Julen Tomas Cortazar 2019

Julen Tomás Cortázar

Dr Julen Tomás Cortázar

University College Dublin, Ireland

Elucidating the mechanisms of protection of the Burkholderia pseudomallei antigen, BpOmp


Poster Abstract

Burkholderia pseudomallei is a Gram-negative bacterium and the causative agent of melioidosis, a complex infection that is endemic across tropical areas, such as Southeast Asia and northern Australia. Recently it has also emerged in subtropical countries, including Brazil and Mexico. It is a highly antibiotic resistant, facultative intracellular pathogen that survives and replicates within macrophages. Diabetes is the major risk factor for severe disease and is a co-morbidity in 23 to 60% infected patients. The interferon-γ (IFN-γ) response dominates the host response to melioidosis. We previously showed that a single subunit antigen, BpOmpW affords mice long-lived protection against melioidosis when administered with the monophosphoryl lipid A based adjuvant, SAS (Casey et al., 2016). Here, we immunise a panel of HLA transgenic mice with highly purified, soluble recombinant BpOmpW to determine the immunodominant T cell epitopes using IFN-γ ELISPOT assay. HLA-class II transgenic mice responded to OmpW. We confirm that the BpOmpW antigen contains HLA-class II restricted epitopes that can stimulate the IFN-γ response necessary for pathogen clearance within 10 days of immunization. Intra-cellular cytokine analysis by flow cytometry is being carried out to investigate the nature of the T-cell responses elicited by BpOmpW and elucidate the source of the protective IFN-γ when administered with different adjuvants.



I defended my PhD thesis in October under the direction of Dr. Juan Anguita ́s at CICbioGUNE, Spain. During my thesis work, I have been involved in a European consortium and project (ANTIDotE) to develop anti-tick vaccines to prevent tick-borne diseases in Europe (Sprong et al., 2014). In addition, I have also been focused on deciphering how the use of the immunosuppressive tick salivary protein, Salp15 (15-kDa Salivary Protein), in an autoimmune disease like Graft versus Host Disease (GvHD) affects the cells of the immune system, specially focused on CD4 T cell responses and anergy (Tomás- Cortázar et al., 2017).

Currently, I am working as a postdoctoral researcher under the supervision of Dr. Siobhán McClean at University College Dublin. I am in charge of the part of a project funded by Welcome Trust agency to develop a vaccine against Melioidosis caused by the Gram-negative bacteria Burkholderia pseudomallei. Apart from the purification of new antigens identified by a new method (McClean et al. 2016) and the following characterization of their immunogenic level, my work is also focused on the characterization of the T cell response against these new and other antigens like BpOmpW (McClean et al. 2016).