Quantitative expression analysis of HHV-6 cell receptor CD46 on cells of human cord blood, peripheral blood and G-CSF mobilised leukapheresis cells.

Human herpesvirus-6 (HHV-6) can infect blood cells and thereby may inhibit hematopoietic stem and progenitor cell expansion and differentiation. In this context, it has been discussed if early progenitor cells can be infected by HHV-6. CD46 was identified as one possible cellular surface receptor for HHV-6.

Antiviral activity of Arthrospira-derived spirulan-like substances.

Natural substances offer interesting pharmacological perspectives for antiviral drug development in regard to broad-spectrum antiviral properties and novel modes of action. In this study we analyzed polysaccharide fractions isolated from Arthrospira platensis. Fractions containing intracellular or extracellular spirulan-like molecules showed a pronounced antiviral activity in the absence of cytotoxic effects.

Infections with human herpesvirus 6 variant B delay platelet engraftment after allogeneic haematopoietic stem cell transplantation.

The clinical significance of human herpesvirus (HHV-6) infections after allogeneic stem cell transplantation (SCT) remains controversial. We analysed cryoconserved plasma samples from 82 patients after allogeneic SCT by quantitative polymerase chain reaction for HHV-6 variants A and B. Platelet engraftment was delayed in patients with HHV-6B infections but not with HHV-6A infections detected before day +28.

Reference gene selection for quantitative real-time PCR analysis in virus infected cells: SARS corona virus, Yellow fever virus, Human Herpesvirus-6, Camelpox virus and Cytomegalovirus infections.

Ten potential reference genes were compared for their use in experiments investigating cellular mRNA expression of virus infected cells. Human cell lines were infected with Cytomegalovirus, Human Herpesvirus-6, Camelpox virus, SARS coronavirus or Yellow fever virus. The expression levels of these genes and the viral replication were determined by real-time PCR.

Inhibition of cord blood cell expansion by human herpesvirus 6 in vitro.

To elucidate the role of human herpesvirus 6 (HHV-6) in hematopoiesis, the influence of HHV-6A and HHV-6B on the in vitro expansion and differentiation of cord blood (CB) progenitor cells was investigated in liquid culture. Nonfractionated CB mononuclear cells (CB-MNC) or MACS-enriched CD34+ CB cells were seeded in liquid culture under conditions allowing maximal expansion of nucleated cells. Cells were either incubated with HHV-6A- or HHV-6B-containing cell culture supernatants or a virus-free control.

Guideline to reference gene selection for quantitative real-time PCR.

Today, quantitative real-time PCR is the method of choice for rapid and reliable quantification of mRNA transcription. However, for an exact comparison of mRNA transcription in different samples or tissues it is crucial to choose the appropriate reference gene. Recently glyceraldehyde 3-phosphate dehydrogenase and beta-actin have been used for that purpose.

Interleukin-3 promotes proliferation and differentiation of human hematopoietic stem cells but reduces their repopulation potential in NOD/SCID mice.

In the present study we explored systematically the influence of human interleukin-3 (IL-3) on the cord blood (CB) cell-derived production of human hematopoietic cells in the bone marrow, blood, and spleen of chimeric nonobese/severe combined immunodeficient mice ((NOD/SCID) mice. CB mononuclear cells and MACS-enriched CB CD34(+) cells were injected into irradiated NOD/SCID mice. The mice were additionally transplanted with a stably transfected rat fibroblast cell line expressing the human IL-3 gene (Rat-IL-3) constitutively, or with the nontransfected rat fibroblast cell line as a control (Rat-1).