Medicine and Health Sciences Commons^™

An Investigation On The Effect Of Conserved Hinge Histidine On Influenza Hemagglutinin(Ha2) Protein Conformation Using Md Simulations, Nada Tolba

Chemistry & Biochemistry Undergraduate Honors Theses

Hemagglutinin is a protein on the surface of Human Influenza Viruses.¹ It is composed of two glycopolypeptide domains, the HA1 and HA2 domains. Previous studies have found that across different strains of Influenza viruses, HIS435 residues remain conserved.⁴ In studies where mutations occurred in hinge-site histadine residues, the Influenza virus was inactive.⁴ These investigations indicated a significant role of HIS435 (hinge-site histadines) in virulence. Four systems were created using Molecular dynamics (MD) simulations. Each system was composed of an Isolated HA2 trimer solvated in a 150 mM NaCl rectangular water box at 310 K under isobaric and …

Crucial Role Of T Follicular Helper Cell-Derived Ifn-Γ In Lung Resident Memory B Cell Responses, Nicole Michelle Arroyo-Diaz

All ETDs from UAB

T follicular helper (Tfh) cells constitute a distinct subset of CD4 T cells that reside within B cell follicles, playing an indispensable role in orchestrating the Germinal Center (GC) response. In response to polarizing environments, such as Influenza A virus infection (IAV), Tfh cells secrete effector cytokines, including IFN-γ and IL-4. Nevertheless, the specific functions of cytokine-producing Tfh cell subsets, beyond their involvement in driving class switch recombination (CSR), remain largely unexplored. Here, we demonstrate that, following IAV infection, Tfh cell cytokine production undergoes a dynamic shift, transitioning from early IFN-γ dominance to later predominance of IL-4. The initial IFN-γ …

Attenuation Of Interferon Responses In The Obese Host And Ramifications For Influenza Virus Evolution, Rebekah Reed Honce

Theses and Dissertations (ETD)

The most insidious pandemic of modern life does not arise from an infectious agent but rather from malnutrition. With its global incidence tripling over the past three decades, obesity is a major public health concern. Obesity’s rising prevalence has also illuminated its impact on communicable diseases. Following the 2009 H1N1 influenza A virus pandemic, obesity was identified as a risk factor for increased disease severity and mortality in infected individuals. Obesity causes a chronic state of meta-inflammation with systemic implications for immunity, including delayed antiviral responses to influenza virus infection, poor recovery, and impaired immunological memory. However, the majority of …

Reverse Zoonosis Of Pandemic A(H1n1)Pdm09 Influenza Viruses At The Swine/Human Interface, Daniel Gene Darnell

Theses and Dissertations (ETD)

The 2009 pandemic influenza A(H1N1)pdm09 virus emerged from the swine population. Despite frequent zoonotic events, swine influenza viruses had not become established in humans previously and little is known about host-barriers which prevent swine influenza viruses from efficiently infecting humans. Thus, the emergence of the H1N1pdm09 viruses in humans and the subsequent reverse zoonoses back to swine offered an extremely valuable opportunity to expand current knowledge. We used our active swine farm surveillance platform in combination with viruses from the USDA surveillance program to look for evidence of interspecies transmission of H1N1pdm09 viruses in the US. We found phylogenetic evidence …

Evaluating The Potential Of Repurposing Commercially Available Drugs For The Treatment Of Viral Infections, Brennan Connor Mcewan

Undergraduate Honors Capstone Projects

Viral infections that are often overlooked as common seasonal illnesses such as influenza can rapidly become a public threat. They threaten society as new, more dangerous strains of these common viruses emerge and as strains develop resistance to current vaccines and antiviral treatments (Kochanek, Murphy, Xu, & Tejada-Vera, 2014). To combat this, the development of antiviral treatments with novel mechanisms of action is essential. Repurposing drugs instead of developing new drugs can save years of development time and hundreds of millions of dollars (DiMasi, Hansen, & Grabowski, 2003). To support the effort to discover drugs with unique mechanisms of action, …

Roles Of Γδ T Cells In Influenza Infections And Methods For Tcr Expression And Characterization, Xizhi Guo

Theses and Dissertations (ETD)

"Influenza virus is a significant pathogen in humans and animals with the ability to cause extensive morbidity and mortality. Exuberant immune responses associated with immune cell migration/activation and cytokine/chemokine release, can be induced after infections. Recent studies have painted a complex picture of viral clearance and tissue repair in adults. The immune responses in neonatal influenza infections and the potential methods to engineer antigen-specific T cells for immunotherapy against cancers and infections will be the focus of this dissertation." "Compared to adults, infants suffer higher rates of hospitalization, severe clinical complications, and mortality due to influenza infection. We found that …

Structural And Functional Insights Into The Influenza A Virus Non-Structural Protein 1 Effector Domain, Alex Kleinpeter

All ETDs from UAB

The influenza A virus (IAV) non-structural protein 1 (NS1) is a highly multifunctional viral protein responsible for antagonizing the type-I interferon (IFN) response to infection. NS1 has therefore been identified as a potentially effective target for the development of novel anti-influenza compounds. Furthermore, it is important to understand the molecular underpinnings driving NS1 function to more effectively elucidate antiviral targets. In this dissertation, we have contributed significant insight into NS1’s potential as an antiviral target, and the structure-function relationships driving its activity in an infected cell. First, we structurally characterized the binding of two known influenza inhibitors (A9 and A22) …

Structural And Functional Insights Into Influenza A Virus Ns1-Mediated Rig-I Antagonism, Alexander Jureka

All ETDs from UAB

The influenza virus non-structural protein 1 is well known to antagonize the host innate immune response through its interaction with the innate immune sensor, retinoic acid induc-ible gene I (RIG-I). While the complete mechanism of the NS1:RIG-I interaction remains unclear, we were the first to demonstrate a direct interaction between the NS1 RNA-binding domain (NS1RBD) from the 1918H1N1 influenza virus and the second caspase activa-tion and recruitment domain (CARD2) of RIG-I using NMR. In addition, we also identi-fied that mutation of Arg 21 in the 1918H1N1 NS1RBD to Gln (R21Q) completely abrogated the NS1:CARD2 interaction. Given that CARD2 plays a …

A Novel Role For T-Bet And Ifng In Directing B Cell Differentiation, Sara Stone Stone

All ETDs from UAB

The transcription factor T-bet regulates the epigenetic programming and differentiation of cytotoxic and helper T (Th) cells. Several studies recently identified T-bet expression in B cells after stimulation with TLR7 or interferon alpha or gamma. T-bet controls isotype switching to IgG2a in B cells; however, the mechanism by which T-bet exerts this effect and whether T-bet regulates fate decision beyond isotype choice is not clear. When activated by interferon gamma-producing Th cells, B cells rapidly upregulate T-bet and undergo T-bet dependent changes in chromatin accessibility and wide-scale transcriptional reprogramming. T-bet controls expression of the core transcription factors required for antibody …

Dissecting The Novel Roles Of Trim56 In Antiviral Innate Immunity, Baoming Liu

Theses and Dissertations (ETD)

The tripartite motif-containing (TRIM) proteins have emerged as a new class of host antiviral restriction factors, with several demonstrating roles in regulating innate antiviral responses. Of >70 known TRIMs, TRIM56 inhibits replication of bovine viral diarrhea virus, a ruminant pestivirus of the family Flaviviridae, but has no appreciable effect on VSV, a rhabdovirus. We have also shown that TRIM56 forms a complex with the Toll-like receptor-3 (TLR3) adaptor, TRIF, via its C-terminal residues 621-750, and augments TLR3-mediated interferon (IFN) induction and establishment of an antiviral state. Yet, TRIM56’s antiviral spectrum and the precise underlying mechanisms by which TRIM56 executes …

The Mechanism Of Small Molecule Viral Fusion Inhibitors, Michael Joseph Rowse

All ETDs from UAB

All negative stranded RNA viruses (NSRV) have genomes encapsidated by oligomerized nucleoprotein (N). The N-RNA complex acts as the template for both transcription and replication. The crystal structure of the N protein from the model NSRV vesicular stomatitis virus (VSV) established the structural basis for the oligomerization of N-protein and the encapsidation of RNA. To determine how the structure of N protein changes in response to specific sequences of RNA, we developed a strategy to digest the random RNA encapsidated in the recombinant N-protein and reencapsidated specific RNA sequences. Poly-rA, poly-rC, poly-rU, and poly-rG sequences were encapsidated and co-crystallized with …

The Effects Of Vitamin D Supplementation On Influenza, Jonah M. Spoerndle

Williams Honors College, Honors Research Projects

Recently the role of vitamin D in other non-classical capacities has been evaluated. One of these non-classical vitamin D roles is assisting in maintaining proper immune system health. One disease that has a great effect on the immune system is influenza. Vitamin D helps to prevent and limit influenza by moderating the inflammatory cytokines as well as promoting the production of monocytes that help destroy the invading materials. Through the use of vitamin D supplementation the recommended daily amount of vitamin D can be assured and optimal health could be achieved. The purpose of this project was to design a …

Influenza Hospitalizations In New York State 2007-2013 : Impact Of Vaccine And Antiviral Treatment Effectiveness In Reducing Severity Of Illness, Mary Dundas

Legacy Theses & Dissertations (2009 - 2024)

Background: Underlying medical conditions are known risk factors for increased severity of infectious diseases, including influenza. Although most studies on disease severity, underlying medical conditions, and prevention/treatment effectiveness occurred during the pandemic 2009-2010 season, data is also available for seasons when influenza virus B and influenza virus A subtypes pH1N1, seasonal H1N1, and H3N2 were circulating.

Expression Of The Influenza Protein M2 During Viral Infection Inhibits Cftr Activity, James David Londino

All ETDs from UAB

The purpose of these dissertation studies was to 1) determine whether influenza infection alters CFTR activity in polarized epithelium; 2) measure CFTR expression and activity in cells co-expressing influenza M2 protein; and 3) examine the role of M2 on the alteration of CFTR during viral infection. We determined that infection of polarized primary epithelial cells with influenza decreases CFTR expression and activity. In addition, individual cells infected with influenza had decreased CFTR conductance as measured by whole-cell patch clamp. We also found that the influenza ion channel, matrix protein 2 (M2), alone reduced CFTR expression and activity. M2 is expressed …

A Novel Mechanism Of Enhanced Susceptibility To Bacterial Pneumonia In Influenza-Infected Hosts, Hazem Elsayed Ghoneim

Theses and Dissertations (ETD)

Viruses such as influenza suppress host immune function by a variety of methods. This may result in a significant morbidity through several pathways, including facilitation of secondary bacterial pneumonia from pathogens such as Streptococcus pneumoniae. Lungresident alveolar macrophages (AMs) act as the first line of innate cellular immunity against respiratory bacterial pathogens, including pneumococcus. Therefore, they represent an attractive target for study Before investigating the impact of influenza infection on resident AMs, we first characterized different subsets of lung-resident macrophages in naïve mice using a novel in vivo labeling approach in conjunction with multicolor flow cytometric analysis and confocal microscopic …

Impact Of Adjuvants On The Antibody Responses To Pre-Pandemic H5n1 Influenza Vaccines, Ali Hassan Ellebedy

Theses and Dissertations (ETD)

Human influenza pandemics occur when influenza viruses to which the population has little or no immunity emerge and acquire the ability to transmit among humans. Since their emergence in 1996, human infections with highly pathogenic avian influenza A (H5N1) viruses presented a serious public health challenge. Additionally, H5N1 viruses caused significant agricultural and economic losses in the communities it has affected. Human infections with these viruses are rare but when they occur, these infections are highly fatal. A greater public health concern stems from the rapid evolution displayed by these viruses so far, which in turn might result in viruses …

H5n1 Influenza Virus Induces A Parkinsonian Pathology, Haeman Jang

Theses and Dissertations (ETD)

The greatest threat for an influenza pandemic at this time is posed by the highly pathogenic H5N1 avian influenza virus. To date, 63% of the 436 known human cases of H5N1 infection have proven fatal. Animals infected by H5N1 viruses have demonstrated acute neurological signs ranging from mild encephalitis to motor disturbances and coma. However, no studies have examined the longer-term neurologic consequences of H5N1 infection. We show that this virus travels from the peripheral nervous system into the central nervous system (CNS) to higher levels of the neuroaxis, using C57BL/6J mice that are infected by the A/VN/1203/04 H5N1 virus …

Glycan Shielding Of The Influenza Virus Hemagglutinin Elicits Evasion Of The Adaptive Immune Response And T-Cell-Driven Pathology, Keith C. Wanzeck

Theses and Dissertations (ETD)

Three separate influenza pandemics have emerged in the human population since 1918, each characterized by viruses that lack N-linked glycosylation sites on the globular head of the hemagglutinin protein. In contrast, recent non-pandemic isolates have acquired such sites. Here we constructed isogenic viruses containing differing numbers of additional N-linked glycosylation sites to assess the impact on the host immune response. These studies show that mice infected with a glycosylated virus remain susceptible to challenge with a non-glycosylated virus, glycosylated viruses elicit an inferior immune response, and in this context T-cell pathology and death may occur. We conclude from these data …

Pandemic Potential Of Reassortant Swine Influenza A Viruses, Christy Brockwell Staats

Theses and Dissertations (ETD)

Influenza A viruses are capable of causing disease in several species, including birds, humans and swine. Host specificity of the viruses is not absolute, and is influenced by a range of factors. Swine play a pivotal role in the interspecies transmission of influenza A viruses, as they are susceptible to infection with both human and avian strains and have been implicated as a “mixing vessel” for the reassortment of influenza A viruses from different species. The reassortment of influenza A viruses of human and avian origin led to human influenza pandemics in 1957 and 1968.

The dynamics of swine influenza …