Celine Walmacq

Lead scientist for the upstream process development for mammalian cell culture-based biologicals (monoclonal antibodies, fusion proteins) to support research and discovery, pre-clinical and clinical activities of NexImmune pipeline projects. Technical subject matter expert (SME) for scale-up, technology transfer of upstream processes, and GMP clinical manufacturing oversight and technical support at multiple CMOs. =>Supported the development of high-yield, robust and scalable CHO cell culture processes and process platform including medium development, feeding strategies, process parameters optimization with hands-on experience using automated microbioreactors, benchtop bioreactors for pilot production and GMP manufacturing =>Accountable Lead for 3 FTEs fostering collaborative, cross-functional, and empowerment-style approach =>Oversaw tech transfer and completion of 6+ drug fill products by partnering with Manufacturing Sciences and Technology, Downstream, Analytical, Quality, Regulatory, NexImmune Operations, and CMOs. =>In response to Covid-related supply chain issues, redirected 2 manufacturing campaigns from external CMOs to local CMOs/in-house delivering within 6 months enabling ongoing clinical trials and advancing programs into IND-enabling studies for viral-driven infectious diseases. =>Authored, reviewed, and approved production batch records, protocols, raw material specifications, technical and development reports at NexImmune and CMOs. Supported manufacturing site in person providing daily troubleshooting and coordinating with technical lead at CMOs, MSAT and QA. =>Oversaw and managed clone suitability evaluation, clone screening strategy with early critical quality attributes assessment, and lead clone selection for GMP manufacturing at CMOs =>Provided production support of reagents and new targets for pre-clinical research

Played pivotal role for IND-enabling studies and supported cell culture process development, scale-up and technology transfer for early to clinical stage development through IND regulatory submission and approval of tumor adoptive T cell immunotherapies for the treatment of refractory acute myeloid lymphoma (AML) and multiple myeloma (MM). =>Promoted into foundational leadership role to support the launch and development of the Process Development & Manufacturing department and serve as the scientific lead for Cell Culture Process Development team, GMP adaptation and technology transfer to GMP manufacturing =>Built the Cell Culture Process Development laboratory core capabilities (space, equipment, material, resource, budget), developed and managed the team by identifying top talent and standout performers with a focus on scientific excellence, teamwork, accountability, innovation, and urgency. =>Supported 2 regulatory submissions (IND) under accelerated timelines by directing scientific evidence generation and authorship of relevant CMC sections and responses to questions from health authorities. =>Adhoc-member of project technical development teams to oversee CHO cell line development, lead clone selection and process development activities at CMOs. =>Implemented focus group to develop cross-functional data management workflow and gating strategies between Cell Line development, Cell Culture Process development, Downstream, Analytical, Nanoparticle Sciences and Pre-clinical teams

Department focused on developing Adoptive T Cell immunotherapies using tumor-specific antigens and nanoparticle-based artificial Antigen Presenting Cells (nano-aAPC) for oncology and autoimmune indications. =>Supported cell culture processes development to optimize cell culture growth conditions, media and growth factor supplements to deliver T cell based therapeutic products that meet quality targets and required release specifications for preclinical and clinical needs =>Conducted isolation and expansion (E+E) of acute myeloid lymphoma and multiple myeloma antigen-specific CD8 T cells from PBMCs and Leukopak =>Executed, analyzed process data, interpreted results, and reported flow cytometry experiments, including phenotypic analysis of antigen-specific CD8 T cell pre and post-E+E, and presented project updates to internal meetings and upper management =>Supported the development and optimization of functional characterization of antigen-specific CD8 T cells, including intracellular cytokine staining, cytolytic activity and tetramer/dimer staining analysis =>Facilitated the technology transfer and in-house development of therapeutic protein reduction for nano-aAPC conjugation =>Authored and reviewed experimental plans, technical reports, and standard operating procedures

Supported the development of protein therapeutics of non-human origin, NicA2, a nicotine-degrading enzyme from Pseudomonas putida, as an aid for smoking cessation treatment. • Responsible for protein engineering, including design, construction, expression, characterization, and optimization of ~20 NicA2 recombinant protein variants with increased catalytic properties using molecular biology and biochemical assays: o Site-directed mutagenesis, molecular cloning, high throughput screening, sequencing and characterization of bacterial clones, protein expression and small-scale purification, ELISA, fluorescent-based high throughput screening assay for detection of NicA2 activity. • Evaluated chemical conjugation of non-toxic polyethylene glycol chains (PEGylation) using random and site-specific PEGylation to reduce NicA2’s immunogenic potential and increase serum half-life extension.

Developed research program on mechanisms of transcription across various oxidative DNA damage (cyclopurines, abasic sites, 8-oxoguanine) and its impact on cancer and development of neurodegenerative disorders ▪ Designed and optimized DNA templates assembly strategies with synthetic lesion-containing DNA and RNA oligonucleotides using purified yeast and mammalian RNA polymerase II ▪ Developed and conducted wide range of biochemical and enzymatic assays for characterization of pathways involved in transcriptional lesion bypass using solid phase in vitro translesion transcription assay with immobilized Pol II, DNA footprinting analysis, pre-steady state kinetics using cutting-edge rapid quench flow technology, cell culture, yeast lysate preparation, gel electrophoresis ▪ Developed and managed collaborations with intramural and extramural investigators by setting meetings, monitoring the project progress, promoting scientific discussions, solving problems and adjusting project proposals accordingly ▪ Studied funtcional connection between transcription elongation and homologous recombination pathways ▪ Primary author and technical lead of one peer-review publication, presented oral and poster presentations at national and international conferences, mentored and trained two undergraduate students

Developed and managed research project focused on the biological functions and mechanisms of yeast RNA polymerase II bypass of UV-induced cyclobutane pyrimidine dimers (CPD) and its link to Transcription-Coupled DNA repair (TC-NER) and DNA damage tolerance using biochemical, genetic and structural approaches ▪ Designed DNA templates assembly techniques for structure/function analysis of lesion processing during transcription and for single molecule analysis using DNA unzipping technique ▪ Developed and standardized quantitative and qualitative assays for assessment of in vitro DNA lesion bypass efficacy by purified yeast RNA polymerase II (wild-type and mutant proteins) ▪ Utilized molecular and cell biology techniques for yeast strain engineering (extraction of genomic DNA, PCR, cloning, site-directed mutagenesis, yeast transfection) for use in genetic studies, in vivo plate-based assays and affinity protein purification and analysis of mutant proteins ▪ Performed gene and strand specific in vivo repair assays to identify lesion bypass as a step in TC-NER utilizing primer extension, Southern Blotting ▪ Initiated and led collaborations with intramural, extramural and international research team to engage crystallographic studies of lesion bypass intermediates ▪ Wrote one peer-reviewed journal article highlighting the connection between transcriptional CPD lesion bypass and UV cellular resistance in yeast ▪ Provided timely updates on research progress and performance both informally and by formal report writing, scientific proposals, protocols, record of oral/poster presentations at national and international conferences, supervised and trained two undergraduate students

Research focused on dissecting mechanisms involved in regulation of transcription fidelity in yeast to evaluate impact of error-prone transcription on genome integrity ▪ Project involved biochemical (protein expression, purification and analysis, operating multiple analytical instruments such as SDS-Page, HPLC, ion-metal affinity chromatography, ion-exchange chromatography), molecular biology (PCR, cloning, DNA sequencing) and genetic techniques (cross between yeast strains, tetrad dissection, synthetic lethality) ▪ Developed, optimized and validated in vitro assays to identify, quantify and analyze transcriptional mRNA errors and to characterize wild-type and mutant proteins activities (cognate/non-cognate NTP binding affinity, NTP incorporation kinetics, NTP induced translocation...) ▪ Authored one peer-reviewed journal article selected Paper of the Week by the Editorial Board of JBC on the role of Rpb9 subunit in transcription fidelity control ▪ Presented scientific data at lab meetings, exchanged ideas and constructive criticisms ▪ Prepared oral and poster presentations at national and international conferences ▪ Supervised and trained two students and actively participated in cross-functional teams

Investigated the biological functions of the transcription termination factor Rho of E. coli using biochemistry, biophysics and molecular biology techniques ▪ Designed and developed assembly techniques and purification of RNA-DNA chimeric substrates mimicking Rho natural terminator DNA sequences to dissect Rho mechanism and kinetics ▪ Assessed RNA-protein interactions using filter-binding assays to optimize transduction of Rho enzymatic activities and stability of transient Rho-substrate complexes ▪ Developed and conducted analytical assays to monitor Rho-translocase activity (promoter-based in vitro transcription, ATP hydrolase activity using thin-layer chromatography, RNA-DNA helicase activity, bacterial culture and lysate preparation, Rho expression and purification, SDS-PAGE, Western Blotting) ▪ Authored and co-authored 4 peer-reviewed journal articles ▪ Presented data in national and international meetings

Developed experimental methods to assess the RNA-DNA helicase activity of the factor Rho of Escherichia coli

Centre de Genetique Moleculaire Performed synthesis and characterization of vectors used for the labelling of phagic protein implied in the virulence of Salmonella typhimurium