SYSTEMATIC CHARACTERIZATION OF THE T AND B CELL REPERTOIRE USING NEXT GENERATION SEQUENCING IN AT PATEINTS.

author.DisplayName ^1,2 author.DisplayName ¹ author.DisplayName ² author.DisplayName ¹

¹Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, pediatric Department a and Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Israel
²Bar-Ilan University, The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Israel

Background and aims:

Ataxia telangiectasia (AT) is a rare genetic, multi-system disorder characterized by neurodegeneration, chromosome instability, B and T cell immunodeficiency and a predisposition to cancer. Disturbed B and T cell homeostasis in affected patients leads to development of an abnormal receptor repertoire and subsequently increased susceptibility to infections. In this work, we characterized cell receptor repertoires in AT patients and portrayed their immune signature using next generation sequencing (NGS).

Methods:

Genomic DNA was isolated from the peripheral blood of 10 AT patients. Multiplex primers for various TRG and IGH genes were used to determine the immune repertoire using Next Generation Sequencing. The resulting PCR products were sequenced using Mi-Seq from Illumina.

Results:

In the TRG repertoire, we observed restricted diversity and clonal expansion in AT patients, whereas the TRGV gene usages were similar to controls. Furthermore, in the IGH repertoire, we detected reduced diversity with no clonal expansion. In contrast to TRG repertoire, there were skewed IGHV gene usages.

Conclusion:

ATM is a master regulator of DNA repair pathways that affects the overall diversity of both TRG and IGH repertoires. With these analyses, we confirm the effect of ATM in T cells and expand its role in B cell development and function. Investigating T and B cell receptor repertoire, in such patients enables diagnosing and portraying immune signatures, following diseases exacerbations, monitoring response to disease therapy, and will extend our knowledge on the immune system in health and disease.