Background aims Many studies have demonstrated that the immunogenicity of chronic

Background aims Many studies have demonstrated that the immunogenicity of chronic lymphocytic leukemia (CLL) cells can be increased by manipulation of the CD40/CD40-ligand (CD40L) pathway. of CD40L was associated with up-regulation of the co-stimulatory molecules CD80 and CD86 and Rabbit Polyclonal to GPR82. adhesion molecule CD54. In contrast transgenic IL-2 secretion was greater following plasmid transduction. These phenotypic differences in the vaccines were associated Caudatin with different functionality both and following administration to patients. Thus adenoviral vaccines induced greater activation of leukemia-reactive T cells than plasmid vaccines. In treated patients specific T-cell (T helper 1 (Th1) and T helper 2 (Th2) and humoral anti-leukemia responses were detected following administration of the adenoviral vaccine (= 15) while recipients of the plasmid vaccine (= 9) manifested only a low-level Th2 response. Progression-free survival at 2 years was 46.7% in the adenoviral vaccine recipients versus 11.1 % in those receiving plasmid vaccine Conclusions CLL vaccines expressing the same transgenes but produced by distinct ways of gene transfer varies within the polarity from the defense response they induce in individuals. and in individuals with the condition (7 10 We’ve also shown how the immunostimulatory properties of the CD40L vaccine are potentiated by co-transfecting a second adenoviral vector encoding interleukin (IL)-2 (11 12 Initial clinical studies with this combination vaccine showed leukemia-specific T-cell and humoral immune responses and limited anti-tumor effects (13). Because of the complexities and expense of manufacture of viral vectors and because of their lingering safety concerns we determined whether it was feasible to substitute a physical means of gene transfer [using plasmid electroporation with the MaxCyte good manufacturing practice (GMP)-compliant device] for vaccine manufacture. We compared the properties of autologous CLL CD40L/IL-2 vaccines prepared by adenoviral gene transfer and by plasmid electroporation analyzing their phenotype and immunostimulatory activity in individuals receiving one or other vaccine for treatment of CLL. Methods Patient and treatment protocols This paper describes the and effects of two different CD40L/IL-2 CLL vaccines one made using adenoviral vectors the other using plasmid vectors administered between 2003 and 2009. One or other vaccine was administered to a patient under concurrent phase I/II clinical protocols that were otherwise identical in inclusion and exclusion criteria Caudatin and end-points as described previously (7 10 13 In brief we assessed the toxicity (vaccine-related grade 3 or 4 Caudatin 4 toxicity grade 2 allergic or autoimmune reactions; see (accessed date: 14 December 2010) and disease response by standard criteria. Nine patients received between three and nine injections of the adenoviral vaccines between 2003 and 2005 as reported previously (13). Six additional patients received Caudatin the same vaccine between 2007 and 2009 (total receiving adenoviral vaccine = 15). Nine patients received six injections of the plasmid vaccines between 2004 and 2007. Both protocols were approved by the Institutional Review Board of the Baylor College of Medicine (Houston TX USA) the Food and Drug Administration and the Recombinant DNA Advisory Committee of the National Institute of Health. An informed consent was obtained from each patient enrolled in the study according to the Helsinki Declaration. Patients were eligible for peripheral blood collection and vaccine preparation if they had a diagnosis of CLL with measurable disease of any stage unless they were in Richter transformation. Eligibility to receive the vaccine required: (i) sufficient gene-modified CLL cells for six injections; (ii) a life expectancy of ≥10 weeks; (iii) an absolute neutrophil count of ≥500/μL an absolute lymphocyte count of ≥200/μL hemoglobin ≥ Caudatin 8 g/dL and a platelet count of ≥50 000/μL; (iv) no treatment with other investigational agents within the last 4 weeks; (v) adequate liver (total bilirubin ≤ 1.5 mg/dL serum glutamic oxaloacetic transaminase (AST) (SGOT) ≤ 3 times normal normal prothrombin time) and renal (creatinine less than three times the normal for age or creatinine clearance >80 mL/min/1.73 m2) function; (vi) no immunosuppressive drugs within 6 weeks; and (vii) no autoimmune disorders. Individual patient characteristics are summarized in Table I. Table I Characteristics of patients and.