Transcription factor 7 (T-cell specific, HMG-box) (TCF7)

Transcription factor 7 (T-cell specific, HMG-box) (TCF7) is expressed in naive and memory T cells, playing a crucial role in T cell differentiation and maintenance. TCF7+ stem-like CD8+ T cells (CD8+ SL) are vital for sustaining T cell populations during chronic antigen exposure. The immune response to chronic viral infections is sustained by memory-like CD8(+) T cells that express Transcription factor 7 (T-cell specific, HMG-box) (TCF7).

These cells can differentiate into cytolytic cells lacking TCF7 but expressing CD279 (Programmed cell death protein 1 (PD-1) and granzyme B. Blocking the PD-1 pathway enhances this process. Type I interferons (IFN-I) promote CD8+ T cell effector differentiation, reducing the TCF7+ Stem-like CD8+ T cells (CD8+SL) pool. The cross-priming of CD8+ T cells is stimulated by virus-induced type I interferon. Blocking the IFN-I receptor during chronic viral infection can increase the Stem-like CD8+ T cells (CD8+SL) population, dependent on Interleukin-27 (IL-27). The cytokine IL-27 encourages the growth of self-renewing CD8(+) T cells during ongoing viral infections.

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Huang et al. 2019 J Exp Med 216: 1791-1808

see also:
Chronic Viral Infection
Hepatitis C (HCV) & Stem-like CD8+ T cells (CD8+SL)
Interferons Type I (IFN Type I)