Development of therapeutic human monoclonal antibodies against virulence factors of Pseudomonas aeruginosa

Monoclonal antibodies are increasingly used in clinical practice to treat cancers, inflammatory diseases and infectious diseases. They also represent a very promising alternative to antibiotics in the fight against multi-resistant bacteria. This project aims to isolate for therapeutic purposes human monoclonal antibodies targeting virulence factors of Pseudomonas aeruginosa. P. aeruginosa is becoming increasingly resistant to antibiotics and thus an important global public health threat. Furthermore, this bacterium is highly prevalent in cystic fibrosis patients and its acquisition is a major predictor of the severity of this disease. We have chosen to target two essential virulence factors of P. aeruginosa, the type III secretion system proteins PcrV, PscF,and PopB/PopD), and the type Vb secretion system protein Pdta protein. We propose to isolate and characterize human monoclonal antibodies against these factors in order to develop them as therapeutic molecules.

Intra-tumor cytotoxic bystander T lymphocytes with anti-tumor potential are inhibited by the HLA-G/ILT2 checkpoint: study of a new paradigm with therapeutic perspectives.

Objective of the thesis: to participate in the research theme summarized below and to take charge of part of it. This project is financed by a PRT-K grant and is a collaborative work Saclay/Paris/Grenoble
Knowledge of immunology and basic immunology techniques. Valued multidisciplinarity, in particular in relation to bioinformatics/biostatistics.
Summary of the research theme 2023-2025
T cells specific for tumor antigens play a central role in anti-tumor immunity and immunotherapy. However, recent data show that they constitute only a fraction of tumor-infiltrating T cells (TILs), and that many TILs (called 'bystanders') recognize non-tumor antigens.
Immunotherapeutic strategies using these bystander T cells are at the preclinical stage. Our work on the HLA-G/ILT2 inhibitory checkpoint in patients with urological cancers shows that alongside PD1+ TILs known to be antitumor and specific for tumor antigens, ILT2+ TILs constitute a significant reservoir of highly cytotoxic lymphocytes, sensitive to inhibition by HLA-G but not by PDL1, and therefore insensitive to anti-PD1/-PDL1 immunotherapies. These ILT2+ TILs are anti-viral, and their activation may be of the innate type, independent of the TCR. ILT2+ T lymphocytes are therefore potentially anti-tumor bystander TILs. This situation is specifically human and cannot be observed in animal models in which the HLA-G/ILT2 checkpoint does not exist. The transition from preclinical to clinical therefore requires studies in humans.
Our goal is to demonstrate in urological cancers that
(i) when designing new immunotherapies based on bystander TILs, HLA-G, their main inhibitory checkpoint must absolutely be taken into account,
(ii) a therapeutic strategy can take advantage of the large population of intratumoral ILT2+ bystanders and their large reservoir of peripheral precursors, to redirect their functions specifically towards tumor cells while blocking their main inhibitory checkpoint HLA-G.
To achieve this objective, we brought together scientists from the CEA in onco-immunology (Paris) and bioinformatics (Grenoble), and oncologists, urologists and pathologists from Saint-Louis Hospital (Paris)

Monkeypox Sexual Transmission: Understanding Pathogenesis, Immunity and Vaccine Development in a non-human primate model (MONKIVAX)

In 2022-2023, an unprecedented global outbreak of Monkeypox virus (MPXV), a double-stranded DNA virus related to smallpox, emerged in non-endemic areas, causing over 87,000 reported cases in 170 countries. This prompted the WHO to classify it as a Public Health Emergency of International Concern (PHEIC). France alone documented 5,014 cases, with 83% confirmed biologically.
The outbreak strain, responsible for the 2022-2023 epidemic, was identified as the West African B.1 lineage Clade 2b, known as "mpox”.This outbreak was characterized by its rapid global spread, unique clinical symptoms, and high prevalence among men who have sex with men (MSM). Transmission of mpox can occur through various forms of contact, but sexual contact plays a significant role, with over 91% of cases linked to it. Lesions in genital, perianal, and oral areas suggest sexual transmission, and MPXV DNA has been found in the semen of infected patients.
No specific mpox vaccines exist, but previous evidence indicates that smallpox vaccines can provide some protection due to cross-reaction. JYNNEOSTM, a live, non-replicating Modified Vaccinia Ankara (MVA)-based vaccine, was recently approved for mpox prevention but showed varying efficacy against the 2022 outbreak, highlighting the need for more effective vaccines.
Our understanding of mpox pathogenesis, immunity, and transmission is limited, especially during the recent outbreak. To address these questions, a study using cynomolgus macaques as a model to simulate mucosal MPXV infection with the current outbreak strain is proposed.
The project has two main aims:
1) Elucidate the mechanisms of mpox pathogenesis and the immune response to natural infection using a non-human primate (NHP) model of sexual transmission.
2) Assess the immune response elicited by the currently available MVA vaccine, and identify novel mechanisms that future vaccine candidates may need to activate in order to enhance vaccine effectiveness and improve the immune response to vaccination.
The PhD candidate will receive comprehensive training in theoretical and practical aspects of immunology, virology, and microbiology. This includes experimental techniques for studying virus transmission and the host's immune response to natural infection and vaccination. In addition, the student will gain proficiency in a wide range of techniques, such as cell/tissue cultures, flow cytometry, histology, transcriptomic, and more, using both in vitro and in vivo approaches with an NHP model.
Overall, this project aims to deepen our understanding of mpox pathogenesis and immunity, guide vaccine development, and contribute to public health efforts in combating this emerging infectious disease.