Cx1Mab-1: A Novel Anti-mouse CXCR1 Monoclonal Antibody for Flow Cytometry.

The C-X-C motif chemokine receptor-1 (CXCR1) is a rhodopsin-like G-protein-coupled receptor, expressed on the cell surface of immune cells and tumors. CXCR1 interacts with some C-X-C chemokines, such as CXCL6, CXCL7, and CXCL8/interleukin-8, which are produced by various cells. Since CXCR1 is involved in several diseases including tumors and diabetes mellitus, drugs targeting CXCR1 have been developed. Therefore, the development of sensitive monoclonal antibodies (mAbs) for CXCR1 has been desired for the diagnosis and treatment. This study established a novel anti-mouse CXCR1 (mCXCR1) mAb, Cx1Mab-1 (rat IgG1, kappa), using the Cell-Based Immunization and Screening method. Cx1Mab-1 reacted with mCXCR1-overexpressed Chinese hamster ovary-K1 (CHO/mCXCR1) and mCXCR1-overexpressed LN229 glioblastoma (LN229/mCXCR1) in flow cytometry. Cx1Mab-1 demonstrated a high binding affinity for CHO/mCXCR1 and LN229/mCXCR1 with a dissociation constant of 2.6 × 10-9 M and 2.1 × 10-8 M, respectively. Furthermore, Cx1Mab-1 could detect mCXCR1 by Western blot analysis. These results indicated that Cx1Mab-1 is useful for detecting mCXCR1, and provides a possibility for targeting mCXCR1-expressing cells in vivo experiments.

PMab-314: An Anti-Giant Panda Podoplanin Monoclonal Antibody.

The giant panda (Ailuropoda melanoleuca) is one of the important species in worldwide animal conservation. Because it is essential to understand the disease of giant panda for conservation, histopathological analyses of tissues are important to understand the pathogenesis. However, monoclonal antibodies (mAbs) against giant panda-derived proteins are limited. Podoplanin (PDPN) is an essential marker of lung type I alveolar epithelial cells, kidney podocytes, and lymphatic endothelial cells. PDPN is also overexpressed in various human tumors, which are associated with poor prognosis. Here, an anti-giant panda PDPN (gpPDPN) mAb, PMab-314 (mouse IgG1, kappa) was established using the Cell-Based Immunization and Screening method. PMab-314 recognized N-terminal PA16-tagged gpPDPN-overexpressed Chinese hamster ovary-K1 cells (CHO/PA16-gpPDPN) in flow cytometry. The KD value of PMab-314 for CHO/PA16-gpPDPN was determined as 1.3 × 10-8 M. Furthermore, PMab-314 is useful for detecting gpPDPN in western blot analysis. These findings indicate that PMab-314 is a useful tool for the analyses of gpPDPN-expressed cells.

Epitope Mapping of an Anti-CD44v4 Monoclonal Antibody (C44Mab-108) Using Enzyme-Linked Immunosorbent Assay.

CD44 is a type I transmembrane glycoprotein and possesses various isoforms which are largely classified into CD44 standard (CD44s) and CD44 variant (CD44v) isoforms. Some variant-encoded regions play critical roles in tumor progression. However, the function of CD44 variant 4 (CD44v4)-encoded region has not been fully understood. Using peptide immunization, we developed an anti-CD44v4 monoclonal antibody, C44Mab-108, which is useful for flow cytometry, western blotting, and immunohistochemistry. In this study, we determined the critical epitope of C44Mab-108 by enzyme-linked immunosorbent assay (ELISA). We used the alanine (or glycine)-substituted peptides of the CD44v4-encoded region (amino acids 271-290 of human CD44v3-10) and found that C44Mab-108 did not recognize the alanine-substituted peptides of D280A and W281A. Furthermore, these peptides could not inhibit the recognition of C44Mab-108 in flow cytometry and immunohistochemistry. The results indicate that the critical binding epitope of C44Mab-108 includes Asp280 and Trp281 of CD44v3-10.

Cx3Mab-4: A Novel Anti-Mouse CXCR3 Monoclonal Antibody for Flow Cytometry.

C-X-C motif chemokine receptor 3 (CXCR3, CD183) is a G-protein-coupled receptor for CXCL9, CXCL10, and CXCL11. CXCR3 induces chemotaxis of immune cells and promotes inflammation. Various mouse models have been developed to mimic the pathogenesis of diseases and used in the evaluation of therapeutics for these diseases. Although CXCR3 is an attractive target to suppress inflammation, anti-CXCR3 therapeutic agents have not been approved. In this study, we established a novel anti-mouse CXCR3 (mCXCR3) monoclonal antibody, Cx3Mab-4 (rat IgG1, kappa), using the Cell-Based Immunization and Screening method. Flow cytometric analysis demonstrated that Cx3Mab-4 bound to mCXCR3-overexpressed Chinese hamster ovary-K1 (CHO/mCXCR3) cells, but did not react to parental CHO-K1 cells. The dissociation constant of Cx3Mab-4 was determined as 1.3 × 10-9 M, indicating that Cx3Mab-4 possesses a high affinity to mCXCR3-expressing cells. Cx3Mab-4 could be useful for targeting CXCR3-expressing cells in preclinical mouse models.

Locally misfolded HER2 expressed on cancer cells is a promising target for development of cancer-specific antibodies.

Overexpression of human epidermal growth factor receptor 2 (HER2) in breast and gastric cancers is associated with a poor prognosis, making it an important therapeutic target. Here, we establish a novel cancer-specific anti-HER2 antibody, H2Mab-214. H2Mab-214 reacts with HER2 on cancer cells, but unlike the therapeutic antibody trastuzumab, it does not react with HER2 on normal cells in flow cytometry measurements. A crystal structure suggests that H2Mab-214 recognizes a structurally disrupted region in the HER2 domain IV, which normally forms a ß-sheet. We show that this misfolding is inducible by site-directed mutagenesis mimicking the disulfide bond defects that also may occur in cancer cells, indicating that the local misfolding in the Cys-rich domain IV governs the cancer-specificity of H2Mab-214. Furthermore, we show that H2Mab-214 effectively suppresses tumor growth in xenograft mouse models. Our findings offer a potential strategy for developing cancer-specific therapeutic antibodies that target partially misfolded cell surface receptors.

Epitope Mapping of an Anti-Mouse CD39 Monoclonal Antibody Using PA Scanning and RIEDL Scanning.

A cell-surface ectonucleotidase CD39 mediates the conversion of extracellular adenosine triphosphate into immunosuppressive adenosine with another ectonucleotidase CD73. The elevated adenosine in the tumor microenvironment attenuates antitumor immunity, which promotes tumor cell immunologic escape and progression. Anti-CD39 monoclonal antibodies (mAbs), which suppress the enzymatic activity, can be applied to antitumor therapy. Therefore, an understanding of the relationship between the inhibitory activity and epitope of mAbs is important. We previously established an anti-mouse CD39 (anti-mCD39) mAb, C39Mab-1 using the Cell-Based Immunization and Screening method. In this study, we determined the critical epitope of C39Mab-1 using flow cytometry. We performed the PA tag (12 amino acids [aa])-substituted analysis (named PA scanning) and RIEDL tag (5 aa)-substituted analysis (named RIEDL scanning) to determine the critical epitope of C39Mab-1 using flow cytometry. By the combination of PA scanning and RIEDL scanning, we identified the conformational epitope, spanning three segments of 275-279, 282-291, and 306-323 aa of mCD39. These analyses would contribute to the identification of the conformational epitope of membrane proteins.

Establishment of a Novel Anti-Mouse CCR1 Monoclonal Antibody C1Mab-6.

C-C motif chemokine receptor 1 (CCR1/CD191) is a member of G-protein-coupled receptors and is expressed on myeloid cells, such as neutrophils and macrophages. Because the CCR1 signaling promotes tumor expansion in the tumor microenvironment (TME), the modification of TME is an effective strategy for cancer therapy. Although CCR1 is an attractive target for solid tumors and hematological malignancies, therapeutic agents for CCR1 have not been approved. Here, we established a novel anti-mouse CCR1 (mCCR1) monoclonal antibody (mAb), C1Mab-6 (rat IgG2b, kappa), using the Cell-Based Immunization and Screening method. Flow cytometry and Western blot analyses showed that C1Mab-6 recognizes mCCR1 specifically. The dissociation constant of C1Mab-6 for mCCR1-overexpressed Chinese hamster ovary-K1 was determined as 3.9 × 10-9 M, indicating that C1Mab-6 possesses a high affinity to mCCR1. These results suggest that C1Mab-6 could be a useful tool for targeting mCCR1 in preclinical mouse models.

Assessment of the 2021 AASLD Practice Guidance for Albumin Infusion in Elective Therapeutic Paracentesis: A Regression Discontinuity Design.

INTRODUCTION: The 2021 American Association for the Study of Liver Disease (AASLD) Practice Guidance recommends albumin infusion when removing ≥5 L of ascites to prevent post-paracentesis circulatory dysfunction. However, the optimal criteria and scenarios for initiating albumin infusion subsequent to therapeutic paracentesis (TP) have been subject to limited scientific inquiry. METHODS: We conducted a retrospective cohort study at a US academic healthcare center. Participants received elective, outpatient TP between July 2019 and December 2022. Patients with spontaneous bacterial peritonitis, post-TP clinical adjustments, and/or hospitalization were excluded. The institution strictly followed the AASLD Guidance. We used a sharp regression discontinuity (RD) design to estimate the effect of albumin infusion at the AASLD Guidance-recommended cutoff of 5 L on serum creatinine and sodium trajectory after TP. RESULTS: Over the study period, 1,457 elective TPs were performed on 235 unique patients. Albumin infusion at the threshold of 5 L of ascites removal reduced serum creatinine levels by 0.046 mg/dL/d (95% confidence interval 0.003-0.116, P = 0.037) and increased serum sodium levels by 0.35 mEq/L/d (95% confidence interval 0.15-0.55, P = 0.001) compared with those who did not receive albumin infusion. The RD plots indicated worsened serum creatine/sodium levels after draining 3 L of fluid, approaching levels similar to or worse than with albumin infusion at 5 L or more. DISCUSSION: Our RD models supported the 2021 AASLD Guidance with robust estimation of causal effect sizes at the cutoff level of 5 L. Nevertheless, the findings also highlight the need to further evaluate the efficacy of albumin infusion in patients who undergo elective TP and have 3-5 L of ascites removed.

A Cancer-Specific Monoclonal Antibody against HER2 Exerts Antitumor Activities in Human Breast Cancer Xenograft Models.

Monoclonal antibody (mAb)-based and/or cell-based immunotherapies provide innovative approaches to cancer treatments. However, safety concerns over targeting normal cells expressing reactive antigens still exist. Therefore, the development of cancer-specific mAbs (CasMabs) that recognize cancer-specific antigens with in vivo antitumor efficacy is required to minimize the adverse effects. We previously screened anti-human epidermal growth factor receptor 2 (HER2) mAbs and successfully established a cancer-specific anti-HER2 mAb, H2Mab-250/H2CasMab-2 (IgG1, kappa). In this study, we showed that H2Mab-250 reacted with HER2-positive breast cancer cells but did not show reactivity to normal epithelial cells in flow cytometry. In contrast, a clinically approved anti-HER2 mAb, trastuzumab, recognized both breast cancer and normal epithelial cells. We further compared the affinity, effector activation, and antitumor effect of H2Mab-250 with trastuzumab. The results showed that H2Mab-250 exerted a comparable antitumor effect with trastuzumab in the mouse xenograft models of BT-474 and SK-BR-3, although H2Mab-250 possessed a lower affinity and effector activation than trastuzumab in vitro. H2Mab-250 could contribute to the development of chimeric antigen receptor-T or antibody-drug conjugates without adverse effects for breast cancer therapy.

Establishment of Anti-Dog Programmed Cell Death Ligand 1 Monoclonal Antibodies for Immunohistochemistry.

Immune checkpoint blockade therapy has shown successful clinical outcomes in multiple human cancers. In dogs, several types of tumors resemble human tumors in many respects. Therefore, several groups have developed the anti-dog programmed cell death ligand 1 (dPD-L1) monoclonal antibodies (mAbs) and showed efficacy in several canine tumors. To examine the abundance of dPD-L1 in canine tumors, anti-dPD-L1 diagnostic mAbs for immunohistochemistry are required. In this study, we immunized the peptide in the dPD-L1 intracellular domain, and established anti-dPD-L1 mAbs, L1Mab-352 (mouse IgG1, kappa), and L1Mab-354 (mouse IgG1, kappa). In enzyme-linked immunosorbent assay, L1Mab-352 and L1Mab-354 showed high-binding affinity to the dPD-L1 peptide, and the dissociation constants (KD) were determined as 6.9 × 10-10 M and 7.2 × 10-10 M, respectively. Furthermore, L1Mab-352 and L1Mab-354 were applicable for the detection of dPD-L1 in immunohistochemical analysis in paraffin-embedded dPD-L1-overexpressed cells. These results indicated that L1Mab-352 and L1Mab-354 are useful for detecting dPD-L1 in immunohistochemical analysis.

Proceedings of the 28th Annual Congress of the International Liver Transplantation Society.

The 2023 Joint International Congress of the International Liver Transplantation Society (ILTS), the European Liver and Intestine Transplant Association (ELITA), and the Liver Intensive Care Group of Europe (LICAGE) held in Rotterdam, the Netherlands, marked a significant recovery milestone for the liver transplant community after COVID-19. With 1159 participants and a surge in abstract submissions, the event focused on "Liver Disorders and Transplantation: Innovations and Evolving Indications." This conference report provides a comprehensive overview of the key themes discussed during the event, encompassing Hepatology, Anesthesia and Critical Care, Acute Liver Failure, Infectious Disease, Immunosuppression, Pediatric Liver Transplantation, Living Donor Liver Transplantation, Transplant Oncology, Surgical Approaches, and Machine Perfusion. The congress provided a platform for extensive discussions on a wide range of topics, reflecting the continuous advancements and collaborative efforts within the liver transplant community.

Antitumor activities against breast cancers by an afucosylated anti-HER2 monoclonal antibody H2 Mab-77-mG2a -f.

Breast cancer patients with high levels of human epidermal growth factor receptor 2 (HER2) expression have worse clinical outcomes. Anti-HER2 monoclonal antibody (mAb) is the most important therapeutic modality for HER2-positive breast cancer. We previously immunized mice with the ectodomain of HER2 to create the anti-HER2 mAb, H2 Mab-77 (mouse IgG1 , kappa). This was then altered to produce H2 Mab-77-mG2a -f, an afucosylated mouse IgG2a . In the present work, we examined the reactivity of H2 Mab-77-mG2a -f and antitumor effects against breast cancers in vitro and in vivo. BT-474, an endogenously HER2-expressing breast cancer cell line, was identified by H2 Mab-77-mG2a -f with a strong binding affinity (a dissociation constant [KD ]: 5.0 × 10-9 M). H2 Mab-77-mG2a -f could stain HER2 of breast cancer tissues in immunohistochemistry and detect HER2 protein in Western blot analysis. Furthermore, H2 Mab-77-mG2a -f demonstrated strong antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) for BT-474 cells. MDA-MB-468, a HER2-negative breast cancer cell line, was unaffected by H2 Mab-77-mG2a -f. Additionally, in the BT-474-bearing tumor xenograft model, H2 Mab-77-mG2a -f substantially suppressed tumor development when compared with the control mouse IgG2a mAb. In contrast, the HER2-negative MDA-MB-468-bearing tumor xenograft model showed no response to H2 Mab-77-mG2a -f. These findings point to the possibility of H2 Mab-77-mG2a -f as a treatment regimen by showing that it has antitumor effects on HER2-positive breast tumors.

Differential Impact of the UNOS Simultaneous Liver-kidney Transplant Policy Change Among Patients With Sustained Acute Kidney Injury.

BACKGROUND: Simultaneous liver-kidney transplant (SLK) allocation policy in the United States was revised in August 2017, reducing access for liver transplant candidates with sustained acute kidney injury (sAKI) and potentially adversely impacting vulnerable populations whose true renal function is overestimated by commonly used estimation equations. METHODS: We examined national transplant registry data containing information for all liver transplant recipients from June 2013 to December 2021 to assess the impact of this policy change using instrumental variable estimation based on date of listing. RESULTS: Posttransplant survival was compared for propensity-matched patients with sAKI who were only eligible for liver transplant alone (LTA_post; n = 638) after the policy change but would have been SLK-eligible before August 2017, with similar patients who were previously able to receive an SLK (SLK; n = 319). Overall posttransplant patient survival was similar at 3 y (81% versus 80%; P = 0.9). However, receiving an SLK versus LTA increased survival among African Americans (87% versus 61% at 3 y; P = 0.029). A trend toward survival benefit from SLK versus LTA, especially later in the follow-up period, was observed in recipients ≥ age 60 (3-y survival: 84% versus 76%; P = 0.2) and women (86% versus 80%; P = 0.2). CONCLUSIONS: The 2017 United Network for Organ Sharing SLK Allocation Policy was associated with reduced survival of African Americans with end-stage liver disease and sAKI and, potentially, older patients and women. Our study suggested the use of race-neutral estimation of renal function would ameliorate racial disparities in the SLK arena; however, further studies are needed to reduce disparity in posttransplant outcomes among patients with liver and kidney failure.

The landscape of inpatient admissions for alcoholic hepatitis in the era of early liver transplantation.

INTRODUCTION AND OBJECTIVES: Liver transplant (LT) is a recent option available in the United States (US) to treat those with severe, refractory alcoholic hepatitis (AH). We examined changes in clinical characteristics of patients admitted with AH and tracked hospital outcomes as practice changes involving LT have shifted. MATERIALS AND METHODS: Using the National Inpatient Sample, we performed a cross-sectional analysis of patients admitted with AH during the years 2016-2020 in the US. Differences in clinical characteristics over time were assessed. To compare outcomes between 2016-2017 (when LT was less common) and 2018-2020 (when LT was more common), we conducted linear and logistic regression. Propensity-score matching was used to compare outcomes between patients with and without LT. RESULTS: From 2016-2017 to 2018-2020, patients admitted with AH tended to have a higher frequency of infection (p = 0.006), hepatorenal syndrome (<0.001), and ascites (<0.001). Hospital costs and length of stay (LOS) were highest in transplant hospitals, and costs rose over time in both non-transplant (NT) teaching and non-teaching hospitals (p < 0.001). Mortality decreased in NT teaching hospitals [aOR 0.7 (95% CI: 0.6-0.8)] and slightly decreased in NT non-teaching hospitals [aOR 0.7 (95% CI: 0.5-1.0)]. In the propensity-matched cohort involving LT versus non-LT patients, there was a 10% absolute reduction in-hospital mortality, but this came at a higher cost (p < 0.001) and length of stay (p < 0.001). CONCLUSIONS: The severity of AH has been increasing over time, yet mortality has declined after adjusting for severity of disease. Patients who underwent LT survived; however, the healthcare burden of LT is substantial.

Cx4Mab-1: A Novel Anti-Mouse CXCR4 Monoclonal Antibody for Flow Cytometry.

The CXC chemokine receptor 4 (CXCR4, CD184) is a member of the G protein-coupled receptor family that is expressed in most leukocytes. Overexpression of CXCR4 is associated with poor prognosis in not only hematopoietic malignancy but also solid tumors. Because CXCR4 is an attractive target for tumor therapy, reliable preclinical murine models using anti-CXCR4 monoclonal antibodies (mAbs) have been warranted. This study established a novel anti-mouse CXCR4 (mCXCR4) mAb using the Cell-Based Immunization and Screening method. Flow cytometric analysis showed that an anti-mCXCR4 mAb, Cx4Mab-1 (rat IgG2a, kappa), recognized mCXCR4-overexpressed Chinese hamster ovary-K1 (CHO/mCXCR4) cells and endogenously mCXCR4-expressing mouse myeloma P3X63Ag8U.1 (P3U1) cells. Furthermore, Cx4Mab-1 did not recognize mCXCR4-knockout P3U1 cells. The dissociation constants of Cx4Mab-1 for CHO/mCXCR4 and P3U1 were determined as 6.4 × 10-9 M and 2.3 × 10-9 M, respectively, indicating that Cx4Mab-1 possesses a high affinity to both endogenous and exogenous mCXCR4-expressing cells. These results indicate that Cx4Mab-1 could be a useful tool for preclinical mouse models.

Role of PPARα in inflammatory response of C2C12 myotubes.

Recent studies have shown a role of inflammation in muscle atrophy and sarcopenia. However, no anti-inflammatory pharmacotherapy has been established for the treatment of sarcopenia. Here, we investigate the potential role of PPARα and its ligands on inflammatory response and PGC-1α gene expression in LPS-treated C2C12 myotubes. Knockdown of PPARα, whose expression was upregulated upon differentiation, augmented IL-6 or TNFα gene expression. Conversely, PPARα overexpression or its activation by ligands suppressed 2-h LPS-induced cytokine expression, with pemafibrate attenuating NF-κB or STAT3 phosphorylation. Of note, reduction of PGC-1α gene expression by LPS treatment for 24 hours was partially reversed by fenofibrate. Our data demonstrate a critical inhibitory role of PPARα in inflammatory response of C2C12 myotubes and suggest a future possibility of PPARα ligands as a candidate for anti-inflammatory therapy against sarcopenia.

Dapsone-Induced Granulomatous Cholestatic Hepatitis Unmasked by Steroid Taper: A Case Report.

Introduction: Dapsone is known to cause drug-induced liver injury (DILI) but can rarely induce the formation of hepatic granulomas. We describe a patient with jaundice who demonstrated granulomas on liver biopsy in response to dapsone. Her symptoms were only evident once steroids, used to also treat her pyoderma gangrenosum, had been tapered. Case Presentation: In this case, a 67-year-old female was hospitalized due to 1 day of jaundice. She had started dapsone and prednisone concurrently 7 weeks ago to treat her pyoderma gangrenosum. Steroids were discontinued 4 days prior to symptoms. Her laboratories were notable for newly elevated alkaline phosphatase (756 U/L), aspartate transaminase (199 U/L), alanine transaminase (273 U/L), and total bilirubin (12.6 mg/dL). Dapsone was held due to suspicion for DILI. A liver biopsy was performed and disclosed non-necrotizing hepatic granulomas. After infectious and autoimmune causes were excluded, dapsone was determined to be the cause of her hepatic granulomas. Her bilirubin and liver enzymes steadily normalized over the next 4 weeks following discontinuation of dapsone. Conclusion: Thus, dapsone-related liver injury may present following a steroid taper if dapsone and steroids had been initially started together. Hepatic granulomas, though rare, can be seen when dapsone causes DILI.

Incidence of Colorectal Cancer in Patients Diagnosed With Pyogenic Liver Abscess.

Importance: Colorectal cancer (CRC) can compromise the mucosal barrier and subsequently allow a route for bacterial invasion into the portal system or systemic circulation. Despite preliminary data suggesting that patients who experienced pyogenic liver abscess (PLA) have higher CRC incidence rates, data from outside the Southeast Asian population are sparse. Objective: To investigate whether there is an association between PLA and the subsequent incidence of diagnosed CRC using the Veterans Health Administration (VHA) cohort. Design, Setting, and Participants: A patient-level matched retrospective cohort study was conducted at 127 VHA hospitals across the US from January 1, 2003, to December 31, 2020. Patients were followed up to 10 years from PLA diagnosis. Data analysis was performed from April 14, 2002, to October 31, 2023. All patients who were admitted to VHA hospitals with a diagnosis of PLA were included. For each patient with PLA, up to 3 controls without diagnosis of PLA, matching age, sex, and health care facility, were selected. Exposure: Pyogenic liver abscess. Main Outcomes and Measures: The primary outcome was CRC diagnosis during the follow-up period. A multivariable Fine-Gray subdistribution regression model with time-dependent coefficient was used to estimate the time-varying hazard ratio (HR) of CRC incidence while accounting for mortality as a competing event. Results: A total of 8286 patients with PLA (male, 96.5%; mean [SD] age, 65.8 [11.9] years) and 23 201 patient-level matched controls (male, 96.3%; mean age, 65.3 [11.7] years) were included. A diagnosis of CRC was found in a significantly higher proportion of patients with PLA compared with controls (1.9% [159 of 8286] vs 0.8% [196 of 23 201]; P < .001). The incidence of CRC was significantly higher among patients with PLA during the first 3 years from PLA diagnosis (HR, 3.64; 95% CI, 2.70-4.91 at 0.5 years; HR, 2.51; 95% CI, 1.93-3.26 at 1 year; HR, 1.74; 95% CI, 1.33-2.28 at 2 years; and HR, 1.41; 95% CI, 1.05-1.89 at 3 years), but not significant after 3 years. This association was not observed among patients whose PLA was likely secondary to cholangitis or cholecystitis (HR, 1.78; 95% CI, 0.89-3.56 at 0.5 years). Conclusions and Relevance: In this patient-level matched retrospective cohort study, a significantly higher incidence of CRC was observed up to 3 years from PLA diagnosis. The findings suggest that offering CRC screening for patients with cryptogenic PLA may be useful, especially patients who have not been screened according to guidelines.

A Rat Anti-Mouse CD39 Monoclonal Antibody for Flow Cytometry.

By converting extracellular adenosine triphosphate to adenosine, CD39 is involved in adenosine metabolism. The extracellular adenosine plays a critical role in the immune suppression of the tumor microenvironment. Therefore, the inhibition of CD39 activity by monoclonal antibodies (mAbs) is thought to be one of the important strategies for tumor therapy. In this study, we developed novel mAbs for mouse CD39 (mCD39) using the Cell-Based Immunization and Screening (CBIS) method. One of the established anti-mCD39 mAbs, C39Mab-2 (rat IgG2a, lambda), reacted with mCD39-overexpressed Chinese hamster ovary-K1 (CHO/mCD39) and an endogenously mCD39-expressed cell line (SN36) by flow cytometry. The kinetic analysis using flow cytometry indicated that the dissociation constant (KD) values of C39Mab-2 for CHO/mCD39 and SN36 were 5.5 × 10-9 M and 4.9 × 10-9 M, respectively. These results indicated that C39Mab-2 is useful for the detection of mCD39 in flow cytometry.

PMab-301: An Anti-Giraffe Podoplanin Monoclonal Antibody for Immunohistochemistry.

Immunohistochemistry staining is an essential method in pathological diagnoses. Podoplanin (PDPN) is a specific maker of alveolar epithelium, lymphatic vessels, and glomeruli. In this study, we established a novel anti-giraffe PDPN (girPDPN) mAb, PMab-301, using the Cell-Based Immunization and Screening (CBIS) method. PMab-301 (mouse IgG1, kappa) detected girPDPN in various applications, such as flow cytometry, western blot, and immunohistochemistry. PMab-301 specifically stained type-I alveolar cells using formalin-fixed paraffin-embedded giraffe lung tissues. Our findings suggest the potential usefulness of PMab-301 for the pathophysiological analyses of giraffe tissues.