Influence of the Chlamydia pneumoniae AR39 bacteriophage ϕCPAR39 on chlamydial inclusion morphology

Abstract

The human respiratory tract pathogen Chlamydia pneumoniae AR39 is naturally infected by the bacteriophage ϕCPAR39. The phage genome encodes six ORFs, [ORF8, ORF4, ORF5, and viral protein (VP) 1, VP2 and VP3]. To study the growth of the phage, antibodies were generated to VP1 and used to investigate the ϕCPAR39 infection. Using immunofluorescence laser confocal microscopy and two-dimensional gel electrophoresis, we investigated the ϕCPAR39 infection of C. pneumoniae AR39. It was observed that ϕCPAR39 infection differentially suppressed the C. pneumoniae protein synthesis as the polymorphic membrane protein 10 and the secreted chlamydial protein Cpn0796 was hardly expressed while the secreted chlamydial protein Cpaf was expressed, but not secreted. The inclusion membrane protein, IncA, was demonstrated to surround the phage-infected abnormal reticulate bodies (RB) as well as being located in the inclusion membrane. As IncA is secreted by the type 3 secretion (T3S) system, it is likely that the T3S is disrupted in the phage-infected chlamydiae such that it accumulates around the infected RB.