Article
Rapamycin Improves the Response of Effector and Memory CD8+ T Cells Induced by Immunization With ASP2 of Trypanosoma cruzi
Registro en:
MORASCHI, Barbara Ferri et al. Rapamycin Improves the Response of Effector and Memory CD8+ T Cells Induced by Immunization With ASP2 of Trypanosoma cruzi. Front. Cell. Infect. Microbiol., v. 11, Article 676183, 16 p, May 2021.
2235-2988
10.3389/fcimb.2021.676183
Autor
Moraschi, Barbara Ferri
Noronha, Isaú Henrique
Ferreira, Camila Pontes
Cariste, Leonardo M.
Monteiro, Caroline B.
Denapoli, Priscila
Vrechi, Talita
Pereira, Gustavo J. S.
Gazinelli, Ricardo T.
Lannes-Vieira, Joseli
Rodrigues, Mauricio M.
Bortoluci, Karina R.
Vasconcelos, José Ronnie C.
Resumen
Deficiency in memory formation and increased immunosenescence are pivotal features of
Trypanosoma cruzi infection proposed to play a role in parasite persistence and disease
development. The vaccination protocol that consists in a prime with plasmid DNA followed
by the boost with a deficient recombinant human adenovirus type 5, both carrying the
ASP2 gene of T. cruzi, is a powerful strategy to elicit effector memory CD8+ T-cells against
this parasite. In virus infections, the inhibition of mTOR, a kinase involved in several
biological processes, improves the response of memory CD8+ T-cells. Therefore, our aim
was to assess the role of rapamycin, the pharmacological inhibitor of mTOR, in CD8+ T
response against T. cruzi induced by heterologous prime-boost vaccine. For this purpose,
C57BL/6 or A/Sn mice were immunized and daily treated with rapamycin for 34 days.
CD8+ T-cells response was evaluated by immunophenotyping, intracellular staining,
ELISpot assay and in vivo cytotoxicity. In comparison with vehicle-injection, rapamycin
administration during immunization enhanced the frequency of ASP2-specific CD8+ T cells and the percentage of the polyfunctional population, which degranulated (CD107a+
)
and secreted both interferon gamma (IFNg) and tumor necrosis factor (TNF). The beneficial
effects were long-lasting and could be detected 95 days after priming. Moreover, the
effects were detected in mice immunized with ten-fold lower doses of plasmid/adenovirus.
Additionally, the highly susceptible to T. cruzi infection A/Sn mice, when immunized with
low vaccine doses, treated with rapamycin, and challenged with trypomastigote forms of
the Y strain showed a survival rate of 100%, compared with 42% in vehicle-injected group.
Trying to shed light on the biological mechanisms involved in these beneficial effects on
CD8+ T-cells by mTOR inhibition after immunization, we showed that in vivo proliferation
was higher after rapamycin treatment compared with vehicle-injected group. Taken together, our data provide a new approach to vaccine development against intracellular
parasites, placing the mTOR inhibitor rapamycin as an adjuvant to improve effective CD8+
T-cell response.