Compositions and methods including at least one PNP inhibitor or at least one PNP inhibitor in combination with one or more agents identified as endogenous adjuvants useful in the treatment of pathogen infection and cancer are disclosed. The compositions may be formulated as pharmaceutical dosage forms and components may be assembled as kits. Methods for increasing levels of endogenous adjuvants to enhance an immune response and to potentiate/augment antiviral, antibacterial or anticancer effects of therapeutic agents are also disclosed.
