No description available.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 98-107).

In the search for a better vaccine against Ehrlichia ruminantium infection in ruminants, four E. ruminantium open reading frames (ORFs) derived from the Welgevonden isolate were tested using either DNA vaccination or DNA primemodified viral or DNA prime-recombinant protein boost strategies. Both the DNA vaccination and the DNA prime.recombinant protein boost strategy provided complete protection against E. ruminantium Welgevonden needle challenge, while the DNA prime.modified viral boost strategy only provided 90 % protection. The DNA prime.recombinant protein boost strategy also coincided with elevated cellular immunology as was evident from increased IFN-ã production. Furthermore, we could show that the 1H12 DNA vaccine could induce protection against heterologous needle challenge when animals were immunised with the Welgevonden-derived 1H12 ORFs and challenged with selected E. ruminantium stocks. Unfortunately the DNA only and the DNA prime.recombinant protein boost strategy were not protective in the field. Therefore, our results suggest that there is a vast difference between needle challenge and natural tick infestation and that E. ruminantium organisms transmitted by ticks have the ability to evade the protective immunity induced by immunization with the four 1H12 ORFs. / Thesis (PhD)--University of Pretoria, 2007. / Veterinary Tropical Diseases / unrestricted

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 104-125).

Thesis (Ph. D.)--University of Virginia, 2001. / In title: the [kappa] is the Greek symbol. Includes bibliographical references (leaves 129-140). Also available online through Digital Dissertations.

Thesis (M.S.)--Uniformed Services University of the Health Sciences, 2006 / Typescript (photocopy)

Thesis (Ph. D.)--Cornell University, August, 2007. / Vita. Includes bibliographical references (leaves 165-176).

Jaagsiekte sheep retrovirus (JSRV) is a simple betaretrovirus that causes a contagious lung adenocarcinoma in sheep. One unique feature of JSRV is that its envelope (Env) glycoprotein functions as an active oncogene that induces oncogenic transformation in vitro and in vivo. While oncogenesis by JSRV Env protein has been extensively studied, the entry mechanism of JSRV has not been investigated. In this study, we showed that JSRV entry was specifically inhibited by lysosomotropic agents and bafilomycin Al (BafAl), indicating that JSRV is pH-dependent. Interestingly, oncoretroviral pseudotypes bearing JSRV Env protein were not inactivated by an acidic pH treatment, suggesting that additional factors besides low pH are involved in JSRV entry. Indeed, we found that JSRV entry was also blocked by dominant-negative mutants of dynamin and caveolin, raising the possibility that JSRV may use a dynamin-dependent, caveolae-associated pathway for entry. To determine a possible role of JSRV receptor, hyaluronidase 2 (Hyal2), in JSRV entry, we replaced the glycosylphosphatidyl-inositol (GPI) anchor of Hyal2 with the membrane-spanning domain and cytoplasmic tail of vesicular stomatitis virus G protein (VSV-G). We showed that although the transmembrane version of Hyal2 functioned efficiently as a JSRV receptor, JSRV entry mediated by the mutated Hyal2 was no longer inhibited by lysosomotropic agents and BafAl. Taken together, we conclude that JSRV entry is pH-dependent, but appears to use a non-classical pathway for entry. JSRV may provide an exciting novel model for a better understanding of retrovirus entry.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 85-91).

No description available.