Journal article
Anaplasma marginale Infection with Persistent High-Load Bacteremia Induces a Dysfunctional Memory CD4+ T Lymphocyte Response but Sustained High IgG Titers
Clinical and vaccine immunology, Vol.17(12), pp.1881-1890
12/2010
Handle:
https://hdl.handle.net/2376/114697
PMCID: PMC3008194
PMID: 20943884
Abstract
Control of blood-borne infections is dependent on antigen-specific effector and memory T cells and high-affinity IgG responses. In chronic infections characterized by a high antigen load, it has been shown that antigen-specific T and B cells are vulnerable to downregulation and apoptosis.
Anaplasma marginale
is a persistent infection of cattle characterized by acute and chronic high-load bacteremia. We previously showed that CD4
+
T cells primed by immunization with an
A. marginale
outer membrane protein were rapidly deleted following infection. Furthermore, peripheral blood T cell responses to bacteria were not observed after acute infection was controlled, suggesting dysfunctional T cell priming to other
A. marginale
antigens. The current study more closely investigated the kinetics of
A. marginale
-specific CD4
+
T cell responses primed during infection. Frequent sampling of peripheral blood and spleens revealed that antigen-specific CD4
+
T cell responses were first detected at 5 to 7 weeks, but the responses were sporadic and transient thereafter. A similar pattern was observed in animals sampled weekly for nearly 1 year. Paradoxically, by 2 weeks of infection, cattle had developed high titers of
A. marginale
-specific IgG, which remained high throughout persistent infection. This dysfunctional CD4
+
T cell response to infection is consistent with continual downregulation or deletion of newly primed effector T cells, similar to what was observed for immunization-induced T cells following
A. marginale
infection. The failure to establish a strong memory T cell response during
A. marginale
infection likely contributes to bacterial persistence.
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Details
- Title
- Anaplasma marginale Infection with Persistent High-Load Bacteremia Induces a Dysfunctional Memory CD4+ T Lymphocyte Response but Sustained High IgG Titers
- Creators
- Sushan Han - Department of Veterinary Microbiology and PathologyJunzo Norimine - Department of Veterinary Microbiology and PathologyKelly A Brayton - Department of Veterinary Microbiology and PathologyGuy H Palmer - Department of Veterinary Microbiology and PathologyGlen A Scoles - Department of Veterinary Microbiology and PathologyWendy C Brown - Department of Veterinary Microbiology and Pathology
- Publication Details
- Clinical and vaccine immunology, Vol.17(12), pp.1881-1890
- Academic Unit
- Veterinary Microbiology and Pathology, Department of; Paul G. Allen School for Global Animal Health
- Publisher
- American Society for Microbiology (ASM)
- Identifiers
- 99900547524101842
- Language
- English
- Resource Type
- Journal article