Suppression of MHV3 virus-activated macrophages by dieldrin

Area of Science:

• Immunology
• Toxicology
• Virology

Background:

• Mouse hepatitis virus 3 (MHV3) infection in A/J mice typically activates peritoneal macrophages, conferring resistance.
• Dieldrin is an organochlorine pesticide with known immunomodulatory effects.

Purpose of the Study:

• To investigate the impact of dieldrin on MHV3 infection recovery and the host immune response in A/J mice.
• To determine if dieldrin affects the antiviral activity of MHV3-activated peritoneal macrophages.

Main Methods:

• A/J mice were infected with MHV3 and treated with dieldrin (36 mg/kg).
• Peritoneal macrophages were isolated and rechallenged with MHV3 in vitro.
• Macrophage antiviral activity, cellular parameters, and virus uptake were assessed.

Main Results:

• Dieldrin administration prolonged MHV3 infection recovery and suppressed humoral IgG response.
• Dieldrin inhibited the intrinsic antiviral activity of MHV3-activated peritoneal macrophages in vitro.
• Dieldrin's suppressive action targeted the cellular restriction of MHV3 replication by macrophages, without affecting viability or virus uptake.

Conclusions:

• Dieldrin compromises host resistance to MHV3 by inhibiting macrophage antiviral function.
• The pesticide's mechanism involves interfering with the cellular restriction of viral replication within macrophages.
• These findings highlight dieldrin's detrimental effects on innate antiviral immunity.