Effect of interferon gamma and CD40 ligation on intracellular monocyte survival of nontypeable Haemophilus influenzae

Abstract

Nontypeable Haemophilus influenzae (NTHi) is a mucosal pathogen that is a major cause of respiratory infection, including sinusitis, otitis media and bronchitis. This bacterium has evolved a number of mechanisms to facilitate its survival in the human host. Recently it has been recognized that it is capable of intracellular survival in monocytes/macrophages and epithelial cells. Previous work by the authors has demonstrated that the protective response to NTHi is Th1 predominant. This information led to the hypothesis that the intracellular survival of NTHi in human monocytes may be reduced by two key effector mechanisms of Th1-mediated immunity: interferon gamma and ligation of CD40. This s..