Journal article
CD4+ T-Lymphocyte and Immunoglobulin G2 Responses in Calves Immunized with Anaplasma marginale Outer Membranes and Protected against Homologous Challenge
Infection and immunity, Vol.66(11), pp.5406-5413
11/1998
Handle:
https://hdl.handle.net/2376/116420
PMCID: PMC108677
PMID: 9784551
Abstract
Protective immunity against the ehrlichial pathogen Anaplasma marginale has been hypothesized to require induction of immunoglobulin G2 (IgG2) antibody against outer membrane protein epitopes and coordinated activation of macrophages for phagocytosis and killing. In the present study, cell-mediated immune responses, including induction of IgG isotype switching, were characterized in calves immunized with purified outer membranes of the Florida strain of A. marginale . Importantly, these calves were subsequently shown to be protected upon experimental challenge with the Florida strain, and calves which developed the highest IgG2 titers were completely protected against infection. Peripheral blood mononuclear cells (PBMC) obtained after immunization proliferated strongly in response to both whole A. marginale homogenates and purified outer membranes, and this responsiveness persisted until the time of challenge. Responding cells were shown to be CD4 + T cells, and CD4 + T-cell lines cultured for 2 to 4 weeks also proliferated specifically in response to A. marginale and produced high titers of gamma interferon. The helper T-cell response included recognition of conserved epitopes, as PBMC proliferation was stimulated by the homologous Florida strain, four genetically distinct A. marginale strains, and Anaplasma ovis . The outer membrane proteins stimulating the PBMC responses in protected calves included major surface proteins (MSPs) MSP-1, MSP-2, and MSP-3, which were previously shown to induce partial protection against infection. These studies demonstrate, for the first time, potent helper T-cell responses in cattle protectively immunized with outer membranes against A. marginale challenge and identify three MSPs that are recognized by immune T cells. These experiments provide the basis for subsequent identification of the helper T-cell epitopes on MSP-1, MSP-2, and MSP-3 that are needed to evoke anamnestic antibody and effector T-cell responses elicited by protein or nucleic acid immunization.
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Details
- Title
- CD4+ T-Lymphocyte and Immunoglobulin G2 Responses in Calves Immunized with Anaplasma marginale Outer Membranes and Protected against Homologous Challenge
- Creators
- Wendy C Brown - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164Varda Shkap - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164Daming Zhu - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164Travis C McGuire - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164Wenbin Tuo - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164Terry F McElwain - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164Guy H Palmer - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164
- Publication Details
- Infection and immunity, Vol.66(11), pp.5406-5413
- Academic Unit
- Paul G. Allen School for Global Animal Health; Department of Veterinary Microbiology and Pathology
- Publisher
- American Society for Microbiology
- Identifiers
- 99900547572801842
- Language
- English
- Resource Type
- Journal article