Here today--not gone tomorrow: roles for activating receptors in sustaining NK cells during viral infections

Area of Science:

• Immunology
• Virology
• Cell Biology

Background:

• Natural killer (NK) cells play a vital role in antiviral defense.
• NK cell numbers can increase or decrease during viral infections, a phenomenon not fully understood.
• The basal frequency of NK cells is already high, making the advantage of proliferation unclear.

Purpose of the Study:

• To elucidate the mechanisms regulating NK cell numbers during viral infections.
• To understand the role of activating receptors in NK cell maintenance and function.
• To resolve the paradox of observed NK cell increases and decreases during viral pathogenesis.

Main Methods:

• Investigated NK cell proliferation in response to virus-induced ligands.
• Analyzed the role of activating receptors in NK cell survival and function.
• Studied NK cell dynamics during viral infections in relevant models.

Main Results:

• Proliferation dependent on activating receptors for virus-induced ligands is essential for NK cell maintenance.
• This pathway ensures the continued availability of NK cells for controlling adaptive immune responses and immunopathology.
• Non-selection via this pathway limits access to beneficial NK cell functions.

Conclusions:

• Activating receptors are critical for sustaining NK cells during viral infections, resolving long-standing questions about NK cell dynamics.
• This mechanism highlights a previously unappreciated role for activating receptors in maintaining NK cell populations for ongoing immune surveillance and control.
• The findings suggest a generalizable pathway for subset selection and rescue during homeostatic challenges, with specific implications for NK cell function.