Martin L Moore

Emory University, Atlanta, GA, USA

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Publications (23)111.39 Total impact

  • Article: A stabilized respiratory syncytial virus reverse genetics system amenable to recombination-mediated mutagenesis.
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    ABSTRACT: We describe the first example of combining bacterial artificial chromosome (BAC) recombination-mediated mutagenesis with reverse genetics for a negative strand RNA virus. A BAC-based respiratory syncytial virus (RSV) rescue system was established. An important advantage of this system is that RSV antigenomic cDNA was stabilized in the BAC vector. The RSV genotype chosen was A2-line19F, a chimeric strain previously shown to recapitulate in mice key features of RSV pathogenesis. We recovered two RSV reporter viruses, one expressing the red fluorescent protein monomeric Katushka 2 (A2-K-line19F) and one expressing Renilla luciferase (A2-RL-line19F). As proof of principle, we efficiently generated a RSV gene deletion mutant (A2-line19FΔNS1/NS2) and a point mutant (A2-K-line19F-I557V) by recombination-mediated BAC mutagenesis. Together with sequence-optimized helper expression plasmids, BAC-RSV is a stable, versatile, and efficient reverse genetics platform for generation of a recombinant Pneumovirus.
    Virology 10/2012; · 3.35 Impact Factor
  • Article: An adjuvanted respiratory syncytial virus fusion protein induces protection in aged BALB/c mice.
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    ABSTRACT: BACKGROUND: Respiratory Syncytial Virus (RSV) causes significant disease in the elderly, in part, because immunosenescence impairs protective immune responses to infection in this population. Despite previous and current efforts, there is no RSV vaccine currently licensed in infants or elderly adults. Adjuvanted RSV subunit vaccines have the potential to boost waning immune responses and reduce the burden of RSV disease in the elderly population. RESULTS: We used an aged BALB/c mouse model to evaluate immune responses to RSV Fusion (F) protein in the absence and presence of an alum adjuvant. We demonstrate that aged BALB/c mice immunized with alum-adjuvanted RSV F protein had significantly reduced lung viral titers at day 4 following challenge with wild-type (wt) RSV. Serum neutralizing antibody titers measured on day 27 correlated with protection in both young and aged vaccinated mice, although the magnitude of antibody titers was lower in aged mice. Unlike young mice, in aged mice, alum-adjuvanted RSV F did not induce lung TH2-type cytokines or eosinophil infiltration compared to non-adjuvanted F protein following wt RSV challenge. CONCLUSION: Our studies demonstrate that neutralizing anti-RSV antibody titers correlate with protection in both young and aged BALB/c mice vaccinated with RSV F protein vaccines. The F + alum formulation mediated greater protection compared to the non-adjuvanted F protein in both young and aged mice. However, while alum can boost F-specific antibody responses in aged mice, it does not completely overcome the reduced ability of a senescent immune system to respond to the RSV F antigen. Thus, our data suggest that a stronger adjuvant may be required for the prevention of RSV disease in immunosenescent populations, to achieve the appropriate balance of protective neutralizing antibodies and effective TH1-type cytokine response along with minimal lung immunopathology.
    Immunity & Ageing 10/2012; 9(1):21.
  • Article: Vaccine-elicited CD8+ T cells protect against respiratory syncytial virus strain A2-line19F-induced pathogenesis in BALB/c mice.
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    ABSTRACT: CD8(+) T cells may contribute to vaccines for respiratory syncytial virus (RSV). Compared to CD8(+) T cells responding to RSV infection, vaccine-elicited anti-RSV CD8(+) T cells are less well defined. We used a peptide vaccine to test the hypothesis that vaccine-elicited RSV-specific CD8(+) T cells are protective in RSV pathogenesis. BALB/c mice were treated with a mixture (previously termed TriVax) of a M2(82-90) peptide representing an immunodominant CD8 epitope, the TLR agonist poly (I:C), and a costimulatory anti-CD40 antibody. TriVax vaccination induced potent effector anti-RSV CD8(+) CTL. Mice were challenged with RSV strain A2-line19F, a model of RSV pathogenesis leading to airway mucus expression. Mice were protected against RSV infection and against RSV-induced airway mucus expression and cellular lung inflammation when challenged six days after vaccination. Compared to A2-line19F infection alone, TriVax vaccination followed by challenge resulted in effector CD8(+) T cells with greater cytokine expression and the more rapid appearance of RSV-specific CD8(+) T cells in the lung. When challenged 42 days after TriVax vaccination, memory CD8(+) T cells were elicited with RSV-specific tetramer responses equivalent to TriVax-induced effector CD8(+) T cells. These memory CD8(+) T cells had lower cytokine expression than effector CD8(+) T cells, and protection against A2-line19F was partial during the memory phase. We found that vaccine-elicited effector anti-RSV CD8(+) T cells protected mice against RSV infection and pathogenesis, and waning protection correlated with reduced CD8(+) T cell cytokine expression.
    Journal of Virology 09/2012; · 5.40 Impact Factor
  • Article: Independent structural domains in paramyxovirus polymerase protein.
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    ABSTRACT: All enzymatic activities required for genomic replication and transcription of nonsegmented negative strand RNA viruses (or Mononegavirales) are believed to be concentrated in the viral polymerase (L) protein. However, our insight into the organization of these different enzymatic activities into a bioactive tertiary structure remains rudimentary. Fragments of Mononegavirales polymerases analyzed to date cannot restore bioactivity through trans-complementation, unlike the related L proteins of segmented NSVs. We investigated the domain organization of phylogenetically diverse Paramyxovirus L proteins derived from measles virus (MeV), Nipah virus (NiV), and respiratory syncytial virus (RSV). Through a comprehensive in silico and experimental analysis of domain intersections, we defined MeV L position 615 as an interdomain candidate in addition to the previously reported residue 1708. Only position 1708 of MeV and the homologous positions in NiV and RSV L also tolerated the insertion of epitope tags. Splitting of MeV L at residue 1708 created fragments that were unable to physically interact and trans-complement, but strikingly, these activities were reconstituted by the addition of dimerization tags to the fragments. Equivalently split fragments of NiV, RSV, and MeV L oligomerized with comparable efficiency in all homo- and heterotypic combinations, but only the homotypic pairs were able to trans-complement. These results demonstrate that synthesis as a single polypeptide is not required for the Mononegavirales polymerases to adopt a proper tertiary conformation. Paramyxovirus polymerases are composed of at least two truly independent folding domains that lack a traditional interface but require molecular compatibility for bioactivity. The functional probing of the L domain architecture through trans-complementation is anticipated to be applicable to all Mononegavirales polymerases.
    Journal of Biological Chemistry 01/2012; 287(9):6878-91. · 4.77 Impact Factor
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    Article: A critical phenylalanine residue in the respiratory syncytial virus fusion protein cytoplasmic tail mediates assembly of internal viral proteins into viral filaments and particles.
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    ABSTRACT: Respiratory syncytial virus (RSV) is a single-stranded RNA virus in the Paramyxoviridae family that assembles into filamentous structures at the apical surface of polarized epithelial cells. These filaments contain viral genomic RNA and structural proteins, including the fusion (F) protein, matrix (M) protein, nucleoprotein (N), and phosphoprotein (P), while excluding F-actin. It is known that the F protein cytoplasmic tail (FCT) is necessary for filament formation, but the mechanism by which the FCT mediates assembly into filaments is not clear. We hypothesized that the FCT is necessary for interactions with other viral proteins in order to form filaments. In order to test this idea, we expressed the F protein with cytoplasmic tail (CT) truncations or specific point mutations and determined the abilities of these variant F proteins to form filaments independent of viral infection when coexpressed with M, N, and P. Deletion of the terminal three FCT residues (amino acids Phe-Ser-Asn) or mutation of the Phe residue resulted in a loss of filament formation but did not affect F-protein expression or trafficking to the cell surface. Filament formation could be restored by addition of residues Phe-Ser-Asn to an FCT deletion mutant and was unaffected by mutations to Ser or Asn residues. Second, deletion of residues Phe-Ser-Asn or mutation of the Phe residue resulted in a loss of M, N, and P incorporation into virus-like particles. These data suggest that a C-terminal Phe residue in the FCT mediates assembly through incorporation of internal virion proteins into virus filaments at the cell surface. IMPORTANCE: Respiratory syncytial virus (RSV) is a leading cause of bronchiolitis and pneumonia in infants and the elderly worldwide. There is no licensed RSV vaccine and only limited therapeutics for use in infected patients. Many aspects of the RSV life cycle have been studied, but the mechanisms that drive RSV assembly at the cell surface are not well understood. This study provides evidence that a specific residue in the RSV fusion protein cytoplasmic tail coordinates assembly into viral filaments by mediating the incorporation of internal virion proteins. Understanding the mechanisms that drive RSV assembly could lead to targeted development of novel antiviral drugs. Moreover, since RSV exits infected cells in an ESCRT (endosomal sorting complexes required for transport)-independent manner, these studies may contribute new knowledge about a general strategy by which ESCRT-independent viruses mediate outward bud formation using viral protein-mediated mechanisms during assembly and budding.
    mBio 01/2012; 3(1). · 5.31 Impact Factor
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    Chapter: Animal Models of Respiratory Syncytial Virus Pathogenesis and Vaccine Development: Opportunities and Future Directions
    Amelia R. Woolums, Sujin Lee, Martin L. Moore
    11/2011; , ISBN: 978-953-307-718-5
  • Article: Viruslike particle vaccine induces protection against respiratory syncytial virus infection in mice.
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    ABSTRACT: Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and viral death in infants. Despite decades of research with traditional or subunit vaccine approaches, there are no approved RSV vaccines. New approaches are therefore urgently needed to develop effective RSV vaccines. We developed viruslike particles (VLPs) consisting of an influenza virus matrix (M1) protein core and RSV-F or -G on the surface. We tested the immunogenicity and vaccine efficacy of these VLPs (RSV-F, RSV-G) in a mouse model. Intramuscular vaccination with RSV-F or RSV-G VLPs elicited IgG2a dominant RSV-specific immunoglobulin G (IgG) antibody responses against RSV-A2 viruses in both serum and lung extract. Mice immunized with VLPs (RSV-F or RSV-G) showed higher viral neutralizing antibodies in vitro and significantly decreased lung virus loads in vivo after live RSV-A2 challenge. RSV-G VLPs showed better protective efficacy than RSV-F VLPs as determined by the levels of lung virus loads and morbidity postchallenge. This study demonstrates that VLP vaccination provides effective protection against RSV infection. VLPs containing RSV-F and/or RSV-G are potential vaccine candidates against RSV.
    The Journal of Infectious Diseases 10/2011; 204(7):987-95. · 6.41 Impact Factor
  • Article: Differential pathogenesis of respiratory syncytial virus clinical isolates in BALB/c mice.
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    ABSTRACT: Airway mucus is a hallmark of respiratory syncytial virus (RSV) lower respiratory tract illness. Laboratory RSV strains differentially induce airway mucus production in mice. Here, we tested the hypothesis that RSV strains differ in pathogenesis by screening six low-passage RSV clinical isolates for mucogenicity and virulence in BALB/cJ mice. The RSV clinical isolates induced variable disease severity, lung interleukin-13 (IL-13) levels, and gob-5 levels in BALB/cJ mice. We chose two of these clinical isolates for further study. Infection of BALB/cJ mice with RSV A2001/2-20 (2-20) resulted in greater disease severity, higher lung IL-13 levels, and higher lung gob-5 levels than infection with RSV strains A2, line 19, Long, and A2001/3-12 (3-12). Like the line 19 RSV strain, the 2-20 clinical isolate induced airway mucin expression in BALB/cJ mice. The 2-20 and 3-12 RSV clinical isolates had higher lung viral loads than laboratory RSV strains at 1 day postinfection (p.i.). This increased viral load correlated with higher viral antigen levels in the bronchiolar epithelium and greater histopathologic changes at 1 day p.i. The A2 RSV strain had the highest peak viral load at day 4 p.i. RSV 2-20 infection caused epithelial desquamation, bronchiolitis, airway hyperresponsiveness, and increased breathing effort in BALB/cJ mice. We found that RSV clinical isolates induce variable pathogenesis in mice, and we established a mouse model of clinical isolate strain-dependent RSV pathogenesis that recapitulates key features of RSV disease.
    Journal of Virology 04/2011; 85(12):5782-93. · 5.40 Impact Factor
  • Article: Impact of pollution, climate, and sociodemographic factors on spatiotemporal dynamics of seasonal respiratory viruses.
    Chantel Sloan, Martin L Moore, Tina Hartert
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    ABSTRACT: Seasonal viruses present a major cause of morbidity and mortality in temperate climates. Through major pandemics and smaller annual epidemics, viruses such as influenza, respiratory syncytial virus (RSV) and human rhinovirus (HRV) result in lost school and work days for most that are infected and more serious complications for the immunocompromised. The reasons for these viruses showing strict seasonality include but are not limited to the influence of cold weather and humidity on virus particles, human physiology, and human behavior. The relative importance of each is dependent on what geographic scale is being explored as well as the individual region and time period. Theoretical mathematics has also revealed that climatic changes are likely not the only reasons for strong seasonal cycles, but these are also based in periodic resonance with the natural cycles of immunity and antigenic variance, as well as nationwide synchrony through transportation networks. Investigations of seasonality will aid in understanding disease transmission, and thereby effective prevention strategies. The authors present a review of the literature on seasonal viruses, their annual diffusion through populations, and factors that reduce or enhance their seasonal spread. They also offer suggestions for targeted interventions to reduce the disease burden from seasonal viruses.
    Clinical and Translational Science 02/2011; 4(1):48-54. · 1.13 Impact Factor
  • Article: STAT1 negatively regulates lung basophil IL-4 expression induced by respiratory syncytial virus infection.
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    ABSTRACT: IL-4 contributes to immunopathology induced in mice by primary respiratory syncytial virus (RSV) infection. However, the cellular source of IL-4 in RSV infection is unknown. We identified CD3(-)CD49b(+) cells as the predominant source of IL-4 in the lungs of RSV-infected BALB/c mice. We ruled out T cells, NK cells, NKT cells, mast cells, and eosinophils as IL-4 expressors in RSV infection by flow cytometry. Using IL4 GFP reporter mice (4get) mice, we identified the IL-4-expressing cells in RSV infection as basophils (CD3(-)CD49b(+)FcepsilonRI(+)c-kit(-)). Because STAT1(-/-) mice have an enhanced Th2-type response to RSV infection, we also sought to determine the cellular source and role of IL-4 in RSV-infected STAT1(-/-) mice. RSV infection resulted in significantly more IL-4-expressing CD3(-)CD49b(+) cells in the lungs of STAT1(-/-) mice than in BALB/c mice. CD49b(+)IL-4(+) cells sorted from the lungs of RSV-infected STAT1(-/-) mice and stained with Wright-Giemsa had basophil characteristics. As in wild-type BALB/c mice, IL-4 contributed to lung histopathology in RSV-infected STAT1(-/-) mice. Depletion of basophils in RSV-infected STAT1(-/-) mice reduced lung IL-4 expression. Thus, we show for the first time that a respiratory virus (RSV) induced basophil accumulation in vivo. Basophils were the primary source of IL-4 in the lung in RSV infection, and STAT1 was a negative regulator of virus-induced basophil IL-4 expression.
    The Journal of Immunology 09/2009; 183(3):2016-26. · 5.79 Impact Factor
  • Article: A functional IL-13 receptor is expressed on polarized murine CD4+ Th17 cells and IL-13 signaling attenuates Th17 cytokine production.
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    ABSTRACT: IL-17A is produced from Th17 cells, and is involved in many autoimmune and inflammatory diseases. IL-13R has not previously been reported to be functionally expressed on T cells; however, we found that purified BALB/c CD4(+) cells polarized to Th17 with TGF-beta, IL-6, and IL-23 have increased mRNA and protein expression of IL-13R alpha1 and mRNA expression of IL-4R alpha compared with Th0, Th1, or Th2 polarized cells. The addition of IL-13 at Th17 polarization negatively regulated IL-17A and IL-21 expression, and reduced the number of CD4(+) T cells producing IL-17A. Further, adding IL-13 at the time of Th17 cell restimulation attenuated IL-17A expression. CD4(+) Th17 polarized cells from IL-4 knockout (KO) mice also had IL-13-induced inhibition of IL-17A production, but this was not observed in IL-4R KO and STAT6 KO mice. Addition of IL-13 at polarization increased IL-13R expression in wild-type Th17 cells. Further, IL-13 administration during Th17 polarization down-regulated retinoic acid-related-gammaT, the transcription required for Th17 development; increased STAT6 phosphorylation, and up-regulated GATA3, the transcription factor activated during the development of Th2 cells. This IL-13-mediated effect was specific to Th17 cells as IL-13 neither decreased IFN-gamma expression by Th1 cells nor affected Th2 cell production of IL-4. Collectively, we have shown that Th17 cells express a functional IL-13R and that IL-13 negatively regulates IL-17A and IL-21 production by decreasing retinoic acid-related-gammaT expression and while increasing phosphorylation of STAT6 and GATA3 expression. Therefore, therapeutic intervention inhibiting IL-13 production could have adverse consequences by up-regulating Th17 inflammation in certain disease states.
    The Journal of Immunology 06/2009; 182(9):5317-21. · 5.79 Impact Factor
  • Article: A chimeric A2 strain of respiratory syncytial virus (RSV) with the fusion protein of RSV strain line 19 exhibits enhanced viral load, mucus, and airway dysfunction.
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    ABSTRACT: Respiratory syncytial virus (RSV) is the leading cause of respiratory failure and viral death in infants. Abundant airway mucus contributes to airway obstruction in RSV disease. Interleukin-13 (IL-13) is a mediator of pulmonary mucus secretion. It has been shown that infection of BALB/c mice with the RSV line 19 strain but not with the RSV A2 laboratory strain results in lung IL-13 and mucus expression. Here, we sequenced the RSV line 19 genome and compared it to the commonly used A2 and Long strains. There were six amino acid differences between the line 19 strain and both the A2 and Long RSV strains, five of which are in the fusion (F) protein. The Long strain, like the A2 strain, did not induce lung IL-13 and mucus expression in BALB/c mice. We hypothesized that the F protein of RSV line 19 is more mucogenic than the F proteins of A2 and Long. We generated recombinant, F-chimeric RSVs by replacing the F gene of A2 with the F gene of either line 19 or Long. Infection of BALB/c mice with RSV rA2 line 19F resulted in lower alpha interferon lung levels 24 h postinfection, higher lung viral load, higher lung IL-13 levels, greater airway mucin expression levels, and greater airway hyperresponsiveness than infection with rA2-A2F or rA2-LongF. We identified the F protein of RSV line 19 as a factor that plays a role in pulmonary mucin expression in the setting of RSV infection.
    Journal of Virology 03/2009; 83(9):4185-94. · 5.40 Impact Factor
  • Article: Cyclooxygenase inhibition during allergic sensitization increases STAT6-independent primary and memory Th2 responses.
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    ABSTRACT: Immune sensitization and memory generation are required for the development of allergic inflammation. Our previous studies demonstrate that the cyclooxygenase (COX) metabolic pathway is actively involved in allergic responses and COX inhibition increases allergic airway inflammation in a STAT6-independent fashion. To test the hypothesis that COX inhibition augments allergic inflammation by enhancing immune sensitization and memory, we sensitized STAT6 knockout mice with an i.p. injection of OVA with aluminum hydroxide as an adjuvant and treated the mice with the COX inhibitor indomethacin or vehicle for analyses of the primary and memory immune responses. We found that COX inhibition during immune sensitization, but not the allergic challenge phase, was necessary and sufficient to increase allergic inflammation. COX inhibition during sensitization increased the numbers of mature dendritic cells and activated CD4 T cells in the spleen and augmented OVA-specific IL-5 and IL-13 responses of the splenic CD4 T cells at day 5 after sensitization. COX inhibition during sensitization also augmented allergic Th2 response to OVA challenge 90 days after the sensitization. Therefore, COX inhibition during allergic sensitization augments allergic responses by enhancing Th2 cell activation and memory generation and the proallergic effect is STAT6-independent. These findings provide a mechanistic explanation for the increased allergic inflammation previously shown in the mice treated with COX inhibitors and in COX-deficient mice and suggest that use of COX-inhibiting drugs during initial allergen exposure may increase the risk of developing allergic responses.
    The Journal of Immunology 11/2008; 181(8):5360-7. · 5.79 Impact Factor
  • Article: Differential regulation of GM1 and asialo-GM1 expression by T cells and natural killer (NK) cells in respiratory syncytial virus infection.
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    ABSTRACT: We previously reported that respiratory syncytial virus (RSV) infection increases lung CD8(+) T cell GM1 expression. The related lipid asialo-GM1 (ASGM1) is expressed by T cells in viral infection and by natural killer (NK) cells. The in vivo co-expression of GM1 and ASGM1 by immune cells is not defined. Here we analyzed lung lymphocyte GM1 and ASGM1 expression in RSV-infected mice. GM1 and ASGM1 were coordinately upregulated by activated CD8(+) T cells in RSV-infected BALB/c and C57BL/6 mice. In contrast, RSV infection had no effect on constitutively high NK cell GM1 expression, while increasing NK cell ASGM1 expression. GM1 and ASGM1 co-localized in lipid raft structures in NK and CD8(+) T cells sorted from the lungs of RSV-infected mice. Anti-ASGM1 Ab treatment of RSV-infected BALB/c mice depleted GM1/ASGM1-expressing NK cells and GM1/ASGM1-expressing T cells, reduced lung IFN-gamma levels, increased viral load, delayed viral clearance, and reduced illness. STAT1(-/-) mice are more susceptible to RSV replication and disease than wild-type mice. In RSV-infected STAT1(-/-) mice, anti-ASGM1 Ab altered cytokine levels, but in contrast to BALB/c mice, antibody treatment had no effect on viral load or illness. Taken together, GM1 and ASGM1 expression are differentially regulated by T and NK cells in RSV infection. Also, GM1/ASGM1-expressing cells are important for control of RSV in BALB/c mice, whereas STAT1(-/-) mice clear RSV by an alternative pathway.
    Viral immunology 10/2008; 21(3):327-39. · 1.78 Impact Factor
  • Article: A mechanistic advance in understanding RSV pathogenesis, but still a long way from therapy.
    R Stokes Peebles, Martin L Moore
    American Journal of Respiratory Cell and Molecular Biology 11/2007; 37(4):375-7. · 5.13 Impact Factor
  • Article: Cutting Edge: Oseltamivir decreases T cell GM1 expression and inhibits clearance of respiratory syncytial virus: potential role of endogenous sialidase in antiviral immunity.
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    ABSTRACT: The sialoglycosphingolipid GM1 is important for lipid rafts and immune cell signaling. T cell activation in vitro increases GM1 expression and increases endogenous sialidase activity. GM1 expression has been hypothesized to be regulated by endogenous sialidase. We tested this hypothesis in vivo using a mouse model of respiratory syncytial virus (RSV) infection. RSV infection increased endogenous sialidase activity in lung mononuclear cells. RSV infection increased lung CD8+ T cell surface GM1 expression. Activated CD8+ T cells in the lungs of RSV-infected mice were GM1(high). Treatment of RSV-infected mice with the sialidase/neuraminidase inhibitor oseltamivir decreased T cell surface GM1 levels. Oseltamivir treatment decreased RSV-induced weight loss and inhibited RSV clearance. Our data indicate a novel role for an endogenous sialidase in regulating T cell GM1 expression and antiviral immunity. Also, oseltamivir, an important anti-influenza drug, inhibits the clearance of a respiratory virus that lacks a neuraminidase gene, RSV.
    The Journal of Immunology 04/2007; 178(5):2651-4. · 5.79 Impact Factor
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    Article: Respiratory syncytial virus disease mechanisms implicated by human, animal model, and in vitro data facilitate vaccine strategies and new therapeutics.
    Martin L Moore, R Stokes Peebles
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    ABSTRACT: Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis, pneumonia, mechanical ventilation, and respiratory failure in infants in the US. No effective post-infection treatments are widely available, and currently there is no vaccine. RSV disease is the result of virus-induced airway damage and complex inflammatory processes. The outcome of infection depends on host and viral genetics. Here, we review disease mechanisms in primary RSV infection that are implicated by clinical studies, in vitro systems, and animal models. Defining RSV disease mechanisms is difficult because there is a wide range of RSV disease phenotypes in humans, and there are disparities in RSV disease phenotypes among the animal models of RSV infection. However, host factors identified by multiple lines of investigation as playing important roles in RSV pathogenesis are providing key insights. A better understanding of RSV molecular biology and RSV pathogenesis is facilitating rational vaccine design strategies and molecular targets for new therapeutics.
    Pharmacology [?] Therapeutics 12/2006; 112(2):405-24. · 8.56 Impact Factor
  • Article: Differential immune responses and pulmonary pathophysiology are induced by two different strains of respiratory syncytial virus.
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    ABSTRACT: In this study we performed comparisons of pulmonary responses between two different respiratory syncytial virus (RSV) antigenic subgroup A strains, A2 and Line 19. Line 19 strain induced significant dose-responsive airway hyperreactivity (AHR) in BALB/c mice at days 6 and 9 after infection, whereas the A2 strain induced no AHR at any dose. Histological examination indicated that A2 induced no goblet cell hyper/metaplasia, whereas the Line 19 induced goblet cell expansion and significant increases in gob5 and MUC5AC mRNA and protein levels in vivo. When examining cytokine responses, A2 strain induced significant interleukin (IL)-10 expression, whereas Line 19 strain induced significant IL-13 expression. When IL-13-/- mice were infected with Line 19 RSV, the AHR responses were abrogated along with gob5 gene expression. There was little difference in viral titer throughout the infection between the line 19- and A2-infected mice. However, the A2 strain grew to significantly higher titers than the Line 19 strain in HEp-2 cells in vitro. Thus, RSV Line 19-induced airway dysfunction does not correlate with viral load in vivo. These data demonstrate that different RSV strains of the same antigenic subgroup can elicit differential immune responses that impact the phenotypic expression of RSV-induced illness.
    American Journal Of Pathology 10/2006; 169(3):977-86. · 4.89 Impact Factor
  • Article: Update on the role of prostaglandins in allergic lung inflammation: separating friends from foes, harder than you might think.
    Martin L Moore, R Stokes Peebles
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    ABSTRACT: Prostaglandins (PGs), small lipid molecules derived from arachidonic acid by COX enzymes, are critical mediators of allergic inflammation. Our understanding of the role of PGs in allergic lung inflammation has been hampered by the very short biologic half-life of these mediators, which has made mechanistic studies difficult in human subjects. However, advances in molecular biology and pharmacology have given investigators the opportunity to examine the role of specific prostanoids in the development of allergic inflammation in animal models. Studies investigating specific PG receptors are also elucidating the mechanisms by which PGs regulate the pulmonary allergic phenotype. This review summarizes the current literature on the role of PGs and PG receptors in allergic lung inflammation.
    Journal of Allergy and Clinical Immunology 06/2006; 117(5):1036-9. · 11.00 Impact Factor
  • Article: Allergen-induced airway hyperresponsiveness mediated by cyclooxygenase inhibition is not dependent on 5-lipoxygenase or IL-5, but is IL-13 dependent.
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    ABSTRACT: Cyclooxygenase (COX) inhibition during allergic sensitization and allergen airway challenge results in augmented allergic inflammation. We hypothesized that this increase in allergic inflammation was dependent on increased generation of leukotrienes that results from COX inhibition, as leukotrienes are important proinflammatory mediators of allergic disease. To test this hypothesis, we allergically sensitized and challenged mice deficient in 5-lipoxygenase (5-LO). We found that 5-LO knockout mice that were treated with a COX inhibitor during allergic sensitization and challenge had significantly increased airway hyperresponsiveness (AHR) (p < 0.01) and airway eosinophilia (p < 0.01) compared with 5-LO knockout mice that were treated with vehicle. The proinflammatory cytokines have also been hypothesized to be critical regulators of airway inflammation and AHR. We found that the increase in airway eosinophilia seen with COX inhibition is dependent on IL-5, whereas the increase in AHR is not dependent on this cytokine. In contrast, the COX inhibition-mediated increase in AHR is dependent on IL-13, but airway eosinophilia is not. These results elucidate the pathways by which COX inhibition exerts a critical effect of the pulmonary allergen-induced inflammatory response and confirm that COX products are important regulators of allergic inflammation.
    The Journal of Immunology 01/2006; 175(12):8253-9. · 5.79 Impact Factor