antibody Research Articles

Immunohistochemical Localization of Fibroblast Activation Protein in Coronary Arteries with Different Forms of Atherosclerosis

Background: Fibroblast activation protein (FAP) is a cell surface glycoprotein expressed by myofibroblasts in areas of active tissue remodeling. It plays a potentially important role in cardiac remodeling, atherosclerotic plaque formation, and plaque rupture. Given the distinct pathophysiology and morphology of different forms of atherosclerosis, we analyzed FAP expression in human coronary vessels with no coronary artery disease, atherosclerotic plaques at different levels of progression, and other distinct forms of coronary disease in post bypass vein grafting and cardiac allograft vasculopathy after a heart transplant. Methods: Immunohistochemical staining with monoclonal F19 mouse anti-human FAP antibody was performed to identify FAP in human atherosclerotic plaques, coronary bypass atherosclerosis, and post-transplant arteriosclerosis. The presence and distribution of FAP in different types and stages of human atherosclerosis were compared. Results: There was no FAP staining in patients with no significant coronary disease. All different types of human atherosclerotic lesioning lesions showed the presence of FAP expression, with different staining patterns in advanced atherosclerotic plaque, vein graft atherosclerosis lesions, and arteriosclerosis after a heart transplant. Conclusions: These data suggest that FAP may be a potential diagnostic marker and target for interventions, not only in coronary atherosclerotic plaque, but also in other forms of coronary disease, which have distinct pathophysiologies and currently limited treatment options.

Monoclonal antibody targeting CEACAM1 enhanced the response to anti-PD1 immunotherapy in non-small cell lung cancer

Carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1), an extensively studied cell surface molecule, mainly expressed by certain epithelial, endothelial, lymphoid and myeloid cells, and is an attractive target for cancer immunotherapy. Here, to investigate the anti-tumor effects and mechanisms of CEACAM1 antibody, we prepared the antibody and explored its anti-tumor effects on Non-small Cell Lung Cancer (NSCLC) in vitro and in vivo. Firstly, antigen of human CEACAM1 recombinant protein was immunized on BALB/c mice and the high-affinity mouse anti-human monoclonal antibody 3C11 was selected by hybridoma technique. Next, ELISA was applied to detect the blocking effects of 3C11 on CEACAM1-CEACAM1 and CEACAM1-CEACAM5. Then, cell assays and ELISA were used to evaluate the role of 3C11 in blocking CEACAM1-CEACAM1 immunosuppressive signal transduction between dendritic cells (DCs) and T cells or natural killer cells (NK) and tumor cells. Finally, the synergistic anti-tumor effect of 3C11 combined with anti-PD-1 antibody was evaluated through cell stimulation assays and NCI-H358-induced tumor models in mice. The results showed the EC50 of 3C11 binding to NCI-H358 or exhausted T cells were 0.04971 μg/mL and 0.03475 μg/mL, respectively. 3C11 activated the exhausted T cells and enhanced the killing effect of NK by blocking CEACAM1-CEACAM1. In addition, the combination of 3C11 and anti-PD1 antibody produced synergistic anti-tumor effect on NSCLC. Its improved tumor growth inhibition value (TGI) of anti-PD-1 from 18 % to 85 % in vivo. These findings suggest that 3C11 can be considered an effective immunotherapy drug for NSCLC.

Development and Epitope Mapping of Seven Mouse Anti-Human Coagulation Factor XIII-B Subunit Monoclonal Antibodies.

Coagulation factor XIII (FXIII) is an enzyme that strengthens hemostatic clots, and its deficiency can cause life-threatening bleeding. We immunized mice with human plasma-derived FXIII to generate monoclonal antibodies (mAbs) against the B subunit (FXIII-B), which stabilizes the A subunit (FXIII-A) of FXIII, and analyzed their properties. The epitopes of the seven mouse antihuman FXIII-B mAbs obtained were found to be the 3rd, 5th, 6th, 9th, and 10th Sushi domains. One of these mAbs, mAb 5-6C, recognized the 10th Sushi domain and inhibited the fibrin cross-linking reaction without affecting the amine incorporation activity of FXIII. We previously reported that the 10th Sushi domain is the site where FXIII-B binds to fibrin and functions to bring FXIII-A closer to the substrate fibrin. Except for mAb 5-6C, mouse mAbs with high yields were used to measure the amount of FXIII-B antigen by an immunochromatography test (ICT), which showed a high correlation with enzyme-linked immunosorbent assay-obtained results. In addition, we developed a prototype ICT to detect anti-FXIII-B autoantibodies using mAb 1-3C, which showed good results in measuring the amount of FXIII-B antigen. Thus, mouse mAbs may be useful for clinical applications. mAb 5-6C targeting the 10th Sushi domain may also be useful for inhibiting thrombosis progression when humanized as antibody medicines.

P-302 Oral ofloxacin combined with vaginal metronidazole for chronic endometritis: a prospective open-label cohort study

Abstract Study question Does oral ofloxacin 2x200 mg for 10 days combined with vaginal metronidazole 1x500 mg for 10 days reduce the activity of chronic endometritis? Summary answer The investigated antibiotics may be beneficial in some cases of chronic endometritis, except in cases of concomitant endometrial polyp, where they adversely affect treatment outcome. What is known already Chronic endometritis (CE) is characterized by the presence of atypical plasma cell infiltrates (CD138 positive) in the endometrial stroma. CE may adversely affects fertility by reducing endometrial receptivity, impairing decidualization and uterine contractility, thus increasing the risk of recurrent pregnancy loss and implantation failure. Some idiopathic infertility cases are attributed to CE. The diagnostics of CE is challenging because the clinical evaluation is nonspecific and the immunohistochemical criteria are not consistent between research centers. Literature data suggested that successful treatment of CE with antibiotics could improve live birth rates, but a preferred treatment regimen has not been identified. Study design, size, duration A prospective cohort study included women undergoing office hysteroscopy (OH) at a tertiary referral center in 2021-2023. Women diagnosed with CE were assigned, based on their preference, to the intervention arm of ofloxacin 2x200 mg orally for 10 days + metronidazole 500 mg vaginally for 10 days or to the control arm (no antibiotics). 100 women underwent repeated hysteroscopy after 3 cycles, of which 77 received antibiotics and 23 were controls. Participants/materials, setting, methods Women aged 18-45 who met eligibility criteria for OH were included. Karl Storz 5.0 mm Bettocchi® operating sheath with a 2.9 mm 30° telescope and a 5Fr working channel was used. Endometrial lesions or biopsy specimens were collected with grasping forceps, blunt scissors or bipolar needle electrode. Saline was used as the dilating medium. Tissue samples were subjected to histopathological examination. Plasma cells were detected by immunohistochemical staining with Monoclonal Mouse Anti-Human CD138 antibodies. Main results and the role of chance The most common findings identified at hysteroscopy were endometrial polyps (43%), polypoid endometrium (38%), micropolyps (23%), focal (27%) and diffuse hyperemia (18%) and cesarean scar defect (14%). CE was defined as the presence of > 2 plasma cells/mm2. The Mann-Whitney U test showed a significantly higher plasma cell count (PCC) in the presence of a cesarean scar defect than in other cases (23 vs. 18/mm2, p = 0.031) and a tendency towards a lower PCC in micropolyps (9 vs. 21/mm2, p = 0.063). The correlation of hysteroscopic findings with CE activity was weaker than expected. Using repeated measures ANOVA, no difference in PCC between primary and follow-up hysteroscopy was found in either arm (p = 0.8), while post-hoc tests showed that the mean PCC decreased from 12 to 5/mm2 (p = 0.02) in the intervention arm, and from 14 to 6 (p = 0.23) in the control arm. On follow-up hysteroscopy, polyp remission was observed significantly more often in the control arm than in the intervention arm (61% vs. 27%, pChi2=0.02), in which de novo polyp was observed in 4%. In polypoid endometrium, the remission rate was similar in both arms (19% vs. 22%), and the rate of de novo lesions was significantly lower in interventional arm (16% vs. 39%, pChi2=0.035). Limitations, reasons for caution The limitations include the small sample size, the CE definition based on the number of plasma cells calculated using the Receiver Operating Characteristic curve for the purposes of the study, and the empirical selection of antibiotic therapy. Wider implications of the findings Due to the weak correlation of hysteroscopic findings with CE activity, the diagnostics and treatment of CE based on clinical evaluation of the uterine cavity is not justified. Poorly selected antibiotic therapy may adversely affect the outcomes of treatment. Trial registration number 1072.6120.322.2020

A novel enzyme-linked immunosorbent assay tool to evaluate plasma soluble CD226 in primary Sjögren's syndrome

CD226 is an important receptor constitutively expressed on most immune cells, performing vital functions in immune responses. However, the levels of soluble CD226 (sCD226) and its roles in primary Sjögren syndrome (pSS) remain unclear. In this study, we developed two novel mouse anti-human CD226 monoclonal antibodies (mAbs) and established a novel sandwich enzyme-linked immunosorbent assay (ELISA) system, which proved to be highly effective in detecting human sCD226. We then analyzed the expression of sCD226 in the plasma of pSS patients. Our results showed that the levels of sCD226 were significantly lower in patients with pSS compared to healthy controls. The significant decline was also observed in active group and the patients with high levels of IgG or positive anti-SSB. Additionally, reduced sCD226 was found to be negatively correlated with the disease activity of pSS and several clinical manifestations, including arthralgia, fatigue, decayed tooth and interstitial lung disease (ILD). Furthermore, receiver operator characteristics (ROC) curve analysis showed that sCD226 displayed outstanding capacity in discriminating pSS and predicting the disease activity. Altogether, plasma sCD226 emerges as a promising candidate for diagnostic markers in the context of pSS.

Identification of Specific Cell Surface Markers on Immune Cells of Squirrel Monkeys (Saimiri sciureus).

Nonhuman primates are an important experimental model for the development of targeted biological therapeutics because of their immunological closeness to humans. However, there are very few antibody reagents relevant for delineating the different immune cell subsets based on nonhuman primate antigens directly or with cross-reactivity to those in humans. Here, we report specific expression of HLA-DR, PD-1, and CD123 on different circulating immune cell subsets in the peripheral blood that included T cells (CD3+), T cells subsets (CD4+ and CD8+), B cells (CD20+), natural killer (NK) cells (CD3-CD16+), and natural killer T cells (CD3+CD16+) along with different monocyte subsets in squirrel monkey (Saimiri sciureus). We established cross-reactivity of commercial mouse antihuman monoclonal antibodies (mAbs), with these various immune cell surface markers. These findings should aid further future comprehensive understanding of the immune parameters and identification of new biomarkers to significantly improve SQM as a model for biomedical studies.

Serum autoantibodies against α7-nicotinic receptors in subgroups of patients with bipolar disorder or schizophrenia: clinical features and link with peripheral inflammation

There is growing evidence that autoantibodies (AAbs) against proteins expressed in the brain are playing an important role in neurological and psychiatric disorders. Here, we explore the presence and the role of peripheral AAbs to the α7-nicotinic acetylcholine receptor (nAChR) in inflammatory subgroups of psychiatric patients with bipolar disorder (BD) or schizophrenia (SCZ) and healthy controls. We have identified a continuum of AAb levels in serum when employing a novel ELISA technique, with a significant elevation in patients compared to controls. Using unsupervised two-step clustering to stratify all the subjects according to their immuno-inflammatory background, we delineate one subgroup consisting solely of psychiatric patients with severe symptoms, high inflammatory profile, and significantly increased levels of anti-nAChR AAbs. In this context, we have used monoclonal mouse anti-human α7-nAChR antibodies (α7-nAChR-mAbs) and shown that TNF-α release was enhanced upon LPS stimulation in macrophages pre-incubated with α7-nAChR-mAbs compared to the use of an isotype control. These findings provide a basis for further study of circulating nicotinic AAbs, and the inflammatory profile observed in patients with major mood and psychotic disorders.

8 Humanization of the mouse anti-human complement C6 monoclonal antibody as a potential therapeutic for certain complement-mediated diseases

8 Humanization of the mouse anti-human complement C6 monoclonal antibody as a potential therapeutic for certain complement-mediated diseases

RETRACTED: Aptamer/doxorubicin-conjugated nanoparticles target membranous CEMIP2 in colorectal cancer

The objectives were to identify the functional domains of a potential oncoprotein, cell migration inducing hyaluronidase 2 (CEMIP2), evaluate its expression levels and roles in colorectal cancer (CRC), and develop an aptamer-based nanoparticle for targeted therapy. Data mining on TCGA identified that CEMIP2 might play oncogenic roles in CRC. In a local cohort, CEMIP2 mRNA levels significantly stepwise increase in CRC patients with higher stages, and high CEMIP2 confers worse disease-free survival. In addition, CEMIP2 mRNA levels significantly correlated to hyaluronan levels in sera from CRC patients. Deletion mapping identified that CEMIP2 containing G8 and PANDER-like domains preserved hyaluronidase activity and oncogenic roles, including cell proliferation, anchorage-independent cell growth, cell migration and invasion, and human umbilical vein endothelial cell (HUVEC) tube formation in CRC-derived cells. A customized monoclonal mouse anti-human CEMIP2 antibody probing the PANDER-like domain (anti-289307) counteracted CEMIP2-mediated carcinogenesis in vitro. Cell-SELEX pinpointed an aptamer, aptCEMIP2(101), specifically interacted with the full-length CEMIP2, potentially involving its 3D structure. Treatments with aptCEMIP2(101) significantly reduced CEMIP2-mediated tumorigenesis in vitro. Mesoporous silica nanoparticles (MSN) carrying atpCEMIP2(101) and Dox were fabricated. Dox@MSN, MSN-aptCEMIP2(101), and Dox@MSN-aptCEMIP2(101) significantly suppressed tumorigenesis in vitro compared to the Mock, while Dox@MSN-aptCEMIP2(101) showed substantially higher effects compared to Dox@MSN and MSN-aptCEMIP2(101) in CRC-derived cells. Our study identified a novel oncogene and developed an effective aptamer-based targeted therapeutic strategy.

Association of high expression of CD44 in clinicopathological factors of endometrial cancer.

Clinical stages, histologic type, degree of cell differentiation, myometrial invasion, and lymph-vascular space invasion (LVSI) have been identified as clinicopathological factors that are predictive for endometrial cancer, however, further prognostic indicators are still required to account for the heterogeneity of this cancer. Adhesion molecule CD44, affects the invasion, metastasis, and prognosis of many forms of cancer. The purpose of this study is to examine the expression of CD44 in endometrial cancer and its correlation with established prognostic variables. A cross-sectional study was conducted on 64 samples of endometrial cancer from Wahidin Sudirohusodo Hospital and Hasanuddin University Hospital. Immunohistochemical analysis was used to detect CD44 expression using mouse anti-human CD44 monoclonal antibody. Differences in Histoscore were studied to determine the association between CD44 expression and clinicopathological factors of endometrial cancer. Of the overall sample, 46 samples were in the early stage, whereas 18 samples were in the advanced stage. High expression of CD44 was associated with advanced stage compare than early stage (P=0.010), poor differentiation compare than well-moderate differentiation (P=0.001), myometrial invasion ≥50% compare than myometrial invasion <50% (P=0.004), and positive LVSI compare than negative LVSI (P=0.043) in endometrial cancer, but not associated with histological type of endometrial cancer (P=0.178). High expression of CD44 may be considered as a poor prognostic marker and predictive marker for targeted therapy in endometrial cancer.

IMMU-37. ANTI-CD47 TREATMENT POTENTIATES PHAGOCYTOSIS OF MEDULLOBLASTOMA BY M1 POLARIZED MACROPHAGES FOLLOWING IRRADIATION

Abstract Medulloblastoma (MB) is the most common malignant brain tumor of childhood and accounts for 15–20% of all pediatric brain tumors. Despite significant advancements over the last decade in our understanding of the molecular underpinnings of MB, the overall risk of recurrence remains high, prognosis remains poor, and available treatment modalities remain limited for patients with this disease. Accordingly, the area of targeting tumor immune resistance has garnered increasing interest as a potentially safe and effective adjunctive therapy. CD47 is a cell surface protein that acts as a primary “don’t eat me” signal to the innate immune system and has been shown to be crucial in allowing tumor cells to evade phagocytosis by tumor-associated macrophages. Several preclinical studies aimed at blocking this “don’t eat me signal” through the application of a mouse anti-human monoclonal antibody (Ab) to CD47 (anti-CD47) have shown promise in pediatric brain tumor models. Further, chemotherapy and irradiation have been shown to increase the expression of pro-phagocytic signals on the surfaces of tumor cells. The authors examined the use of anti-CD47 Ab on the rates of phagocytosis of MB cells undergoing different single-fraction doses of external beam irradiation in vitro. The use of anti-CD47 Ab in the D425 MB cell line phagocytosis assay significantly increased rates of phagocytosis for 0 Gy (4.1% without vs. 20.3% with anti-CD47 Ab; p &amp;lt; 0.0001), 2 Gy (7.4% without vs. 23.4% with anti-CD47 Ab; p &amp;lt; 0.0001), 5 Gy (11.9% without vs. 27.3% with anti-CD47 Ab; p &amp;lt; 0.0001), 10 Gy (21.7% without vs. 34% with anti-CD47 Ab; p &amp;lt; 0.0001), and 20 Gy treatment groups (27.2% without vs. 43.9% with anti-CD47 Ab; p &amp;lt; 0.0001). A similar pattern of phagocytosis potentiation through use of anti-CD47 Ab with increasing doses of radiation was seen in D458 and D341 MB cell lines.

Establishment of a Monoclonal Antibody-Based Enzyme-Linked Immunosorbent Assay to Measure Soluble B7-H5 in Patients with Cancer.

B7-H5, an immune checkpoint molecule, is markedly upregulated in multiple cancers and plays an important role in tumor progression and immune escape. However, the expression and significance of soluble B7-H5 (sB7-H5) in cancer remain unclear. Herein, we generated two novel mouse anti-human B7-H5 monoclonal antibodies (mAbs) 2E5 and 7B10, which had different epitopes. Based on the two mAbs, a sandwich enzyme-linked immunosorbent assay (ELISA) system was developed. Using this ELISA, we found that compared with healthy controls (HCs), sB7-H5 levels were significantly increased in the serum of patients with gastric cancer (GC), colorectal cancer (CRC), and lung cancer (LC) and were associated with TNM stage and metastasis. Receiver operating characteristic (ROC) curve analysis showed that sB7-H5 has diagnostic value for GC, CRC, and LC. Collectively, our findings delineate that sB7-H5 may be used as a predictor for diagnosis of cancer and a potential therapeutic target for cancer treatment.

Expression of endoglin, CD105, in conjunctival melanocytic nevi: Is it suspicious like in thyroidology? Oculi plus vident quam oculus?

The aim of this study was to evaluate the expression of endoglin and its correlation with histopathological and clinical findings in conjunctival nevi. The study included archival formalin-fixed, paraffin-embedded tissue sections of 44 patients with conjunctival nevi. Immunohistochemical staining for CD105 had been performed with monoclonal mouse antihuman CD105 antibodies. The intratumoral microvessel density for quantification of tumoral vascularization had been determined by this marker. The expression of CD105 was positive in 30 (68.2%) cases. There was a statistically significant difference in the level of CD105 expression regarding the histological type of nevus (p=0.03) and intralesional cysts status (p=0.02). Spearman's rho (ρ -0.316) revealed a significant negative correlation between the expression of endoglin and the histological type of nevus (p=0.03) and between the expression of endoglin and the presence of intralesional cysts (ρ -0.380, p=0.01). This study suggests that endoglin could be a useful diagnostic and prognostic marker in differentiating between benign and malignant melanocytic ocular lesions.

Development of a T cell-redirecting bispecific antibody targeting B-cell maturation antigen for the suppression of multiple myeloma cell growth.

BackgroundMultiple myeloma (MM) is the second most common hematological malignancy. It has emerged as one of the next possible hematological diseases amenable to immunotherapy. B-cell maturation antigen (BCMA), a member of the tumor necrosis factor receptor superfamily, is highly expressed in MM cells and is one target with the most potential for developing MM-targeting immunotherapy. Other than the FDA-approved BCMA-targeting CAR T-cell therapy, such as Abecma and CARVYKTI, T cell-engaging multi-specific antibody is another promising therapeutic modality for BCMA-targeting MM treatment. We develop a T-cell redirecting BCMA-targeting bispecific antibody (bsAb) and evaluate its anti-MM activity.MethodsWe first generated several clones of mouse anti-human BCMA monoclonal antibodies using DNA immunization. One of the anti-BCMA antibodies was then used to design and produce a T cell-redirecting BCMA × CD3 bsAb in CHO cells. Finally, we examined the effect of the bsAb on MM cell growth both in vitro and in vivo.ResultsThe BCMA × CD3 bsAb was designed in a FabscFv format and produced in CHO cells with good yield and purity. Moreover, the bsAb can trigger robust T cell proliferation and activation and induce efficient T cell-mediated MM cell killing in vitro. Using a MM xenograft mouse model, we demonstrate that the bsAb can effectively suppress MM cell growth in vivo.ConclusionsOur results suggest that the BCMA × CD3 bsAb in the FabscFv format can efficiently inhibit MM cell growth and have promising potential to be developed into a therapeutic antibody drug for the treatment of MM.

A rapid and quantitative detection method for plasma soluble growth stimulating gene protein 2 based on time resolved fluorescence immunochromatography.

Background: plasma soluble growth stimulating gene protein 2 (sST2) is a new generation biomarker in heart failure (HF), which is an independent predictor of adverse outcomes of heart failure. Thus, the establishment of a rapid and sensitive method for detecting sST2 is urgently needed. Methods: lanthanide element Eu3+ coated fluorescent nanometer microspheres (Eu3+@FMN) can be used as markers to label monoclonal mouse anti-human sST2 antibody ST-01 (ST-01-Eu3+@FMN). When the immune sandwich complex formed between the monoclonal mouse anti-human sST2 antibody ST-02 and ST-01-Eu3+@FMN on the test band with the appearance of target object sST2, we can detect the fluorescence intensity of Eu3+ on the test band and the quality control band using a dry fluorescence analyzer. We calculated the T/C value (T/C = fluorescence intensity of the test band/fluorescence intensity of the quality control band), fitted to the calibration curve, and measured the concentration value of sST2 in the corresponding sample. Results: the best reaction time was 15 min after condition exploration, and the optimal sample volume was 80 μL. The detection sensitivity of the scheme was 2.14 ng mL-1. The calibration curve of the assay was y = 0.0113x + 0.0033, and the linear range was 5-200 ng mL-1. No cross reaction was found when the samples contained BNP, NT-proBNP, and galectin-3, indicating a good specificity. The precision was good with a relative deviation < 15%. The coefficient of variation of detection results of low-concentration samples and high-concentration samples was 4.20% and 3.30% respectively in the same batch of strip tests, so the intra-assay CV was set as <10%; when different batches of strips were used for testing, the coefficient of variation of detection results of low-concentration samples and high-concentration samples was 10.06% and 8.38% respectively, so the inter-assay CV was set as <15%. Stability test results showed that the relative deviation of test results at each time node was <15%, indicating good stability of the assay strips. The correlation coefficient between the ST-01-Eu3+@FMN based time-resolved fluorescence immunochromatography analysis and sST2 ELISA kit was 0.98. To confirm the usage of our proposed TRF-ICA for clinical samples, it was used to determine the concentration of sST2 in samples obtained from 34 patients with heart insufficiency, acute and chronic heart failure. As a result, we successfully detected a minimal concentration of 5.21 ng mL-1 and a maximum concentration of 184.26 ng mL-1 for sST2. Conclusion: this technique provides a rapid, simple and quantitative detection method for sST2 in clinics. It can help clinicians to predict the incidence of adverse events in patients with HF.

Macrophages and Natural Killer Cells Characteristics in Variously Colored Endometriotic Lesions: A Cross-Sectional Analytic Study.

Background:Dysregulation of the immune response contribute to a significant role in endometriosis. This research examined macrophages and natural killer (NK) cells numbers in endometriotic lesions and their association with the different lesion colors: red, black, and white. To investigate the amount of the CD68 and CD56 in eutopic endometrium and different type of the endometriotic lesions.Materials and Methods:A cross-sectional analytic study was conducted. Women suspected endometriosis requiring laparoscopic surgery between July 2016 and January 2017 were recruited. Their lesions were classified as red, black, or white and these lesions were excised by standard laparoscopic surgery. Twenty-four endometriotic lesions from each color group were obtained from 45 women who met the inclusion criteria. One type of lesion was collected from 25 women. Two different lesion types and three-color lesion types were collected from the same women in 13 and 7 subjects, respectively. Immunohistochemistry staining with anti-human mouse cluster of differentiation (CD) 68 monoclonal antibody for macrophages and mouse anti-human CD56 monoclonal antibody for NK cells were performed.Results:The number of CD68 macrophages in red lesions was higher than in black and white lesions [median (25th-75th percentile); 10 (5-19.4), 0 (0-6.9), 0 (0-2.5) cells per mm2, respectively, adjusted P=0.001 for red vs. black lesions and red vs. white lesions, and adjusted P=1.000 for black and white lesions]. The number of CD56 NK cells was not significantly different among red, black, and white lesions [median (25th-75th percentile; 5 (2-16.5), 3.8 (0-14.4), 1.3 (0-6.9) respectively, adjusted P=1.000 for red vs. black lesions and black vs. white lesions, and adjusted P=0.617 for red vs. white lesions].Conclusion:The dynamic changes in the immune cells in ectopic endometrium were specific to the macrophages but not to the NK cells, as demonstrated by the highest number of CD68 macrophages in the red lesion, the earliest established ectopic endometrium. NK cells in endometriosis may have a role in the uterus.

A Novel Allogeneic Cell Therapy That Targets Pathogenic Autoantibodies for the Treatment of Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by low platelet counts (<100x10 9/L) and increased risk of bleeding. ITP is predominantly driven by immunoglobulin G (IgG)-autoantibodies directed against platelet surface antigens resulting in platelet destruction by the spleen and/or impaired platelet production by bone marrow megakaryocytes. Approximately 60% of ITP patients have measurable levels of anti-platelet autoantibodies in plasma and about 70% of them have autoantibodies directed against the fibrinogen receptor glycoprotein (GP) IIbIIIa.Current treatment strategies for ITP include non-specific immunosuppression (steroids, rituximab), inhibition of platelet clearance (immunoglobulins, splenectomy, anti-D immunoglobulin, and the Syk inhibitor fostamatinib) and stimulation of platelet production (thrombopoietin receptor agonists). In addition, therapeutics targeting the neonatal Fc receptor, responsible for IgG recycling, are under clinical investigation for ITP. Despite these treatment options, some patients with ITP are refractory or have inadequate responses to existing therapy.Here we describe a novel allogeneic cellular therapy, entitled platelet-like cells (PLC), that specifically targets pathogenic IgG for the treatment of thrombocytopenia in ITP. PLC are produced by differentiating a human induced pluripotent stem cell (hiPSC) line into megakaryocyte-like cells (MLC) which are further processed in a proprietary bioreactor that mimics the bone marrow environment and induces the release of anucleate PLC which are then cryopreserved. Analyses of PLC demonstrate sizes ranging between 65 nm and 10 μm. Expression of GPIIbIIIa protein as measured by enzyme-linked immunosorbent assay (ELISA) is evident in all particle sizes. PLC were administered intravenously (IV) into NOD-scid IL2Rgamma null (NSG) mice to evaluate their pharmacokinetics and biodistribution. PLC were rapidly cleared from the mouse circulation and predominantly distributed to the mouse liver where they colocalized primarily with Kupffer cells. PLC clearance through the liver was significantly inhibited by pre-treating mice with liposomes expressing phosphatidylserine (PS), indicating that one mechanism of PLC clearance is dependent on PS exposure on the PLC outer plasma membrane.The ability of PLC to bind anti-GPIIbIIIa autoantibodies was evaluated in an in vitro assay where PLC were incubated with ITP patient plasmas and subsequently removed by centrifugation and filtration. The concentration of anti-GPIIbIIIa autoantibodies remaining in the plasmas decreased following PLC treatment (96.6% ± 2.4%).The ability of PLC to clear anti-human GPIIbIIIa antibodies in circulation was evaluated by using a passive mouse model of ITP. Here, a fluorescently labeled mouse anti-human GPIIbIIIa monoclonal antibody (PAB-1) was dosed intravenously (IV) into NSG mice to achieve a circulating level of antibody comparable to those observed in ITP patients. The GPIIbIIIa antibody persisted in circulation for over 24 hours following a single dose in untreated mice and did not induce clearance of mouse platelets. Following administration of PLC in the passive ITP model, a decrease in antibody fluorescence in blood was observed within 2 minutes and full antibody clearance was observed at 3 hours post dosing. Furthermore, clearance of the antibody was observed to be both dose responsive and specific since PLC treatment did not affect the antibody concentration of an isotype matched control antibody. PLC activity in clearing the anti-GPIIbIIIa antibody was observed in all particle sizes. Fluorescence quantification of liver and spleen tissue demonstrated that PLC driven anti-GPIIbIIIa antibody clearance occurred preferentially in the liver. Taken together, these data indicate that by specifically binding and rapidly removing anti-platelet antibodies from circulation, PLC may disrupt the platelet degradation mechanisms underlying ITP pathogenesis and restore platelet counts. DisclosuresPatel-Hett: PlateletBio: Current Employment. Giannini: Platelet Biogenesis: Current Employment. Peters: Platelet Biogenesis: Current Employment. Dykstra: Platelet Biogenesis: Current Employment. Lehmann: Platelet Biogenesis: Current Employment. Russo: Platelet Biogenesis: Current Employment. Kohnke: Platelet Biogenesis: Current Employment. Carpenter: Platelet Biogenesis: Current Employment. Tomczak: Platelet Biogenesis: Current Employment. Lazarus: Platelet Biogenesis: Consultancy. Masuko: Platelet Biogenesis: Current Employment. Leung: Platelet Biogenesis: Current Employment. Meredith: Platelet Biogenesis: Current Employment. Pete: Platelet Biogenesis: Current Employment. Lee: Platelet Biogenesis: Current Employment. Falb: Platelet Biogenesis: Current Employment.

Establishment of a novel double-monoclonal antibody sandwich enzyme-linked immunosorbent assay (ELISA): tool for human B7-H4 detection in autoimmune diseases.

B7-H4, one of the immunoregulatory proteins, plays an inhibitory role by inhibiting T cell proliferation and cytokine production. Nevertheless, the significance of soluble B7-H4 (sB7-H4) in autoimmune diseases is unclear. In our study, we developed two novel mouse anti-human B7-H4 monoclonal antibodies (mAbs) (clones 8D4 and 7E1) with utilities for flow cytometry, immunoblotting and immunofluorescence. We characterized 7E1 as a functional antibody with antagonistic activity, which could promote T cell proliferation and regulate cytokine production. Furthermore, based on the different epitope specificities, we established a novel enzyme-linked immunosorbent assay (ELISA) which could detect sB7-H4 sensitively and specifically. Using this ELISA kit, sB7-H4 was observed in a high proportion of autoimmune diseases patients. We found that the levels of sB7-H4 were significantly higher in patients with systemic lupus erythematosus (SLE), type I diabetes (T1D) and Graves' disease (GD). Together, sB7-H4 in human serum is regarded not only as a regulator of T cell activation but may also be a diagnostic marker of autoimmune diseases.

Overexpression of B7-H4 is associated with infiltrating immune cells and poor prognosis in metastatic colorectal cancer

Metastasis commonly occurs in colorectal cancer (CRC) patients and confers a poor prognosis. B7-H4, an immune checkpoint molecule, has been found to be expressed in numerous tumor tissues and play critical roles in tumor progression. However, B7-H4 expression and its prognostic significance in different metastases from CRC remain unclear. In the present study, we screened a novel mouse anti-human B7-H4 monoclonal antibody (mAb) which exhibited a higher degree of recognition and sensitivity than the commercial reagent in immunohistochemistry (IHC). Using this antibody, overall 110 metastatic and paired primary lesions of CRC were analyzed for their expression of B7-H4, CD8 and CD68. Our results showed that expression of B7-H4 and CD68 in metastastic lesions was significantly higher than that in matched primary lesions (P = 0.0016, P < 0.0001). We also found a significant increase of CD68-positive immune cell infiltration in the B7-H4 high expressing metastases (P = 0.041). Moreover, upregulated B7-H4 in metastatic lesions was correlated with poor prognosis of patients (P = 0.014), while in primary lesions, B7-H4 combined with CD8 was associated with the overall survival (OS) (P = 0.043). Further, B7-H4 expression in metastatic lesions was significantly correlated with hazard ratio (HR) both in univariate and multivariate analysis. Altogether, B7-H4 in metastatic lesions is promising to be a potential prognostic indicator of CRC, and may promote tumor progression and metastasis of this cancer.

The Immunostimulative Effect and Mechanisms of a Novel Mouse Anti-Human PD-1 Monoclonal Antibody on Jurkat Lymphocytic Cells Cocultured with Hepatoma Cells.

BackgroundMonoclonal antibodies (mAbs) that target the programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint have demonstrated substantial clinical benefit for a variety of solid tumors. However, their applications in patients with hepatocellular carcinoma (HCC) are reported with unclear molecular mechanisms. Here, we report a novel mouse anti-human PD-1 mAb that can reverse the immunosuppressive effect of HePG2 cells on Jurkat cells.Materials and MethodsHepG2 liver cancer cells, which were induced to overexpress PD-L1 by IFN-γ, were co-cultured with PHA-activated Jurkat lymphocytic cells to investigate the immunostimulative effect and mechanisms of the 14 newly generated PD-1 mAbs. Multiple cellular and molecular biology experiments were performed in this study, such as CCK-8, ELISA, flow cytometry, immunofluorescence and Western blot.ResultsWe found that mAb B1C4 significantly enhanced the tumor-killing cytokine secretion level by Jurkat cells in the co-culture system and increased the killing ability of Jurkat cells on HepG2 cells. Co-culture with HePG2 cells led to Jurkat cell cycle delay in S phase, and B1C4 promoted cell cycle progression from S to G2/M. Co-culture with HePG2 cells also caused apoptosis in Jurkat cells, which was inhibited by B1C4. B1C4 reversed the immunosuppression of Jurkat cells resulted from co-cultured with HePG2 cells through inhibiting PTEN and activating PI3K/AKT/mTOR signaling pathways.ConclusionOur study demonstrated that anti-PD-1 mAb B1C4 could inhibit the apoptosis of Jurkat cells induced by HePG2 hepatoma cells and reverse the immunosuppressive effect of HePG2 cells on Jurkat cells. The study provides a vital basis for applying PD-1 monoclonal antibodies in the treatment of HCC and provides antibody selection for the development of novel PD-1 mAb with blocking activity.