The murine antibody response to lactate dehydrogenase-elevating virus

Area of Science:

• Immunology
• Virology

Background:

• Lactate dehydrogenase-elevating virus (LDV) infection in mice elicits a robust antibody response.
• Understanding the specific antibody subclasses and viral targets is crucial for characterizing the immune response to LDV.

Purpose of the Study:

• To investigate the characteristics of the IgG antibody response to LDV infection in mice.
• To identify the specific viral proteins recognized by anti-LDV antibodies.

Main Methods:

• Mice were infected with LDV, and serum antibody titers were measured over time.
• Antibody subclass analysis (IgG1, IgG2a, IgG2b, IgG3) was performed.
• Western blot analysis was used to determine antibody reactivity against viral proteins (VP1, VP2, VP3).
• Hybridoma analysis was conducted to characterize antibody specificities.

Main Results:

• High titers of IgG anti-LDV antibodies persisted for over a year post-infection.
• The antibody response was T-dependent and showed a strong preference for IgG2a, with variable amounts of IgG2b and IgG3, and minimal IgG1.
• Antibodies predominantly reacted with VP3, the glycosylated envelope protein, and to a lesser extent with VP1, the nucleocapsid protein.
• No antibodies against VP2, a non-glycosylated envelope protein, were detected.
• Hybridoma analysis confirmed a preponderance of anti-VP3 specificities.
• VP3 appears to possess a common polypeptide moiety with at least two major epitopes.

Conclusions:

• LDV infection induces a long-lasting, T-dependent IgG antibody response with a distinct subclass profile (IgG2a-dominant).
• The primary target of the humoral immune response is the VP3 protein of the viral envelope.
• VP3's antigenic structure includes a conserved polypeptide core with major epitopes, making it a key target for neutralizing antibodies.