Abstract
The cofactors nicotinamide adenine dinucleotide (NAD+) and its phosphateform, NADP+, are crucial molecules present in all living cells. The delicate balancebetween the oxidized and reduced forms of these molecules is tightly regulated byintracellular metabolism assuring the maintenance of homeostatic conditions, whichare essential for cell survival and proliferation. A recent cluster of data has highlightedthe importance of the intracellular NAD+/NADH and NADP+/NADPH ratios duringhost–pathogen interactions, as fluctuations in the levels of these cofactors and inprecursors’ bioavailability may condition host response and, therefore, pathogenpersistence or elimination. Furthermore, an increasing interest has been given towardshow pathogens are capable of hijacking host cell proteins in their own advantage and,consequently, alter cellular redox states and immune function. Here, we review thebasic principles behind biosynthesis and subcellular compartmentalization of NAD+and NADP+, as well as the importance of these cofactors during infection, with aspecial emphasis on pathogen-driven modulation of host NAD+/NADP+ levels andcontribution to the associated immune response.