Journal article
Merozoite Surface Antigen 2 Proteins of Babesia bovis Vaccine Breakthrough Isolates Contain a Unique Hypervariable Region Composed of Degenerate Repeats
Infection and immunity, Vol.73(11), pp.7180-7189
11/2005
Handle:
https://hdl.handle.net/2376/116706
PMCID: PMC1273907
PMID: 16239512
Abstract
The merozoite surface antigen 2 (MSA-2) proteins of
Babesia bovis
are members of the variable merozoite surface antigen (VMSA) family that have been implicated in erythrocyte invasion and are important targets for antibody-mediated blocking of invasion. Extensive sequence variation in another VMSA member, MSA-1, has been shown in all vaccine breakthrough isolates. To test the hypothesis that the
msa-2
genes of vaccine breakthrough isolates would also encode a diverse set of proteins, the complete
msa-2
locus was characterized from 12 Australian
B. bovis
strains and isolates, including two vaccine strains and eight vaccine breakthrough isolates, and compared to the loci in previously and newly characterized American strains. In contrast to American strains, the
msa-2
loci of all Australian strains and isolates examined contain, in addition to
msa-2c
, only a solitary gene (designated
msa-2a/b
) closely related to American strain
msa-2a
and
msa-2b
. Nevertheless, the proteins encoded by these genes are quite diverse both between and within geographic regions and harbor evidence of genetic exchange among other VMSA family members, including
msa-1
. Moreover, all but one of the Australian breakthrough isolate MSA-2a/b proteins is markedly different from the vaccine strain from which immune escape occurred, consistent with their role in strain-specific protective immunity. The densest distribution of polymorphisms occurs in a hypervariable region (HVR) within the carboxy third of the molecule that is highly proline rich. Variation in length and content of the HVR is primarily attributable to differences in the order and number of degenerate nucleotide repeats encoding three motifs of unknown function.
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Details
- Title
- Merozoite Surface Antigen 2 Proteins of Babesia bovis Vaccine Breakthrough Isolates Contain a Unique Hypervariable Region Composed of Degenerate Repeats
- Creators
- Shawn J Berens - Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Kelly A Brayton - Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040John B Molloy - Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Russell E Bock - Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Ala E Lew - Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Terry F McElwain - Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040
- Publication Details
- Infection and immunity, Vol.73(11), pp.7180-7189
- Academic Unit
- Veterinary Microbiology and Pathology, Department of; Paul G. Allen School for Global Animal Health
- Publisher
- American Society for Microbiology
- Identifiers
- 99900547936001842
- Language
- English
- Resource Type
- Journal article