Inflammation programs self-reactive CD8+ T cells to acquire T-box-mediated effector function but does not prevent...

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• CD8(+) T cells are crucial for fighting infections but must distinguish foreign from self-antigens to prevent autoimmunity.
• Peripheral tolerance mechanisms normally inhibit effector function when self-antigens are recognized.
• The precise molecular mechanisms by which naive T cells interpret environmental signals for appropriate immune responses remain unclear.

Purpose of the Study:

• To investigate the role of T-box transcription factors (T-bet and Eomes) in CD8(+) T cell fate decisions.
• To understand how inflammatory signals influence T cell responses to self-antigens.
• To identify molecular targets for manipulating T cell activity in cancer and autoimmune diseases.

Main Methods:

• Utilized an in vivo murine model to study CD8(+) T cell responses to self-tissue.
• Correlated self-tolerance with the expression of T-bet and Eomes.
• Induced inflammation via microbial infections (Listeria and LCMV) to assess effector differentiation.

Main Results:

• Self-tolerance was associated with a failure to induce T-bet and Eomes expression in CD8(+) T cells.
• Microbial infection-induced inflammation promoted T-bet and Eomes expression, leading to effector differentiation of self-reactive T cells.
• Listeria infection relied on T-bet, while LCMV infection relied on Eomes for effector cytokine production.

Conclusions:

• T-box transcription factors (T-bet and Eomes) act as critical molecular switches between CD8(+) T cell anergy and effector function.
• Inflammation during T cell priming dictates whether self-reactive CD8(+) T cells become tolerant or develop effector functions.
• These findings have implications for developing therapies targeting T cell responses in cancer and autoimmunity.