T cell proliferation, MHC class II restriction and cytokine products of gliadin-stimulated peripheral blood mononuclear cells (PBMC)

The immune response of PBMC to gliadin was investigated in patients with coeliac disease (CoD) by examining proliferation, MHC restriction and cytokine production. Gliadin induced low levels of proliferation in 63% of eight untreated patients, 32% of 28 treated patients and 35% of 31 healthy control subjects. In MHC restriction studies, the proliferative response to gliadin was inhibited (range 47–98% inhibition) in the presence of a MoAb to HLA-DR in each of three coeliac and three control donors studied. Using flow cytometry, increased expression of activation markers (HLA-DR and IL-2R) was demonstrated on gliadin-stimulated T cells from four of nine coeliac patients and three of seven healthy control donors. Cytokines were studied in culture supernatants using ELISA. Gliadin was a potent inducer of IL-6 and IL-10 in 100% of coeliac patients and controls, whereas IL-4 was not produced in either subject group. Gliadin induced IL-2 production in 40% of untreated patients, 42% of treated patients and 35% of healthy control donors. Interferon-gamma (IFN-γ) in gliadin-stimulated cultures was found only in coeliac patients, observed in 33% of untreated patients and 25% of treated patients. Spontaneous secretion of both IL-2 and IFN-γ was found more frequently in patients with untreated disease (87% of cases versus 21% of controls for IFN-γ and 40% versus 0% for IL-2). These results suggest, as manifest by IFN-γ production, that gliadin stimulates a Th1/Th0-like response in coeliac patients and a Th0-like response in healthy controls

Pilot study of mutant ras peptide-based vaccine as an adjuvant treatment in pancreatic and colorectal cancers

INTRODUCTION: There is mounting evidence describing the immunosuppressive role of bulky metastatic disease, thus countering the therapeutic effects of tumor vaccine. Therefore, adjuvant immunotherapy may have a better impact on clinical outcome. In this phase II clinical trial, we aimed to test the feasibility of using a specific mutant ras peptide vaccine as an adjuvant immunotherapy in pancreatic and colorectal cancer patients. MATERIALS AND METHODS: Twelve patients with no evidence of disease (NED), five pancreatic and seven colorectal cancer patients were vaccinated subcutaneously with 13-mer mutant ras peptide, corresponding to their tumor's ras mutation. Vaccinations were given every 4 weeks, up to a total of six vaccines. RESULTS: No serious acute or delayed systemic side effects were seen. We detected specific immune responses to the relevant mutant ras peptide by measuring IFN-gamma mRNA expression by quantitative real-time PCR. Five out of eleven patients showed a positive immune response. Furthermore, the five pancreatic cancer patients have shown a mean disease-free survival (DFS) of 35.2+ months and a mean overall survival (OS) of 44.4+ months. The seven colorectal cancer patients have shown a mean disease-free survival (DFS) of 27.2+ months and a mean overall survival (OS) of 41.5+ months. CONCLUSION: In this study, we found that it is feasible to use mutant ras vaccine in the adjuvant setting. This vaccine is safe, can induce specific immune responses, and it appears to have a positive outcome in overall survival. Therefore, we believe that such an approach warrants further investigation in combination with other therapies