Methods of modulating type-I interferon production in a cell are provided. Aspects of the methods include modulating cytosolic cyclic di-adenosine monophosphate (c-di-AMP) activity in the cell in a manner sufficient to modulate type-I interferon production in the cell. Additional aspects of the invention include c-di-AMP activity modulatory compositions, e.g., c-di-AMP, mutant Listeria bacteria, cyclase and/or phosphodiesterase nucleic acid or protein compositions, etc. The subject methods and compositions find use in a variety of applications, including therapeutic applications.
