Efficient use of a small genome to generate antigenic diversity in tick-borne ehrlichial pathogens.
Ehrlichiae are responsible for important tick-transmitted diseases, including anaplasmosis, the most prevalent tick-borne infection of livestock worldwide, and the emerging human diseases monocytic and granulocytic ehrlichiosis. Antigenic variation of major surface proteins is a key feature of these pathogens that allows persistence in the mammalian host, a requisite for subsequent tick transmission. In Anaplasma marginale pseudogenes for two antigenically variable gene families, msp2 and msp3, appear in concert. These pseudogenes can be recombined into the functional expression site to generate new antigenic variants. Coordinated control of the recombination of these genes would allow these two gene families to act synergistically to evade the host immune response.
Program in Vector Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA. kbrayton@vetmed.wsu.edu
K A
KA
Brayton
D P
DP
Knowles
T C
TC
McGuire
G H
GH
Palmer
D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics*; D004536:Ehrlichia / Q000235:genetics*; D016873:Ehrlichiosis / Q000382:microbiology; D000939:Epitopes; D014644:Genetic Variation; D016680:Genome, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D011544:Pseudogenes; D017386:Sequence Homology, Amino Acid; D017282:Tick-Borne Diseases / Q000382:microbiology
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D000939:Epitopes; C103346:major surface protein 3, Anaplasma marginale; C103348:msp2 protein, Anaplasma marginale