Project description:We have developed a monoclonal antibody (mAb) C7 that reacts with Als3p and enolase present in Candida albicans cell wall and exerts three anti-Candida activities: candidacidal activity and inhibition of both adhesion and filamentation. To investigate the mode of action of mAb C7 on fungal viability, we examined changes in the genome-wide gene expression profile of C. albicans grown in presence of a subinhibitory concentration of mAb C7 (12.5 µg/ml) by using microarrays. A total of 49 genes were found to be differentially expressed upon treatment with mAb C7. Of these, 28 were found to be up-regulated and 21 down-regulated. The categories of up-regulated genes with the largest number of variations were those involved in iron uptake or related to iron homeostasis (42.86%), while the energy-related group accounted for 38.10% of the down-regulated genes (8/21). Results were validated by real time PCR. Since these effects resembled those found under iron-limited conditions, the activity of mAb C7 on C. albicans mutants with deletions in key genes implicated in the three iron acquisition systems described in this yeast was also assessed. Only mutants lacking TPK1 gene, and TPK2 to a lesser extent were less sensitive to the candidacidal effect of mAb C7. FeCl3 or hemin at concentrations ≥ 7.8µM reversed the candidacidal effect of mAb C7 on C. albicans, on a concentration dependent manner. The results presented in this study provide evidence that the candidacidal effect of mAb C7 is related to the blockage of the reductive iron uptake pathway of C. albicans.
Project description:We have developed a monoclonal antibody (mAb) C7 that reacts with Als3p and enolase present in Candida albicans cell wall and exerts three anti-Candida activities: candidacidal activity and inhibition of both adhesion and filamentation. To investigate the mode of action of mAb C7 on fungal viability, we examined changes in the genome-wide gene expression profile of C. albicans grown in presence of a subinhibitory concentration of mAb C7 (12.5 µg/ml) by using microarrays. A total of 49 genes were found to be differentially expressed upon treatment with mAb C7. Of these, 28 were found to be up-regulated and 21 down-regulated. The categories of up-regulated genes with the largest number of variations were those involved in iron uptake or related to iron homeostasis (42.86%), while the energy-related group accounted for 38.10% of the down-regulated genes (8/21). Results were validated by real Time PCR. Since these effects resembled those found under iron-limited conditions, the activity of mAb C7 on C. albicans mutants with deletions in key genes implicated in the three iron acquisition systems described in this yeast was also assessed. Only mutants lacking TPK1 and TPK2 genes were less sensitive to the candidacidal effect of mAb C7. FeCl3 or hemin at concentrations ≥ 7.8µM reversed the candidacidal effect of mAb C7 on C. albicans, on a concentration dependent manner. The results presented in this study provide evidence that the candidacidal effect of mAb C7 is related to the blockage of the reductive iron uptake pathway of C. albicans. A saturated culture of C. albicans grown overnight was diluted to an optical density at 600 nm of approximately 0.1 and divided in two aliquots. One of them was used untreated as control and the second one was treated with a subinhibitory concentration (12.5 µg/ml) of monoclonal antibody C7 . Both cultures were incubated for 18 h at 37ºC before harvesting cells. Antibody added and control samples were obtained each time. The experiment was repeated once. Dye-swap technique was used for hybridization and four arrays were analyzed to compare the expresion of over six thousands genes in response to antibody C7.
Project description:Monoclonal antibodies (mAbs) are widely applied as highly specific and efficient thera-peutic agents for various diseases, including cancer, inflammatory and autoimmune diseases. As protein production in cellular systems inherently generates a multitude of molecular variants, manufacturing of mAbs requires stringent control in order to ensure safety and efficacy of the drug. Moreover, monitoring of mAb variants in the course of the fermentation process may allow instant tuning of process parameters to maintain optimal cell culture conditions. Here, we describe a fast and robust workflow for the characterization of mAb variants in fermentation broth. Sample preparation is minimal in that the fermentation broth is shortly centrifuged before dilution and HPLC-MS analysis in a short 15-min gradient run. In a single analysis, N-glycosylation and truncation variants of the expressed mAb can be identified at the intact protein level. The molecular attributes of the expressed therapeutic protein may thus be continuously monitored to ensure the desired product profile. Simultaneously, absolute quantification of mAb content in fermentation broth yielded concentrations of 67 and 2578 ng.mL-1 at the beginning and end of fermentation, respectively. The whole workflow features excellent robustness as well as retention time and peak area stability of 0.3% and 4.9% RSD. Additional enzymatic removal of N-glycans enables determination of mAb glycation levels, which are subsequently considered in relative N-glycoform quantification to correct for isobaric galactosylation. Application of the described workflow in an industrial environment may therefore substantially enhance in-process control in mAb production as well as targeted biosimilar development.
Project description:The aim of the study was to determine the epitope targeted by 31E10/E7 mouse monoclonal antibody (mAb). mAb 31E10/E7 was diluted at 1:2000 and incubated on a non-commercial Protein Microarray platform printed with NHBA specific recombinant protein fragments and full length NHBA of different variants.
Project description:Here, we examined the utility of AI-ETD for sequencing of the intact NIST monoclonal antibody on a modified Fusion Lumos Orbitrap platform using direct infusion. We also tested other dissociation techniques including HCD, ETD, and EThcD.
Project description:The aim of the study was to determine the epitope targeted by 31E10/E7 mouse monoclonal antibody (mAb) and the cross-reactivity to linear peptide epitopes of 10 different Neisserial Heparin Binding Antigen (NHBA) variants. mAb 31E10/E7 was diluted at 1:200 and incubated on a custom PepStar Peptide Microarray platform printed with 560 different peptides in three independent experiments.
Project description:Patents of some therapeutic monoclonal antibodies (mAb) used for cancer treatment are ending soon, allowing for the entry of similar analogs (biosimilars) onto the market. To have a biosimilar approved by health agencies, the manufacturer must typically demonstrate functional and physicochemical similarity between the biosimilar and the approved reference product. Functional similarity is often validated with cell-based assays, but the information gained is limited. In contrast, RNA-seq methods enable a sensitive transcriptomic analysis, providing detailed information on pathways and cellular responses. Trastuzumab inhibits signaling of the cell-surface receptor HER2, which is overexpressed in approximately 30% of all breast cancer patients. Here, we compare the functional effect of the mAb Trastuzumab and a corresponding biosimilar. The BT-474 breast cancer cell line was treated with the reference product, Trastuzumab (Herceptin®), or a proposed biosimilar (ApoTras), and the cellular transcriptomes were analyzed by RNA-seq. Functional similarity was assessed using two statistical contrasts. One contrast evaluated the mechanism of action by comparing treated samples (Her and ApoTras, n = 19) vs. untreated controls (n = 10), which identified 2623 differentially expressed genes (DEG) at a minimum fold change of 1.25. The other contrast directly compared ApoTras (n = 9) vs. Her (n = 10) to determine differences in expression between treatments and identified 24 DEG using a 1.25 fold- change threshold. This low DEG number reveals a very high similarity of effect of both mAb treatments on the cancer cells. A gene set overrepresentation analysis of DEG for mAb treatments revealed mechanisms of action, which were consistent with known trastuzumab effects. Supporting the small number of changes between both treatments, a post-hoc power analysis for the between-treatment comparison estimated power of 0.88 to detect a gene expression fold-changes of 2.0. To summarize these data, we introduce an overall similarity index (SI) to quantify treatment similarity based on changes in gene expression. Using statistical contrasts with RNA-seq analysis provides a powerful tool for the comparison of biological effects of biosimilar and originator compounds and can be broadly used for functional comparisons of drug treatments.
Project description:In order to investigate the effect of anti-TNFα mAb on colorectal cancer, we generated a orthotopic transplantation model of colorecatal cancer. We performed a comprehensive gene expression profiling analysis by extracting total RNA from cecal tumor of mice treated with and without anti-TNFα mAb (MP6-XT22)
Project description:At present work we have used PCMT1-/- (premature aging) and PCMT1+/- (aged) as the animal model to studies the role of isoDGR in the ageing and age associated disease in the pulmonary system We performed gene expression profiling analysis using data obtained from RNA-seq of Lung of PCMT1+/+, PCMT1+/- PCMT1-/- and PCMT1-/- +mAB at 5-6 weeks .
Project description:Mature NK cell activation relies on a balance of activating, co-stimulatory and inhibitory receptors involved during target recognition. Immunotherapy strategies has been developed to finely tune this balance in order to enhance NK cell cytotoxic functions against cancer cells and secretory functions to enhance adaptative immunity activation. CD28H, a new member of the CD28 family, has been recently studied in T cells and on NK cells as a part of CD28H-CAR-NKL strategy. Given the impressive expression of CD28H molecule on circulating NK cells, we evaluated the use an anti-CD28H mAb on NK cell activation.