Passively transferred M2e-specific monoclonal antibody reduces influenza A virus transmission in mice

Area of Science:

• Virology
• Immunology
• Vaccinology

Background:

• Influenza A poses a global health risk, with current vaccines lacking protection against novel strains.
• Vaccine candidates targeting conserved epitopes, like the M2e protein, offer broad protection.
• M2e-based vaccines rely on M2e-specific IgG antibodies for efficacy.

Purpose of the Study:

• To investigate the protective potential of M2e-specific IgG2a monoclonal antibody 65 (MAb 65) against influenza A.
• To determine if MAb 65 can reduce viral replication and transmission in vivo.
• To elucidate the Fcγ receptor-dependent mechanisms of MAb 65-mediated protection.

Main Methods:

• Assessed MAb 65's ability to reduce plaque formation of influenza A viruses.
• Evaluated the effect of passive MAb 65 transfer on viral loads and transmission in mice.
• Compared MAb 65 efficacy in wild-type versus Fcγ receptor-deficient mice.

Main Results:

• MAb 65 significantly reduced plaque formation for influenza A/Udorn/72 and A/Hong Kong/68 strains.
• Passive transfer of MAb 65 decreased viral loads in mouse airways and reduced virus transmission to contacts.
• Protection was diminished in Fcγ receptor-deficient mice, indicating Fcγ receptor-mediated mechanisms.

Conclusions:

• M2e-specific MAb 65 demonstrates efficacy in reducing influenza A virus replication and transmission.
• Fcγ receptor engagement is crucial for the in vivo protective effects of MAb 65.
• M2e-based antibody immune therapy presents a promising strategy for controlling influenza A.