Recombinant human adenoviruses (Ads) that replicate in the intestinal tract offer a novel, yet practical, means of immunoprophylaxis against a wide variety of viral and bacterial pathogens. For some infectious agents such as human immunodeficiency virus (HIV), the potential for residual infectious material in vaccine preparations must be eliminated. Therefore, recombinant human Ads that express noninfectious HIV or other microbial proteins are attractive vaccine candidates. To test such an approach for HIV, we chose an experimental model of AIDS based on simian immunodeficiency virus (SIV) infection of macaques. Our data demonstrate that the SIV Env gene products are expressed in cultured cells after infection with a recombinant Ad containing both SIV env and rev genes. An E3 deletion vector derived from a mutant of human Ad serotype 5 that efficientiy replicates in both human and monkey cells was used to bypass the usual host range restriction

SummaryEndothelial cell growth factor (ECGF) stimulates the synthesis of t-PA and u-PA by confluent, diploid human lung fibroblasts, and this activity is potentiated considerably by heparin. In contrast, the malignant cell lines, Bowes melonoma and CALU-3, producers of t-PA and u-PA, respectively, are insensitive to ECGF, Studies with metabolic inhibitors and direct measurements of PA-specific mRNAs show that EccF-mediated production of PA by human lung fibroblasts is dependent on de novo protein and RNA synthesis. The mechanism by which heparin potentiates this effect is thought to reside in its ability to prolong or strengthen the interaction of ECGF with cell surface receptors. The results raise the possibility that endogenous ECGF or related polypeptides (and heparin) may act to regulate PA synthesis by lung fibroblasts and possibly other responsive target cells in vivo.

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