Journal article
Emergence of Anaplasma marginale Antigenic Variants during Persistent Rickettsemia
Infection and immunity, Vol.67(11), pp.5834-5840
11/1999
Handle:
https://hdl.handle.net/2376/113324
PMCID: PMC96963
PMID: 10531237
Abstract
Anaplasma marginale
is an ehrlichial pathogen of cattle, in the order
Rickettsiales
, that establishes persistent cyclic rickettsemia in the infected host. Within each rickettsemic cycle,
A. marginale
expressing antigenically variant major surface protein 2 (MSP2) emerge. By cloning 17 full-length
msp2
transcripts expressed during cyclic rickettsemia, we determined that emergent variants have a single, central hypervariable region encoding variant B-cell epitopes. The N- and C-terminal regions are highly conserved among the expressed
A. marginale
variants, and similar sequences define the MSP2 homologues in the agent of human granulocytic ehrlichiosis (HGE). This is in contrast to the MSP2 homologues in ehrlichial genogroup I pathogens,
Ehrlichia chaffeensis
,
Ehrlichia canis
, and
Cowdria ruminantium
, that have multiple hypervariable regions. By defining the variable and conserved regions, we were able to show that the single hypervariable region of
A. marginale
MSP2 encodes epitopes that are immunogenic and induce variant-specific antibody responses during persistent infection. These findings demonstrate that the MSP2 structural variants that emerge during each cycle of persistent rickettsemia are true antigenic variants, consistent with MSP2 antigenic variation as a mechanism of
A. marginale
persistence.
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Details
- Title
- Emergence of Anaplasma marginale Antigenic Variants during Persistent Rickettsemia
- Creators
- Dorothy M French - Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Wendy C Brown - Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Guy H Palmer - Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040
- Publication Details
- Infection and immunity, Vol.67(11), pp.5834-5840
- Academic Unit
- Veterinary Microbiology and Pathology, Department of; Paul G. Allen School for Global Animal Health
- Publisher
- American Society for Microbiology
- Identifiers
- 99900547589101842
- Language
- English
- Resource Type
- Journal article