Adenoviral-mediated gene transfer to the caudate nucleus of Macaca mulatta was accomplished using stereotactic injection of two distinct recombinant Ad5 vectors containing the gene for Escherichia coli beta-galactosidase and the cDNA for rat hypoxanthine-guanine phosphoribosylphosphotransferase (HPRT), respectively. Multiple analyses (including immunohistochemistry, histochemistry, transmission electron microscopy, RNA in situ hybridization, nucleotide pool analysis, and enzyme assay) confirmed efficient expression of beta-galactosidase and rat HPRT. Transgene expression was evident in both neurons and glia. Clinically, no evidence of meningitis or cerebritis was observed and no focal neurological deficits were detected in the animal. These preliminary studies indicate that recombinant adenovirus is capable of mediating high level transgene expression to the brains of higher order mammals.

In this report, we present data showing that a recombinant adenoviral vector (Ad.RSVIL-1ra) containing the cDNA for human interleukin-1 receptor antagonist protein (IL-1ra) can genetically modify synoviocytes both in vitro and in vivo. Human synoviocytes infected with Ad.RSVIL-1ra in vitro expressed and secreted high levels of human IL-1ra that were detected by ELISA of tissue culture supernatants. New Zealand White rabbits that received intra-articular injections of Ad.RSVIL-1ra expressed transgenic IL-1ra in synoviocytes, and secretion was detected for at least 4 weeks post-infection. Further, biological activity of the transgenic IL-1ra was demonstrated by its ability to inhibit IL-1-induced prostaglandin E2 (PGE2) synthesis in vitro and IL-1-induced glycosaminoglycan (GAG) degradation in vivo. These data demonstrate that recombinant adenoviral vectors can mediate the intra-articular expression of anti-inflammatory proteins and may be a reasonable method to deliver therapeutically relevant proteins for the regional treatment of synovial inflammation.

Expression plasmid DNA for the human interleukin-1 receptor antagonist (IL-1ra) protein was formulated with nonionic:cationic (NC) liposomes or phosphatidylcholine:cationic (PC) liposomes and applied to the auricular skin of hamsters in single- and multiple-dose protocols. Confocal microscopy identified delivery of plasmid DNA proximal to perifollicular cells, and successful transfection of perifollicular cells was identified by immunohistochemistry and ELISA. Skin treated for 3 days with the NC liposomes had statistically significant levels of transgenic IL-1ra present for 5 days post-treatment. Expression of transgenic IL-1ra was specific to areas of skin treated with NC liposomes but not PC liposomes. The results indicate that the NC liposomes can deliver expression plasmid DNA to perifollicular cells and mediate transient transfection in vivo.

Hairy cell leukemia is a chronic lymphoproliferative disorder of B-cell lineage, whose malignant cells express the interleukin-2 (IL-2) receptor. A soluble form of the IL-2 receptor is released by these cells in culture, and the sera of patients with hairy cell leukemia contain elevated levels of this soluble receptor. Four hundred twenty- seven serum samples from 101 patients were analyzed for soluble IL-2 receptor (sIL-2R). The clinical status of patients appeared to be associated with the serum level of sIL-2R. The hairy cell index (a measure of tumor cell burden) was correlated with the square root of the serum sIL-2R level (r = .77). Improved clinical status was associated with decreasing serum sIL-2R levels, whereas disease relapse was associated with increasing levels. Notably, every patient who responded to therapy had a decline in serum sIL-2R level, and every patient with disease progression had an increase in serum sIL-2R level. This phenomenon was observed for several different treatments, including standard-dose interferon, low-dose interferon, and deoxycoformycin. The predictive reliability of this test is currently being prospectively evaluated.

Sixteen patients with metastatic melanoma or metastatic renal cell carcinoma were treated with six weekly 24-hour infusions of recombinant interleukin-2. At least three patients were treated at each dose, beginning at 3.0 mU/m2 for 24 hours each week for 6 weeks. Subsequent patients were treated at 4.5, 6.0, 8.0, and 10.0 mU/m2 for 24 hours. The incidence of diarrhea, rigors, rash, edema, and symptomatic hypotension was positively correlated with dose level. Symptomatic hypotension was dose limiting at the 10-mU/m2 level. Fever, nausea, and vomiting were seen at each dose level and could not be correlated with dose level. Lymphopenia and eosinophilia were observed at the completion of each 24-hour infusion, and an increase in peripheral blood absolute lymphocytes and eosinophils was observed over the 6-week treatment period. No thrombocytopenia was observed. No change in delayed-type hypersensitivity (type IV) as determined by skin testing could be demonstrated at any dose level. Natural killer cell cytotoxicity of peripheral blood lymphocytes increased over the treatment period, but the increase was unrelated to dose level in the range studied. One minor response was documented in a patient with renal cell carcinoma.