4.

Background In inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), nonadherence to biologic therapy increases risk of disease flare. The aim of this study was to identify risk factors for nonadherence. Methods This was a single-center retrospective study evaluating patients with IBD treated at a tertiary care center and prescribed self-injectable biologic therapy using the center’s specialty pharmacy. Adherence was defined using medication possession ratio (MPR). Nonadherence was defined as MPR <0.86. Results Four hundred sixty patients (n = 393 with CD and n = 67 with UC) were evaluated with mean MPR (interquartile range) equaling 0.89 (0.48–1). Overall, 69% of patients were adherent (defined as MPR ≥0.86), 66% of patients with CD and 87% of patients with UC. In univariate analysis, several factors increased risk of nonadherence: CD diagnosis, insurance type, psychiatric history, smoking, prior biologic use, and narcotic use (P < 0.05). In multivariable analysis, Medicaid insurance (odds ratio [OR], 5.5; 95% confidence interval [CI], 1.85–15.6) and CD diagnosis (OR, 2.8; 95% CI, 1.3–6.0) increased risk of nonadherence. In CD, as the number of risk factors increased (narcotic use, psychiatric history, prior biologic use, and smoking), the probability of nonadherence increased. Adherence was 72% in patients with 0–1 risk factors, decreasing to 62%, 61%, and 42% in patients with 2, 3, and 4 risk factors, respectively (P < 0.05). Conclusions This study identified risk factors for nonadherence to biologic therapy. In patients with CD, the probability of nonadherence increased as the number of risk factors increased.

Vaccination with tumor-associated antigens can induce cancer-specific CD8+ T cells. A recent improvement has been the targeting of antigen to dendritic cells (DC) using antibodies that bind DC surface molecules. This study explored the use of multi-trimers of CD40L to target the gp100 melanoma tumor antigen to DC. The spontaneously-multimerizing gene Surfactant Protein D (SPD) was used to fuse gp100 tumor antigen and CD40L, creating the recombinant protein SPD-gp100-CD40L. This ―third generation‖ DC-targeting vaccine was designed to both target antigen to DC and optimally activate dendritic cells by aggregating CD40 trimers on the DC membrane surface. SPD-gp100-CD40L expressed as a 110 kDa protein. Analytical light scattering analysis gave elution data corresponding to 4-trimer and multi-trimer SPD-gp100-CD40L oligomers. The protein was biologically active on dendritic cells and induced CD40-mediated NF-κB signaling. DNA vaccination with SPD-gp100-CD40L plasmid, together with plasmids encoding IL-12p70 and GM-CSF, significantly enhanced survival and inhibited tumor growth in a B16-F10 melanoma model. Expression of gp100 and SPD-CD40L as separate molecules did not enhance survival, highlighting the requirement to encode gp100 within SPD-CD40L for optimal vaccine activity. These data support a model where DNA vaccination with SPD-gp100-CD40L targets gp100 to DC in situ, induces activation of these DC, and generates a protective anti-tumor response when given in combination with IL-12p70 and GM-CSF plasmids.

b CD40 ligand (CD40L, CD154) is a membrane protein that is important for the activation of dendritic cells (DCs) and DC-induced CD8؉ T cell responses. To be active, CD40L must cluster CD40 receptors on responding cells. To produce a soluble form of CD40L that clusters CD40 receptors necessitates the use of a multitrimer construct. With this in mind, a tripartite fusion protein was made from surfactant protein D (SPD), HIV-1 Gag as a test antigen, and CD40L, where SPD serves as a scaffold for the multitrimer protein complex. This SPD-Gag-CD40L protein activated CD40-bearing cells and bone marrow-derived DCs in vitro. Compared to a plasmid for Gag antigen alone (pGag), DNA vaccination of mice with pSPD-Gag-CD40L induced an increased number of Gag-specific CD8 ؉ T cells with increased avidity for major histocompatibility complex class I-restricted Gag peptide and improved vaccine-induced protection from challenge by vaccinia-Gag virus. The importance of the multitrimeric nature of the complex was shown using a plasmid lacking the N terminus of SPD that produced a single trimer fusion protein. This plasmid, pTrimer-Gag-CD40L, was only weakly active on CD40-bearing cells and did not elicit strong CD8؉ T cell responses or improve protection from vaccinia-Gag challenge. An adenovirus 5 (Ad5) vaccine incorporating SPD-Gag-CD40L was much stronger than Ad5 expressing Gag alone (Ad5-Gag) and induced complete protection (i.e., sterilizing immunity) from vaccinia-Gag challenge. Overall, these results show the potential of a new vaccine design in which antigen is introduced into a construct that expresses a multitrimer soluble form of CD40L, leading to strongly protective CD8 ؉ T cell responses.