Cardiolipin remodeling in eukaryotic cells infected with Chlamydia trachomatis is linked to elevated mitochondrial metabolism.

Cardiolipin remodeling in mammalian eukaryotic cells was examined subsequent to infection with Chlamydia trachomatis, an intracellular parasite of eukaryotic cells. HeLa cells were labeled for 6 h with [1-14C]myristate or [1-14C]palmitate or [1-14C]oleate 20 h post infection with C. trachomatis and the radioactivity incorporated into glycerophospholipids examined. Chlamydia infection resulted in a 2-4 fold elevation of radioactive myristate, palmitate or oleate incorporation into phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine and phosphatidylinositiol compared to mock-infected cells. However, a 4-10 fold elevation in radioactivity incorporated into the mitochondrial glycerophospholipids phosphatidylglycerol and cardiolipin was observed in chlamydia-infected cells compared to mock-infected controls. Glycerophospholipid remodeling in CCL16-B2 cells, a mitochondrial respiration mutant with elevated glycerophospholipid metabolism, was compared to its parental cell line CCL16-B1 infected with C. trachomatis. Infection of the wild type CCL16-B1 cells with C. trachomatis resulted in an almost identical pattern of [1-14C]-palmitate labeling of glycerophospholipids compared to the uninfected mitochondrial mutant CCL16-B2 cells. The results suggest that cardiolipin, and glycerophospholipid, fatty acid molecular remodeling in eukaryotic cells infected with C. trachomatis may be linked to an elevation in mitochondrial metabolism.