Encapsulated plasmid DNA treatment for human papillomavirus 16-associated anal dysplasia: a Phase I study of ZYC101.

High-grade dysplasia induced by high-risk types of human papillomavirus (HPV) precedes invasive cancer in anal squamous epithelium just as it does in the cervix. A therapeutic HPV vaccine strategy as a potential treatment for anal dysplasia was tested in a standard Phase I dose escalation trial. The primary objective was to evaluate the safety of the agent; additional study aims were to evaluate the histological response, immune response, and effect on anal HPV-16 infection. Each subject was treated with four i.m. injections of 50-400 microg of ZYC101 at 3-week intervals. ZYC101 is composed of plasmid DNA encapsulated in biodegradable polymer microparticles. The plasmid DNA encodes for multiple HLA-A2-restricted epitopes derived from the HPV-16 E7 protein, one of two HPV oncoproteins consistently expressed in neoplastic cells. Fifty-six potential anal dysplasia subjects were screened to identify 12 eligible subjects with HPV-16 anal infection and a HLA-A2 haplotype. The investigational agent was well tolerated in all subjects at all dose levels tested. Three subjects experienced partial histological responses, including one of three subjects receiving the 200-microg dose and two subjects at the 400-microg dose level. Using a direct Elispot, 10 of 12 subjects demonstrated increased immune response to the peptide epitopes encoded within ZYC101; each continued to show elevated immune responses 6 months after the initiation of therapy. These results support the continued investigation of a therapeutic vaccination strategy for anal dysplasia.

Enhanced early innate and T cell-mediated responses in subjects immunized with Anthrax Vaccine Adsorbed Plus CPG 7909 (AV7909).

NuThrax™ (Anthrax Vaccine Adsorbed with CPG 7909 Adjuvant) (AV7909) is in development. Samples obtained in a phase Ib clinical trial were tested to confirm biomarkers of innate immunity and evaluate effects of CPG 7909 (PF-03512676) on adaptive immunity. Subjects received two intramuscular doses of commercial BioThrax(®) (Anthrax Vaccine Adsorbed, AVA), or two intramuscular doses of one of four formulations of AV7909. IP-10, IL-6, and C-reactive protein (CRP) levels were elevated 24-48 h after administration of AV7909 formulations, returning to baseline by Day 7. AVA (no CPG 7909) resulted in elevated IL-6 and CRP, but not IP-10. Another marker of CpG, transiently decreased absolute lymphocyte counts (ALCs), correlated with transiently increased IP-10. Cellular recall responses to anthrax protective antigen (PA) or PA peptides were assessed by IFN-γ ELISpot assay performed on cryopreserved PBMCs obtained from subjects prior to immunization and 7 days following the second immunization (study day 21). One-half of subjects that received AV7909 with low-dose (0.25mg/dose) CPG 7909 possessed positive Day 21 T cell responses to PA. In contrast, positive T cell responses occurred at an 11% average rate (1/9) for AVA-treated subjects. Differences in cellular responses due to dose level of CPG 7909 were not associated with differences in humoral anti-PA IgG responses, which were elevated for recipients of AV7909 compared to recipients of AVA. Serum markers at 24 or 48 h (i.e. % ALC decrease, or increase in IL-6, IP-10, or CRP) correlated with the humoral (antibody) responses 1 month later, but did not correlate with cellular ELISpot responses. In summary, biomarkers of early responses to CPG 7909 were confirmed, and adding a CpG adjuvant to a vaccine administered twice resulted in increased T cell effects relative to vaccine alone. Changes in early biomarkers correlated with subsequent adaptive humoral immunity but not cellular immunity.

Comparison of human immunodeficiency virus antigens as stimulants for lymphocyte proliferation assays.

CD4 proliferative responses to the human immunodeficiency virus (HIV) type 1 (HIV-1) p24 (gag) antigen inversely correlate with the plasma viral load in HIV-infected subjects who control viral replication without antiretroviral therapy. Use of a single HIV-1 protein to assess CD4 proliferative responses may not reflect the global response to this pathogen. We compared the abilities of HIV p24 and gp120 antigens from two different vendors, an inactivated whole HIV-1 MN virion preparation and an HIV-1E culture supernatant antigen, to elicit proliferative responses in HIV-seropositive and HIV-seronegative donors. Peripheral blood mononuclear cells from 12 HIV-seropositive donors (each with HIV-1 loads <4,000 copies/ml of plasma, >350 CD4 T lymphocytes/mm(3), and no antiretroviral therapy) and 15 HIV-seronegative donors were assessed with multiple concentrations of each stimulant by standard lymphocyte proliferation assays. Wide variations in response rates were found, with zero, three, five, and eight individuals demonstrating stimulation indices of >3 for the HIV culture antigen supernatant, gp120, p24, and inactivated whole-virus preparations, respectively. These results suggest that the use of the inactivated whole virus resulted in a more sensitive assay for detection of CD4 T-lymphocyte function in HIV-infected subjects.

Effect of contaminating red blood cells on OKT3-mediated polyclonal activation of peripheral blood mononuclear cells.

Erythrocytes are typically present as impurities in the majority of peripheral blood mononuclear cell (PBMC) preparations. This study was undertaken to investigate the effects of contaminating red blood cells (RBC) on the ability of OKT3 to activate CD4(+) and CD8(+) T cells. Surprisingly, the levels of gamma interferon, tumor necrosis factor alpha, and interleukin-1 beta (IL-1 beta) produced by PBMC upon stimulation by OKT3 were increased (P < 0.05) in a dose-dependent manner when increasing amounts of autologous RBC (RBC-to-PBMC ratios of 2:1, 10:1, and 50:1) were spiked into PBMC preparations. The OKT3-driven induction of the IL-2 receptor (CD25) and the proliferation of T lymphocytes in response to phorbol myristate acetate were not affected by the addition of RBC.

Prognostic value of baseline human immunodeficiency virus type 1 DNA measurement for disease progression in patients receiving nucleoside therapy.

Human immunodeficiency virus (HIV) type 1 DNA assay data were obtained at baseline from 111 HIV-1-positive subjects who were treated with nucleosides. Higher baseline DNA level, HIV-1 RNA level, and infectious titer were comparably associated with an increased hazard of disease progression (each P<.03). Only DNA level was significantly associated with survival (adjusted hazard ratio for 1 log(10) higher level, 3.99; 95% confidence interval, 1.44-11.09; P=.008).