Papers by Amanda Jamieson
Physiological Reports, May 1, 2021
This study gives important insight into the early immune and anti-viral responses to initial SARS... more This study gives important insight into the early immune and anti-viral responses to initial SARS-CoV-2 infection of the upper respiratory tract. Understanding these early stages of infection will allow us to more fully understand the pathology of COVID-19.
PLOS Pathogens, Aug 23, 2018
The innate immune system is responsible for many important functions in the body including respon... more The innate immune system is responsible for many important functions in the body including responding to infection, clearing cancerous cells, healing wounds, and removing foreign substances. Although many of these functions happen simultaneously in life, most laboratory studies of the innate immune response focus on one activity. How the innate immune system responds to concurrent insults in different parts of the body is not well understood. This study explores the impact of a lung infection on the cutaneous wound healing process. We used two complimentary models of injury: the excisional tail wound and subcutaneous implantation of polyvinyl alcohol (PVA) sponges. These models allow for assessment of the rate of closure and measurement of cellular and cytokine responses during acute wound healing, respectively. When mice with these healing wounds were infected with influenza A virus (IAV) in the lung there was a delay in wound healing. The viral lung infection suppressed the innate immune response in a healing wound, including cellular infiltrate, chemokines, growth factors, and cytokines. However, there was not a global immune suppression as there was an increase in inflammation systemically in mice with both infection and healing wounds compared to mice with only wounds or IAV infection. In addition, the lung immune response was largely unaffected indicating that responding to a lung infection is prioritized over a healing wound. This study introduces the concept of immune triage, in that when faced with multiple insults the immune system prioritizes responses. This paradigm likely applies to many situations that involve the innate immune system, and understanding how the innate immune system handles multiple insults is essential to understanding how it can efficiently clear pathogens while responding to other inflammatory events.
The Journal of Immunology
Infection by the Influenza A Virus (IAV) remains a persistent issue contributing to increased ris... more Infection by the Influenza A Virus (IAV) remains a persistent issue contributing to increased risk of morbidity and mortality, especially for susceptible individuals. IAV infection can lead to increased susceptibility to bacterial infections, which further exacerbate disease. Therapeutics targeting pathogens are often ineffective as pathogens can mutate to avoid potential vaccines and antimicrobials. Improving our understanding of IAV/bacteria-host interactions can allow us to improve host-specific approaches to tackle potential morbidity and mortality brought on by coinfections that are primarily found in epithelial cells. Lung epithelial cells not only serve as an integral part of the respiratory system, but are also crucial in host defense against respiratory infections. Therefore, we adopted an Air-Liquid Interface (ALI) strategy for the culture of human bronchial epithelial cells (HBEC) to mimic the structure and function of respiratory epithelial tissue. ALI cultures were then...
Journal of Immunology, May 1, 2016
The Journal of Immunology
Individuals who are hospitalized with traumatic injuries are susceptible to nosocomial pneumonia.... more Individuals who are hospitalized with traumatic injuries are susceptible to nosocomial pneumonia. While the effect of the injury on pulmonary infection has been examined in many contexts, it is less well understood how lung infection affects healing wounds. To address this, we examined the outcomes of laparotomized patients with and without pneumonia using the American College of Surgeons NSQIP database. Individuals who developed pneumonia were twice as likely to experience wound dehiscence compared to those without pneumonia. We hypothesized that the immune response could not to meet the demands of competing inflammatory insults in the skin and lungs. To examine this, we developed murine models of post-operative lung infection. Mice were wounded by the dorsal subcutaneous implantation of polyvinyl alcohol (PVA) sponges or tail skin excision, then infected intranasally with Klebsiella oxytoca. PVA sponge wounds allow for the examination of cellular and cytokine responses during acut...
Future Virology, Jul 1, 2016
Recently, two coronaviruses, severe acute respiratory syndrome coronavirus and Middle East respir... more Recently, two coronaviruses, severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus, have emerged to cause unusually severe respiratory disease in humans. Currently, there is a lack of effective antiviral treatment options or vaccine available. Given the severity of these outbreaks, and the possibility of additional zoonotic coronaviruses emerging in the near future, the exploration of different treatment strategies is necessary. Disease resilience is the ability of a given host to tolerate an infection, and to return to a state of health. This review focuses on exploring various host resilience mechanisms that could be exploited for treatment of severe acute respiratory syndrome coronavirus, Middle East respiratory syndrome coronavirus and other respiratory viruses that cause acute lung injury and acute respiratory distress syndrome.
Journal of Immunology, May 1, 2021
Annually in the U.S, the cost to treat the more than 6 million sufferers of chronic, non-healing ... more Annually in the U.S, the cost to treat the more than 6 million sufferers of chronic, non-healing wounds exceeds 50 billion U.S.D. Despite extensive characterization of the functionally diverse cellular and molecular constituents found in the wound bed, wound healing therapies are lacking. The pro- and anti-inflammatory capabilities of the innate immune system make it critical in the wound healing process. Natural killer (NK) cells are innate lymphocytes which exhibit similar pro- and anti-inflammatory capabilities. Despite the breadth of their functions, ranging from anti-microbial to maintaining a healthy pregnancy, there is a paucity of information regarding NK cells in the wound healing process. Using mouse wound models, we have identified 2 distinct populations of NK cells abundantly present in seven-day old sterile, cutaneous wounds. In addition, we have identified NK cells in the wound effluent of patients who underwent corrective surgery for idiopathic scoliosis. Previous work in different models suggests that these 2 NK cell populations exhibit proliferative effector functions related to their potential to facilitate organogenesis and T cell activation. Interestingly, these are both processes implicated in late stage wound healing. Using our mouse model of cutaneous wound healing we have shown that NK cell depletion delays closure. Furthermore, we show that NK cell depleted wounds demonstrate an aberrant growth factor response. With this work we aim to determine the impacts wound natural killer cell phenotype and function have on cutaneous wound healing outcomes and to determine the role of natural killer cells in wound growth factor expression.
Nature Immunology, Nov 11, 2002
Optimal lymphocyte activation requires the simultaneous engagement of stimulatory and costimulato... more Optimal lymphocyte activation requires the simultaneous engagement of stimulatory and costimulatory receptors. Stimulatory immunoreceptors are usually composed of a ligand-binding transmembrane protein and noncovalently associated signal-transducing subunits. Here, we report that alternative splicing leads to two distinct NKG2D polypeptides that associate differentially with the DAP10 and KARAP (also known as DAP12) signaling subunits. We found that differential expression of these isoforms and of signaling proteins determined whether NKG2D functioned as a costimulatory receptor in the adaptive immune system (CD8 + T cells) or as both a primary recognition structure and a costimulatory receptor in the innate immune system (natural killer cells and macrophages). This strategy suggests a rationale for the multisubunit structure of stimulatory immunoreceptors.
Blood, Jun 1, 2005
It is widely believed that self-tolerance of natural killer (NK) cells occurs because each NK cel... more It is widely believed that self-tolerance of natural killer (NK) cells occurs because each NK cell expresses at least one inhibitory receptor specific for a host major histocompatibility complex (MHC) class I molecule. Here we report that some NK cells lack all known self-MHC-specific inhibitory receptors, yet are nevertheless self-tolerant. These NK cells exhibit a normal cell surface phenotype and some functional activity. However, they respond poorly to class I-deficient normal cells, tumor cells, or cross-linking of stimulatory receptors, suggesting that self-tolerance is established by dampening stimulatory signaling. Thus, self-tolerance of NK cells in normal animals can occur independently of MHC-mediated inhibition, and hyporesponsiveness plays a role in self-tolerance of NK cells, as also proposed for B and T cells. (Blood. 2005; 105:4416-4423)
Nature, Sep 13, 2001
Natural killer cells attack many tumor cell lines and have long been thought to play a critical r... more Natural killer cells attack many tumor cell lines and have long been thought to play a critical role in anti-tumor immunity 1-7 , but the interaction between NK cells and tumor targets is poorly understood. The stimulatory lectin-like NKG2D receptor 8-13 is expressed by NK cells, activated CD8 + T cells and activated macrophages in mice 11. Several distinct cell surface ligands related to class I MHC molecules have been identified 11-14 , some of which are expressed at high levels by tumor cells but not by normal cells in adults 11,13,15,16. However, no direct evidence links the expression of these "induced self" ligands and tumor cell rejection. Here we demonstrate that ectopic expression of the murine NKG2D ligands Rae1β or H60 in several tumor cell lines results in dramatic rejection of the tumor cells by syngeneic mice. Rejection is mediated by NK cells and/ or CD8 + T cells. The ligand-expressing tumor cells induce potent priming of cytotoxic T cells and sensitization of NK cells in vivo. Strikingly, mice exposed to live or irradiated tumor cells expressing Rae1 or H60 are specifically immune to subsequent challenge with tumor cells lacking NKG2D ligands, suggesting application of the ligands in the design of tumor vaccines. As demonstrated by staining with a tetramerized derivative of the extracellular portion of NKG2D, NKG2D ligands are expressed by the majority of tumor cells tested, including various lymphoid, myeloid, and carcinoma cell lines (ref. 12 and unpublished data). Northern blot analysis revealed that many of the positive cell lines express Rae1 transcripts, while H60 transcripts were limited to only one or two of the cell lines tested (data not shown). Rae1 transcripts have not been detected in normal cells from adult mice 15 , suggesting that these genes are specifically upregulated in tumor cell lines. To investigate whether tumor cells expressing NKG2D ligands stimulate anti-tumor immune responses, we used a retrovirus expression system to ectopically express high levels of Rae1β or H60 in EL4, a thymoma, RMA, a T cell lymphoma and B16-BL6, a melanoma. These cell lines are all from C57BL/6 (hereafter B6) mice and do not normally express NKG2D ligands 11. Ligand-transduced cells were selected based on staining with NKG2D tetramers. To serve as controls, tumor cells transduced with empty retrovirus vector (designated as EL4/−, B16/− and RMA/−) were selected by genomic PCR (see Methods). For analysis of the response to EL4 and B16-BL6 tumor cells, groups of five B6 mice were inoculated subcutaneously with syngeneic tumor cell transductants. Control-transduced EL4 or B16-BL6 cells grew progressively at a rate similar to untransduced cells (Fig. 1a, c, d, data not shown), leading to uniform terminal morbidity by approximately 28 days. Strikingly, Rae1β-or H60-transduced tumor cells of both types were rejected rapidly and completely, as they failed to yield detectable tumors at any time point (Fig. 1a, c, d). A tenfold increase in the dose of Rae1β-or H60-transduced EL4 cells (to 5 × 10 7 cells) did not Correspondence and request for materials should be addressed to D.H.R.
Journal of Immunology, Dec 1, 2003
Frontiers in Immunology, Jan 17, 2023
The lung is a complex and unique organ system whose biology is strongly influenced by environment... more The lung is a complex and unique organ system whose biology is strongly influenced by environmental exposure, oxygen abundance, connection to extrapulmonary systems via a dense capillary network, and an array of immune cells that reside in the tissue at steady state. The lung also harbors a low biomass community of commensal microorganisms that are dynamic during both health and disease with the capacity to modulate regulatory immune responses during diseases such as cancer. Lung cancer is the third most common cancer worldwide with the highest mortality rate amongst cancers due to the difficulty of an early diagnosis. This review discusses the current body of work addressing the interactions between the lung microbiota and the immune system, and how these two components of the pulmonary system are linked to lung cancer development and outcomes. Bringing in lessons from broader studies examining the effects of the gut microbiota on cancer outcomes, we highlight many challenges and gaps in this nascent field.
Frontiers in Immunology, Oct 29, 2018
Pneumonia is a world health problem and a leading cause of death, particularly affecting children... more Pneumonia is a world health problem and a leading cause of death, particularly affecting children and the elderly (1, 2). Bacterial pneumonia following infection with influenza A virus (IAV) is associated with increased morbidity and mortality but the mechanisms behind this phenomenon are not yet well-defined (3). Host resistance and tolerance are two processes essential for host survival during infection. Resistance is the host's ability to clear a pathogen while tolerance is the host's ability to overcome the impact of the pathogen as well as the host response to infection (4-8). Some studies have shown that IAV infection suppresses the immune response, leading to overwhelming bacterial loads (9-13). Other studies have shown that some IAV/bacterial coinfections cause alterations in tolerance mechanisms such as tissue resilience (14-16). In a recent analysis of nasopharyngeal swabs from patients hospitalized during the 2013-2014 influenza season, we have found that a significant proportion of IAV-infected patients were also colonized with Klebsiella oxytoca, a gram-negative bacteria known to be an opportunistic pathogen in a variety of diseases (17). Mice that were infected with K. oxytoca following IAV infection demonstrated decreased survival and significant weight loss when compared to mice infected with either single pathogen. Using this model, we found that IAV/K. oxytoca coinfection of the lung is characterized by an exaggerated inflammatory immune response. We observed early inflammatory cytokine and chemokine production, which in turn resulted in massive infiltration of neutrophils and inflammatory monocytes. Despite this swift response, the pulmonary pathogen burden in coinfected mice was similar to singly-infected animals, albeit with a slight delay in bacterial clearance. In addition, during coinfection we observed a shift in pulmonary macrophages toward an inflammatory and away from a tissue reparative phenotype. Interestingly, there was only a small increase in tissue damage in coinfected lungs as compared to either single infection. Our results indicate that during pulmonary coinfection a combination of Lee et al. Resistance and Tolerance of IAV/K. oxytoca Coinfection seemingly modest defects in both host resistance and tolerance may act synergistically to cause worsened outcomes for the host. Given the prevalence of K. oxytoca detected in human IAV patients, these dysfunctional tolerance and resistance mechanisms may play an important role in the response of patients to IAV.
Hybridoma, Aug 1, 1999
We produced a novel hamster monoclonal antibody (MAb), 14B11, that recognizes the majority of mou... more We produced a novel hamster monoclonal antibody (MAb), 14B11, that recognizes the majority of mouse natural-killer (NK) cells. Transfection studies demonstrated that 14B11 MAb binds a subset of Ly49 receptors, including three putative inhibitory receptors, Ly49F, I, and C. No binding to Ly49A, B, D, or G was detected. In addition, 14B11 was shown to bind the putative activating receptor Ly49H, which required co-transfection of the signaling molecule DAP12 for detectable cell surface expression. Thus, 14B11 is the first reported MAb to bind Ly49H and F. At the functional level, 14B11 MAb enhanced the lysis by IL-2 activated NK cells of an FcR+ target cell line (Daudi), but not an FcR- target cell (EL-4). Because F(ab')2 fragments of 14B11 failed to enhance lytic activity, the enhancement of lysis by intact antibody is apparently due to "redirected lysis," in which stimulatory receptors on the NK cell are bridged by antibody to Fc receptors on the target cell. Cell separation experiments demonstrated that the 14B11-dependent redirected lysis was markedly increased using NK cell populations that had been depleted of Ly49F,+ I,+ or C+ NK cells. Because such depletions are expected to enrich for Ly49H+ NK cells, these results suggest that the enhancement of lysis mediated by 14B11 MAb may be due to stimulation of the activating Ly49H receptor. In conjunction with other anti-Ly49 MAbs, the 14B11 MAb will be useful in further studies of Ly49 receptor function and specificity.
Journal of Experimental Medicine, Jan 29, 2001
Ly49 receptor genes are expressed by subsets of natural killer (NK) cells in an overlapping fashi... more Ly49 receptor genes are expressed by subsets of natural killer (NK) cells in an overlapping fashion, accounting for the capacity of NK subsets to attack host cells that have selectively downregulated self-major histocompatibility complex (MHC) class I molecules. It was shown previously that most NK cells express only one or the other allele of a given Ly49 gene, while a smaller population expresses both alleles. However, the methods used to detect monoallelic and biallelic cells were nonquantitative. Here, new allele-specific antibodies were used to provide the first quantitative examination of biallelic and monoallelic expression of Ly49A and Ly49G2. The results demonstrate conclusively that most Ly49A ϩ and Ly49G2 ϩ NK cells express the corresponding gene in a monoallelic fashion, with a smaller subset expressing both alleles. Unexpectedly, biallelic Ly49A ϩ NK cells were more numerous than predicted by completely independent allelic expression, suggesting some heterogeneity among NK progenitors in the potential to express a given Ly49 gene. The data also show that cells expressing one allele of Ly49G2 may express Ly49A from the same or opposite chromosome with equal likelihood, indicating that the expressed allele is chosen independently for different Ly49 genes. Finally, the data demonstrate that biallelic expression of Ly49A or Ly49G2 occurs least frequently in mice that express ligands for these receptors (H-2 d mice), and most frequently in class I-deficient mice. Thus, biallelic expression of Ly49 genes is regulated by interactions of NK cell progenitors with MHC class I molecules.
Frontiers in Immunology, Jun 22, 2018
Much research on infectious diseases focuses on clearing the pathogen through the use of antimicr... more Much research on infectious diseases focuses on clearing the pathogen through the use of antimicrobial drugs, the immune response, or a combination of both. Rapid clearance of pathogens allows for a quick return to a healthy state and increased survival. Pathogen-targeted approaches to combating infection have inherent limitations, including their pathogen-specific nature, the potential for antimicrobial resistance, and poor vaccine efficacy, among others. Another way to survive an infection is to tolerate the alterations to homeostasis that occur during a disease state through a process called host tolerance or resilience, which is independent from pathogen burden. Alterations in homeostasis during infection are numerous and include tissue damage, increased inflammation, metabolic changes, temperature changes, and changes in respiration. Given its importance and sensitivity, the lung is a good system for understanding host tolerance to infectious disease. Pneumonia is the leading cause of death for children under five worldwide. One reason for this is because when the pulmonary system is altered dramatically it greatly impacts the overall health and survival of a patient. Targeting host pathways involved in maintenance of pulmonary host tolerance during infection could provide an alternative therapeutic avenue that may be broadly applicable across a variety of pathologies. In this review, we will summarize recent findings on tolerance to host lung infection. We will focus on the involvement of innate immune responses in tolerance and how an initial viral lung infection may alter tolerance mechanisms in leukocytic, epithelial, and endothelial compartments to a subsequent bacterial infection. By understanding tolerance mechanisms in the lung we can better address treatment options for deadly pulmonary infections.
PLOS Pathogens, Jun 12, 2009
Dendritic cells (DCs) are specialized phagocytes that internalize exogenous antigens and microbes... more Dendritic cells (DCs) are specialized phagocytes that internalize exogenous antigens and microbes at peripheral sites, and then migrate to lymphatic organs to display foreign peptides to naïve T cells. There are several examples where DCs have been shown to be more efficient at restricting the intracellular replication of pathogens compared to macrophages, a property that could prevent DCs from enhancing pathogen dissemination. To understand DC responses to pathogens, we investigated the mechanisms by which mouse DCs are able to restrict replication of the intracellular pathogen Legionella pneumophila. We show that both DCs and macrophages have the ability to interfere with L. pneumophila replication through a cell death pathway mediated by caspase-1 and Naip5. L. pneumophila that avoided Naip5-dependent responses, however, showed robust replication in macrophages but remained unable to replicate in DCs. Apoptotic cell death mediated by caspase-3 was found to occur much earlier in DCs following infection by L. pneumophila compared to macrophages infected similarly. Eliminating the pro-apoptotic proteins Bax and Bak or overproducing the anti-apoptotic protein Bcl-2 were both found to restore L. pneumophila replication in DCs. Thus, DCs have a microbial response pathway that rapidly activates apoptosis to limit pathogen replication.
Human Vaccines & Immunotherapeutics, Jun 19, 2015
Proceedings of the National Academy of Sciences of the United States of America, Jan 8, 2002
Natural killer (NK) cells are believed to achieve self-tolerance through the expression of self-M... more Natural killer (NK) cells are believed to achieve self-tolerance through the expression of self-MHC-specific inhibitory receptors, such as members of the Ly49 and CD94͞NKG2 families. Individual Ly49 genes are stochastically expressed by NK subsets and are expressed in a monoallelic fashion, but little is known about the mechanisms underlying CD94͞NKG2A expression. We show here that, like Ly49 genes, mouse Nkg2a is stochastically and monoallelically expressed. Thus, a single general mechanism controls expression of all known MHC-specific receptors by mouse NK cells. In addition, we find that DBA͞2J mice are naturally CD94-deficient and do not express cell-surface CD94͞NKG2A receptors, even on neonatal NK cells. Thus, self-tolerance of neonatal NK cells cannot be attributed to CD94͞NKG2A expression. Taken together, the results lead to a reconsideration of current models of NK cell development and self-tolerance. Transient Transfections of COS-7 Cells. COS-7 cells were transfected with supercoiled DNA (Qiagen, Chatsworth, CA), using Lipofectamine reagent (GIBCO͞BRL), and analyzed after 2 days. Transfected cDNAs were cloned into the pME18S expression vector (GenBank accession no. AB009864), as described (4, 20-22). Reverse Transcription (RT)-PCR to Distinguish NKG2A BALB and NKG2A B6. Radioactive RT-PCR was performed as described (20), except that primers NKG2A 5Јex3 (5Ј-TTAATTGTCGCTGT-GGTTGTAATTACTAC-3Ј) and NKG2 3ЈBALB (5Ј-TCA-GATGGG(A͞G)AATTTACACTTACAAAGATATGG-3Ј) This paper was submitted directly (Track II) to the PNAS office. Abbreviations: NK, natural killer; NKC, NK complex; PE, phycoerythrin; RT, reverse transcription; SP, single positive (16a11 Ϫ 20d5 ϩ); DP, double positive (16a11 ϩ 20d5 ϩ).
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Papers by Amanda Jamieson