ABSTRACT
Pathogens reprogram host cell metabolism toward dierent metabolic pathways depending on the pathogen and host cell type. In addition, metabolic fuel is a prerequisite for the proliferating immune cells and their functional responses. Several bacteria also actively respond to the nutrient status of host cells by transforming to diverse types of altered metabolic forms such as dormant or persistent forms. ese various metabolic states of bacteria contribute to antibiotic resistance and chronic infections, which are important clinical problems. e molecular pathways behind the essential metabolic changes in most pathogens and their host cells can be attributed to genetic modications. However, in case of the obligate intracellular bacteria such as the Chlamydia spp., where genetic modication is limited, alternative techniques have to be used to characterize host and pathogen metabolic interaction. Two-photon uorescence lifetime imaging microscopy (FLIM) of the metabolic coenzymes, NAD(P)H, allows for independent characterization of Chlamydia and host cell metabolic changes in living cells. e metabolic changes of Chlamydia during the developmental cycle can be monitored in real time by
16.1 Introduction ......................................................................................347 16.2 Infection-Induced Metabolic Changes in Host Cells ..................348
