Characterization of Semliki Forest virus infection of the hematopoietic stem cell line, K-562

Author

Barbara E. Brady

Date of Award

8-1986

Degree Type

Thesis

Degree Name

Master of Science

Major

Microbiology

Major Professor

Carl J. Wust

Committee Members

Arthur Brown, Carmen Lozzio

Abstract

The human hematopoietic stem cell line, K-562, derived a patient with chronic myelogenous leukemia in terminal blast crisis, was infected with SFV. Viral titers of 10³ pfu/cell were produced at two days postinfection with no observable cytopathic effect. Viral titers decreased after the third day until, approximately one month post-infection, no virus was detectable in the supernatant fluids of the infected cultures. Although the cells did not proliferate after infection, and DNA and cell protein synthesis decreased to less than 1% of uninfected controls, the cells did not lyse and remained intact for months. Cell associated viral glycoproteins were detected by immunoblots and immunofluorescence for many months but they were not synthesized in detectable quantities by two weeks after infection. The capsid protein appears to be degraded by 30 days post-infection.

Electron microscopy studies of infected K-562 cells indicated that rather than budding from the plasma membrane, as is usually seen in vertebrate cells, the final assembly of virus takes place in cytoplasmic vesicles in the area of the Golgi complex. The nucleocapsids affix to the vesicles and budding occurs into the vacuoles. Nucleocapsids that bind to these vesicles form a symmetrical array and it is not clear if binding is to protruding virus glycoproteins as is believed to occur at the plasma membrane, or if there are receptor sites on the vesicles for nucleocapsids. A similar assemblage of nucleocapsids in vesicles is described for infection of mosquito cell lines with SFV. Such infections do not abrogate cell proliferation, and they lead to the establishment of a persistent infection in which low titers of virus are detectable in the supernatant fluids for as long as the culture is maintained.

Recommended Citation

Brady, Barbara E., "Characterization of Semliki Forest virus infection of the hematopoietic stem cell line, K-562. " Master's Thesis, University of Tennessee, 1986.
https://trace.tennessee.edu/utk_gradthes/13654