Nfatc2 and Tob1 have non-overlapping function in T cell negative regulation and tumorigenesis

Area of Science:

• Immunology
• Cellular Biology
• Molecular Biology

Background:

• Nfatc2 and Tob1 are intrinsic negative regulators of T cell activation.
• The independent or overlapping roles of Nfatc2 and Tob1 in regulating T cell responses remain unclear.

Purpose of the Study:

• To investigate the distinct and overlapping roles of Nfatc2 and Tob1 in T cell regulation and lymphocyte homeostasis.

Main Methods:

• Comparison of T cell activation, proliferation, and regulatory function in Nfatc2 knockout (KO) and Tob1 KO mice.
• In vivo analysis of T cell populations, memory cell compartment, and organ infiltrates.
• In vitro assessment of T cell proliferation and regulatory T cell (Treg) suppressive activity.
• Evaluation of B-cell malignancies in KO mice.

Main Results:

• Nfatc2 KO mice, unlike Tob1 KO mice, exhibited age-associated accumulation of persistently activated T cells, expanded memory cell compartment, and organ lymphocytic infiltrates.
• Both Nfatc2 KO and Tob1 KO conventional T cells (Tconvs) showed increased proliferation in vitro.
• Tregs from Nfatc2 KO mice maintained normal suppressive function, while Tob1 KO Tregs displayed enhanced suppressive activity.
• Nfatc2 KO mice developed increased B-cell malignancies, independent of Tob1 absence.

Conclusions:

• Nfatc2 and Tob1 function as non-redundant regulators of lymphocyte homeostasis.
• Nfatc2 plays a critical role in preventing age-associated T cell activation and B-cell malignancies.