ALTERED FOLLICULAR HELPER T CELL (TFH) DIFFERENTIATION IN TONSILS OF CHILDREN WITH TRISOMY 21

JEREMIAS DUTTO; PAULA ARAYA; LUCÍA BOFFELLI; NÚÑEZ NICOLAS GONZALO; ESPINOSA, JOAQUÍN M.; MACCIONI, MARIANA

Mar del Plata

Congreso; Reunion Anual de Sociedades de Biociencias SAIC SAI-FAIC SAFIS; 2022

SAIC SAI-FAIC SAFIS

Down Syndrome, which is caused by trisomy 21 (T21), is characterized by immune dysregulation, anatomical differences in the upper respiratory tract and higher rate of comorbidities. Since tonsils are the first barrier against airborne pathogens, we studied if the immune response generated in these secondary lymphoid organs could be related to some of the differences observed.We characterized the T cell compartment obtained from hypertrophied tonsils in children with T21 versus age-matched controls (n=4/group). We studied the frequency of activated non-Tfh cells (CD3+ CD4+ CD45RA- CXCR5-PD1+), Tregs (CD3+ CD4+ CD45RA- Foxp3+), pre-Tfh (CD3+ CD4+ CD45RA- CXCR5low PD1int) and Tfh (CD3+ CD4+ CD45RA- CXCR5hi PD1hi) by multiparametric flow cytometry and multiplex immunofluorescence. The expression of CXCR3 (related to a Th1 profile) and the cytokines IL21, IFNγ and IL17 were analyzed.Lymphoid follicles exhibited smaller size in T21 tonsils compared to controls, which was not accompanied of altered frequencies of CD3+, CD4+, CD8+, Tregs and CD19+ cells. However, we found a 40% increase in the fraction of activated non-Tfh cells (p