Reduction of CD4+ and CD8+ T lymphocytes during febrile periods in horses experimentally infected with equine infectious anemia virus.
Abstract: Three horses were experimentally infected with equine infectious anemia virus (EIAV). All horses were febrile after inoculation with EIAV and then developed chronic symptoms with intermittent fever. The febrile period was characterized by a rise in body temperature with reduced PBL and erythrocyte counts. Flow cytometric analysis showed that the reduced number of lymphocytes was due to significant decreases in CD4+ and CD8+ T cells in the absence of any change in B cell number. At the end of the febrile period the body temperature began to recover and numbers of CD4+ and CD8+ T cells showed a tendency to increase. For CD8+ T cells, this increase continued for several days after the febrile period. B cell number also significantly increased after the febrile period in two out of three horses. The decrease of CD8+ T cells was greater than that of CD4+ T cells. Although the PBL numbers and the CD4/CD8 ratio returned to the level of the preinoculation period, erythrocyte numbers decreased as the body temperature normalized after each intermittent fever. These results suggest that the recurring cycle of fever accompanied with viremia is caused by a reciprocal relationship between EIAV replication and the host immune response. Furthermore, we demonstrate that the lymphocytic response mitigates fever and viremia in EIAV infection despite the absence of virus neutralizing antibody.
Publication Date: 1999-03-17 PubMed ID: 10077419DOI: 10.1016/s0165-2427(98)00225-6Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This research investigates how infection with the equine infectious anemia virus affects T lymphocyte counts during periods of fever in horses. It reveals a cyclic relationship between viral replication and the horse’s immune response, with changes in body temperature and blood cell counts impacting the course of the disease.
Introduction
The researchers aim to understand the effect of equine infectious anemia virus (EIAV), a viral disease affecting horses, on CD4+ and CD8+ T lymphocytes (types of white blood cells that play a crucial role in the body’s immune response). The study was conducted on three horses that were experimentally infected with EIAV.
Observation during Febrile Period
- The experimental infection resulted in all horses developing a fever (raised body temperature) and showing chronic symptoms.
- These febrile periods were marked by reduced PBL (Peripheral Blood Lymphocyte) and erythrocyte (red blood cell) counts.
- The decrease in lymphocyte numbers was linked to a noticeable decrease in CD4+ and CD8+ T cells, whereas the number of B cells was unchanged.
- As the febrile period ended and body temperature began to normalize, there was an observable increase in the number of CD4+ and CD8+ T cells.
Post-Febrile Observations
- For CD8+ T cells, the increase continued for several days after the fever subsided. For two out of the three horses, B cell count also increased significantly after the febrile period.
- Interestingly, the decrease in CD8+ T cells was greater compared to CD4+ T cells during the febrile period.
- While PBL numbers and the CD4/CD8 ratio normalized to pre-inoculation levels, erythrocyte counts decreased as the body temperature stabilized after each fever episode.
Conclusion
- The study suggests that the cyclical fever episodes which accompany viremia (the presence of viruses in the blood) are brought on by an interplay between virus replication and the host’s immune response.
- Furthermore, despite the apparent lack of virus neutralizing antibody, the lymphocytic response manages to alleviate fever and viremia during EIAV infection.
Cite This Article
APA
Murakami K, Sentsui H, Shibahara T, Yokoyama T.
(1999).
Reduction of CD4+ and CD8+ T lymphocytes during febrile periods in horses experimentally infected with equine infectious anemia virus.
Vet Immunol Immunopathol, 67(2), 131-140.
https://doi.org/10.1016/s0165-2427(98)00225-6 Publication
Researcher Affiliations
- Laboratory of Viral Ecology, National Institute of Animal Health, Tsukuba, Ibaraki, Japan. kenji.murakami@yale.edu
MeSH Terms
- Animals
- Antibodies, Monoclonal / immunology
- CD4-Positive T-Lymphocytes / immunology
- CD8-Positive T-Lymphocytes / immunology
- Cell Separation
- Equine Infectious Anemia / complications
- Equine Infectious Anemia / immunology
- Fever / complications
- Fever / immunology
- Fever / veterinary
- Flow Cytometry
- Horses
- Infectious Anemia Virus, Equine
Citations
This article has been cited 1 times.- Mealey RH, Sharif A, Ellis SA, Littke MH, Leib SR, McGuire TC. Early detection of dominant Env-specific and subdominant Gag-specific CD8+ lymphocytes in equine infectious anemia virus-infected horses using major histocompatibility complex class I/peptide tetrameric complexes. Virology 2005 Aug 15;339(1):110-26.
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