We have investigated the in vivo efficacy of a systemic gene transfer method, which combines a liposomal delivery system (DLS liposomes) Systemic gene therapy by direct delivery of plasmid DNA coupled to synthetic carriers is appealing because of its simplicity, low toxicity, and potential for multiorgan targeting. Although the efficiency of in vitro transfection of DNA plasmids is limited when compared to delivery by viral vectors, recent advances, especially in liposomal delivery, have demonstrated that nonviral gene transfer offers exciting potential (1, 2). Recent attempts to deliver genetic material have provided an impetus to liposome technology (3-6), in particular formation of complexes of DNA with cationic liposomes (7-11). A few therapeutic clinical trial protocols using local administration of these complexes are ongoing but data on systemic administration are still poorly documented (12,13). In this study, we describe a liposomal formulation for gene delivery called DLS, which could be suitable for systemic administration. To obtain long-term expression from a nonintegrated transgene, episomal self-replicating plasmid vectors were constructed and tested. Using the luciferase gene (luc) as a reporter gene (14), we detected transgene expression in various mouse tissues using measurements of luciferase activity, PCR analysis, and immunohistochemistry. Our results demonstrated that a single injection of an episomal DNA vector using the DLS liposome delivery system yielded widespread and long-lasting transgene expression.MATERIALS AND METHODS Materials. Dioctadecylamidoglycylspermidine (7) (15) were deleted to remove expression of these potentially immunogenic proteins. The resultant episomal/reporter expression vector was termed pBKd2RSV-luc. In addition, a second series of pBKdl and pBKd2 vectors were made in which luc expression was placed under the control of the enhancer/promoter sequences from the immediate-early gene of the human cytomegalovirus (CMV) and the polyadenylylation signal and transcriptional termination sequences from the bovine growth hormone gene. The resultant episomal/reporter expression vectors were termed pBKdlCMV-Iuc and pBKd2CMV-Iuc, respectively. The details of these constructs will be reported elsewhere (L.C.M., unpublished data). The nonepisomal pRSV-luc containing luc under control of the RSV long terminal repeat was constructed as reported (14). pCMVintlux plasmid encodes luc under the control of human CMV immediate-early promoter with intron A (16) (generously provided by M. Mansthorpe, Vical, CA). Preparation of the DLS Liposomes. Liposomes were formed by mixing 1 mg of dioctadecylamidoglycylspermidine and 1 mg of dioleoyl phosphatidylethanolamine. After thorough stirring, the mixture was evaporated to dryness in a round-bottomed borosilicate tube using a rotary Vortex evaporator under vacuum. Then the dry lipid film was hydrated with a maximum volume (60 ,ul per mg of lipid) of a solution containing 160 ,ug of plasmid DNA and was slightly Vortex mixed. After in...

KS Y-1 cells in the in vivo mouse model can be used to study the effects of therapeutic compounds in advanced KS.

The effects of clinical grade crude preparations of human chorionic gonadotropin (hCG) on Kaposi's sarcoma, HIV, SIV and hematopoiesis were examined in vitro and in vivo. In contrast to previous studies, we report that the antiviral activity of hCG associated factors is not due to the native hCG heterodimer, including its purified subunits or its major degradation product, the beta-core. Using gel permeation chromatography of the clinical grade hCG and urine concentrates from pregnant women, we demonstrate that an as yet unidentified hCG associated factor (HAF) with anti-HIV, anti-SIV, anti-KS and pro-hematopoietic activities elutes as two peaks corresponding to 15-30 kDa and 2-4 kDa.

Interleukin-10 (IL-10) is an acid-sensitive protein of 35 kD that has pleiotropic effects including inhibition of cytotoxic T-cell response, induction of major histocompatibility complex type II in B lymphocytes, induction of B-cell growth and differentiation, and autocrine growth factor activity in monocytes. We and others have shown that IL-10 is produced spontaneously by blood mononuclear cells from human immunodeficiency virus-seropositive patients. In an attempt to ascertain the potential role of IL-10 in acquired immunodeficiency syndrome (AIDS)-related B-cell lymphoma, we evaluated the expression of human IL-10 in both tumor-derived B-cell lines and primary tumor cells. Expression of human IL-10 (hIL-10) mRNA and protein was detected in four of five cell lines examined. An IL-10 antisense oligonucleotide inhibited IL-10 mRNA expression and IL-10 protein production. The proliferation of all B-cell lines was inhibited by an antisense oligonucleotide in a dose-dependent manner that was abrogated by the addition of recombinant hIL-10 protein. No effect of antisense oligonucleotide was observed in the B-cell line not producing hIL-10. Evaluation of primary tumor cells from patients with AIDS-lymphoma cells showed similar production and response to IL-10. These data suggest an autocrine growth mechanism for IL-10 in AIDS-related lymphoma cells and that IL-10 may be important in its pathogenesis.