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Ustekinumab, a human anti-interleukin (IL)-12/IL-23p40 monoclonal antibody has demonstrated significant efficacy in patients with moderate-to-severe psoriasis. Skin lesion biopsies, cell surface markers on peripheral blood lymphocytes, and ex vivo T-helper (Th)1/Th2 cytokine responses from peripheral blood mononuclear cells (PBMC) from patients receiving ustekinumab 45 or 90 mg, or placebo were evaluated at baseline and week 12. Inflammatory serum protein levels were measured at baseline, week 2 and week 12. At week 12, median epidermal thickness decreased from 312.1 to 132.7 microm, and median levels of cellular proliferation (Ki67) and T-cell infiltration (CD3) decreased by 84.3% and 70.7%, respectively, in the combined ustekinumab group (all P < or = 0.002). Serum levels of tumor necrosis factor (TNF)-alpha, C-C motif ligand 27 (CCL27) and other inflammatory cytokines remained unchanged. Minimal variation in the percentage of T cells expressing cutaneous lymphocyte antigen (CLA) was observed following ustekinumab treatment, with no significant variation in the percentage of cells expressing CD45RA, CD45RO, CD25, human leukocyte antigen-DR (HLA-DR), and C-X-C motif receptor 3 (CXCR3). No apparent effect on the magnitude of Th1/Th2 responses to external stimuli in PBMC was observed following placebo or ustekinumab treatment. Ustekinumab improves histological psoriasis measures, with minimal impact on the systemic immune system.

Interleukin-12 (IL-12) promotes specific and long-lasting anti-tumor immunity mediated by T cells in a variety of murine tumor models. IL-12 also synergizes with B7.1 (CD80) co-stimulation to induce proliferation and cytokine production by both human and murine T cells in vitro. We evaluated the combined anti-tumor efficacy of IL-12 and B7.1 gene delivery in two apparently poorly immunogenic tumor models (TS/A and MCA207). In both of these models, expression of B7.1 and production of IL-12 in the inoculum led to improved anti-tumor immunity, with up to 80% long-term tumor-free animals (vs 0-20% of mice remaining tumor free when inoculated with either B7.1- or IL-12-transfected tumors alone). Tumor-free mice were capable of rejecting a subsequent rechallenge with the wild-type tumor in 66% of the cases. Cooperativity was dependent upon the level of IL-12 secreted by engineered cells. IL-12 delivery required B7 expression of therapeutic effects to be observed in these models. Vaccines provided at a site distal to a control, non-transfected tumor slowed (TS/A) or abrogated (MCA207) the progression of wild-type tumors. The synergistic anti-tumor effects associated with combined application of B7.1- and IL-12-transfected tumors were partially negated by systemic administration of the CD28-B7.1/B7.2 antagonist CTLA4-Ig or by inoculation with neutralizing antibodies directed against murine interferon-gamma or tumor necrosis factor-alpha, two cytokines elicited in response to IL-12 stimulation. These data support the potential clinical utility of combined gene therapy using IL-12- and B7.1-engineered autologous cells (tumor or fibroblasts) as a vaccine to elicit specific anti-tumor immunity.

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