Search

Abstract: Objective: Influenza can trigger heart attacks, and vaccination against influenza reduces the risk of cardiovascular events. Currently, it is believed that influenza virus in general does not disseminate to extra-pulmonary tissues. We assessed the vascular effects of influenza infection and whether the virus can directly infect atherosclerotic arteries in mice. Methods/Results: We intranasally infected 4 different types of mice—atherosclerotic apo E-deficient (our primary model), LDL receptor knockout, C57BL/6, and outbred Swiss,—with influenza A/HK (H3/N2) virus. On day 7 after infection, we cultured viable virus from lung, aorta, and heart tissue, but not from the blood of apo E-deficient mice. Immunofluorescence studies showed influenza A virus NP1 protein and real time polymerase chain reaction (PCR) assay showed RNA in the aorta of infected apo E-deficient mice. Infected mice had significantly higher blood levels of chemokines and cytokines than control mice. At the local level, gene expression for several chemokines and cytokines was increased and eNOS expression was decreased. Infected mice had a higher density of macrophages in plaque than did control mice. Conclusions: We have shown for the first time that influenza virus can directly infect and reside in atherosclerotic arteries and that infection was associated with systemic and arterial-level pro-inflammatory changes. [Copyright &y& Elsevier]

Abstract: Hispid cotton rats were inoculated with two different human metapneumovirus (hMPV) subtype A strains and one subtype B hMPV. Although no overt disease was seen in any virus-inoculated animal, following an eclipse phase, significant pulmonary virus titers were observed in every hMPV-inoculated animal through day 7 post virus inoculation (p.i.) and in most through day 10. Peak virus titers occurred four days p.i., while virus-induced histopathology was most evident in lung sections obtained from animals 7 to 10 days p.i. The latter consisted primarily of desquamating and hypertrophic columnar epithelial cells lining the bronchi and bronchioles and the presence of large numbers of leukocytes in and around the bronchi and bronchioles. In fluorescent antibody studies, virus antigen-specific fluorescence was most evident in the desquamating tall columnar epithelial cells lining bronchi and bronchioles, in pneumocytes lining alveoli and in single or small groups of free cells, most probably leukocytes, present in the lumen of alveoli, bronchi and bronchioles. Virus was generally not detected in inoculated animals >10 days p.i. Although the pattern of virus replication in cotton rats was similar for all the three virus stains, the B subtype consistently grew to lower levels than the two A strains. Regardless, these findings indicate that hMPV replicates in cotton rats and that these animals may be used as a small animal model of hMPV infection and to facilitate the identification and development of vaccines and antivirals for preventing and/or ameliorating infections caused by this virus. [Copyright &y& Elsevier]

Cotton rats exposed to continuous small droplet aerosols of 2[[2-[[1-(2-aminoethyl)-4-piperidinyl]amino]-4-methyl-1H-benzimidazol-1-yl]methyl]-6-methyl-3-pyridinol (JNJ 2408068) or its hydrochloric salt for only 15 min, one day prior to virus inoculation or one day after, were significantly protected from pulmonary respiratory syncytial virus (RSV) infection compared to control animals similarly infected but exposed to aerosols of placebo at these times. No evidence of toxicity was seen in any of these animals or in cotton rats administered 10 times the minimum cotton rat efficacious dose (i.e. 10×0.39 mg of active compound per kilogram of body weight) for four continuous days. The marked selective antiviral activity observed in the cotton rats mirrored that seen for these compounds in cytotoxicity and antiviral assays performed against RSV in vitro. Plasma kinetics and tissue distribution of JNJ 2408068 in cotton rats following inhalation were determined in separate experiments performed using conditions similar to those utilized in the in vivo efficacy studies. The data from these experiments indicated that significant levels of the test compound were delivered to the lungs of exposed animals, but that extrapulmonary distribution was limited. [Copyright &y& Elsevier]

A cell-based assay was used to discover compounds inhibiting respiratory syncytial virus (RSV)-induced fusion in HeLa/M cells. A lead compound was identified and subsequent synthesis of >300 analogues led to the identification of JNJ 2408068 (R170591), a low molecular weight (MW 395) benzimidazole derivative with an EC50 (0.16 nM) against some lab strains almost 100,000 times better than that of ribavirin (15 μM). Antiviral activity was confirmed for subgroup A and B clinical isolates of human RSV and for a bovine RSV isolate. The compound did not inhibit the growth of representative viruses from other Paramyxovirus genera, i.e. HPIV2 and Mumps Virus (genus Rubulavirus), HPIV3 (genus Respirovirus), Measles virus (genus Morbillivirus) and hMPV. Efficacy in cytopathic effect inhibition assays correlated well with efficacy in virus yield reduction assays. A concentration of 10 nM reduced RSV production 1000-fold in multi-cycle experiments, irrespective of the multiplicity of infection. Time of addition studies pointed to a dual mode of action: inhibition of virus–cell fusion early in the infection cycle and inhibition of cell–cell fusion at the end of the replication cycle. Two resistant mutants were raised and shown to have single point mutations in the F-gene (S398L and D486N). JNJ 2408068 was also shown to inhibit the release of proinflammatory cytokines IL-6, IL-8 and Rantes from RSV-infected A549 cells. [Copyright &y& Elsevier]