As CTL adhere to and lyze their targets, they extract cognate Ag-MHC and represent this on their own cell surface. Whether such self-presented cognate Ag stimulate the TCR of a CTL is uncertain. To analyze this, we examined TCR capping in response to self-presented Ag. We found that OVA peptide-specific OT-1 CTL that were pulsed with cognate peptide Ag did not cap their TCR, implying that the a...

A bovine viral diarrhea virus (BVDV) amplification method combined with an enzyme immunoassay was developed to detect BVDV antigens in seropositive cattle. Reconstitution assays conducted by adding decreasing amounts of BVDV (Singer strain) to Madin-Darby bovine kidney (MDBK) cells showed that the sensitivity threshold of the combined assay was 10-7 TCID50. BVDV amplification was carried out in...

Ross River virus (RRV) and Semliki Forest virus (SFV) are two alphaviruses that have a high degree of amino acid homology, as well as a very broad host range. We show here that envelope glycoproteins derived from both viruses can pseudotype human immunodeficiency virus type 1 (HIV-1)-derived lentivirus vectors. Both RRV and SFV glycoproteins considerably expand the host range of the lentivirus ...

The primary immunodeficiencies are attractive candidates for the development of gene therapy approaches based on the transduction of hematopoietic cells. We have constructed a high-titer recombinant retrovirus for expression of gp91-phox, deficiencies of which cause the X-linked form of chronic granulomatous disease (X-CGD). We have used this vector to transduce human bone marrow, using either ...

C ATIONIC PROTEINS are important constituents of polymorphonuclear ( PMN ) leukocyte lysosomes. These proteins are rich in arginine and lysine. This accounts for their strong electro-positivity.13 These proteins are without apparent enzyme activity; nevertheless they possess a variety of biological activities.1’4#{176} We have recently described an anticoagulant activity of these proteins that ...

The colony formation assay is the most commonly used titration method for defining the concentration of replication-incompetent murine leukemia virus-derived retroviral vectors. However, titer varies with target cell type and number, transduction time, and concentration of polycation (e.g., Polybrene). Moreover, because most of the viruses cannot encounter target cells due to Brownian motion, t...

An efficient technique for hybridization of mammalian cells was developed by combining agglutination by pretreatment with polycations, such as polyarginine, and conventional polyethylene glycol(PEG)-mediated cell fusion. Polyarginine and subsequent PEG treatment resulted in markedly decreased viability in the treated cells, but addition of polyvinyl pyrrolidone or glycerol to the polyarginine p...

ATP-dependent polycation-stimulated phosphorylation of highly purified phytochrome preparations from etiolated Avena seedlings has been reported previously (Y-S Wong, H-C Cheng, DA Walsh, JC Lagarias [1986] J Biol Chem 261: 12089-12097). In this study, we present a more detailed description of the properties of this protein kinase based on the analysis of over 30 different Avena phytochrome pre...

Retrovirus-mediated gene transfer is currently limited by random Brownian motion ofthe retrovirus. This limitation can be overcome by flowing the retrovirus solution through a porous membrane that supports the target cells, leading to a significant increase in the transduction efficiency. This procedure is termed "flow-through transduction." In this study, we characterized the effects of the fl...