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Antje Ksienzyk Department of Gene Regulation and Differentiation aks08@helmholtz-hzi.de. model of systemic virus infection. Infection. Replication in first organ Primary viremia. Secondary viremia. other organs. dissemination. Replication. MCMV. Herpesviridae herpesvirus
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Antje Ksienzyk Department of Gene Regulation and Differentiation aks08@helmholtz-hzi.de
model of systemic virus infection Infection Replication in first organ Primary viremia Secondary viremia other organs dissemination Replication
MCMV • Herpesviridae • herpesvirus • Cytomegalovirus • MCMV: mouse cytomegalovirus HCMV :major risk factor for immunoincompetent and immunocompromised patients (AIDS patients and organ transplant recipients) MCMV: represents the rodent model MCMV replicates in a broad spectrum of cell types: vascular endothelial cells and hepatocytes
EC and HC are important cell types for MCMV replication 106 PFU of MCMV flox Analyses of MCMV-rec and MCMV-flox plaque forming units Tie2-cre: Cre under control of Tie2 (endothelial tyrosinkinase receptors: only in EC) promoter in vascular EC Alb-cre: Cre under control of albumin promoter in hepatocytes
Hepatocytes are the main producer cell type Hepatocytes derived MCMV-rec do not disseminate from the liver to other organs (alb-cre)
Influence of route and dose Alb-cre Amount of cre expression, the route and dose of infection have no influence on the results
Hc-derived MCMV has potential to replicate in spleen and lung Virus isolation out of liver Alb-cre i.v. injection C57BL/6
Bidirectional spread of MCMV between EC and Hc Tie2-cre: MCMV from EC to Hc Alb-cre: MCMV from Hc to EC EC and Hc produce virus which can infect neighboring cells No explanation that Hc derived virus can’t disseminate
MCMV infection is controlled by CD3+ cells Elimination of MCMV is correlated with liver infiltrating T-cells Reason for dissemination stop?
Immunosuppression has no influence on Hc- derived virus dissemination • untreated • + immunodepleted 1 untreated 2, 3 -irradiation 4 immune suppression by cyclophosphamide 5 proinflammatory stimuli. Con A No increase of dissemination after immune suppression and proinflammatory stimuli
summary • Hepatocytes and EC are target cells of MCMV in vivo (replication) • HC are important target cells but are not involved in virus dissemination • Infected EC contribute to viremic dissemination by serving as transport vehicle and by uptake and release of virus • Hc derived MCMV never leads to a second viremia (unlike to former publications) • But what is the reason for that? • Independent on immune cells or irradiation • Independent on ability to infect other cells • IFN???