Passive immunization with neutralizing antibodies interrupts the mouse mammary tumor virus life cycle

Area of Science:

• Virology
• Immunology
• Monoclonal Antibody Therapy

Background:

• Mouse mammary tumor virus (MMTV) establishes chronic infections by exploiting host immune systems.
• Viral entry occurs through mucosal surfaces, leading to systemic spread.
• Retroviral envelope glycoprotein gp52 is a key target for neutralizing antibodies.

Purpose of the Study:

• To evaluate the efficacy of a neutralizing rat monoclonal antibody against MMTV envelope glycoprotein gp52.
• To determine the antibody's effectiveness in preventing acute and chronic mucosal and systemic MMTV infection.
• To assess the antibody's impact on viral spread, immune responses, and viral life cycle interruption.

Main Methods:

• Administration of a neutralizing rat monoclonal antibody specific for MMTV gp52.
• Assessment of antibody efficacy in preventing infection following systemic or nasal MMTV challenge.
• Monitoring of viral load, superantigen response, and adaptive immune cell activation (B- and T-cells).

Main Results:

• The antibody completely inhibited superantigen response and chronic viral infection after systemic or nasal MMTV exposure.
• Early infection of antigen-presenting cells in lymph nodes was only partially inhibited.
• Despite initial incomplete protection, systemic viral spread and superantigen-specific B- and T-cell responses were abolished, leading to viral clearance.

Conclusions:

• Systemic neutralizing monoclonal antibodies targeting viral glycoproteins are effective against chronic retroviral infections.
• Antibody therapy can interrupt the viral life cycle by preventing amplification and persistence.
• Targeting MMTV gp52 with monoclonal antibodies provides a promising strategy for controlling retroviral spread.