Abstract

Chikungunya virus (CHIKV) is classified as an alphavirus in the Togaviridae family. This virus is known to rely on Aedes arthropod vectors for its dissemination. Human infection is characterized by rash, high fever, and severe chronic polyarthritis that can last for years. Recently, efforts in developing animal models have been made in an attempt to better understand CHIKV pathogenesis. CHIKV infection starts with a 7 to 10 day long febrile acute phase, in which most of the symptoms occur (rash, fever, and incapacitating pain in joints and muscle). Once the immune system clears most of the viral infection, a chronic phase starts in as many as 70% of the infected patients. Long term virus-related polyarthralgia is the hallmark of the CHIKV chronic phase. It is believed that CHIKV-infected macrophages infiltrate the joints during the acute phase, and CHIKV infects joint tissue and persists in it. Research into the effects of CHIKV infection in human and murine macrophages revealed that CHIKV-infected human macrophages produce high amounts of virions as well as induce the production of pro-inflammatory cytokines and monocyte recruiting chemokines. This contrasts with murine macrophage infection where low quantities of the virus were detected as well as lower production of pro-inflammatory cytokines. This may contribute to the lack of polyarthritis in murine animal models. Current literature suggests that CHIKV’s viral proteins bind and interact with human host cell machinery promoting viral replication more efficiently in humans than in mice. CHIKV-related neuropathology is not the most common outcome of the disease. However, recent outbreaks suggest that this pathology is becoming more prevalent, affecting as many as 30% of confirmed patients. The role of adaptive and innate immunity in CHIKV disease amelioration has been extensively, yet separately, explored. A RAG2-/-γc-/- Balb/c mouse model was used to study the role of these immune pathways and their associated immune cells in CHIKV infection. The mice in this study developed local arthritis at the site of inoculation as well as showed signs of viral invasion in the brain. This study added to the hypothesis that both innate and adaptive immune responses are necessary to ameliorate the disease and that the lack of adequately matured lymphocytes and STAT6-activation deficient macrophages may result in more severe pathologies.

Degree

PhD

College and Department

Life Sciences; Microbiology and Molecular Biology

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2020-04-07

Document Type

Dissertation

Handle

http://hdl.lib.byu.edu/1877/etd11182

Keywords

Chikungunya virus, polyarthralgia, macrophage, cytokine, RAG2-/-γc-/- Balb/c mouse model, neuropathology

Language

English

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