Immunology of Infectious Disease Commons^™

Role Of Cd38 In Pulmonary Host Defense Against Gram-Negative Pneumonia, Xiaoqian Shan

LSU Master's Theses

The Gram-negative bacterium, Klebsiella pneumoniae, is a major cause of hospital-acquired pneumonia in the U.S. In particular, the dramatic increase in carbapenem-resistant K. pneumoniae infections poses a serious threat to the public health both in the United States and worldwide. Clearance of bacteria in the lungs depends on effective pulmonary immune response. It may be possible to design improved therapies that augment host immune responses while attenuating excessive pulmonary inflammation through modulation of key innate immunity molecules during pneumonic infections. Cluster differentiation CD38 (CD38) has been detected on the surface of many immune cells or intracellular compartments, acting as …

Mechanism Of Neutrophil Homeostasis And Immunity In Pneumonia And Sepsis, Sagar Paudel

LSU Doctoral Dissertations

Severe bacterial pneumonia and septicemia are pressing health problems. A better understanding of cellular and molecular players of neutrophil immunity and homeostasis in bacterial pneumonia and sepsis is critical for inspiring novel therapeutics. Chemokine CXCL1 is a widely secreted neutrophil attractant and Nod-like receptor (NLRC4) is commonly expressed cytoplasmic pathogen sensor in hematopoietic compartments. How these innate mediators convert pathogen signals into molecular cues of immune response in context of Gram-positive bacterial pneumonia and septicemia largely remain unknown. Utilizing Cxcl1 gene deficient mice, we demonstrate CXCL1 regulates neutrophil influx, bacterial clearance, and host survival in pneumococcal pneumonia-derived sepsis. Furthermore, Cxcl1 …

Nlrp6 In Gram-Positive Pneumonia And Sepsis, Laxman Ghimire

LSU Doctoral Dissertations

Acute lower respiratory infections (pneumonia) and pneumonia-derived sepsis are among the leading causes of death in the world causing 7.8 million deaths annually. In this regard, Methicillin-resistant Staphylococcus aureus (MRSA) is endemic in the US and implicated for causing high mortality-associated necrotizing pneumonia and aggravating viral pneumonia with superinfection. Additionally, sepsis is the 7^th leading cause of death among newborns in the US and is responsible for more than 750,000 hospitalization cases every year. Although there is a plethora of research in both pneumonia and sepsis, the detailed pathophysiology still remains elusive. Understanding the host defense mechanism will help …

A Case-Study Approach To Investigate Transmission, Co-Infection, And Clinical Sequelae During Epidemics Of Dengue And Ebola Virus Disease, Jennifer Elizabeth Giovanni

LSU Doctoral Dissertations

From within their ecologic niches, zoonotic viruses emerge from animal reservoirs into the edges and centers of human habitation to exploit opportunities for unabated transmission within immunologically–naïve populations. Our understanding of where, in whom, and how these viruses emerge is under direct challenge, driving the evolution of modern infectious disease epidemiology within a rapidly-connected global community. The studies presented herein are based on analyses of both aggregate and case-level data, which, we argue, provide unique insight into the complexities of transmission, co-infection, and clinical sequelae occurring within, and arising from, epidemics of emerging zoonotic viruses. In Chapter II, we investigate …

Role Of Neutrophils In The Modulation Of Host Responses To Human Respiratory Pneumovirus Infection, Nagarjuna Reddy Cheemarla

LSU Doctoral Dissertations

Neutrophils are the most abundant leukocytes (50% to 70%) in humans and are the first immune cell population recruited to the sites of infection. They are known to act as the first line of innate immune defense against invading pathogens, and more recently, to playing a crucial role in orchestrating adaptive immune responses. The role of neutrophils in the respiratory viral infections till date remains unclear and controversial. Previous studies demonstrated both beneficial as well as pathogenic role for neutrophils in respiratory viral infections, especially influenza.

Previous findings reported an early and high influx of neutrophils into the airways early …

Characterization Of The Interaction Between R. Conorii And Human Host Vitronectin In Rickettsial Pathogenesis, Abigail Inez Fish

LSU Doctoral Dissertations

Spotted Fever Group Rickettsia are inoculated into the mammalian host during hematophagous arthropod feeding. Once in the bloodstream and during dissemination, the survival of these pathogens is dependent upon their ability to evade innate host defenses until a proper cellular target is reached. The establishment of a successful infection also relies on the ability of the bacteria to attach and invade target cells, as failure to do so results in destruction of the bacterium. Rickettsia conorii expresses an outer membrane protein, Adr1, which binds the multifunctional human glycoprotein, vitronectin, to promote resistance to complement mediated killing. Homologs of Adr1 are …

Role Of Mucin 19 In The Respiratory Tract, Kaitlin Mcbride

LSU Master's Theses

Human metapneumovirus (HMPV) is a negative sense, single stranded RNA virus belonging to the Pneumoviridae family, and represents an important pathogen that causes severe respiratory disease worldwide. There is currently no vaccine against HMPV, so it is important to study the aspects of the immune response induced by HMPV. Because infiltration of mucus is a hallmark of HMPV infection, it is warranted to study the role of mucus in the disease process. Mucin proteins make up the major component of mucus and can be found within the airway and lungs. Previous work from our laboratory demonstrated a high upregulation of …