Meijers RWJ, Dzierzanowska-Fangrat K, Zborowska M, Solarska I, Tielemans D, van Turnhout BAC, Driessen G, van der Burg M, van Dongen JJM, Chrzanowska KH, Langerak AW. Circulating T Cells of Patients with Nijmegen Breakage Syndrome Show Signs of Senescence.
J Clin Immunol 2016;
37:133-142. [PMID:
28000062 PMCID:
PMC5325864 DOI:
10.1007/s10875-016-0363-5]
[Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/06/2016] [Indexed: 11/27/2022]
Abstract
Purpose
The Nijmegen breakage syndrome (NBS) is an inherited genetic disorder characterized by a typical facial appearance, microcephaly, growth retardation, immunodeficiency, and a strong predisposition to malignancies, especially of lymphoid origin. NBS patients have a mutation in the NBN gene which involves the repair of DNA double-strand breaks (DSBs). Here we studied the peripheral T cell compartment of NBS patients with a focus on immunological senescence.
Methods
The absolute numbers and frequencies of the different T cell subsets were determined in NBS patients from young age till adulthood and compared to age-matched healthy individuals (HI). In addition, we determined the expression of senescent T cell markers and the signal joint T cell receptor excision circles (sjTRECs) content.
Results
Our results demonstrate that NBS patients have reduced T cell numbers. NBS patients showed lower numbers of αβ+ T cells, but normal γδ+ T cell numbers compared to HI. Concerning the αβ+ T cells, both CD4+ as well as CD8+ T cells were excessively reduced in numbers compared to aged-matched HI. In addition, NBS patients showed higher frequencies of the more differentiated T cells expressing the senescent cell marker CD57 and did not express co-stimulatory molecule CD28. These effects were already present in the youngest age group. Furthermore, NBS patients showed lower sjTREC content in their T cells possibly indicative of a lower thymic output.
Conclusions
We conclude that circulating T cells from NBS patients show signs of a senescent phenotype which is already present from young age on and which might explain their T cell immune deficiency.
Electronic supplementary material
The online version of this article (doi:10.1007/s10875-016-0363-5) contains supplementary material, which is available to authorized users.
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