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1.
J Virol Methods ; 287: 114003, 2021 01.
Article in English | MEDLINE | ID: mdl-33164863

ABSTRACT

The last major Rift Valley fever outbreak in South Africa was between 2008 and 2011. Viruses isolated between 2008 and 2010 were phylogenetically assigned to Lineage C, Lineage K and the novel lineage H. The 2011 outbreaks occurred primarily in the Eastern, Western and Northern Cape provinces, with no sequence data or phylogenetic relationship published. Samples from these outbreaks were submitted to the Faculty of Veterinary Sciences, University of Pretoria, for immunohistochemical confirmation of Rift Valley fever phlebovirus presence. These samples were formalin-fixed and paraffin-embedded (FFPE) and stored at the Pathology section for several years. This study describes a modified extraction method used to obtain RNA from the FFPE samples, as well as the primer combinations used to phylogenetically classify them as belonging to the novel lineage H.


Subject(s)
Rift Valley Fever , Rift Valley fever virus , Animals , Disease Outbreaks , Formaldehyde , Paraffin Embedding , Phylogeny , Retrospective Studies , Rift Valley Fever/epidemiology , Rift Valley fever virus/genetics , South Africa/epidemiology
3.
Vaccines (Basel) ; 6(3)2018 Sep 14.
Article in English | MEDLINE | ID: mdl-30223475

ABSTRACT

The antigenically conserved hemagglutinin stalk region is a target for universal influenza virus vaccines since antibodies against it can provide broad protection against influenza viruses of different subtypes. We tested a universal influenza virus vaccination regimen based on sequential immunization with chimeric hemagglutinin (HA) containing viruses in a swine influenza virus pig model with maternal antibodies against pandemic H1N1. Vaccines were administered as live attenuated virus or inactivated influenza virus split vaccine (+/- Emulsigen adjuvant). As controls, we included groups that received trivalent inactivated influenza vaccine that contained pandemic H1N1 antigens, inactivated adjuvanted H1N2 vaccine (control group for vaccine associated enhanced respiratory disease in the pig model) or mock-vaccination. No induction of H1 head or stalk-specific antibody responses was observed upon vaccination, while responses against H3 and influenza B HA were elicited in the group vaccinated with the trivalent vaccine. Four weeks post vaccination, pigs were intratracheally challenged with pandemic H1N1 virus and euthanized 5 days after challenge. Despite the lack of detectable anti-stalk immunity, the chimeric hemagglutinin vaccine resulted in better clinical outcomes compared to control groups.

4.
Cancer Res ; 70(14): 5706-16, 2010 Jul 15.
Article in English | MEDLINE | ID: mdl-20570886

ABSTRACT

Breast cancer that recurs as metastatic disease many years after primary tumor resection and adjuvant therapy seems to arise from tumor cells that disseminated early in the course of disease but did not develop into clinically apparent lesions. These long-term surviving, disseminated tumor cells maintain a state of dormancy, but may be triggered to proliferate through largely unknown factors. We now show that the induction of fibrosis, associated with deposition of type I collagen (Col-I) in the in vivo metastatic microenvironment, induces dormant D2.0R cells to form proliferative metastatic lesions through beta1-integrin signaling. In vitro studies using a three-dimensional culture system modeling dormancy showed that Col-I induces quiescent D2.0R cells to proliferate through beta1-integrin activation of SRC and focal adhesion kinase, leading to extracellular signal-regulated kinase (ERK)-dependent myosin light chain phosphorylation by myosin light chain kinase and actin stress fiber formation. Blocking beta1-integrin, Src, ERK, or myosin light chain kinase by short hairpin RNA or pharmacologic approaches inhibited Col-I-induced activation of this signaling cascade, cytoskeletal reorganization, and proliferation. These findings show that fibrosis with Col-I enrichment at the metastatic site may be a critical determinant of cytoskeletal reorganization in dormant tumor cells, leading to their transition from dormancy to metastatic growth. Thus, inhibiting Col-I production, its interaction with beta1-integrin, and downstream signaling of beta1-integrin may be important strategies for preventing or treating recurrent metastatic disease.


Subject(s)
Collagen Type I/metabolism , Lung Neoplasms/secondary , Mammary Neoplasms, Experimental/metabolism , Mammary Neoplasms, Experimental/pathology , Pulmonary Fibrosis/pathology , Actins/metabolism , Animals , Cell Growth Processes/physiology , Extracellular Matrix/metabolism , Extracellular Matrix/pathology , Extracellular Signal-Regulated MAP Kinases/metabolism , Female , Focal Adhesion Kinase 1/metabolism , Integrin beta1/metabolism , Lung Neoplasms/metabolism , Mice , Mice, Inbred BALB C , Mice, Nude , Myosin-Light-Chain Kinase/metabolism , Phosphorylation , Pulmonary Fibrosis/metabolism , Rats , Signal Transduction , Transforming Growth Factor beta/metabolism , src-Family Kinases/metabolism
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