Journal article
Expression of Major Surface Protein 2 Variants with Conserved T-Cell Epitopes in Anaplasma centrale Vaccinates
Infection and immunity, Vol.70(2), pp.642-648
02/2002
Handle:
https://hdl.handle.net/2376/114183
PMCID: PMC127678
PMID: 11796593
Abstract
Major surface protein 2 (MSP-2), identified as a protection-inducing immunogen against
Anaplasma marginale
challenge, is an immunodominant outer membrane protein with orthologues in all examined
Anaplasma
species. Although immunization with live
Anaplasma centrale
has long been used to induce protection against acute disease upon challenge with virulent
A. marginale
, its MSP-2 structure and whether MSP-2 variants are generated during persistence of the vaccine strain was unknown. In this study, we showed that the
A. centrale
vaccine strain persisted for a minimum of 4 years postvaccination and generated sequential MSP-2 variants. Comparison of amino acid sequences encoded by
A. centrale msp-2
transcripts from the initial postimmunization period and from sequential time points during persistence of the vaccine strain revealed a central hypervariable domain flanked by conserved amino and carboxy-terminal regions. This structure corresponded to that shown in
A. marginale
MSP-2, where the central hypervariable region encodes variant B-cell epitopes in the extracellular domain and the flanking transmembrane domains are rich in CD4
+
-T-cell epitopes. Importantly, at least four CD4
+
-T-cell epitopes are conserved between the two species, a finding consistent with
A. marginale
challenge triggering a recall response of CD4
+
T cells induced by
A. centrale
vaccination. The genomic arrangement is conserved between
A. centrale
and
A. marginale
with multiple
msp-2
pseudogenes and a single operon-linked expression site for the full-length
msp-2
. This conservation of both genomic structure for generating MSP-2 variants and the CD4
+
-T-cell epitopes between these two genetically distinct
Anaplasma
species indicates that they present a similar repertoire of MSP-2 epitopes to the immune system and that this similarity may be responsible for all or part of the
A. centrale
vaccine efficacy.
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Details
- Title
- Expression of Major Surface Protein 2 Variants with Conserved T-Cell Epitopes in Anaplasma centrale Vaccinates
- Creators
- Varda Shkap - Department of Parasitology, Kimron Veterinary Institute, Bet Dagan, IsraelThea Molad - Department of Parasitology, Kimron Veterinary Institute, Bet Dagan, IsraelKelly A Brayton - Department of Parasitology, Kimron Veterinary Institute, Bet Dagan, IsraelWendy C Brown - Department of Parasitology, Kimron Veterinary Institute, Bet Dagan, IsraelGuy H Palmer - Department of Parasitology, Kimron Veterinary Institute, Bet Dagan, Israel
- Publication Details
- Infection and immunity, Vol.70(2), pp.642-648
- Academic Unit
- Veterinary Microbiology and Pathology, Department of; Paul G. Allen School for Global Animal Health
- Publisher
- American Society for Microbiology
- Identifiers
- 99900547432101842
- Language
- English
- Resource Type
- Journal article