Search

Foot-and-mouth disease (FMD) is a highly infectious disease of cloven-hoofed animals with a significant economic impact. Early diagnosis and effective prevention and control could reduce the spread of the disease which could possibly minimize economic losses. Epitope characterization based on monoclonal antibodies provide essential information for developing diagnostic assays and vaccine designs. In this study, monoclonal antibodies raised against FMD virus (FMDV) were produced. Sixty-six monoclonal antibodies demonstrated strong reactivity and specificity to FMDV. The purified monoclonal antibodies were further used for bio-panning to select phage expressing specific epitopes from phage-displayed 12 mer-peptide library. The phage peptide sequences were analyzed using multiple sequence alignment and evaluated by peptide ELISA. Two hybridoma clones secreted monoclonal antibodies recognizing linear epitopes on VP2 of FMDV serotype O. The non-neutralizing monoclonal antibody 6F4.D11.B6 recognized the residues 67–78 on antigenic site 2 resinding in VP2, while the neutralizing monoclonal antibody 8D6.B9.C3 recognized a novel linear epitope encompassing residues 115–126 on VP2. This information and the FMDV-specific monoclonal antibodies provide valuable sources for further study and application in diagnosis, therapeutics and vaccine designs to strengthen the disease prevention and control measures. [ABSTRACT FROM AUTHOR]

This article explores missed opportunities in the development of monoclonal antibodies using mice and hybridoma technology. It emphasizes the importance of antigen presentation and the role of major histocompatibility complex (MHC) antigens in determining immunogenicity. The article suggests that using a diverse range of mouse strains or genetically engineered mouse models (GEMMs) could enhance antibody production. It also highlights the success of monoclonal antibody development in mice and proposes alternative approaches to generate a greater number of antibodies for diagnostic and therapeutic purposes. The authors clarify that their views are their own and do not represent their affiliated organizations or the publisher. [Extracted from the article]

Botulism is one of the most serious food intoxications, manifesting as prolonged paralytic conditions. This disease is usually the result of the consumption of poor quality canned or smoked foods, so the inhabitants of many countries of the world are exposed to the risk of this kind of poisoning every year. In view of the severity of poisonings caused by botulinum neurotoxins, monoclonal antibodies (mAbs) show great promise because of their targeting action, lack of allergic reactions and serum sickness. The use of a cocktail of mAbs increases the "functional specificity" of their mixture, allowing them to bind to the active domains of different toxin chains and block their action. In this work, we obtained 14 murine mAbs to the catalytic and receptor-binding domain of botulinum toxin type A. The Sp2/0-Ag14 murine myeloma cell line and splenocytes from immunized mice of the BALB/c line were used as fusion partners. We have shown that the selected cocktail of three antibodies neutralizes native toxin more effectively than antibodies separately—complete neutralization is achieved at a toxin dose of 3LD50 and partial neutralization at 5LD50. We presume that this cocktail may be promising as a prototype for the creation of a therapeutic drug capable of neutralizing the toxin in the blood of patients. [ABSTRACT FROM AUTHOR]

Abstract Background To predict outcomes and identify potential therapeutic targets for cancers, it is critical to find novel specific biomarkers. The objective of this study was to search for and explore novel bladder cancer-associated protein biomarkers. Methods A library of monoclonal antibodies (mAbs) against the JAM-ICR cell line was first generated, and clones with high affinity were selected. Hybridomas were screened using bladder cancer (BLCA) cell lines and normal cells. The target of the selected mAb was then characterized through immunoaffinity purification, western blotting, and mass spectrometry analysis. Expression of the target antigen was assessed by flow cytometry and IHC methods. Several databases were also used to evaluate the target antigen in BLCA and other types of cancers. Results Based on screenings, a 6D6 clone was selected that recognized an isoform of beta-actin (ACTB). Our data showed that ACTB expression on different cell lines was heterogeneous and varied significantly from low to high intensity. 6D6 bound strongly to epithelial cells while showing weak to no reactivity to stromal, endothelial, and smooth muscle cells. There was no association between ACTB intensity and related prognostic factors in BLCA. In silico evaluations revealed a significant correlation between ACTB and overexpressed genes and biomarkers in BLCA. Additionally, the differential expression of ACTB in tumor and healthy tissue as well as its correlation with survival time in a number of cancers were shown. Conclusions The heterogeneous expression of ACTB may suggest the potential value of this marker in the diagnosis or prognosis of cancer.

Zika virus (ZIKV) is an emerging flavivirus associated with several neurological diseases such as Guillain-Barré syndrome in adults and microcephaly in newborn children. Its distribution and mode of transmission (via Aedes aegypti and Aedes albopictus mosquitoes) collectively cause ZIKV to be a serious concern for global health. High genetic homology of flaviviruses and shared ecology is a hurdle for accurate detection. Distinguishing infections caused by different viruses based on serological recognition can be misleading as many anti-flavivirus monoclonal antibodies (mAbs) discovered to date are highly cross-reactive, especially those against the envelope (E) protein. To provide more specific research tools, we produced ZIKV E directed hybridoma cell lines and characterized two highly ZIKV-specific mAb clones (mAbs A11 and A42) against several members of the Flavivirus genus. Epitope mapping of mAb A11 revealed glycan loop specificity in Domain I of the ZIKV E protein. The development of two highly specific mAbs targeting the surface fusion protein of ZIKV presents a significant advancement in research capabilities as these can be employed as essential tools to enhance our understanding of ZIKV identification on infected cells ex vivo or in culture. [ABSTRACT FROM AUTHOR]

Kazakhstan became one of the few cohorts of countries that were able to produce its one vaccine against the COVID-19 virus. This fact showed the way of new development paths in the biotechnological direction, especially, since the current situation in the world. Kazakhstan's location allows its bio-technological development to attract not only academic but also investment interests to make everything possible for producing not only vaccines against the SARS-COV2 virus but also to make biotechnological oriented drug development and antiviral drug production. Also, this article gives the generalized view on current clinical success in combating COVID-19 using novice approaches in biotechnological advancement like humanized IgG 'Xenomice' technology in hybridoma technology - REG N10987, produced from transgenic mice and SARS-CoV-2-infected patients [1-3] as well as in human recombinant IgG derived from monoclonal B-cells via Phage display- CT-P59 scFv phage display library generated from cells of a convalescent SARS patient [4]. Along with 'classical monoclonal IgG LY-CoV555, human Antibody gene cloning of B cells from a COVID-19 patient [5]. All these three 'antivirals' are already used and approved by the FDA (U.S. Food and Drug Administration) clinically and demonstrate trustworthy therapeutic effects. The biggest upper hand of these approaches is that they can be used not only against the COVID-19 virus but also against various receptor-dependent disorders like lupus or some types of cancer and/or malignant tumors. Last three decades, two main approaches or methods became headliners in research and clinical implementation Hybridoma (B-cell-fusion with 'immortal' myeloma cells), and recombination technologies - bound with phage display technologies. [ABSTRACT FROM AUTHOR]

Type C nosemosis caused by the microsporidian fungus Nosema ceranae is a major disease that affects the beekeeping industry worldwide. Nosemosis is very difficult to diagnose as it lacks characteristic symptoms, and any symptoms, presented by a Nosema spp. infections are indistinguishable from those of other diseases seen in honey bees. For these reasons, a novel method was developed for the rapid and accurate diagnosis of nosemosis. Three monoclonal antibodies (mAbs) were developed from three different monoclones (9A4, 14A8, and 19B2) and were found to be reactive to the whole spores during ELISA. The 9A4-, 14A8-, and 19B2-derived mAbs were suitable for western blot analysis and classified as IgG1, IgG2b, and IgG3, respectively. mAbs manufactured in this study have practical applications for nosemosis rapid diagnostic tests. These novel methods, and the production of such kits, may aid the early detection and treatment of nosemosis, help prevent the indiscriminate and needless use of toxic medicines, and prevent hive collapse and monetary losses for beekeepers. [ABSTRACT FROM AUTHOR]

Prostacyclin or prostaglandin I2 (PGI2), a metabolite of arachidonic cyclooxygenase pathway, has been demonstrated as an effector of adipocyte differentiation. However, due to its instability in biological fluid, it is difficult to evaluate the role of PGI2 in regulating adipocyte differentiation in different stages in culture. Therefore, this study aimed to establish a simple and rapid method for the production of monoclonal antibody against 6-Keto PGF1α, a stable PGI2 metabolite, and its quantification to determine the role of PGI2 in culture medium. Eight-week-old female BALB/c mice were immunized with the hapten of 6-Keto PGF1α and BSA for several weeks until a higher antibody titer (absorbance value > 0.9 at 1000-times dilution) against 6-Keto PGF1α was found. Then, fusion of antibody-producing spleen lymphocytes with SP-2 myeloma cells and thymocytes was performed and cultured in HAT-medium supplemented with hypoxanthine, aminopterin, and thymine. Specific antibody-producing cells (M2-A4-B8-D10) against 6-Keto PGF1α were identified and separated. A standard ELISA calibration curve was developed with 100% reactivity for 6-Keto-PGF 1 α ranging from 0.26 pg to 6.44 ng corresponding to 90% and 10% of the maximum binding capacity for the immobilized antigen respectively. This method can easily be applied to monitor PGI2 regulation in different stages of cultured adipocytes to reveal the regulatory roles of PGI2 in maintaining homeostasis and adipocyte differentiation.

Junctional adhesion molecule-A (JAM-A) is an adhesion molecule that exists on the surface of certain types of cells, including white blood cells, endothelial cells, and dendritic cells. In this study, the cDNA sequences of JAM-A-Fc were chemically synthesized with optimization for mammalian expression. Afterward, we analyzed JAM-A protein expression through transient transfection in HEK293 cell lines. Mice were immunized with JAM-A-Fc protein, and hybridoma was prepared by fusing myeloma cells and mouse spleen cells. Antibodies were purified from the hybridoma supernatant and four monoclonal strains were obtained and numbered 61H9, 70E5, 71A8, and 74H3 via enzyme-linked immunosorbent assay screening. Immunofluorescence staining assay showed 61H9 was the most suitable cell line for mAb production due to its fluorescence signal being the strongest. Flow cytometric analysis proved that 61H9 possessed high affinity. Moreover, antagonism of JAM-A mAb could attenuate the proliferative, migrative, and invasive abilities of ESCC cells and significantly inhibit tumor growth in mice. By examining hematoxylin-eosin staining mice tumor tissues, we found inflammatory cells infiltrated lightly in the anti-JAM-A group. The expression of BCL-2 and IκBα in the anti-JAM-A group were decreased inmice tumor tissues compared to the control group. Ultimately, a method for preparing high-yield JAM-A-Fc protein was created and a high affinity mAb against JAM-A with an antitumor effect was prepared. [ABSTRACT FROM AUTHOR]

Foot-and-mouth disease (FMD) is a highly infectious disease of cloven-hoofed animals with a significant economic impact. Early diagnosis and effective prevention and control could reduce the spread of the disease which could possibly minimize economic losses. Epitope characterization based on monoclonal antibodies provide essential information for developing diagnostic assays and vaccine designs. In this study, monoclonal antibodies raised against FMD virus (FMDV) were produced. Sixty-six monoclonal antibodies demonstrated strong reactivity and specificity to FMDV. The purified monoclonal antibodies were further used for bio-panning to select phage expressing specific epitopes from phage-displayed 12 mer-peptide library. The phage peptide sequences were analyzed using multiple sequence alignment and evaluated by peptide ELISA. Two hybridoma clones secreted monoclonal antibodies recognizing linear epitopes on VP2 of FMDV serotype O. The non-neutralizing monoclonal antibody 6F4.D11.B6 recognized the residues 67–78 on antigenic site 2 resinding in VP2, while the neutralizing monoclonal antibody 8D6.B9.C3 recognized a novel linear epitope encompassing residues 115–126 on VP2. This information and the FMDV-specific monoclonal antibodies provide valuable sources for further study and application in diagnosis, therapeutics and vaccine designs to strengthen the disease prevention and control measures.

The spread of the disease caused by monkeypox virus (MPox) since 2022 has shown the urgency of developing countermeasures. The development of modern methods of clinical laboratory diagnostics of MPox contributes to this. Enzyme-linked immunosorbent assay (ELISA) is an accessible and sensitive platform for developing diagnostic tools. Detection of MPox antigens using ELISA kits based on monoclonal antibodies (MAbs) is promising due to the quick time of analysis and minimal requirements for sample preparation. We have developed and deposited two strains of Escherichia coli that produce recombinant proteins. Mice were immunized with the AgPOX protein, which contains unique antigenic sequences of MPox. The Trx + A29 protein for selecting MAb producers includes the original amino acid sequence A29L. The absence of antibody crossover to Trx protein and native preparations of variola virus and vaccinia virus tested by ELISA. As a result of hybridization of splenocytes from immunized mice, MAb producers were obtained. Fifteen MAb-producing hybridomas were selected based on ELISA results with three specific MPox antigens and three nonspecific ones. Three hybridomas were selected for deposit according to the productivity criteria. The possibility of detection by means of its MAbs of the native MPox antigen at various concentrations was tested and method sensitivity was determined. The MAbs a-A29L_MPoxV of three hybridomas detected the native antigen MPox at a concentration of 102 PFU/mL. It is likely that the method is even more sensitive when selecting analysis conditions. Based on labeled MAbs a-A29L_MPoxV, it is possible to develop a sensitive and specific indirect two-step ELISA kit for immunodiagnostics of MPox. [ABSTRACT FROM AUTHOR]

Nattokinase is a protease produced by Bacillus subtilis var. natto that exhibits various beneficial biological effects. Thus, a reliable assay to determine nattokinase levels is needed. In this study, we developed novel mouse monoclonal antibodies (mAbs) that recognize nattokinase, and created a specific and sensitive enzyme-linked immunosorbent assay (ELISA) to measure nattokinase levels. The ELISA was developed using a combination of new mouse antinattokinase mAbs used as capture antibodies coated onto 96-well plates, with a peroxidase-conjugated antibody used for detection. This ELISA enabled detection of nattokinase at 1 ng/mL. We believe that the novel mAbs developed in this study will be useful in future for elucidating nattokinase function. [ABSTRACT FROM AUTHOR]

Botulism is one of the most serious food intoxications, manifesting as prolonged paralytic conditions. This disease is usually the result of the consumption of poor quality canned or smoked foods, so the inhabitants of many countries of the world are exposed to the risk of this kind of poisoning every year. In view of the severity of poisonings caused by botulinum neurotoxins, monoclonal antibodies (mAbs) show great promise because of their targeting action, lack of allergic reactions and serum sickness. The use of a cocktail of mAbs increases the “functional specificity” of their mixture, allowing them to bind to the active domains of different toxin chains and block their action. In this work, we obtained 14 murine mAbs to the catalytic and receptor-binding domain of botulinum toxin type A. The Sp2/0-Ag14 murine myeloma cell line and splenocytes from immunized mice of the BALB/c line were used as fusion partners. We have shown that the selected cocktail of three antibodies neutralizes native toxin more effectively than antibodies separately—complete neutralization is achieved at a toxin dose of 3LD50 and partial neutralization at 5LD50. We presume that this cocktail may be promising as a prototype for the creation of a therapeutic drug capable of neutralizing the toxin in the blood of patients.

The main advantage of transformed cell lines as compared to primary ones is that they allow generation of the stable material suitable for long-term research and practical use. Therefore, development of new continuous cell cultures from various animal tissues is of great practical importance. Results of examination of transformed cell lines derived from organs of domestic pigs (Sus scrofa L.) for their biological, cytomorphological and karyological features are described in the paper. The said cell cultures are confirmed to be susceptible to various animal viruses. Also, a procedure for preparation of new diploid cell culture from porcine spleen (SSs – Splеen Sus scrofa) is described. Based on the obtained data analysis it was concluded that the epithelial cells derived from trypsinized porcine spleens could be successfully immortalized. All transformed cell lines of porcine origin have similar morphology with predominated epithelium-like forms. Some of them – SPEV, А4 С2 , RSK – tend to adopt a spherical shape in suspension. Such cell lines as PSGK-30 and PPES cell lines form partial multilayer or they are characterized by significant monolayer compaction with pseudosyncytium formation. Only pseudodiploid cell culture (SPEV cell culture) tends to grow in suspension, it also grows in rotating culture flasks. Karyological transformations in different cell cultures stabilized at certain level. Spontaneous increase in chromosome numbers in the main population of transformed cell lines towards triploidy resulted in stabilization of culture properties and increase in proliferation. PSGK-30 cell culture has the highest modal class – 64 chromosomes. Near-diploid cultures (А4 С2 , RSK) demonstrate stable growth properties and are similar to SPEV cell culture in adopting spherical cell forms in medium, monolayer character and cell morphology. PK-15 cell culture having a distinct karyotype under different cultivation conditions while retaining other culture properties is found to be the most adaptive. A new transformed diploid SSs cell culture is developed by long-term incubation, subcultivation (more than 80 passages) and selection at the FGBI “ARRIAH” laboratory; it can remain diploid or may spontaneously become heteroploid-immortalized during further passaging. The cell hyperploidy is very likely to enhance telomerase activity, which in turn stabilizes immortalization and results in proliferative activity increase The cell viability has been maintained so far by regular reseedings (split ratio – 1:2–1:3) performed 1–2 times a week.

This study was motivated by the pressing need to obtain monoclonal antibodies (mAb) for research and medical purposes. Screening for mAb-producing hybridomas and evaluating various cell cultures requires a technique that combines the advantages of immunohistochemistry (IHC), heterogeneous enzyme immunoassay (ELISA), and Western blotting. Cellular ELISA (In-Cell ELISA, ICE) is valid for in situ measurement of target analytes in both attached and suspended cells with minimal time, specificity, and reproducibility of ELISA. This method can be successfully used to detect surface and intracellular antigens, as well as to assess phosphorylation, methylation, and acetylation. ICE is a simple, fast, inexpensive, and highly sensitive alternative to various common cyto- and histochemical methods. Here, we explored the potential of ICE for screening and selecting the most promising hybridomas and mAbs for IHC staining. The experiments were carried out with the help of the cultural method, the method of heterogeneous and cellular ELISA, and IHC staining. Comparison of ICE and IHC showed a significant agreement in the intensity and localization of staining with the studied mAbs. The most suitable antibodies for subsequent IHC were selected, saving us much time of selection and the number of expensive mAbs. In heterogeneous ELISA, a negative reaction was noted in some cases. In ICE of whole cells, a pronounced response was detected microscopically. With ICE, it is possible to characterize cell cultures by markers that distinguish one cell line from another, show the stages of cell differentiation, and visualize their structures at different stages of cultivation. In some cases, ICE may be more informative than ELISA for selecting monoclones that produce specific mAbs. A preliminary ICE run can be used to determine the optimal concentration of working dilutions of primary antibodies in a subsequent IHC run.

Though the hybridoma technology has been widely applied in the production of monoclonal antibodies, it has existed some disadvantages including low yield and genetic instability. Therefore, an alternative approach should be taken into account. Recently, recombinant monoclonal antibody technology has emerged as the best choice to cure hybridoma related drawbacks. However, recombinant antibodies require known genes for their generation. The purpose of this study is to collect the full-length genes encoding the anti-human CD45 antibody derived from the hybridoma cell line 16E8-F2. In this research, we designed specific primer pairs to amplify the light and heavy chain genes of the antibody through the PCR method. Afterward, the genes were separately cloned into a cloning vector called pJET1.2/blunt. The generated recombinant pJET1.2 vectors will serve as the main material source to manufacture the recombinant monoclonal antibody recognizing human CD45 protein tomorrow.

For decades, the benefits of utilizing hollow fiber bioreactors for continuous cell culture to produce monoclonal antibodies have been widely recognized. However, the suitability of this technology for laboratories or centers with limited resources and expertise seeking to expand their production capacity is uncertain, mainly due to unknown cost-effectiveness. In this study, a hollow fiber bioreactor with a 4.7-mL culture volume was used to culture a hybridoma clone producing immunoglobulin G antibody specific to hemoglobin F (HbF). The antibody reached a maximum concentration of 1.22 g/L and totaled 21 mg over a 44-day culture period. This preliminary production data was used to estimate the cost of consumables required for using the hollow fiber bioreactor to produce 130 mg of monoclonal antibodies, which was found to be THB35.8k (£880). The cost was slightly more expensive than batch cultivation in typical culture dishes, which ranged from THB27.8 to 30.2k (£680 to 740). Despite the advantages in terms of reduced hands-on time, shorter production duration, and highly concentrated products, the primary challenges associated with using hollow fiber bioreactors were the cost and availability of the cartridges. [ABSTRACT FROM AUTHOR]

Monoclonal antibodies are powerful and versatile tools that enable the study of proteins in diverse contexts. They are often utilized to assist with identification of subcellular localization and characterization of the function of target proteins of interest. However, because there can be considerable sequence diversity between orthologous proteins in Xenopus and mammals, antibodies produced against mouse or human proteins often do not recognize Xenopus counterparts. To address this issue, we refined existing mouse monoclonal antibody production protocols to generate antibodies against Xenopus proteins of interest. Here, we describe several approaches for the generation of useful mouse anti-Xenopus antibodies to multiple Xenopus proteins and their validation in various experimental approaches. These novel antibodies are now available to the research community through the Developmental Study Hybridoma Bank (DSHB). [ABSTRACT FROM AUTHOR]

Monoclonal antibodies are commonly assumed to be monospecific, but anecdotal studies have reported genetic diversity in antibody heavy chain and light chain genes found within individual hybridomas. As the prevalence of such diversity has never been explored, we analyzed 185 random hybridomas, in a large multicenter dataset. The hybridomas analyzed were not biased towards those with cloning difficulties or known to have additional chains. Of the hybridomas we evaluated, 126 (68.1%) contained no additional productive chains, while the remaining 59 (31.9%) contained one or more additional productive heavy or light chains. The expression of additional chains degraded properties of the antibodies, including specificity, binding signal and/or signal-to-noise ratio, as determined by enzyme-linked immunosorbent assay and immunohistochemistry. The most abundant mRNA transcripts found in a hybridoma cell line did not necessarily encode the antibody chains providing the correct specificity. Consequently, when cloning antibody genes, functional validation of all possible VH and VL combinations is required to identify those with the highest affinity and lowest cross-reactivity. These findings, reflecting the current state of hybridomas used in research, reiterate the importance of using sequence-defined recombinant antibodies for research or diagnostic use.

Monoclonal antibodies are an established treatment for many illnesses, including cancer, toxicity and infectious diseases. The goal of this work was to optimize the conditions for obtaining hybridomas secreting human monoclonal IgG antibodies. A new protocol has been developed for efficient electrofusion of human B lymphocytes with partner cells. Electrofusion parameters were optimized, and the preferred partner cell line and ratio of cells involved in the fusion were selected. Two myeloma cell lines, K6H6/B5 and SHM-D33, were tested in detail, and the highest fusion efficiency was observed for K6H6/B5. Three hybridomas that secreted fully human monoclonal IgG antibodies were obtained using the optimized electrofusion protocol; the secretion of antibodies was observed for 1 month, which indicates the stability of the clones and the absence of chromosome segregation. [ABSTRACT FROM AUTHOR]

Hybridoma technology remains a cornerstone of monoclonal antibody (mAb) discovery. Classical screening practices such as ELISA, western blot, and dot blot require laborious, time-consuming procedures, rendering them inefficient in time-restricted decision-making. Additionally, due to these assays' practical and technical limitations, specificity testing of the mAbs is usually omitted during the primary screening of hybridoma libraries. Herein, we present a rapid, dipstick immunoassay (DIA) designed for mAbs screening in cell culture supernatant. The integrated proprietary setup is based on antibody capture and comprises accessible materials such as conjugate pad, nitrocellulose membrane, and absorbent pad. The critical element of this technology is the design of the assay. During the assay run, dipsticks are inserted into supernatant-containing microtiter wells, initiating capillary flow of mAbs towards the conjugate pad where a pre-dried HRP-labeled anti-host species antibody is embedded. This interaction forms an immunocomplex, which migrates to the nitrocellulose membrane and binds to the pre-immobilized target antigen while simultaneously encountering immobilized putative cross-reacting proteins in a multiplex-line fashion. Upon addition of HRP-oxidizable substrate, signal acquisition is performed using a simple camera (colorimetry) or a CCD sensor (chemiluminescence). The system was quantitative up to 2500 ng mL -1 and showed a minimum detectable concentration of 0.61 ng mL -1 . Compared to the gold-standard ELISA, the sensitivity was 8-fold higher, while the dynamic range was similar. Critically, the assay allows for the concurrent assessment of antibody specificity in one run. This immunoassay's unique configuration, simplicity, and rapidity can facilitate antibody discovery., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Robert S. Marks & Frans Kokojka have a patent pending to Ben-Gurion University of the Negev-BGN Technologies Ltd., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Despite their common use in research, monoclonal antibodies are currently not systematically sequenced. This can lead to issues with reproducibility and the occasional loss of antibodies with loss of cell lines. Hybridoma cell lines have been the primary means of generating monoclonal antibodies from immunized animals, including mice, rats, rabbits, and alpacas. Excluding therapeutic antibodies, few hybridoma-derived antibody sequences are known. Sanger sequencing has been “the gold standard” for antibody gene sequencing, but this method relies on the availability of species-specific degenerate primer sets for amplification of light and heavy antibody genes and it requires lengthy and expensive cDNA preparation. Here, we leveraged recent improvements in long-read Oxford Nanopore Technologies (ONT) sequencing to develop Nanopore Antibody sequencing (NAb-seq): a three-day, species-independent, and cost-effective workflow to characterize paired full-length immunoglobulin light- and heavy-chain genes from hybridoma cell lines. When compared to Sanger sequencing of two hybridoma cell lines, long-read ONT sequencing was highly accurate, reliable, and amenable to high throughput. We further show that the method is applicable to single cells, allowing efficient antibody discovery in rare populations such as memory B cells. In summary, NAb-seq promises to accelerate identification and validation of hybridoma antibodies as well as antibodies from single B cells used in research, diagnostics, and therapeutics.

Regulatory T cells (Tregs) are major drivers behind immunosuppressive mechanisms and present a major hurdle for cancer therapy. Tregs are characterized by a high expression of CD25, which is a potentially valuable target for Treg depletion to alleviate immune suppression. The preclinical anti-CD25 (αCD25) antibody, clone PC-61, has met with modest anti-tumor activity due to its capacity to clear Tregs from the circulation and lymph nodes, but not those that reside in the tumor. The optimization of the Fc domain of this antibody clone has been shown to enhance the intratumoral Treg depletion capacity. Here, we generated a stable cell line that produced optimized recombinant Treg-depleting antibodies. A genome engineering strategy in which CRISPR-Cas9 was combined with homology-directed repair (CRISPR-HDR) was utilized to optimize the Fc domain of the hybridoma PC-61 for effector functions by switching it from its original rat IgG1 to a mouse IgG2a isotype. In a syngeneic tumor mouse model, the resulting αCD25-m2a (mouse IgG2a isotype) antibody mediated the effective depletion of tumor-resident Tregs, leading to a high effector T cell (Teff) to Treg ratio. Moreover, a combination of αCD25-m2a and an αPD-L1 treatment augmented tumor eradication in mice, demonstrating the potential for αCD25 as a cancer immunotherapy. [ABSTRACT FROM AUTHOR]

The purpose of this work was to obtain genus-specific monoclonal antibodies against the Legionella spp. recombinant PAL protein, which will subsequently allow to use them as a basis for the development of new express tests for pathogenic legionella detection. A short three-week immunization protocol for Wistar rats was used to generate rat–mouse heterohybridomas producing antibodies against PAL. Mouse myeloma cell line Sp2/0-Ag14 served as the fusion partner. Hybridization was performed using two methods: PEG-mediated fusion and electrofusion. Subsequent screening was performed by indirect solid-phase ELISA against the target protein rPAL. Specificity analysis was performed by dot-blot using a panel of lysates obtained from 39 pure cultures of different strains, which included closely related and heterologous microorganisms among others. No difference in the efficiency of stable hybridoma clones production by the two indicated cell-fusion methods was detected. Twelve clones producing specific rat monoclonal antibodies were obtained based on the screening results. The obtained rat monoclonal antibodies are highly specific towards the PAL protein of L. pneumophila of different serological groups and other pathogenic legionella and are good candidates to be used as the components of diagnostic test systems for the detection of pathogenic representatives of the Legionella genus. [ABSTRACT FROM AUTHOR]

The isolation of single monoclonal antibodies (mAbs) against a given antigen was only possible with the introduction of the hybridoma technology, which is based on the fusion of specific B lymphocytes with myeloma cells. Since then, several mAbs were described for therapeutic, diagnostic, and research purposes. Despite being an old technique with low complexity, hybridoma-based strategies have limitations that include the low efficiency on B lymphocyte-myeloma cell fusion step, and the need to use experimental animals. In face of that, several methods have been developed to improve mAb generation, ranging from changes in hybridoma technique to the advent of completely new technologies, such as the antibody phage display and the single B cell antibody ones. In this review, we discuss the hybridoma technology along with emerging mAb isolation approaches, taking into account their advantages and limitations. Finally, we explore the usefulness of the hybridoma technology nowadays.

Currently, targeted therapeutics against pathogenic filoviruses are very limited, with only two monoclonal antibody (mAb)-based products targeting Ebola virus having received approval from health authorities. More therapeutics are needed to fight against other fatal filoviruses. Here, we describe a protocol using hybridoma technology to generate mAbs that can target not only a single filovirus species but also multiple species for broad protection., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

In view of the toxicological hazard and important applications in analgesics and cancer chemotherapeutics of αB-CTX, it is urgent to develop an accurate, effective and feasible immunoassay for the determination and analysis of αB-CTX in real samples. In this study, MBP-αB-CTX4 tandem fusion protein was used as an immunogen to elicit a strong immune response, and a hybridoma cell 5E4 secreting IgG2b against αB-CTX was successfully screened by hybridoma technology. The affinity of the purified 5E4 monoclonal antibody (mAb) was 1.02 × 108 L/mol, which showed high affinity and specificity to αB-CTX. Epitope 1 of αB-CTX is the major binding region for 5E4 mAb recongnization, and two amino acid residues (14L and 15F) in αB-CTX were critical sites for the interaction between αB-CTX and 5E4 mAb. Indirect competitive ELISA (ic-ELISA) based on 5E4 mAb was developed to detect and analyze αB-CTX in real samples, and the linear range of ic-ELISA to αB-CTX was 117–3798 ng/mL, with a limit of detection (LOD) of 81 ng/mL. All the above results indicated that the developed ic-ELISA had high accuracy and repeatability, and it could be applied for αB-CTX detection and drug analysis in real samples. [ABSTRACT FROM AUTHOR]

Purpose: The therapeutic potential of targeting the human epidermal growth factor receptor-3 (ErbB3/HER3) has long been ignored due to impaired tyrosine kinase function and low expression level in tumor cells compared with EGFR and HER2. Although recent investigations have explored the potential benefit of HER3 targeting and several anti-HER3 agents have been developed, there is still a critical need to design and produce more efficient therapeutics. This study was designed to develop tumor inhibitory monoclonal antibodies (MAbs) against different extracellular subdomains of HER3. Methods: Distinct extracellular subdomains of HER3 (DI+II and DIII+IV) were utilized to produce MAbs by hybridoma technology. Biochemical and functional characteristics of these MAbs were then investigated by various methodologies, including immunoblotting, flow cytometry, cell proliferation, cell signaling, and enzyme-linked immunosorbent assays. Results: Four anti-DI+II and six anti-DIII+IV MAbs were obtained, selected based on their ability to bind recombinant full HER3 extracellular domain (ECD). Our data showed that only one anti-DI+II and four anti-DIII+IV MAbs recognized the native form of HER3 by immunoblotting. Four MAbs recognized the membranous HER3 by flow cytometry leading to induction of different levels of receptor internalization and subsequent degradation. Results of cell proliferation assays using these MAbs indicated that they differentially inhibited proliferation of HER3-expressing cancer cells and showed considerable synergistic effects in combination with trastuzumab. Selected MAb with the highest inhibitory effect significantly inhibited the phosphorylation of AKT and ERK1/2 molecules. Conclusion: Some of the anti-HER3 MAbs produced in this study displayed tumor inhibitory function and may be considered promising candidates for future HER3-targeted cancer therapy. [ABSTRACT FROM AUTHOR]

Objectives: The preS1 region plays an essential role in hepatitis B virus (HBV) infection. We construct an antibody that binds to preS1 and a measurement system for serum preS1 in chronic HBV-infected patients.Methods: Hybridoma clones that produce anti-preS1 antibodies were obtained by the iliac lymph node method. Epitope mapping was conducted, and an enzyme-linked immunosorbent assay (ELISA)-based method was developed. Using this ELISA system, serum preS1 levels were measured in 200 chronic HBV-infected patients.Results: Eight types of hybridomas were obtained, of which antibody 3-55 using amino acids 38-47 as the epitope showed high binding affinity to preS1. Serum preS1 levels measured by ELISA using 3-55 antibody were correlated with HBsAg, HBcrAg and HBV DNA levels. Among HBeAg-negative patients without antiviral therapeutic objective (HBV DNA <3.3 log IU/mL or alanine aminotransferase ≤30 U/L), preS1 was significantly higher in subjects who had progressed to the point of requiring antiviral therapy compared to subjects who had maintained their status for the preceding three years (p<0.01).Conclusions: We constructed an antibody against preS1 and an ELISA system capable of measuring serum preS1 levels. PreS1 may serve as a novel tool to predict the need for antiviral therapy in HBeAg-negative HBV-infected patients. [ABSTRACT FROM AUTHOR]

Monoclonal antibodies have been applied in a wide range of biological and medical studies since the advent of cell fusion technology. Although cell fusion techniques have been improved by using myelomas and reagents, researchers still find it difficult to produce monoclonal antibodies because of the long protocols, high costs, and low efficiency of obtaining hybridomas. To solve these problems, we first developed an iliac lymph node method in 1995 using rats. In this method, an antigen emulsion is injected intramuscularly into the tail base, and then B lymphocytes are isolated from the enlarged iliac lymph nodes. This method is approximately 10 times more productive than the conventional spleen method. Here, we present further improvements to the iliac lymph node method to render it easily applicable in both mice and rats. We found that the frequency of hybridomas secreting specific antibodies was over five times higher using the electro cell fusion method than using the polyethylene glycol (PEG) fusion method. This frequency using the iliac lymph node method with electro cell fusion is at least 50 times higher than that using the traditional spleen method, thereby leading to the reduction in the number of mice or rats to be sacrificed. In addition, only a single injection for immunization is necessary for the iliac lymph node method, opposed to three for the spleen method. Therefore, this method is rapid, inexpensive, and ethical for producing monoclonal antibodies. [ABSTRACT FROM AUTHOR]

Abstract Objective The amoeba Dictyostelium discoideum has been a valuable model organism to study numerous facets of eukaryotic cell biology, such as cell motility, cell adhesion, macropinocytosis and phagocytosis, host–pathogen interactions and multicellular development. However, the relative small size of the Dictyostelium community hampers the production and distribution of reagents and tools, such as antibodies, by commercial vendors. Results For the past 5 years, our laboratory has worked to promote an increased use of recombinant antibodies (rAbs) by academic laboratories. Here we report our efforts to ensure that Dictyostelium researchers have access to rAbs. Using hybridoma sequencing and phage display techniques, we generated a panel of recombinant antibodies against D. discoideum antigens, providing a useful and reliable set of reagents for labelling and characterization of proteins and subcellular compartments in D. discoideum, accessible to the entire Dictyostelium community.

Objective(s): Here, we examined the function of our produced monoclonal antibody (mAb10C3) to recognize one of the most important members of the HEAT shock factor family, Hsf5, in embryonic development and in spermatogenic cells of adult mouse testis.Materials and Methods: The targeting effects of mAb10C3 were investigated by immunohistochemistry analysis in the different phases of the embryo and in the adult testis tissue sections.Results: The results of immunohistochemistry staining on the mouse embryos by the supernatant of hybridoma clone that produced mAb10C3, in the early and late phases (E7.5 and E14.5) of embryonic development, indicated that mAb10C3 could only detect Hsf5 in E7.5 and it did not have any targeting activity in the late phase of development. Therefore, we showed that the hsf5 gene has expressed in early mouse embryonic development. On the other hand, mAb10C3 could detect Hsf5 in spermatogonia and spermatocytes of adult testis in comparison with a known anti-Hsf5 antibody (ab98939) and an anti-PCNA antibody as a marker of spermatogonia cells.Conclusion: Taken together, these data indicated that generated anti-testis mAb10C3 was generated against anti-testis proteins, specifically to target Hsf5, and can be useful as a scientific tool to investigate the critical genes in the development and spermatogenesis.

Monoclonal antibodies are used worldwide as highly potent and efficient detection reagents for research and diagnostic applications. Nevertheless, the specific targeting of complex antigens such as whole microorganisms remains a challenge. To provide a comprehensive workflow, we combined bioinformatic analyses with novel immunization and selection tools to design monoclonal antibodies for the detection of whole microorganisms. In our initial study, we used the human pathogenic strain E. coli O157:H7 as a model target and identified 53 potential protein candidates by using reverse vaccinology methodology. Five different peptide epitopes were selected for immunization using epitope-engineered viral proteins. The identification of antibody-producing hybridomas was performed by using a novel screening technology based on transgenic fusion cell lines. Using an artificial cell surface receptor expressed by all hybridomas, the desired antigen-specific cells can be sorted fast and efficiently out of the fusion cell pool. Selected antibody candidates were characterized and showed strong binding to the target strain E. coli O157:H7 with minor or no cross-reactivity to other relevant microorganisms such as Legionella pneumophila and Bacillus ssp. This approach could be useful as a highly efficient workflow for the generation of antibodies against microorganisms. [ABSTRACT FROM AUTHOR]

Studies were conducted to improve the production of murine ascites with monoclonal antibodies that recognize SARS-CoV-2 proteins. BALB/c mice were primed with 0.5 mL of mineral oil into the abdominal cavity. Seven days after priming, mice were divided in two groups: the group 1 was inoculated intraperitoneally with 2x106 cells/mL of MAb-secreting hybridomas against the nucleocapsid and spike proteins of SARS-CoV-2; the group 2 was injected simultaneously with the same inoculum of hybridoma cells and mineral oil, 18 days after priming. No disturbances or suffering signals were observed in mice from both groups, suggesting that double administration of mineral oil did not produce significant distress with respect to the single dose used for priming, and that none of the hybridoma cell lines were particularly aggressive for the inoculated mice. Ascites was collected in 90.48% and 97.68% of mice from groups 1 and 2, respectively. Ascites was not collected in 7.42% of all mice. The main cause was they never developed ascites tumors but no solid tumors were observed either. The volume of ascitic fluid per mouse was increased significantly in mice from group 2, and there were no significant differences between groups in terms of the concentration of IgG in clarified ascites. According to these results, to obtain higher amounts of MAb the strategy applied in group 2 should be used, since it showed the best results in the development of ascites tumors and it significantly increased the volume of ascites fluid per mouse. This could allow the use of fewer animals for ascites production, which is an ethical and economic benefit.

One of the most important limitations of mammalian cells-based bioprocesses, and particularly hybridoma cell lines, is the accelerated metabolism related to glucose and glutamine consumption. The high uptake rates of glucose and glutamine (i.e., the main sources of carbon, nitrogen and energy) lead to the production and accumulation of large amounts of lactate and ammonia in culture broth. Lactate and/or ammonia accumulation, together with the depletion of the main nutrients, are the major causes of apoptosis in hybridoma cell cultures. The KB26.5 hybridoma cell line, producing an IgG3, was engineered with BHRF1 (KB26.5-BHRF1), an Epstein–Barr virus-encoded early protein homologous to the antiapoptotic protein Bcl-2, with the aim of protecting the hybridoma cell line from apoptosis. Surprisingly, besides achieving effective protection from apoptosis, the expression of BHRF1 modified the metabolism of the hybridoma cell line. Cell physiology and metabolism analyses of the original KB26.5 and KB26.5-BHRF1 revealed an increase of cell growth rate, a reduction of glucose and glutamine consumption, as well as a decrease in lactate secretion in KB26.5-BHRF1 cells. A flux balance analysis allowed us to quantify the intracellular fluxes of both cell lines. The main metabolic differences were identified in glucose consumption and, consequently, the production of lactate. The lactate production flux was reduced by 60%, since the need for NADH regeneration in the cytoplasm decreased due to a more than 50% reduction in glucose uptake. In general terms, the BHRF1 engineered cell line showed a more efficient metabolism, with an increase in biomass volumetric productivity under identical culture conditions. [ABSTRACT FROM AUTHOR]

Monoclonal Antibodies (mAbs) are used for biomedical research, diagnosis, treatment, production, and the quality control of biological products. mAbs are also very helpful in poliovirus research studies because it is still one of the major public health problems in developing countries. The main objective of this study was the production of mAbs against Poliovirus Type 2 (PV2) to be prepared and respond to the re-emergence of this virus. After fusion of immunized B cells prepared from mice with myeloma tumor cells and screening of about 250 hybridoma colonies, 22 with the highest antibody titer and without cross-reaction with others types were selected and cloned by limiting dilution. In the end, two colonies capable of secreting mAbs against epitopes of PV2 were used to produce mAbs. The mAbs were characterized by antibody assays, isotyping, and epitopes analysis using western blotting test, the cross-reactivity with other types, as well as stability, sterility, and mycoplasma tests. The results indicated that the produced mAbs had high specificity, sensitivity and stability against PV2 without any cross-reactivity and were of IgG1 Kappa chain with similar bands at 26 kDa during electrophoresis associated with viral protein VP3 neutralization. These mAbs were specific in serum neutralization tests for PV2 vaccine strain, and therefore, they are potentially valuable for routine polio research, diagnosis, isolation, production, and control of poliovirus vaccines.

ABSTRACT Background and Objectives: Poliomyelitis remains a major public health problem in developing countries, which signify the need for extensive diagnostic and prevention research. The aim of the present study was to design monoclonal antibodies (MAbs) against poliovirus type I with biomedical, diagnostic and therapeutic applications. Methods: B-cells were isolated from a mouse challenged with polio antigen injection. The B-cell were fused with myeloma tumor cells. After evaluation and screening of approximately 250 hybridoma colons by ELISA, 35 colons with the highest antibody titer and no cross-reactivity were selected and subsequently cloned by limiting dilution. Finally, three colons capable of secreting MAbs against epitopes of poliovirus type I were used for MAb production. Next, the MAbs were characterized by antibody assays, isotyping, epitope analysis (western blot), cross-reactivity test, stability test, sterility test and mycoplasma test. Results: The results indicated that the MAbs were of IgG1 kappa chain, had good stability and no cross-reactivity. In western blot, a band at 26 kDa which is associated to VP3 neutralization protein was observed. Conclusion: These serotype-specific MAbs can be potentially used for identification of type I poliovirus for research, diagnostic and prevention purposes. Keywords: Monoclonal antibody, Hybridoma, Poliomyelitis, Poliovirus.