Cell mediated immunity to Chlamydia pneumoniae.

The association of Chlamydia pneumoniae to several chronic diseases such as atherosclerosis has been suggested serologically and by direct demonstration of organisms in disease lesions. Cell mediated immunity is crucial in host defense against intracellular pathogens such as C. pneumoniae. C. pneumoniae is a relatively recently recognized pathogen and the cellular mechanisms in C. pneumoniae immunity have so far remained unstudied. The present review includes the data available on C. pneumoniae proteins and their role as T cell activating antigens and Th1/Th2 balance in C. pneumoniae immunity.