Type I interferon suppresses virus-specific B cell responses by modulating CD8⁺ T cell differentiation

Area of Science:

• Immunology
• Virology
• Infectious Diseases

Background:

• T cells are known to resolve persistent viral infections.
• Emerging evidence suggests both T and B cells are crucial for controlling certain viral infections.
• Persistent infections often show a delayed or absent neutralizing antibody response, hindering pathogen control.

Purpose of the Study:

• To investigate how persistent viral infections suppress neutralizing humoral immunity.
• To examine the role of type I interferon (IFN-I) signaling in B cell deletion during persistent infection.
• To understand the impact of early IFN-I signaling blockade on antiviral humoral immunity.

Main Methods:

• Tracking virus-specific B cells in vivo using lymphocytic choriomeningitis virus (LCMV) as a model.
• Utilizing blockade of type I interferon (IFN-I) signaling.
• Employing two-photon microscopy and in vivo calcium imaging to observe cytotoxic T lymphocyte (CTL) interactions with B cells.

Main Results:

• LCMV-specific B cells were rapidly deleted within days of infection.
• Blockade of IFN-I signaling completely reversed B cell deletion and accelerated neutralizing antibody generation.
• IFN-I blockade protected B cells by impairing CTL function, specifically perforin-dependent killing of B cells.

Conclusions:

• Early events during persistent viral infection, such as IFN-I signaling, can disrupt adaptive immune responses.
• Targeting IFN-I signaling early in infection can enhance B cell survival and promote neutralizing antibody production.
• Therapeutic manipulation of IFN-I signaling may improve humoral immunity against persistent viral infections in humans.