Vehiculización de superantígenos virales para la terapéutica de leucemias y linfomas

MERCEDES PASTORINI; GEBHARD L; SCIALFA L; SANDRA GOÑI; ALEMAN MECEDES

Florencio Varela

Simposio; Jornadas de Investigadores UNAJ; 2022

Superantigens (SAgs) are proteins that activate T or B lymphocytes through non-conventional interactions. Mouse Mammary Tumor Virus (MMTV) is a type B retrovirus that encodes SAg with the ability of stimulating and inducing apoptosis of T cells, but only those that have a determined Vβ chain on the T cell receptor. Virus-like particles (VLPs) are multiprotein nanostructures that mimic the organization and conformation of viral particles. Given their lack of genome, they cannot infect nor replicate but they maintain their immunogenic capacity. The aim of this work is to design and develop a specific treatment for leukemia and lymphoma, using MMTV SAgs vehiculized in JUNV VLPs. Our hypothesis is that VLPs carrying different viral SAgs will be able to induce apoptosis specifically to T cells that bear the respective Vβ. We generated the plasmids pZ-SAgs, carrying the ORF sequences of BALB2, BALB14, LA and mtv-7 SAgs fused to JUNV Z protein, allowing their vehiculization into VLPs. These constructions were employed to transfect HEK 293T cells and the fusion proteins were detected by Western Blotting using a rabbit anti Z serum. We are currently concluding the batch production of Z-mtv7 VLPs to start the in vitro assays with healthy donor samples, patient samples and related cell lines. Besides, it was necessary to use the soluble SAgs as control for immunological assays, but their full sequences were unknown. Thus, we generated the plasmidic constructions pET-28a-SAgs, carrying the ORF of MMTV SAgs, we expressed them in E. coli and detected the presence of the recombinant proteins through Western Blotting. We are currently trying different techniques to purify them. Current therapies for leukemia and lymphoma affect neoplastic cells and also a high proportion of normal cells, impacting on the patient´s health during and after the treatment. The use of SAgs may reduce the undesired effects of those therapies offering a therapy that affects a limited repertoire of cells