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Biomedical subjects

Joseph B Domachowske

Publications and source records attributed to Joseph B Domachowske.

At least 19 recordsLinked to original sources

Mucosal inoculation with an attenuated mouse pneumovirus strain protects against virulent challenge in wild type and interferon-gamma receptor deficient mice.

Protective mechanisms underlying the responses to mucosal vaccination are not yet clearly defined. Using the natural mouse pneumovirus pathogen, pneumonia virus of mice (PVM), we explore responses of wild type and interferon-gamma (IFNgamma) receptor gene-deleted mice to virulent challenge after mucosal vaccination with an attenuated virus strain. Serum neutralizing antibodies develop after intranasal inoculation with 30 pfu of attenuated, replication-competent PVM strain 15, which correlate with diminished gross and microscopic pulmonary pathology and protection from weight loss in response to subsequent challenge with the virulent parent PVM strain J3666. Virus replication in response to challenge was blunted in PVM strain 15 vaccinated mice, as was local production of secretory mediators IFNgamma, TNF-alpha, MIP-1 alpha, and MIP-2. Interestingly, responses of vaccinated IFNgamma receptor gene-deleted mice were indistinguishable from those of the wild type, suggesting that IFNgamma signaling may not be crucial for the generation of adaptive responses to pneumovirus infection in vivo.

Animals↗

Schistosoma mansoni infection in eosinophil lineage-ablated mice.

We explore the controversial issue of the role of eosinophils in host defense against helminthic parasites using the established Schistosoma mansoni infection model in 2 novel mouse models of eosinophil lineage ablation (DeltadblGATA and TgPHIL). No eosinophils were detected in bone marrow of infected DeltadblGATA or TgPHIL mice, despite the fact that serum IL-5 levels in these infected mice exceeded those in infected wild type by approximately 4-fold. Liver granulomata from infected DeltadblGATA and TgPHIL mice were likewise depleted of eosinophils compared with those from their respective wild types. No eosinophil-dependent differences in granuloma number, size, or fibrosis were detected at weeks 8 or 12 of infection, and differential accumulation of mast cells was observed among the DeltadblGATA mice only at week 12. Likewise, serum levels of liver transaminases, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) increased in all mice in response to S mansoni infection, with no eosinophil-dependent differences in hepatocellular damage observed. Finally, eosinophil ablation had no effect on worm burden or on egg deposition. Overall, our data indicate that eosinophil ablation has no impact on traditional measures of disease in the S mansoni infection model in mice. However, eosinophils may have unexplored immunomodulatory contributions to this disease process.

Animals↗

Respiratory dysfunction and proinflammatory chemokines in the pneumonia virus of mice (PVM) model of viral bronchiolitis.

We explore relationships linking clinical symptoms, respiratory dysfunction, and local production of proinflammatory chemokines in the pneumonia virus of mice (PVM) model of viral bronchiolitis. With a reduced inoculum of this natural rodent pathogen, we observe virus clearance by day 9, while clinical symptoms and respiratory dysfunction persist through days 14 and 17 postinoculation, respectively. Via microarray and ELISA, we identify expression profiles of proinflammatory mediators MIP-1alpha, MCP-1, and MIP-2 that correlate with persistent respiratory dysfunction. MIP-1alpha is localized in bronchial epithelium, which is also the major site of PVM replication. Interferon-gamma was detected in lung tissue, but at levels that do not correlate with respiratory dysfunction. Taken together, we present a modification of our pneumovirus infection model that results in improved survival and data that stand in support of a connection between local production of specific mediators and persistent respiratory dysfunction in the setting of acute viral bronchiolitis.

Animals↗

Mazzotti reaction after presumptive treatment for schistosomiasis and strongyloidiasis in a Liberian refugee.

We report a case of the Mazzotti reaction in a 13-year-old Liberian refugee after presumptive treatment of schistosomiasis and strongyloidiasis with ivermectin, praziquantel and albendazole. The patient was hospitalized with fever, urticaria, abdominal pain and angioedema. Twelve hours after treatment with intravenous methylprednisolone he had complete resolution of his symptoms.

Adolescent↗

Ribavirin and cysteinyl leukotriene-1 receptor blockade as treatment for severe bronchiolitis.

In this work we have evaluated the clinical responses of pneumovirus-infected mice to combination therapy with the antiviral agent, ribavirin, and the CysLT1 cysteinyl leukotriene receptor antagonist, montelukast. We observed substantial virus replication in our mouse model of pneumovirus infection and significant accumulation of cysteinyl leukotrienes in lung tissue, the latter detected at levels that correlate directly with granulocyte recruitment to the airways. While administration of the nucleoside analog, ribavirin, reduced virus replication approximately 2,000-fold, the clinical outcomes as measured by morbidity and mortality, in response to ribavirin monotherapy were indistinguishable from those of the no-treatment controls. Similarly, montelukast therapy alone did not reduce granulocyte recruitment nor did it improve the clinical outcome. However, combined therapy with ribavirin and montelukast resulted in a significant reduction in morbidity and a substantial reduction in mortality (50% survival at t = 14 days and onward, compared to 10-20% survival in response to montelukast alone or to ribavirin alone, respectively, p < 0.01). These findings define further the independent contributions made by virus replication and by the ensuing inflammatory response to the detrimental sequelae of pneumovirus infection in vivo.

Acetates↗

Inflammatory responses to pneumovirus infection in IFN-alpha beta R gene-deleted mice.

Pneumonia virus of mice (PVM; family Paramyxoviridae) is a natural pathogen of rodents that reproduces important clinical features of severe respiratory syncytial virus infection in humans. As anticipated, PVM infection induces transcription of IFN antiviral response genes preferentially in wild-type over IFN-alphabetaR gene-deleted (IFN-alphabetaR-/-) mice. However, we demonstrate that PVM infection results in enhanced expression of eotaxin-2 (CCL24), thymus and activation-regulated chemokine (CCL17), and the proinflammatory RNase mouse eosinophil-associated RNase (mEar) 11, and decreased expression of monocyte chemotactic protein-5, IFN-gamma-inducible protein-10, and TLR-3 in lung tissue of IFN-alphabetaR-/- mice when compared with wild type. No differential expression of chemokines MIP-1alpha or MIP-2 or Th2 cytokines IL-4 or IL-5 was observed. Differential expression of proinflammatory mediators was associated with distinct patterns of lung pathology. The widespread granulocytic infiltration and intra-alveolar edema observed in PVM-infected, wild-type mice are replaced with patchy, dense inflammatory foci localized to the periphery of the larger blood vessels. Bronchoalveolar lavage fluid from IFN-alphabetaR-/- mice yielded 7- to 8-fold fewer leukocytes overall, with increased percentages of eosinophils, monocytes, and CD4+ T cells, and decreased percentage of CD8+ T cells. Differential pathology is associated with prolonged survival of the IFN-alphabetaR-/- mice (50% survival at 10.8 +/- 0.6 days vs the wild type at 9.0 +/- 0.3 days; p < 0.02) despite increased virus titers. Overall, our findings serve to identify novel transcripts that are differentially expressed in the presence or absence of IFN-alphabetaR-mediated signaling, further elucidating interactions between the IFN and antiviral inflammatory responses in vivo.

Animals↗

The pneumonia virus of mice infection model for severe respiratory syncytial virus infection: identifying novel targets for therapeutic intervention.

Pneumonia virus of mice (PVM) is the first infection model that replicates features of severe human respiratory syncytial virus (hRSV) disease in the mouse. The PVM model has highlighted the importance of inflammation to the pathogenesis of severe disease, demonstrating that the inflammatory response remains active and acute even when virus replication ceases in response to appropriate antiviral therapy. The fact that the inflammatory response continues and is not completely linked to ongoing virus replication indicates the need for concurrent anti-inflammatory or, ideally, specific immunomodulatory therapy. The chemokine macrophage inflammatory protein-1alpha (MIP-1alpha) and its receptor, CC chemokine receptor 1 (CCR1), have been identified as crucial to the inflammatory response to PVM and hRSV and thus as elements to exploit for potential immunomodulatory control. Biochemical blockade of MIP-1alpha signaling with the CCR1 antagonist met-RANTES prevents the inflammatory response to PVM and results in reduced morbidity and mortality when administered in conjunction with the antiviral agent ribavirin. Ongoing exploration into the biology of PVM infection will identify other pathways and targets to be exploited for immunomodulatory control of hRSV and related severe respiratory virus infections.

Animals↗

Advances in the treatment and prevention of severe viral bronchiolitis.

Viral bronchiolitis continues to be a major public health problem. Prevention of severe RSV-associated bronchiolitis has been achieved in high-risk infants by passive administration of the humanized monoclonal anti-RSV-F antibody, palivizumab. Development of more potent anti-RSV neutralizing antibodies is underway, and vaccine development continues to progress. Supportive therapy is the mainstay for the treatment of established infection while new antiviral and anti-inflammatory strategies are being explored in preclinical trials.

Anti-Inflammatory Agents↗

Allergic bronchopulmonary aspergillosis masquerading as pulmonary tuberculosis.

We present an unusual pediatric patient with severe allergic bronchopulmonary aspergillosis that masqueraded as pulmonary tuberculosis. After antituberculous therapy, the patient's pulmonary disease flared, prompting an aggressive diagnostic evaluation. Radiographic findings included nodular pulmonary densities with superimposed infiltrates. Lung biopsy showed evidence of acute and chronic inflammation with necrotizing granulomas, giant cells, tissue eosinophilia and rare hyphal elements.

Aspergillosis, Allergic Bronchopulmonary↗

Animal models for studying respiratory syncytial virus infection and its long term effects on lung function.

BACKGROUND: Human respiratory syncytial virus (hRSV) infection causes a spectrum of illnesses ranging from mild infection to life-threatening bronchiolitis and respiratory failure. Human studies on the pathogenesis of RSV infection are invaluable, but animal models permit advances with the use of experimental strategies that would be inappropriate in human studies. METHODS: We review the advantages and disadvantages of various animal models for the study of hRSV infection. RESULTS: No animal model of hRSV infection replicates the complete spectrum of disease severity seen in humans. Available models differ in their ability to incorporate genetic technology and to allow the study of immunity, vaccine efficacy and treatment interventions. Although hRSV establishes disease in primates, this advantage is outweighed by the impracticalities and cost of using such models. The study of bovine RSV infection in calves is appealing because of parallels with human disease. Among rodent models, BALB/c mice have helped delineate the mechanisms underlying vaccine-enhanced RSV disease, and cotton rats have been used for preclinical testing. The single major disadvantage of studying hRSV in rodent models is the limited extent to which this host-restricted human pneumovirus replicates in mouse lung tissue. The rodent-specific Pneumovirus pathogen, pneumonia virus of mice, causes an infection that mirrors severe bronchiolitis and pneumonia in infants infected with RSV, including robust virus replication with profound inflammation. CONCLUSION: The recent development of the pneumonia virus of mice model has permitted exploration of the mechanisms of severe Pneumovirus disease in vivo with the use of sophisticated genetic tools and genetically manipulated mouse strains.

Animals↗

Animal pneumoviruses: molecular genetics and pathogenesis.

Pneumoviruses are single-stranded, negative-sense, nonsegmented RNA viruses of the family Paramyxoviridae, subfamily Pneumovirinae, and include pathogens that infect humans (respiratory syncytial virus and human metapneumovirus), domestic mammals (bovine, ovine, and caprine respiratory syncytial viruses), rodents (pneumonia virus of mice), and birds (avian metapneumovirus). Among the topics considered in this review are recent studies focused on the roles of the individual virus-encoded components in promoting virus replication as well as in altering and evading innate antiviral host defenses. Advances in the molecular technology of pneumoviruses and the emergence of recombinant pneumoviruses that are leading to improved virus-based vaccine formulations are also discussed. Since pneumovirus infection in natural hosts is associated with a profound inflammatory response that persists despite adequate antiviral therapy, we also review the recent experimental treatment strategies that have focused on combined antiviral, anti-inflammatory, and immunomodulatory approaches.

Animals↗

First case report of catheter-related bacteremia due to "Mycobacterium lacticola".

This is the first report of infection caused by "Mycobacterium lacticola," a rapidly growing, scotochromogenic mycobacterium that was isolated from the blood of an immunosuppressed child. The organism was identified by sequence analysis of >1,400 bp of the 16S rRNA gene. The clinical relevance of this isolate, coupled with its unique 16S rRNA gene sequence, should prompt further investigation to establish this organism as a valid mycobacterial species.

Bacteremia↗

Functional antagonism of chemokine receptor CCR1 reduces mortality in acute pneumovirus infection in vivo.

We present an antiviral-immunomodulatory therapeutic strategy involving the chemokine receptor antagonist Met-RANTES, which yields significant survival in the setting of an otherwise fatal respiratory virus infection. In previous work, we demonstrated that infection with the natural rodent pathogen pneumonia virus of mice involves robust virus replication accompanied by cellular inflammation modulated by the CC chemokine macrophage inflammatory protein 1alpha (MIP-1alpha). We found that the antiviral agent ribavirin limited virus replication in vivo but had no impact on morbidity and mortality associated with this disease in the absence of immunomodulatory control. We show here that ribavirin reduces mortality, from 100% to 10 and 30%, respectively, in gene-deleted CCR1(-/-) mice and in wild-type mice treated with the small-molecule chemokine receptor antagonist, Met-RANTES. As MIP-1alpha-mediated inflammation is a common response to several distantly related respiratory virus pathogens, specific antiviral therapy in conjunction with blockade of the MIP-1alpha/CCR1 inflammatory cascade may ultimately prove to be a useful, generalized approach to severe respiratory virus infection and its pathological sequelae in human subjects.

Acute Disease↗

Making chicken pox prevention a priority.

School nurses are the IDEAL professionals to catch those kids without a history of chicken pox (varicella illness) who have not been immunized, thereby falling into the susceptible range. We handle charts daily. We have both illness history (if it was provided) and immunization dates. We can call parents. We can talk to kids. Wouldn't it be easy if we could do that and then call (or email) the primary care provider? But there is no longer an "easy" way to communicate health information. Doing things the easy way could be perceived by some as "tattling" and by others as "reporting without permission." Instead, the school nurse must take the time-consuming (and better long range) path of education ... of the student, and the parent. And the priority can slip down below other school nurse requirements such as getting kids their required immunizations, first aid and illness care, individualized health care plans for students with medical problems, parent and teacher phone calls, and endless conversations. It takes a village to raise a child though, and the school nurse is a village resident. The following information is vital to the knowledge base of today's school nurse. Please read it, store it and consider it when planning and intervening with your students in the day-to-day interaction that promotes optimal health and wellness.

Adolescent↗

Gene microarray analysis reveals interleukin-5-dependent transcriptional targets in mouse bone marrow.

Interleukin-5 (IL-5) is a hematopoietic differentiation factor that promotes the development of mature eosinophils from progenitors in bone marrow. We present a multifactorial microarray study documenting the transcriptional events in bone marrow of wild-type and IL-5-deficient mice at baseline and in response to infection with Schistosoma mansoni. The microarray data were analyzed by a 4-way subtractive algorithm that eliminated confounding non-IL-5-related sequelae of schistosome infection as well as alterations in gene expression among uninfected mice. Among the most prominent findings, we observed 7- to 40-fold increased expression of transcripts encoding the classic eosinophil granule proteins (eosinophil peroxidase, major basic protein, the ribonucleases) together with arachidonate-15-lipoxygenase and protease inhibitor plasminogen activator inhibitor 2 (PAI-2), in the IL-5-producing, infected wild-type mice only. This was accompanied by increased transcription of genes involved in secretory protein biosynthesis and granule-vesicle formation. Interestingly, we did not detect increased expression of genes encoding eosinophil-related chemokine receptors (CCR1, CCR3) or members of the GATA or CCAAT/enhancer binding protein (C/EBP) transcription factor families. These data suggest that the IL-5-responsive progenitors in the mouse bone marrow are already significantly committed to the eosinophil lineage and that IL-5 promotes differentiation of these committed progenitors into cells with recognizable and characteristic cytoplasmic granules and granule proteins.

Animals↗

Replication of respiratory syncytial virus is inhibited in target cells generating nitric oxide in situ.

Nitric oxide (NO) is generated by recruited inflammatory cells and by pulmonary epithelial cells in response to respiratory virus infection, although the relative antiviral efficacy of NO from each of these sources had not been clarified. To compare the direct, antiviral potency of NO from an exogenous source with that generated by target epithelial cells in situ, we transduced HEp-2 epithelial cells with the retroviral construct, pMFGS-NOS and cloned transductant lines that generated NO constitutively. We found that NO-producing HEp-2 cells could be infected with RSV, but the titer correlated inversely with NO production, an effect that was reversed by the NOS inhibitor, NG-methyl-L-arginine (NGMMA). Our results demonstrate that NO has significant direct antiviral activity against RSV, and interestingly, that the inhibitory effect is more potent in the presence of continuous, endogenous NO production than in response to NO from an exogenous source.

Cell Line↗

Diminished expression of an antiviral ribonuclease in response to pneumovirus infection in vivo.

The mouse eosinophil-associated ribonucleases (mEars) are species specific, divergent orthologs of the human antiviral RNase A ribonucleases, eosinophil-derived neurotoxin (RNase 2) and eosinophil cationic protein (RNase 3). We show here that mEar 2 is also an antiviral ribonuclease, as micromolar concentrations promote a approximately sixfold reduction in the infectivity of pneumonia virus of mice (PVM) for target respiratory epithelial cells in vitro. Although initially identified as a component of eosinophilic leukocytes, mEar 2 mRNA and protein were also detected in lung tissue accompanied by enzymatically active mEar 2 in bronchoalveolar lavage fluid (BALF). At t=3 days post-inoculation with PVM (strain J3666), we observed the characteristic inflammatory response accompanied by diminished expression of total mEar mRNA and protein in lung tissue and a corresponding fivefold drop in ribonuclease activity in BALF. No change in mEar expression was observed in response to infection with PVM strain 15, a replication-competent strain of PVM that does not elicit a cellular inflammatory response. However, mEar expression is not directly dependent on inflammation per se, as diminished expression of mEar mRNA and BAL ribonuclease activity were also observed in PVM-infected, inflammation-deficient, MIP-1alpha -/- mice. We propose that this mechanism may represent a novel virus-mediated evasion strategy, with a mechanism that is linked in some fashion to virus-specific pathogenicity.

Animals↗