Virology News

Since February 2013, China experienced an outbreak of the novel H7N9 avian flu, causing 131 cases of infection, and a death toll of 39.

Seronegative hepatitis—non-A, non-B, non-C, non-D, non-E hepatitis—is poorly characterized but strongly associated with serious complications. We collected 92 sera specimens from patients with non-A–E hepatitis in Chongqing, China between 1999 and 2007. Ten sera pools were screened by Solexa deep sequencing. We discovered a 3,780-bp contig present in all 10 pools that yielded BLASTx E scores of 7e-05–0.008 against parvoviruses. The complete sequence of the in silico-assembled 3,780-bp contig was confirmed by gene amplification of overlapping regions over almost the entire genome, and the virus was provisionally designated NIH-CQV. Further analysis revealed that the contig was composed of two major ORFs. By protein BLAST, ORF1 and ORF2 were most homologous to the replication-associated protein of bat circovirus and the capsid protein of porcine parvovirus, respectively. Phylogenetic analysis indicated that NIH-CQV is located at the interface of Parvoviridae and Circoviridae. Prevalence of NIH-CQV in patients was determined by quantitative PCR. Sixty-three of 90 patient samples (70%) were positive, but all those from 45 healthy controls were negative. Average virus titer in the patient specimens was 1.05 e4 copies/µL. Specific antibodies against NIH-CQV were sought by immunoblotting. Eighty-four percent of patients were positive for IgG, and 31% were positive for IgM; in contrast, 78% of healthy controls were positive for IgG, but all were negative for IgM. Although more work is needed to determine the etiologic role of NIH-CQV in human disease, our data indicate that a parvovirus-like virus is highly prevalent in a cohort of patients with non-A–E hepatitis.

 Parvovirus virion courtesy of Russell Kightley Media

Hilary Koprowski: A Renaissance scientist

Hilary Koprowski died on the 11th of April 2013 at the age of 96 from respiratory complications...

Sitting at his laboratory bench, a scientist adds mutation after mutation to a strand of rabies virus RNA, unaware that in a few short days, an outbreak of this very mutation would destroy society as we know it.

Phages in mucus aid immune system by killing invading bacteria.

...animal mucus — whether from humans, fish or corals — is loaded with bacteria-killing viruses called phages. These protect their hosts from infection by destroying incoming bacteria. In return, the phages are exposed to a steady torrent of microbes in which to reproduce.

Plant expression systems based on nonreplicating virus-based vectors can be used for the simultaneous expression of multiple genes within the same cell. They therefore have great potential for the production of heteromultimeric protein complexes. This work describes the efficient plant-based production and assembly of Bluetongue virus-like particles (VLPs), requiring the simultaneous expression of four distinct proteins in varying amounts. Such particles have the potential to serve as a safe and effective vaccine against Bluetongue virus (BTV), which causes high mortality rates in ruminants and thus has a severe effect on the livestock trade. Here, VLPs produced and assembled in Nicotiana benthamiana using the cowpea mosaic virus-based HyperTrans (CPMV-HT) and associated pEAQ plant transient expression vector system were shown to elicit a strong antibody response in sheep. Furthermore, they provided protective immunity against a challenge with a South African BTV-8 field isolate.

The results show that transient expression can be used to produce immunologically relevant complex heteromultimeric structures in plants in a matter of days. The results have implications beyond the realm of veterinary vaccines and could be applied to the production of VLPs for human use or the coexpression of multiple enzymes for the manipulation of metabolic pathways.

The current status of phage therapy approaches is reviewed and possible hurdles to a practical medical application of bacteriophages in Western countries are identified as discussed at a recent EMBO meeting on “Viruses of Microbes” in Brussels. In view of the growing antibiotic resistance crisis, a coordinated effort by the public health sector is needed to evaluate the potential of phage therapy as an adjunct to antibiotics.

The Government of India’s Department of Biotechnology (DBT) and Bharat Biotech have announced the development of a rotavirus vaccine that will be sold at $1 per dose, once approved. Results from a Phase III clinical trial showed that the ROTAVAC® vaccine decreased the incidence of severe rotavirus diarrhoea by 56% during the first year of life, and the protection conferred by the vaccine also continued into the second year of life. The clinical trial enrolled 6,799 infants across three sites in India.

The vaccine’s development resulted from a unique partnership between Indian and international researchers, with partners including DBT, Bharat Biotech, the US National Institutes of Health (NIH), the US Centers for Disease Control and Prevention (CDC), Stanford University School of Medicine, and PATH.

Rotavirus graphic courtesy of Russell Kightley Media