Objective To establish a sandwich enzyme-linked immunosorbent assay (ELISA) method for the quantitative detection of Chromogranin A (CHGA) in saliva, and to explore its preliminary application in the testing of saliva samples. Methods Recombinant human CHGA protein was used to immunize BALB/c mice, and monoclonal antibodies (mAbs) were prepared and screened using conventional hybridoma technology. A double-antibody sandwich ELISA detection method was constructed, and the matrix effect of saliva samples was optimized. This method was then applied to detect the concentration of CHGA in the saliva of stressed individuals. Results Twenty-one stable hybridoma cell lines secreting high affinity anti-human CHGA antibodies were obtained. A pair of detection antibodies with the best effect was selected, and the optimal coating concentration was determined to be 10 μg/mL, with the optimal dilution of detection antibodies being 1:32 000. The accuracy and reproducibility of this method were verified, with both intra-batch and inter-batch variation coefficients less than 15×, and the recovery rate between 80× and 120×. The matrix effect was further optimized to make it suitable for saliva sample detection. Saliva samples from individuals in different stress states were collected, and the CHGA levels were detected using the method established in this study, indicating its potential to reflect the intensity of stress. Conclusion A reliable saliva CHGA ELISA detection method has been successfully established, and its potential as a biomarker in stress-related research has been preliminarily explored.
Saliva/metabolism* ; Enzyme-Linked Immunosorbent Assay/methods* ; Humans ; Animals ; Mice, Inbred BALB C ; Mice ; Chromogranin A/immunology* ; Antibodies, Monoclonal/immunology* ; Female ; Male ; Reproducibility of Results ; Adult

Objective To investigate the effects of LBL-007, a novel fully human lymphocyte activation gene 3 (LAG-3) monoclonal antibody, in combination with programmed cell death protein 1 (PD-1) antibody, on the invasion, migration and proliferation of tumor cells, and to elucidate the underlying mechanisms. Methods Human lymphocyte cells Jurkat were co-cultured with A549 and MGC803 tumor cell lines and treated with the isotype control antibody human IgG, LBL-007, anti-PD-1 antibody BE0188, or tumor necrosis factor-alpha (TNF-α, the NF-κB signaling pathway agonist). Tumor cell proliferation was assessed using a colony formation assay; invasion was measured by Transwell^TM assay; migration was evaluated using a wound healing assay. Western blotting was employed to determine the expression levels of NF-κB pathway-related proteins: IκB inhibitor kinase alpha (Ikkα), phosphorylated Ikkα (p-IKKα), NF-κB subunit p65, phosphorylated p65 (p-p65), NF-κB Inhibitor Alpha (IκBα), phosphorylated IκBα (p-IκBα), matrix metalloproteinase 9 (MMP9), and MMP2. Results Compared with the control and IgG isotype groups, LBL-007 and BE0188 significantly reduced tumor cell proliferation, invasion, and migration. They also decreased the phosphorylation of p-IKKα, p-p65 and p-IκBα, and the expression of MMP9 and MMP2 of tumor cells in the co-culture system. The combined treatment of LBL-007 and BE0188 enhanced inhibitory effects. Treatment with the NF-κB signaling pathway agonist TNF-α reversed the suppressive effects of LBL-007 and BE0188 on tumor cell proliferation, invasion, migration, and NF-κB signaling. Conclusion LBL-007 and anti-PD-1 antibody synergistically inhibit the invasion, migration, and proliferation of A549 and MGC803 tumor cells by blocking the NF-κB signaling pathway.
Humans ; Cell Proliferation/drug effects* ; Cell Movement/drug effects* ; Signal Transduction/drug effects* ; NF-kappa B/metabolism* ; Neoplasm Invasiveness ; Antibodies, Monoclonal/pharmacology* ; Programmed Cell Death 1 Receptor/antagonists & inhibitors* ; Cell Line, Tumor ; Antigens, CD/immunology* ; Lymphocyte Activation Gene 3 Protein ; A549 Cells ; I-kappa B Kinase/metabolism* ; Jurkat Cells ; Matrix Metalloproteinase 9/metabolism*

OBJECTIVE: To develop monoclonal antibodies that can specifically recognize human von Willebrand factor (VWF) propeptide (VWFpp) in plasma, and establish a rapid and reliable method for the detection of VWFpp antigen in plasma by using the double-antibody sandwich ELISA with the obtained anti-VWFpp monoclonal antibody. METHODS: The recombinant human VWFpp (D1 and D2 regions) protein expressed in eukaryotic cells was used as immunogen to immunize BALB/c mice with routine method, so as to obtain clones of fusion cells. After screening and identification, hybridoma cell lines secreting monoclonal antibodies against VWFpp were selected, and then double-antibody sandwich ELISA assay was used to construct VWFpp antigen detection kit for the determination of VWFpp in human plasma. The levels of VWFpp antigen in plasma of 12 leukemia patients who underwent bone marrow transplantation were dynamically detected. RESULTS: Two hybridoma cell lines that can be subcultured continuously and secrete monoclonal antibodies against VWFpp were obtained and named SZ175 and SZ176 respectively. Identified by ELISA and Western blot, the antibodies could both specifically recognize VWFpp but couldn't recognize mature VWF (without propeptide). Based on the principle of double-antibody sandwich ELISA, monoclonal antibodies SZ175 and SZ176 were successfully made into a kit for detecting VWFpp antigen. The plasma VWFpp levels of leukemia patients before and after bone marrow transplantation were dynamically detected. The results showed that the plasma VWFpp levels of the patients after transplantation were significantly higher than those before transplantation. CONCLUSION Two monoclonal antibodies against VWFpp were successfully prepared, and a double-antibody sandwich ELISA detection kit for VWFpp antigen was constructed, which provides a powerful tool for further study on the biological function of VWFpp, the clinical diagnosis and classification of von Willebrand disease (VWD), and the prognostic monitoring of endothelial injury-related diseases.
Animals ; Mice ; Humans ; von Willebrand Factor ; Antibodies, Monoclonal ; Protein Precursors/metabolism* ; von Willebrand Diseases/diagnosis* ; Prognosis

In response to the market demand for therapeutic antibodies, the upstream cell culture scale and expression titer of antibodies have been significantly improved, while the production efficiency of downstream purification process is relatively fall behind, and the downstream processing capacity has become a bottleneck limiting antibody production throughput. Using monoclonal antibody mab-X as experimental material, we optimized the caprylic acid (CA) precipitation process conditions of cell culture fluid and low pH virus inactivation pool, and studied two applications of using CA treatment to remove aggregates and to inactivate virus. Based on the lab scale study, we carried out a 500 L scale-up study, where CA was added to the low pH virus inactivation pool for precipitation, and the product quality and yield before and after precipitation were detected and compared. We found that CA precipitation significantly reduced HCP residuals and aggregates both before and after protein A affinity chromatography. In the aggregate spike study, CA precipitation removed about 15% of the aggregates. A virus reduction study showed complete clearance of a model retrovirus during CA precipitation of protein A purified antibody. In the scale-up study, the depth filtration harvesting, affinity chromatography, low pH virus inactivation, CA precipitation and depth filtration, and cation exchange chromatography successively carried out. The mixing time and stirring speed in the CA precipitation process significantly affected the CA precipitation effect. After CA precipitation, the HCP residue in the low pH virus inactivation solution decreased 895 times. After precipitation, the product purity and HCP residual meet the quality criteria of monoclonal antibodies. CA precipitation can reduce the chromatography step in the conventional purification process. In conclusion, CA precipitation in the downstream process can simplify the conventional purification process, fully meet the purification quality criterion of mab-X, and improve production efficiency and reduce production costs. The results of this study may promote the application of CA precipitation in the purification of monoclonal antibodies, and provide a reference for solving the bottleneck of the current purification process.
Cricetinae ; Animals ; Antibodies, Monoclonal/metabolism* ; Caprylates/chemistry* ; Cell Culture Techniques ; Chromatography, Affinity ; CHO Cells ; Cricetulus ; Chemical Precipitation

This study aims to develop a method to detect bovine multi-cytokines based on flow cytometry. Previously we have prepared and screened monoclonal antibodies against bovine cytokines IFN-γ, IL-2, TNF-α, IP-10 and MCP-1. These bovine cytokine monoclonal antibodies were fluorescently labeled, and the combination of antibody and cell surface molecules were used to develop the method for detecting bovine multi-cytokines. Subsequently, the developed method was used to determine the cytokine expression profile of Mycobacterium bovis BCG infected bovine peripheral blood mononuclear cells in vitro, and evaluate the cytokine expression level of peripheral blood CD4⁺ T cells of tuberculosis-positive cattle. The bovine multi-cytokine flow cytometry detection method can effectively determine the cytokine expression of BCG-infected bovine peripheral blood T lymphocytes. Among them, the expression levels of IFN-γ, IL-2, and TNF-α continue to increase after 40 hours of infection, while the expression levels of IP-10 and MCP-1 decreased. The combined detection of IFN-γ, IL-2, and TNF-α on CD4⁺ T lymphocytes in peripheral blood of cattle can effectively distinguish tuberculosis-positive and tuberculosis-negative samples. This method may facilitate evaluating the level of cellular immune response after bovine pathogen infection and vaccine injection.
Cattle ; Animals ; Cytokines ; BCG Vaccine/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-2 ; Flow Cytometry/methods* ; Chemokine CXCL10/metabolism* ; Leukocytes, Mononuclear ; CD4-Positive T-Lymphocytes/metabolism* ; Tuberculosis ; Antibodies, Monoclonal/metabolism*

As a newly emerged class of anticancer bioagents in the most precise and selectively targeted way, antibody-drug conjugate (ADC) combines the cancer-targeting abilities of monoclonal antibodies with the cytotoxicity potency of payload, delivering highly cytotoxic drug into tumors via 'targeted chemotherapy'. ADC has revolutionized the treatment landscape of human epidermal growth factor receptor 2 positive and triple negative subtypes in breast cancer. Three ADCs have been approved by U. S. Food and Drug Administration with breast cancer indications, including trastuzumab emtansine (T-DM1; also approved in China), trastuzumab deruxtecan (T-DXd, DS-8201) and sacituzumab govitecan (IMMU-132; also approved in China). Antibodies, cytotoxic drug, linker, and conjugation process are implicated in ADC profile, resulting in unique adverse drug reactions and toxicity heterogeneity within ADC class. For example, more attention should be paid to the management of thrombocytopenia, hepatotoxicity, and reductions in left ventricular ejection fraction (LVEF) in patients treated with trastuzumab emtansine; clinical physicians should pay attention to the risk of neutropenia, interstitial lung disease/pneumonitis, and reductions in LVEF when treated with trastuzumab deruxtecan; sacituzumab govitecan most frequently caused neutropenia, anemia and diarrhea requiring close monitor. ADC has generally favorable safety profiles, and dose modifications and/or symptomatic supporting treatment are effective in terms of toxicity management. This consensus aims at providing guidance for clinical oncologists of early detection, regular assessment, timely management and follow-up monitor of ADC-associated adverse reactions/events.
Ado-Trastuzumab Emtansine/therapeutic use* ; Antibodies, Monoclonal/therapeutic use* ; Antineoplastic Agents, Immunological/therapeutic use* ; Breast Neoplasms/therapy* ; Camptothecin/adverse effects* ; Consensus ; Cytotoxins/therapeutic use* ; Female ; Humans ; Immunoconjugates/therapeutic use* ; Neutropenia/etiology* ; Receptor, ErbB-2/metabolism* ; Trastuzumab/therapeutic use* ; Triple Negative Breast Neoplasms/therapy* ; Ventricular Function, Left

BACKGROUND: Head and neck cancers (HNCs) are a heterogeneous group of tumors that progress owing to varied enviromental and genetic risk factors. Viral infections are threatening and adept at altering the expression of cellular transcription factors such as nuclear factor kappa B (NF-κB) and deregulation of other cellular proteins like NF kappa B inhibitor alpha (IκBα). The present study was conducted to detect high-risk genotypes of human papillomavirus (HPV) and protein expression of NF-κB signaling pathway in HNC patients with HPV infection. METHODS: For HPV detection, genomic DNA from 152 HNC tumors was extracted formalin-fixed paraffin-embedded tissue DNA kit. For genotyping, polymerase chain reaction (PCR) using a general primer, HPV type-specific primers and agarose gel electrophoresis were performed. Immunohistochemistry (IHC) was also performed on 4-μm thick tissue sections using HPV E6 monoclonal antibody. Protein expression analysis of NF-κB signaling pathway including p50, p65, and IκBα was performed using IHC. RESULTS: PCR analysis showed that 24.3% (37/152) of HNC cases were HPV positive. Among HPV positive, 86.5% (32/37) were tobacco users, while among HPV negative, 66.9% (77/115) were tobacco users. A significant association of HPV positivity and tobacco user was observed by univariate analysis [ P   <  0.01; odds ratio (OR): 0.310, 95% confidence interval (CI): 0.110 to 0.870]. More HPV positive patients were with poor oral hygiene (78.3%) when compared with patients with good oral hygiene (21.6%) [ P  < 0.03, OR: 2.440, 95% CI: 1.650 to 3.600]. The results of the logistic regression analysis showed that age, tobacco use and oral hygiene are significant predictors ( P  < 0.02). PCR and IHC staining results confirmed that HPV16 was predominant among HNC cases (64.8%) when compared with HPV18 (35.2%). Expression of NF-κB proteins (p50, p65, and IκBα inhibitor) were also observed in HPV and non-HPV infected HNC tissues. IHC expression of p50, and p65 showed nuclear staining, while IκBα inhibitor showed cytoplasmic staining. Protein expression in HPV cases was higher as compared to HPV naive cases ( P  < 0.05). CONCLUSIONS From the study, it can be established that the use of tobacco, oral hygiene, and HPV infection may be synergistically involved in modulating the expression of NF-κB signaling pathway for the development and progression of HNC in the Pakistani population.
Alphapapillomavirus ; Antibodies, Monoclonal ; DNA ; DNA, Viral/genetics* ; Formaldehyde ; Head and Neck Neoplasms ; Humans ; NF-KappaB Inhibitor alpha/genetics* ; NF-kappa B/metabolism* ; Oral Hygiene ; Pakistan ; Papillomaviridae/metabolism* ; Papillomavirus Infections/metabolism* ; Signal Transduction ; Tobacco ; Tobacco Use ; Transcription Factors/metabolism*

Influenza C virus is an important respiratory pathogen not only infecting people, but also pigs, dogs, and other animals. Polymerase is central to the replication of influenza C virus and is an important target for studying the mechanism of viral replication. However, there is no commercial monoclonal antibody (MAb) targeting influenza C virus polymerase, which hampers the development of relevant research to some extent. In order to prepare MAb targeting the polymerase basic protein 2 (PB2) of influenza C virus, influenza C virus RNA-dependent RNA polymerase (RdRp, consists of PB1, PB2 and P3) was co-immunoprecipitated with Flag-tagged human acidic nuclear phosphoprotein 32A (huANP32A-Flag) from 293T cells based on the interaction between huANP32A and influenza virus RdRp. The purified RdRp was used as antigen to immunize BALB/c mice. Six positive hybridoma cell lines (7B11-5, 8A4-5, 13D9-6, 8D4-1, 8D4-3, 9F9-4) that stably secrete and recognize PB2 MAb were screened by indirect ELISA and Western blotting. The subtypes of MAb 7B11-5, 8A4-5, 8D4-1 and 8D4-3 antibody were identified as IgG1, the subtypes of MAb 13D9-6 and 9F9-4 were IgG2a and IgG3, respectively. All the light chains of the MAbs were κ chain. A hybridoma cell line 8D4-1 with high titer was further selected to prepare ascites. The titer of mouse ascites antibody was determined to be 1:64 000. Western blotting results showed that the MAb 8D4-1 had a specific immune response with ICV PB2; laser confocal assay showed that the prepared MAb 8D4-1 accurately detected the subcellular localization of PB2 subunits. Moreover, ICV RdRp was highly enriched by ANP32A. The high specific of the prepared PB2 MAb 8D4-1 may facilitate the polymerase detection, structural analysis and mechanism study of influenza C virus.
Animals ; Antibodies, Monoclonal/metabolism* ; Ascites ; Humans ; Influenzavirus C/metabolism* ; Mice ; Nuclear Proteins/metabolism* ; RNA-Binding Proteins ; RNA-Dependent RNA Polymerase/genetics* ; Viral Proteins/metabolism* ; Virus Replication

Coronavirus disease (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), with strong contagiousness, high susceptibility and long incubation period. cell entry by SARS-CoV-2 requires the binding between the receptor-binding domain of the viral spike protein and the cellular angiotensin-converting enzyme 2 (ACE2). Here, we briefly reviewed the mechanisms underlying the interaction between SARS-CoV-2 and ACE2, and summarized the latest research progress on SARS-CoV-2 neutralizing monoclonal antibodies and nanobodies, so as to better understand the development process and drug research direction of COVID-19. This review may facilitate understanding the development of neutralizing antibody drugs for emerging infectious diseases, especially for COVID-19.
Angiotensin-Converting Enzyme 2 ; Antibodies, Monoclonal ; Antibodies, Neutralizing ; Antibodies, Viral ; COVID-19 ; Humans ; Peptidyl-Dipeptidase A/metabolism* ; Protein Binding ; SARS-CoV-2 ; Single-Domain Antibodies ; Spike Glycoprotein, Coronavirus/metabolism*

Puerarin was conjugated with bovine serum albumin(BSA) and ovalbumin(OVA) by periodate oxidation to serve as the immunogen and coating antigen, respectively. BALB/c mice were immunized with puerarin-BSA according to the routine immunization procedure, and the titer and specificity of serum were detected after three immunization. After booster immunization, mouse spleen lymphocytes were fused with mouse myeloma cells, and 24 hybridoma cell lines of the monoclonal antibodies against puerarin were screened by monoclonal antibody screening technique. Ascites was prepared and purified. The cross-reactivity of monoclonal antibody(mAb) M1 with 4'-methoxy puerarin, daidzin, puerarin-6″-O-xyloside, daidzein, mirificin, 3'-methoxy puerarin, and 3'-hydroxy puerarin was 239.84%, 112.18%, 67.89%, 58.28%, 22.37%, 0.40%, and 0.20%, respectively, and those with other analogs such as baicalein and baicalin were all less than 0.10%. The IC_(50) and the working range of the indirect competitive enzyme-linked immunosorbent assay(icELISA) for puerarin were 44.80 ng·mL~(-1) and 8.20-292.30 ng·mL~(-1), respectively. The average recovery was 91.95%-98.20% with an RSD in the range of 0.70%-2.60%. The content of puerarin in different Puerariae Lobatae Radix samples was determined with icELISA and validated by UPLC-MS. The correlation between data obtained from icELISA and UPLC-MS was 0.999 0, indicating that icELISA is suitable for the rapid detection of puerarin in Puerariae Lobatae Radix samples.
Animals ; Antibodies, Monoclonal ; Chromatography, Liquid ; Enzyme-Linked Immunosorbent Assay/methods* ; Hybridomas/metabolism* ; Isoflavones ; Mice ; Mice, Inbred BALB C ; Tandem Mass Spectrometry