Virol. the N4CT1-gag1 and N4CT9-gag1 vectors generated robust Gag-specific immune responses following intramuscular immunization that were equivalent to or greater than immune responses generated by the more virulent prototypic vectors. MncpCT1-gag1 also induced Gag-specific immune responses following intramuscular immunization that were equivalent to immune responses generated by the prototypic rVSV vector. Placement of the gene in the first position of the VSV genome was associated with increased in vitro expression of Gag protein, in vivo expression of Gag mRNA, and enhanced immunogenicity of the vector. These findings demonstrate that through directed manipulation of the rVSV genome, vectors that have reduced neurovirulence and enhanced immunogenicity can be made. The dire need for a human immunodeficiency computer virus (HIV) vaccine has led to an increase in the development of novel methods for vaccination. Early attempts at designing HIV vaccines that could induce a neutralizing antibody response against the envelope of HIV have not been clinically successful; this lack of success has led to the examination of whether cell-mediated immunity against HIV antigens can safeguard individuals from contamination with HIV or at least prevent the progression to AIDS following contamination (9, 40). Several groups have examined the use of recombinant viruses expressing HIV antigens as vaccines that can induce a potent cell-mediated immune response (23). A successful virally vectored vaccine will require the ability to cautiously balance its immunogenicity and security. In general, as viruses are attenuated to increase security, their immunogenicities can be diminished. An ideal viral vaccine vector should replicate sufficiently and express high levels of foreign antigen, inducing potent immune responses without causing pathology in the recipient. Vesicular stomatitis computer virus (VSV) is an enveloped, negative-stranded RNA computer virus of the family (34). In nature, VSV is usually transmitted by insects and infects livestock, causing a self-limiting disease that is marked by vesicular lesions of the (S)-2-Hydroxy-3-phenylpropanoic acid mouth and teats. VSV rarely infects humans, but when contamination does occur, it can result in disease ranging from asymptomatic contamination to moderate flu-like illness (7, 16). VSV has many characteristics that render it an ideal candidate for development as a vaccine vector, including the absence of preexisting immunity to VSV in human populations, ease of genetic manipulation, strong gene expression, and vigorous computer virus propagation in vitro. Since the development of a system for the recovery of recombinant VSV (rVSV) from plasmid DNA (22, 43, 44), rVSV vectors have been assessed in animal models as vaccine vectors for numerous pathogens including HIV-1, herpes simplex virus type 2, influenza computer virus, respiratory syncytial computer virus, hepatitis C computer virus, cottontail rabbit papillomavirus, measles computer virus, Ebola computer virus, Lassa fever computer virus, Marburg computer virus, and severe acute (S)-2-Hydroxy-3-phenylpropanoic acid respiratory syndrome coronavirus (1, 5, 6, 8, 17-20, 24, 29, 31-33, 35, 38). The early development of rVSV for use in humans as an HIV-1 vaccine vector has been recently examined (2). The prototypic rVSV vectors originally developed as HIV-1 vaccines were based on an rVSV genome that was generated Mouse monoclonal to OPN. Osteopontin is the principal phosphorylated glycoprotein of bone and is expressed in a limited number of other tissues including dentine. Osteopontin is produced by osteoblasts under stimulation by calcitriol and binds tightly to hydroxyapatite. It is also involved in the anchoring of osteoclasts to the mineral of bone matrix via the vitronectin receptor, which has specificity for osteopontin. Osteopontin is overexpressed in a variety of cancers, including lung, breast, colorectal, stomach, ovarian, melanoma and mesothelioma. from two laboratory-adapted strains of the VSV Indiana serotype (VSVIN) (10, 12, 33, 35). This rVSV vector backbone was slightly attenuated compared to wild-type VSV (wtVSV) when examined in mice (33). The prototypic rVSV-HIV-1 vectors were shown to induce strong cellular immunity to HIV Gag and HIV Env in small animals (11, 12), and this led to the demonstration that rVSV vectors expressing HIV Env and simian immunodeficiency computer virus Gag were highly protective in the rhesus macaque simian-human immunodeficiency computer virus (SHIV) 89.6P challenge model (35), supporting future clinical assessments of these vectors in humans. While VSV does not cause neurological disease in livestock following natural contamination, it does cause a well-described viral encephalitis in rodents following intranasal (i.n.) or intracranial (i.c.) inoculation of young mice (37, 42). Since regulatory companies typically require nonhuman primate (NHP) neurovirulence screening of replication-competent viral vaccines prior to clinical assessment in humans, we evaluated the neurotropism and neurotoxicity of the prototypic HIV-1 rVSV vectors in an exploratory (S)-2-Hydroxy-3-phenylpropanoic acid NHP neurovirulence study. While this study exhibited no dissemination of the rVSV vectors to the brain following i.n. administration, there was significant neuropathology following intrathalamic inoculation of cynomolgus macaques (15). From that study, it was concluded that the prototypic rVSV vectors were insufficiently attenuated.