CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Ly9 agonist reduces germinal center and plasmablast response in Trypanosoma cruzi infection: role of iNKT and MZB cells.
Autor/es:
FIOCCA VERNENGO F; ENGEL S; GRUPPI A; BECCARIA CG; BOCCARDO S; ALMADA L; MONTES CL; GAZZONI Y; ACOSTA RODRIGUEZ EV
Reunión:
Congreso; SAIC-SAI-SAFIS 2018.; 2018
Resumen:
Ly9 is an inhibitory receptor, a SLAM family member, present onall lymphocytes. Its highest expression is found on innate-like lymphocytessuch as iNKT and MZ B cells. Treatment of mice with aLy9 agonist selectively depletes splenic MZ and B1 B cells, reducesiNKT cells number and impairs IL-4 and IFN-ɣ production by iNKT. Itwas reported that iNKT cells promote the early seeding of germinalcenter (GC) reaction to infections and that MZ B cells could be alsoinvolved in GC reaction due to their location and high expressionof CD1d.The aim of our work is to evaluate the effect of a Ly9 agonist onthe GC and extrafollicular response in T cruzi infection. For this, 1day before intraperitoneal infection with 5000 trypomastigotes ofT cruzi (Tulahuén) or PBS (control), C57BL/6 mice were intraperitoneallyinjected with anti-Ly9 (Ly9-mice) or with control isotype.Splenic lymphocytes were evaluated by FACS. Five days post-treatment,Ly9-mice exhibited a strong reduction in the frequency ofMZB cells (B220+ CD19+ CD21hi CD23lo) and iNKT cells (CD3intα-GalCer-CD1d-Tetramer+ B220-) were diminished in numbers andactivation (quantified by CD69 expression) compared with controls(p?0.05). At 15 days post-infection (dpi), Ly9-mice had a lower frequencyand number of GC B cells (B220+ CD19+ FAS+ GL7+) andPlasmablasts (B220lo CD138int) than infected controls (p?0.05).Finally, we analyzed the phenotype and functions of iNKT cells atearly stages of infection. T cruzi infection increased the frequencyof IL-4- and IFN-ɣ-producing iNKT cells and triggered CXCR5 andFAS-L expression in a percentage of iNKT, at 4 dpi. In this context,iNKT and MZB cells could be involved in the GC and extrafollicularresponses in T cruzi infection. Further studies are needed to testour hypothesis.