Gruber LC, Schneider B, Nothnagel C, Beer-Hammer S. Knockout of
SLy1 decreases double-negative thymocyte proliferation and protects mice from p53-induced tumor formation.
Eur J Immunol 2023;
53:e2250017. [PMID:
36401605 DOI:
10.1002/eji.202250017]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 09/27/2022] [Accepted: 11/17/2022] [Indexed: 11/21/2022]
Abstract
The lymphocyte-specific adapter protein SLy1 has previously been identified as indispensable for thymocyte development and T-cell proliferation and, recently, as a cause of X-linked combined immunodeficiency in humans that recapitulates many of the abnormalities reported in SLy1KO and SLy1d/d mice. As SLy1KO NK cells show increased levels of p53, we focused our research on the interdependency of SLy1 and p53 for thymocyte development. Using RT-PCR and immunoblot analysis, we observed increased levels of p53 as well as DNA damage response proteins in SLy1KO thymocytes. To test for rescue from SLy1-induced deficiencies in thymocyte development like reduced thymocyte numbers and reduced DN to DP progression, we generated a mouse model with T cell-specific p53-deficiency on an SLy1KO background and analyzed lymphocyte populations in these mice and respective controls. Astonishingly, SLy1KO -typical deficiencies were retained, showing that SLy1 is mechanistically independent of p53. Studies of apoptosis and proliferation in SLy1KO thymocytes revealed decreased proliferation in the DN3 subpopulation as a possible reason for the decreased thymocyte number. In mice with p53-deficient T cells, we observed tumor formation leading to reduced survival, preferentially in SLy1WT mice. Thus, we suggest that a SLy1-deficiency reduces proliferation, resulting in less hematologic tumors initiated by the p53-deficiency.
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