Dystrophic epidermolysis bullosa (DEB) is a family of inherited mechano-bullous disorders caused by mutations in the human type VII collagen gene (COL7A1). Individuals with DEB lack type VII collagen and anchoring fibrils, structures that attach epidermis and dermis. The current lack of treatment for DEB is an impetus to develop gene therapy strategies that efficiently transfer and stably express genes delivered to skin cells in vivo. In this study, we delivered and expressed full-length type VII collagen using a self-inactivating minimal lentivirus-based vector. Transduction of lentiviral vectors containing the COL7A1 transgene into recessive DEB (RDEB) keratinocytes and fibroblasts (in which type VII collagen was absent) resulted in persistent synthesis and secretion of type VII collagen. Unlike RDEB parent cells, the gene-corrected cells had normal morphology, proliferative potential, matrix attachment and motility. We used these gene-corrected cells to regenerate human skin on immune-deficient mice. Human skin regenerated by gene-corrected RDEB cells had restored expression of type VII collagen and formation of anchoring fibrils at the dermal-epidermal junction in vivo. These studies demonstrate that it is possible to restore type VII collagen gene expression in RDEB skin in vivo.

A major function of the acinar cells of the lacrimal gland is the production and stimulated release of tear proteins into ocular surface fluid. We investigate the participation of cytoplasmic dynein in carbachol-stimulated traffic to the apical plasma membrane in primary rabbit lacrimal acinar epithelial cells. Confocal fluorescence microscopy revealed a major carbachol-induced, microtubule-dependent recruitment of cytoplasmic dynein and the dynactin complex into the subapical region. Colocalization studies,sorbitol density gradient/phase partitioning analysis and microtubule-affinity purification of membranes showed that some dynein and dynactin complex were associated with VAMP2-enriched membranes. Adenovirus-mediated overexpression of p50/dynamitin inhibited the recruitment and colocalization of dynein, the dynactin complex and VAMP2 in the subapical region. Nocodazole treatment and p50/dynamitin overexpression also depleted subapical stores of rab3D in resting acini, suggesting that dynein activity was also involved in maintenance of rab3D-enriched secretory vesicles. These data implicate cytoplasmic dynein in stimulated traffic to the apical plasma membrane in these secretory epithelial cells.

Although adenovirus (Ad) exhibits tropism for epithelial cells, little is known about the cellular effects of adenoviral binding and internalization on epithelial functions. Here, we examine its effects on the secretory acinar epithelial cells of the lacrimal gland, responsible for stimulated release of tear proteins into ocular fluid. Exposure of reconstituted rabbit lacrimal acini to replication-defective Ad for 16-18 h under conditions that resulted in 480% transduction efficiency did not alter cytoskeletal filament or biosynthetic/endosomal membrane compartment organization. Transduction specifically altered the organization of the stimulated secretory pathway, eliciting major dispersal of rab3D immunofluorescence from apical stores normally associated with mature secretory vesicles. Biochemical studies revealed that this dispersal was not associated with altered rab3D expression nor its release from cellular membranes. Ultraviolet (UV)-inactivated Ad elicited similar dispersal of rab3D immunofluorescence. In acini exposed to replication-defective or UVinactivated Ad, carbachol-stimulated release of bulk protein and b-hexosaminidase were significantly (Pp0.05) inhibited to an extent proportional to the loss of rab3D-enriched mature secretory vesicles associated with these treatments. We propose that the altered secretory compartment organization and function caused by Ad reflects changes in the normal maturation of secretory vesicles, and that these changes are caused by exposure to the Ad capsid.

A type I ribosome inactivating protein, gelonin, was linked to Lym-1, a murine monoclonal antibody reactive with a polymorphic determinant of class I1 HLA-DR histocompatibility leukocyte antigen (HLA) on human lymphoma cells, via a disulfide linkage using the heterobifunctional cross-linking agent, N-succinimidyl-3-(2-pyridyldithio) propionate. This immunotoxin was purified from unreacted gelonin and unconjugated Lym-1 by fast protein liquid chromatography using sephacryl S-300 gel filtration and blue sepharose affinity gradient separation. Binding of Lym-l-gelonin immunoconjugate to human Raji Burkitt's lymphoma cells was demonstrated by indirect immunofluorescence using flow cytometry. Lym-l-gelonin was very active in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium salt and sulforhodamine B in vitro cytotoxicity assays against the Raji lymphoma cell line and confirmed the fact that monoclonal antibody Lym-1 internalizes into human lymphoma cells. A weaker cytostatic antiproliferative effect was also noted for unconjugated Lym-1 . y-interferon augmented the antiproliferative effects of Lym-l-gelonin conjugate and unconjugated Lym-1, by having a direct cytotoxic effect on the Raji cells. Tumor necrosis factor-cr. also enhanced the antiproliferative effect of unconjugated Lym-1 , but did not significantly augment the cytotoxic activity of the Lym-l-gelonin conjugate. These results suggest that anti-HLA class I1 monoclonal antibodies may be useful in constructing immunotoxins for the treatment of human lymphomas and leukemias expressing HLA class I1 antigens, and that unconjugated anti-HLA class I1 monoclonal antibodies may be therapeutically useful in conjunction with recombinant cytokines, especially y-interferon. Key Words: Gelonin immunoconjugate-Recombinant cytokines-Human Burkitt's lymphoma-Antiproliferative and cytotoxic effects.Paul Ehrlich proposed antibody-mediated delivery of toxins >SO years ago (1). Since the developago (2), many attempts have been made to conju-

Fifteen patients with relapsed or refractory acute leukemia were treated in this phase I study of menogaril (7-con-O-methylnogarol), a nogalamycin anthracycline derivative. Doses ranged from 50 mg/m2/day to 130 mg/m2/day, administered daily for 5 days. Pharmacokinetic studies were performed at each dose level and confirmed the findings of pharmacokinetic data derived from previous studies in patients with solid tumors. All patients experienced grade 4 hematologic toxicity and the dose limiting toxicity was mucositis. Two patients, one with acute myeloid leukemia and one with acute lymphoid leukemia, achieved complete responses. The AML complete response lasted 10 months and the ALL patient died in CR at 2+ months. Both patients were treated at a dose of 100 mg/m2/day for five days. At this dose, a second induction or consolidation course could be given without severe mucositis, and this is the dose recommended for further phase II studies in leukemia using this schedule.