GS-9191 is a novel topical prodrug of the nucleotide analog 9-(2-phosphonylmethoxyethyl)guanine with antiproliferative activity and possible utility in the treatment of human papillomavirus lesions.

GS-9191 is a novel double prodrug of the nucleotide analog 9-(2-phosphonylmethoxyethyl)guanine (PMEG) designed as a topical agent to permeate skin and be metabolized to the active nucleoside triphosphate analog in the epithelial layer. The prodrug was shown to be metabolized intracellularly to 9-(2-phosphonylmethoxyethyl)-N(6)-cyclopropyl-2,6,diaminopurine (cPrPMEDAP) and subsequently deaminated to PMEG. The active form, PMEG diphosphate, was shown to be a potent inhibitor of DNA polymerase alpha and beta while showing weaker activity against mitochondrial DNA polymerase gamma (50% enzyme inhibition observed at 2.

GS-9219--a novel acyclic nucleotide analogue with potent antineoplastic activity in dogs with spontaneous non-Hodgkin's lymphoma.

Purpose: GS-9219, a novel prodrug of the nucleotide analogue 9-(2-phosphonylmethoxyethyl)guanine (PMEG), was designed as a cytotoxic agent that preferentially targets lymphoid cells. Our objective was to characterize the antiproliferative activity, pharmacokinetics, pharmacodynamics, and safety of GS-9219.

Experimental Design: GS-9219 was selected through screening in proliferation assays and through pharmacokinetic screening.

Phase I/II study of a candidate vaccine designed against the B and E subtypes of HIV-1.

A phase I/II trial of a candidate vaccine to prevent HIV infection was carried out in Bangkok, Thailand, testing AIDSVAX B/E (VaxGen, Inc., Brisbane, CA), a bivalent subunit vaccine prepared by combining recombinant gp120 from a subtype B virus (HIV-1MN) with gp120 from a subtype E virus (HIV-1A244) in alum adjuvant. The studies provide human data on the immunogenicity of various dose combination of non-subtype B vaccine antigens.

Structure and function of CC-chemokine receptor 5 homologues derived from representative primate species and subspecies of the taxonomic suborders Prosimii and Anthropoidea.

A chemokine receptor from the seven-transmembrane-domain G-protein-coupled receptor superfamily is an essential coreceptor for the cellular entry of human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) strains. To investigate nonhuman primate CC-chemokine receptor 5 (CCR5) homologue structure and function, we amplified CCR5 DNA sequences from peripheral blood cells obtained from 24 representative species and subspecies of the primate suborders Prosimii (family Lemuridae) and Anthropoidea (families Cebidae, Callitrichidae, Cercopithecidae, Hylobatidae, and Pongidae) by PCR with primers flanking the coding region of the gene. Full-length CCR5 was inserted into pCDNA3.

[Development of HIV vaccines].

An effective prophylactic vaccine should reduce frequency of new HIV infections in the target population and delay onset of immunodeficiency among those who become infected after vaccination. A variety of vaccine candidates have been developed, which induce neutralizing antibodies and/or cytotoxic T-lymphocytes. While many of those vaccine candidates exhibited some efficacy in primate model systems, their efficacy against natural HIV-1 infection can only be determined in large-scale phase III clinical trials.

Evolution of a human immunodeficiency virus type 1 variant with enhanced replication in pig-tailed macaque cells by DNA shuffling.

DNA shuffling facilitated the evolution of a human immunodeficiency virus type 1 (HIV-1) variant with enhanced replication in pig-tailed macaque peripheral blood mononuclear cells (pt mPBMC). This variant consists exclusively of HIV-1-derived sequences with the exception of simian immunodeficiency virus (SIV) nef. Sequences spanning the gag-protease-reverse transcriptase (gag-pro-RT) region from several HIV-1 isolates were shuffled and cloned into a parental HIV-1 backbone containing SIV nef.

Determination of a statistically valid neutralization titer in plasma that confers protection against simian-human immunodeficiency virus challenge following passive transfer of high-titered neutralizing antibodies.

We previously reported that high-titered neutralizing antibodies directed against the human immunodeficiency virus type 1 (HIV-1) envelope can block the establishment of a simian immunodeficiency virus (SIV)/HIV chimeric virus (SHIV) infection in two monkeys following passive transfer (R. Shibata et al., Nat.