Journal article
Immunogenicity of Anaplasma marginale Type IV Secretion System Proteins in a Protective Outer Membrane Vaccine
Infection and immunity, Vol.75(5), pp.2333-2342
05/2007
Handle:
https://hdl.handle.net/2376/116689
PMCID: PMC1865776
PMID: 17339347
Abstract
Rickettsial pathogens in the genera
Anaplasma
and
Ehrlichia
cause acute infection in immunologically naive hosts and are major causes of tick-borne disease in animals and humans. Immunization with purified outer membranes induces protection against acute
Anaplasma marginale
infection and disease, and a proteomic and genomic approach recently identified 21 proteins within the outer membrane immunogen in addition to the well-characterized major surface proteins MSP1 to MSP5. Among the newly described proteins were the type IV secretion system (TFSS) proteins VirB9, VirB10, and conjugal transfer protein (CTP). In other gram-negative bacteria, TFSS proteins form channels, facilitate secretion of molecules, and are required for intracellular survival. However, TFSS proteins have not been explored as vaccine antigens. In this study we demonstrate that in
Anaplasma marginale
outer membrane-vaccinated cattle, VirB9, VirB10, and CTP are recognized by serum immunoglobulin G2 (IgG2) and stimulate memory T-lymphocyte proliferation and gamma interferon secretion. VirB9 induced the greatest proliferation in CD4
+
T-cell lines, and VirB9-specific CD4
+
T-cell clones responded to three
A. marginale
strains, confirming the VirB9-specific T-cell responses are directed against epitopes in the native protein. The three TFSS proteins are highly conserved with orthologous proteins in
Anaplasma phagocytophilum
,
Ehrlichia chaffeensis
, and
Ehrlichia canis
. Recognition of TFSS antigens by CD4
+
T cells and by IgG2 from cattle immunized with the protective outer membrane fraction provides a rationale for including these proteins in development of vaccines against
A. marginale
and related pathogens.
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Details
- Title
- Immunogenicity of Anaplasma marginale Type IV Secretion System Proteins in a Protective Outer Membrane Vaccine
- Creators
- Job E Lopez - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Guy H Palmer - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Kelly A Brayton - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Michael J Dark - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Stephanie E Leach - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040Wendy C Brown - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040
- Publication Details
- Infection and immunity, Vol.75(5), pp.2333-2342
- Academic Unit
- Veterinary Microbiology and Pathology, Department of; Paul G. Allen School for Global Animal Health
- Publisher
- American Society for Microbiology
- Identifiers
- 99900548235101842
- Language
- English
- Resource Type
- Journal article