Cleavage of influenza A virus hemagglutinin by avian intestinal bacterial proteases

dc.contributor.advisorChambers, James P.
dc.contributor.authorKing, Marcus David
dc.contributor.committeeMemberGuentzel, M. Neal
dc.contributor.committeeMemberArulanandam, Bernard P.
dc.contributor.committeeMemberBodour, Adria A.
dc.contributor.committeeMemberSharif, Hatim
dc.date.accessioned2024-02-12T14:41:14Z
dc.date.available2024-02-12T14:41:14Z
dc.date.issued2009
dc.descriptionThis item is available only to currently enrolled UTSA students, faculty or staff. To download, navigate to Log In in the top right-hand corner of this screen, then select Log in with my UTSA ID.
dc.description.abstractProteolytic cleavage of hemagglutinin is required for cell entry by receptor-mediated endocytosis and plays a key role in pathogenicity of the influenza virus. Despite a number of studies describing relationships between bacterial proteases and influenza A viral activation in mammals, very little is known about the role of the normal bacterial flora of birds on hemagglutinin activation. This dissertation is a compilation of original research addressing the following objectives: (1) demonstrate the presence of protease-secreting bacteria in the avian gastrointestinal tract; (2) assess the capability of secreted proteases to cleave hemagglutinin in vitro; and (3) assess the effect of secreted proteases on influenza A virus infectivity. Numerous species of bacteria have been shown to exhibit proteolytic activity and cleavage fragmentation patterns similar to trypsin mediated HA1/HA2 hydrolysis; however, no bacterial secreted protease demonstrated viral activation. Surprisingly, all isolates exhibited a negative effect upon the virus' ability to activate the virus and thus cause disease suggesting either inappropriate HA cleavage, lipolytic enzyme viral envelope alteration, and/or a yet-to-be described enzymatic activity. Collectively, these results suggest that proteolytic bacteria found in the avian gastrointestinal tract do not give rise to direct cleavage activation of influenza virus HA.
dc.description.departmentCivil and Environmental Engineering
dc.format.extent105 pages
dc.format.mimetypeapplication/pdf
dc.identifier.isbn9781109538144
dc.identifier.urihttps://hdl.handle.net/20.500.12588/4093
dc.languageen
dc.subjectactivation
dc.subjectbacteria
dc.subjectcleavage
dc.subjecthemagglutinin
dc.subjectInfluenza
dc.subjectprotease
dc.subject.classificationMolecular biology
dc.subject.classificationMicrobiology
dc.subject.lcshInfluenza A virus
dc.subject.lcshAvian influenza A virus
dc.subject.lcshProteolytic enzymes
dc.titleCleavage of influenza A virus hemagglutinin by avian intestinal bacterial proteases
dc.typeThesis
dc.type.dcmiText
dcterms.accessRightspq_closed
thesis.degree.departmentCivil and Environmental Engineering
thesis.degree.grantorUniversity of Texas at San Antonio
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy

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