During the past year, we performed continuing collaborative studies with the laboratory of Richard Childs which has recently described the HLA-A11-restricted tumor-related peptide CT-RCC-1, which is expressed by renal cell carcinoma cells. To facilitate functional studies of CT-RCC-1-specific T cells, we generated antigen-specific T cell lines by incubating lymphocytes from normal donors expressing the MHC molecule HLA-A 11 with peptide pulsed autologous dendritic cells. We were able to produce several antigen-specific cell lines from each of 2 normal donors. These were then used to study the expression of CT-RCC-1 by tumor cell lines, and the susceptibility of tumor cells to lysis.? ? Additional studies were also performed with Dr. Katy Rezvani using ELISPOT techniques to quantitate the incidence of T-cells with specificity for each of 4 HLA-A2-restricted epitopes of the tumor related peptide PRAME in normals and patients who received an allotransplant for treatment of acute or chronic leukemia. The studies documented the presence of PRAME-specific T-cells in low numbers in normal controls. Somewhat broader, stronger T cell responses were noted in some patients with AML, ALL, and CML. This observation is noteworthy because it suggests an endogenous immune response against PRAME occurs commonly in patients with active leukemia. Assuming PRAME-specific T cells can damage antigen-positive tumor cells, the results suggest that PRAME might be a very attractive target antigen for T cell adoptive transfer or anti-tumor vaccine strategies.? ? Other recent studies have focused on improving methods for generating, expanding, and rapidly cloning peptide-specific T-cells. Our particular emphasis has been on identifying optimal methods for rapidly expanding small numbers of antigen specific T cells after identification using tetramers or antigen-specific upregulatiopn of CD137 expression. Technical improvements in these areas may greatly facilitate the process of antigen discovery and simplify the process of generating antigen-specific effectors for use in vitro or in vivo in cancer immunotherapy.
| Rezvani, Katayoun; Yong, Agnes S M; Tawab, Abdul et al. (2009) Ex vivo characterization of polyclonal memory CD8+ T-cell responses to PRAME-specific peptides in patients with acute lymphoblastic leukemia and acute and chronic myeloid leukemia. Blood 113:2245-55 |
| Takahashi, Yoshiyuki; Harashima, Nanae; Kajigaya, Sachiko et al. (2008) Regression of human kidney cancer following allogeneic stem cell transplantation is associated with recognition of an HERV-E antigen by T cells. J Clin Invest 118:1099-109 |
| Mielke, Stephan; Rezvani, Katayoun; Savani, Bipin N et al. (2007) Reconstitution of FOXP3+ regulatory T cells (Tregs) after CD25-depleted allotransplantation in elderly patients and association with acute graft-versus-host disease. Blood 110:1689-97 |
| Rezvani, Katayoun; Mielke, Stephan; Ahmadzadeh, Mojgan et al. (2006) High donor FOXP3-positive regulatory T-cell (Treg) content is associated with a low risk of GVHD following HLA-matched allogeneic SCT. Blood 108:1291-7 |
