Complete genome sequence of a raccoon rabies virus isolate

The entire genome of a mid-Atlantic raccoon strain rabies virus (RRV) isolated in Canada was sequenced; this is the second North American wildlife rabies virus isolate to be fully characterized. The overall organization and length of the genome was similar to that of other lyssaviruses. The nucleotide sequence identity of the raccoon strain ranged between 32.7% and 85.0% when compared to other lyssaviruses, while the deduced amino acid sequence identity ranged between 22.9% and 94.2% with the nucleoprotein and polymerase being the most conserved. Notable features of RRV include the phosphoprotein's four amino acid extension compared to most other rabies viruses, and a nucleotide substitution immediately prior to the normal start codon that results in an additional methionine at the beginning of the L protein. This is the first report of the RRV L gene sequence and its 2128 amino acid product. Rates of non-synonymous and synonymous nucleotide changes within the lyssavirus L gene identified the conserved blocks II, III and IV as being most constrained. Analysis of L gene codon substitution patterns favoured models that supported positive selection, but only one site, corresponding to Leu62 of the RRV L protein, was identified as being under weak positive selection.     

Coronavirus infections of man associated with diseases other than the common cold

About 14,000 paired sera, from patients with various types of acute infectious diseases with suspected viral origin, were screened by complement fixation against a wide set of viral antigens, including coronavirus OC43. A significant change in OC43 antibodies was recorded in 33 cases and a constant high titre, defined as a titre occurring in the respective age group in less than 1% of all sera examined, was found in 45 cases. On the basis of careful retrospective analysis of hospital case records it was concluded that in 28 cases with an increase of OC43 antibody titres, and in two with titre decrease, a disease could be associated with an acute coronavirus infection. In 16 cases the disease was dominated by respiratory symptoms. Eight of these patients, four children and four adults, had pneumonia. Three of the eight pneumonia patients had, however, another concomitant infection, too. Four patients had neurological symptoms, one had severe perimyocarditis, and in five cases fever was the only symptom recorded. Among the patients with a statistically significant high titre of OC43 antibodies, there were 14 cases where a suggestive association with a disease could be envisaged on the basis of hospital records. Five of these patients had pneumonia. These results suggest that human coronaviruses, so far considered only as one group of causative agents of the common cold, may also be associated with other and more severe diseases in all age groups.     

Effect of experimental rhinovirus 16 colds on airway hyperresponsiveness to histamine and interleukin-8 in nasal lavage in asthmatic subjects in vivo

Background Asthma exacerbations are closely associated with respiratory virus infections. However, the pathophysiological consequences of such infections in asthma are largely unclear. Objective To examine the effect of rhinovirus 16 (RV16) infection on airway hypersensitivity to histamine. and on interleukin-8 (IL-8) in nasal lavage. Objective Twenty-seven non-smoking atopic, mildly asthmatic subjects participated in a placebo-controlled, parallel study. A dose of 0.5–2.9 ± 10⁴ TCID50 RV16 or placebo was nasally administered. Cold symptoms were recorded by questionnaire throughout the study. Histamine challenges were performed at entry, and on days 4 and 11 after inoculation. Nasal lavages were obtained at entry, and on days 2 and 9. The response to histamine was measured by PC₂₀ (changes expressed as doubling doses: DD). IL-8 levels were obtained by ELISA, and were expressed in ng/ml. Results RV infection was confirmed by culture of nasal lavage and/or by antibody titre rise in each of the RV16-treated subjects. Among the 19 RV16-treated subjects, eight developed severe cold symptoms. Baseline FEV₁ did not change significantly during the study in either treatment group (P= 0.99). However, in the RV16-treated subjects there was a decrease in PC₂₀ at day 4, which was most pronounced in those with a severe cold (mean change ± SEM: –1.14 ± 0.28 DD, P= 0.01). In addition. IL-8 levels increased in tbe RV16 group at days 2 and 9 (P < 0.001). The increase in nasal IL-8 at day 2 correlated significantly with the change in PC₂₀ at day 4 (r=–0.48, P= 0.04). Conclusion We conclude that the severity of cold, as induced by experimental RV16 infection, is a determinant of the increase in airway hypersensitivity to histamine in patients with asthma. Our results suggest that this may be mediated by an infiammatory mechanism, involving the release of chemokines such as IL-8.     

Experimental rhinovirus 16 infection increases intercellular adhesion molecule-1 expression in bronchial epithelium of asthmatics regardless of inhaled steroid treatment

BACKGROUND: Rhinovirus infections in airway epithelial cells in vitro have been shown to upregulate intercellular adhesion molecule-1 (ICAM-1) expression. Epithelial ICAM-1, in its dual role as the major rhinovirus receptor and as adhesion molecule for inflammatory cells may be involved in the pathogenesis of rhinovirus-induced exacerbations of asthma. OBJECTIVE: We aimed to investigate the effect of experimental rhinovirus 16 (RV16) infection on ICAM-1 expression in bronchial mucosal biopsies in asthma. In addition, the effect of 2 weeks pretreatment with inhaled budesonide (800 microg b.d.) on RV16-associated changes in ICAM-1 expression was studied. METHODS: The study had a parallel, placebo-controlled design in 25 steroid-naive nonsmoking atopic asthmatic subjects. After 2 weeks budesonide (BUD) or placebo (PLAC) pretreatment bronchoscopy was performed 2 days before (day -2) and 6 days after (day 6) RV16 inoculation (on days 0 and 1). Immunohistochemical staining for ICAM-1 was performed on snap-frozen bronchial biopsies. ICAM-1 staining intensity on the basal epithelial cells was scored semiquantitatively from 1 (weak) to 3 (intense). Similarly, epithelial intactness was noted (1 = basal cells only, 2 = basal and parabasal cells, 3 = intact epithelium). RESULTS: ICAM-1 scores were not significantly different between the groups at day -2 (P > or = 0.08). Subsequent RV16 infection was associated with a trend towards an increase in ICAM-1 expression in the BUD-group (P = 0.07), whereas the increase was significant in the PLAC-group (P = 0.03). However, the increase was not significantly different between the groups (P = 0.74). Epithelial intactness score was not different between the groups before RV16 infection (P > or = 0.07), and no significant changes were observed in either group (P > or = 0.59). Moreover, ICAM-1 score did not correlate significantly with epithelium score in either group, at any time-point (P > or = 0.27). CONCLUSION: We conclude that an RV16 common cold in atopic asthmatic subjects is associated with increased ICAM-1 expression in the bronchial epithelium, which is not related to epithelial intactness. Glucocorticoid treatment does not appear to prevent the RV16-associated increased ICAM-1 expression. This suggests that other treatment modalities are required to protect against the spreading of infection during rhinovirus-induced exacerbations in asthma.     

Complete nucleotide sequence of the genome organization of RNA2 of patchouli mild mosaic virus, a new favavirus

Summary.  The complete nucleotide sequence and the genome organization of the RNA 2 of a patchouli mild mosaic virus (PaMMV) was determined. The sequence consists of 3591 nucleotides and contains a single long open reading frame sufficient to code for 118K protein. Three proteins of 52 K, 44 K and 22 K could be encoded by the PaMMV RNA 2 genome. Our analysis of the N-terminal sequences of two species of coat protein (CP) allowed precise location of the CP cistrons within the polyprotein. 44 K and 22 K proteins are the coat proteins. The positions of the cleavage sites are Gln/Ala between 44 K and 22 K coat proteins and Gln/Gly between 52 K and 44 K proteins. Comparison of PaMMV RNA 2 with comoviral and nepoviral RNA 2 showed no sequence similarity. These results as well as previous serological studies strongly suggest that PaMMV is a member in the genus Fabavirus. Received May 29, 1998 Aaccepted July 20, 1998     

Full genome sequence of peste des petits ruminants virus, a member of the Morbillivirus genus

Peste des petits ruminants virus (PPRV) causes an acute febrile illness in small ruminant species, mostly sheep and goats. PPRV is a member of the Morbillivirus genus which includes measles, rinderpest (cattle plague), canine distemper, phocine distemper and the morbilliviruses found in whales, porpoises and dolphins. Full length genome sequences for these morbilliviruses are available and reverse genetic rescue systems have been developed for the viruses of terrestrial mammals, with the exception of PPRV. This paper presents the first published full length genome sequence for PPRV. The genome was found to be consistent with the rule-of-six and open reading frames (ORFs) were identified that encoded the eight proteins characteristic of morbilliviruses. At the nucleotide (nt) level, the full length genome of PPRV was most similar to that of rinderpest, the other ruminant morbillivirus. However, at the protein level five of the six structural proteins and the V protein showed a greater similarity to the dolphin morbillivirus (DMV) while only the C and L proteins showed a high relationship to rinderpest.     

The complete genome sequence of Perina nuda picorna-like virus,an insect-infecting RNA virus with a genome organization similar to that of the mammalian picornaviruses

Perina nuda picorna-like virus (PnPV) is an insect-infecting RNA virus with morphological and physicochemical characters similar to the Picornaviridae. In this article, we determine the complete genome sequence and analyze the gene organization of PnPV. The genome of PnPV consists of 9476 nucleotides (nts) excluding the poly(A) tail and contains a single large open reading frame (ORF) of 8958 nts (2986 codons) flanked by 473 and 45 nt noncoding regions on the 5' and 3' ends, respectively. Northern blotting did not detect the presence of any subgenomic RNA. The PnPV genome codes for four structural proteins (CP1-4), and determination of their N-terminal sequences by Edman degradation, showed that all four are located in the 5' region of the genome. The 3' part of the PnPV genome contains the consensus sequence motifs for picornavirus RNA helicase, cysteine protease, and RNA-dependent RNA polymerase (RdRp) in that order from the 5' to the 3' end. In all of these characters, the genome organization of PnPV resembles the mammalian picornaviruses and two other insect picorna-like viruses, infectious flacherie virus (IFV) of the silkworm and Sacbrood virus (SBV) of the honeybee. In a phylogenetic tree based on the eight conserved domains in the RdRp sequence, PnPV formed a separate cluster with IFV and SBV, which suggests that these three insect picorna-like viruses might constitute a novel group of insect-infecting RNA viruses.     

Bronchial inflammation and the common cold: a comparison of atopic and non-atopic individuals

Background Cold virus infections are associated with asthma attacks and with increased bronchial responsiveness even in normal subjects. Possible mechanisms include epithelial damage, interaction with adhesion molecules or with T-helper cell subsets. Objective To determine whether colds increase lower airway inflammation, comparing atopic with non-atopic normal subjects. Methods Thirty healthy volunteers (15 atopic) took part. Basehne tests included viral serology. microbiological culture and polymerase chain reaction for rhinovirus infection (HRV-PCR), histamine bronchial provocation and bronchoscopy. Twenty subjects (eight atopic) underwent repeat tests when they developed a cold. Results Forced expiratory volume in one second (FEV₁) was significantly lower during colds (-0.19L [95% confidence mterval -0.10, -0.29], P= 0,0004) and there was a significant increase in bronchial responsiveness (+0.62 doublings of the dose-response slope [+0.24, +1.00], P=0.003). Eight subjects (two atopic) had a diagnosed viral infection: two HRV. three coronavirus (HCV), one HRV + HCV, one parainfluenza III(PI) and one respiratory syncytial virus (RSV) (also Haemophilus influenzae). In biopsies, during colds, total eosinophils (EG1⁺) increased significantly (geometric mean 6.73-fold [1.12,40.46], P=O.04). Activated eosinophils (EG2⁺) only increased significantly in the subgroup without diagnosed viral infection and particularly in atopic rhinitics. T-suppressor (CD8⁺) cells also increased significantly (median +178.3 cells mm², P= 0.004). Epithelial expression of intercellular adhesion molecule-1 (ICAM-1) expression increased in four atopic rhinitics during colds. Bronchial washings showed a significant increase in neutrophils (GM 1.53-fold [1.04,2.25], P= 0.02). Conclusion Lower airway inflammation was present in atopic and non-atopic normal subjects with colds. Atopic subjects differed in that they were less likely to have positive virological tests and were more likely to show activated eosinophilia in the lower airway, despite a similar spectrum of symptoms.