Date of Award
4-2000
Degree Name
Doctor of Philosophy
Department
Biological Sciences
First Advisor
Dr. Karim Essani
Second Advisor
Dr. Robert Eisenberg
Third Advisor
Dr. Bruce Bejcek
Fourth Advisor
Dr. Ronald Shebuski
Abstract
Most of the poxvirus encoded virulence factors have been identified as proteins that are secreted from infected host cells. Some of these secretory proteins impede host immune defenses. We have previously demonstrated that tanapox virus (TPV) infected cells secrete a 38 kDa glycopeptide that binds to human (h) interferon-γ, h-interleukin (IL)-2, and hIL-5. We now show an additional activity in the supernatant from TPV infected cells that down-regulates the expression of tumor necrosis factor-a (TNF-α) induced cell adhesion molecule gene expression. This activity was not detected in mock infected cells. Enzyme linked immunosorbent assays (ELISA) on primary human endothelial cells, show the induction of E-selectin, vascular cell adhesion molecule-I (VCAM-1), and intercellular adhesion molecule-1 (VCAM-1) following TNF-α or IL-1β treatment, as expected. Supernatant from TPV infected cells significantly decreased the TNF-α induced activation of the nuclear transcription factor-кB (NF-кB) and transcriptional activation of the E-selectin, VCAM-1 and ICAM-1 genes. Based on TNF-α affinity chromatography, this activity appears to be associated with a 38 kDa protein. This 38 kDa protein was purified and 25 amino acid residues sequenced from the N-terminus. Multiple oligonucleotide probes were designed from this protein sequence to identify the gene encoding the 38 kDa protein. The 5.1 kbp TPV PstI-J genomic fragment was isolated and both strands completely sequenced. Analyses of the TPV PstI-J fragment revealed 7 potential open reading frames with significant homology to other poxviruses including vaccinia virus and Yaba virus. Careful analyses of these open reading frames did not reveal any homology to the N-terminal 25 amino acid sequence of the 38 kDa protein.
Access Setting
Dissertation-Open Access
Recommended Citation
Paulose-Murphy, Mini, "Molecular and Biological Characterization of a Tanapox Virus TNF-Binding Protein and the Complete Nucleotide Sequence of the PstI-J Genomic Fragment" (2000). Dissertations. 3447.
https://scholarworks.wmich.edu/dissertations/3447