Le jeudi 22 février 2024, Monsieur Lorenzo CANTI, titulaire d'un Diplôme de Laurea magistrale in biotecnologie mediche (Université de Bologne) et d’un Certificat de formation à la recherche en sciences biomédicales et pharmaceutiques, présentera l'examen en vue de l'obtention du grade de Doctorat en sciences biomédicales et pharmaceutiques, sous la direction de Monsieur Frédéric BARON et de Monsieur Grégory EHX. 

Cette épreuve consistera en la défense publique d'une thèse intitulée : 

"Contribution to the study of the immune response to the BNT162b2 vaccine in allogeneic hematopoietic stem cell transplant"

Le jury sera composé de :

Christophe DESMET (Président), Souad RAHMOUNI (Secrétaire), Frédéric BARON, Edouard CARR (Univ. College London), Grégory EHX, Laurent GILLET, Stéphanie HUMBLET-BARON (KUL), Tessa KERRE (UGent)

Résumé de la thèse 

Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the best treatment for some fatal blood diseases, it induces long-lasting immune depression due to conditioning, immunosuppressive medications and Graft-versus-Host Disease (GvHD). Hence, allo-HSCT patients are at particularly high risk of death for infections and SARS-CoV-2 outbreaks compelled protection of the population through vaccination. The aim of this project consists in identifying predictors/correlates of immune responses within allo-HSCT subjects immunized by BNT162b2 mRNA vaccine through systems vaccinology. Despite a third-dose of the vaccine allowed to achieve neutralizing Ab in most allo-HSCT patients, bulk RNA sequencing on day 1 versus 0 of the first and third vaccine revealed that modules related to interferon (IFN) signature and activated dendritic cells were significantly enriched already after first dose. In contrast to healthy adults, IFN response did not correlate with serological response as well as CXCL10 but B-cell signature at baseline still predicted serological response. Bulk RNA sequencing also revealed a higher number of upregulated genes at the third dose in respect to the first (146 vs 4005 genes), which was confirmed by multiplex ELISA showing a significant augmentation of IFN-γ, CXCL-10, IL-1Rα, IL-2, IL-6, IL-10, IL-15 and MIP-1α/β (P < 0.001) after the third dose.