Abstract
To investigate whether protective immune responses can be induced in the absence of normal interleukin-12/23/gamma interferon (IL-12/23/IFN-gamma) axis signaling, we vaccinated with the seasonal influenza virus subunit vaccine two patients with complete IL-12/23 receptor beta1 (IL-12/23R beta 1) deficiencies, two patients with partial IFN-gamma receptor I (pIFN-gamma RI) deficiencies, and five healthy controls. Blood samples were analyzed before, 7 days after, and 28 days after vaccination. In most cases, antibody titers reached protective levels. Moreover, although T-cell responses in patients were lower than those observed in controls, significant influenza virus-specific T-cell proliferation, IFN-gamma production, and numbers of IFN-gamma-producing cells were found in all patients 7 days after the vaccination. Interestingly, influenza virus-specific IFN-gamma responses were IL-12/23 independent, in striking contrast to mycobacterium-induced IFN-gamma production. In conclusion, influenza virus vaccination induces IL-12/23-independent IFN-gamma production by T cells and can result in sufficient humoral protection in both IL-12/23R beta 1- and pIFN-gamma RI-deficient individuals.