Vaccination with cell immunoglobulin mucin‐1 antibodies and inactivated influenza enhances vaccine‐specific lymphocyte proliferation, interferon‐γ production and cross‐strain reactivity

Summary Influenza virus causes a contagious and potentially serious infection of the upper respiratory tract. While neutralizing antibodies are protective against infection, the problem of antigenic drift remains, requiring the constant monitoring and development of new vaccines. The magnitude of this situation is underscored by the emergence of new potentially human pathogenic influenza strains, avian H5N1 being the most recent example. We present evidence that antibodies against T cell immunoglobulin mucin‐1 (TIM‐1), a recently identified immunomodulatory molecule, stimulate cellular immunity against influenza viruses and cross‐strain immune reactivity. To determine potential immunostimulatory properties of anti‐TIM‐1, mice were vaccinated with inactivated influenza virus in the presence or absence of TIM‐1‐specific monoclonal antibodies. Development of cellular immunity against both the influenza strain used for immunization and serotypically distinct virus strains was monitored 3 weeks after vaccination by determining antigen‐specific lymphocyte proliferation and cytokine production. Results show that TIM‐1 antibodies enhance antigen‐specific cellular proliferation (P