@article{ReuterSparwasserHuenigetal.2012, author = {Reuter, Dajana and Sparwasser, Tim and H{\"u}nig, Thomas and Schneider-Schaulies, J{\"u}rgen}, title = {Foxp3\(^+\) Regulatory T Cells Control Persistence of Viral CNS Infection}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {3}, doi = {10.1371/journal.pone.0033989}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134248}, pages = {e33989}, year = {2012}, abstract = {We earlier established a model of a persistent viral CNS infection using two week old immunologically normal (genetically unmodified) mice and recombinant measles virus (MV). Using this model infection we investigated the role of regulatory T cells (Tregs) as regulators of the immune response in the brain, and assessed whether the persistent CNS infection can be modulated by manipulation of Tregs in the periphery. CD4\(^+\) CD25\(^+\) Foxp3\(^+\) Tregs were expanded or depleted during the persistent phase of the CNS infection, and the consequences for the virus-specific immune response and the extent of persistent infection were analyzed. Virus-specific CD8\(^+\) T cells predominantly recognising the H-2D(b)-presented viral hemagglutinin epitope MV-H22-30 (RIVINREHL) were quantified in the brain by pentamer staining. Expansion of Tregs after intraperitoneal (i.p.) application of the superagonistic anti-CD28 antibody D665 inducing transient immunosuppression caused increased virus replication and spread in the CNS. In contrast, depletion of Tregs using diphtheria toxin (DT) in DEREG (depletion of regulatory T cells)-mice induced an increase of virus-specific CD8\(^+\) effector T cells in the brain and caused a reduction of the persistent infection. These data indicate that manipulation of Tregs in the periphery can be utilized to regulate virus persistence in the CNS.}, language = {en} } @article{KneisslAbelRasbachetal.2012, author = {Kneissl, Sabrina and Abel, Tobias and Rasbach, Anke and Brynza, Julia and Schneider-Schaulies, J{\"u}rgen and Buchholz, Christian J.}, title = {Measles Virus Glycoprotein-Based Lentiviral Targeting Vectors That Avoid Neutralizing Antibodies}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {10}, doi = {10.1371/journal.pone.0046667}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134993}, pages = {e46667}, year = {2012}, abstract = {Lentiviral vectors (LVs) are potent gene transfer vehicles frequently applied in research and recently also in clinical trials. Retargeting LV entry to cell types of interest is a key issue to improve gene transfer safety and efficacy. Recently, we have developed a targeting method for LVs by incorporating engineered measles virus (MV) glycoproteins, the hemagglutinin (H), responsible for receptor recognition, and the fusion protein into their envelope. The H protein displays a single-chain antibody (scFv) specific for the target receptor and is ablated for recognition of the MV receptors CD46 and SLAM by point mutations in its ectodomain. A potential hindrance to systemic administration in humans is pre-existing MV-specific immunity due to vaccination or natural infection. We compared transduction of targeting vectors and non-targeting vectors pseudotyped with MV glycoproteins unmodified in their ectodomains (MV-LV) in presence of \(\alpha\)-MV antibody-positive human plasma. At plasma dilution 1: 160 MV-LV was almost completely neutralized, whereas targeting vectors showed relative transduction efficiencies from 60\% to 90\%. Furthermore, at plasma dilution 1: 80 an at least 4-times higher multiplicity of infection (MOI) of MV-LV had to be applied to obtain similar transduction efficiencies as with targeting vectors. Also when the vectors were normalized to their p24 values, targeting vectors showed partial protection against \(\alpha\)-MV antibodies in human plasma. Furthermore, the monoclonal neutralizing antibody K71 with a putative epitope close to the receptor binding sites of H, did not neutralize the targeting vectors, but did neutralize MV-LV. The observed escape from neutralization may be due to the point mutations in the H ectodomain that might have destroyed antibody binding sites. Furthermore, scFv mediated cell entry via the target receptor may proceed in presence of a-MV antibodies interfering with entry via the natural MV receptors. These results are promising for in vivo applications of targeting vectors in humans.}, language = {en} }