Ehrlichia chaffeensis expresses macrophage- and tick cell-specific 28-kilodalton outer membrane proteins.
Ehrlichia chaffeensis, a tick-transmitted rickettsial agent, causes human monocyte/macrophage-tropic ehrlichiosis. In this study, proteomic approaches were used to demonstrate host cell-specific antigenic expression by E. chaffeensis. The differentially expressed antigens include those from the 28-kDa outer membrane protein (p28-Omp) multigene locus. The proteins expressed in infected macrophages are the products of p28-Omp19 and p28-Omp20 genes, whereas in tick cells, the protein expressed is the p28-Omp14 gene product. The differentially expressed proteins are posttranslationally modified by phosphorylation and glycosylation to generate multiple expressed forms. Host cell-specific protein expression is not influenced by growth temperatures and is reversible. Host cell-specific protein expression coupled with posttranslational modifications may be a hallmark for the pathogen's adaptation to a dual-host life cycle and its persistence.
Singu
Vijayakrishna
V
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, 1800 Denison Ave., Manhattan, KS 66506, USA.
Liu
Haijie
H
Cheng
Chuanmin
C
Ganta
Roman R
RR
D000595:Amino Acid Sequence; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D015153:Blotting, Western; D002460:Cell Line; D004285:Dogs; D018469:Ehrlichia chaffeensis / Q000378:metabolism*; D008264:Macrophages / Q000382:microbiology*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011499:Protein Processing, Post-Translational; D020543:Proteome; D013696:Temperature; D013987:Ticks / Q000382:microbiology*
D001425:Bacterial Outer Membrane Proteins; D020543:Proteome