Growth of Trichomonas vaginalis in a serum-free McCoy cell culture system

Axenic cultures of Trichomonas vaginalis normally require serum for proliferation, yet serum-containing medium may interfere with the detection of T. vaginalis-secreted virulence factors. Trichomonas vaginalis can, however, grow in coculture with a McCoy cell monolayer in both the presence and absence of serum. For 6 T. vaginalis isolates examined, growth in this serum-free system shows lower peak concentrations of T. vaginalis and longer doubling times than those apparent in a serum-containing McCoy cell system. McCoy cells employed in the system did not appear to secrete soluble growth factors for T. vaginalis. The presence of McCoy cells was required for serum-free proliferation of T. vaginalis possibly indicating that eukaryotic cell membrane components may be important in supporting serum-free growth in this system.