[show abstract][hide abstract] ABSTRACT: MHV-Wüts18 is an RNA-negative, temperature-sensitive mutant of mouse coronavirus, strain murine hepatitis virus (MHV)-A59. We have previously identified the putative causal mutation of MHV-Wüts18 as a C to U transition at codon 2446 in ORF1b, which results in a substitution of proline 12 with serine in non-structural protein 16. Here, we have used a vaccinia virus-based reverse genetic system to produce a recombinant virus, inf-MHV-Wüts18((AGC)) that encodes nsp16 serine 12 with AGC rather than UCU; a difference that facilitates the isolation of second-site revertants. Sequence analysis of nine inf-MHV-Wüts18((AGC)) revertant viruses suggests that their phenotype is most probably due to the intra-molecular substitution of amino acids in nsp16. However, the revertant viruses displayed different plaque sizes and whole genome sequencing of two revertants showed that they were isogenic apart from a mutation in nsp13. These results are discussed in the context of a model of coronavirus MHV nsp16 structure.
Journal of General Virology 10/2010; 92(Pt 1):122-7.
[show abstract][hide abstract] ABSTRACT: Cartilage injuries and osteoarthritis are a leading cause of disability in developed countries. The regeneration of damaged articular cartilage using cell transplantation or tissue engineering holds much promise but requires the identification of an appropriate cell source with a high proliferative propensity and consistent chondrogenic capacity. Human fetal mesenchymal stem cells (MSCs) have been isolated from a range of perinatal tissues including first trimester bone marrow and have demonstrated enhanced expansion and differentiation potential. However their ability to form mature chondrocytes for use in cartilage tissue engineering has not been clearly established. Here we compare the chondrogenic potential of human MSCs isolated from fetal and adult bone marrow and show distinct differences in their responsiveness to specific growth factors. Transforming growth factor beta 3 (TGFβ3) induced chondrogenesis in adult but not fetal MSCs. In contrast, bone morphogenetic protein 2 (BMP2) induced chondrogenesis in fetal but not adult MSCs. When fetal MSCs co-stimulated with BMP2 and TGFβ3 were used for cartilage tissue engineering they generated tissue with type II collagen and proteoglycan content comparable to adult MSCs treated with TGFβ3 alone. Investigation of the TGFβ/BMP signalling pathway showed that TGFβ3 induced phosphorylation of SMAD3 in adult but not fetal MSCs. These findings demonstrate that the initiation of chondrogenesis is modulated by distinct signalling mechanisms in fetal and adult MSCs. This study establishes the feasibility of using fetal MSCs in cartilage repair applications and proposes their potential as an in vitro system for modelling chondrogenic differentiation and skeletal development studies.
[show abstract][hide abstract] ABSTRACT: In this paper we highlight several instances in which there is potential for novel utilization in the near future of relatively recently licenced vaccines, vaccines approaching licensure or vaccines already in established use. Specifically we discuss the potential for universal seasonal influenza immunization and the arrival of live attenuated intranasal vaccine which was licenced for use in children aged 2–17 years in Europe in 2010, the potential use of live oral rotavirus vaccines for infants, two of which have been available in Europe since 2006, pertussis, which despite availability and widespread use throughout Europe of acellular vaccines for many years is causing, if anything, worsening problems in many countries so that novel strategies and solutions are needed and finally endemic meningococcal disease, for which in Europe, conjugate group C vaccines have been in use for 10 years but may now require revised schedules. Novel protein-based vaccines designed to prevent much of this disease caused by the main remaining European serogroup, namely B, are expected to be licenced and available for use imminently.
Paediatrics and Child Health. 03/2013; 23(3):103–108.