Purification of Melanoma Reactive T Cell by Using a Monocyte-based Solid Phase T-cell Selection System for Adoptive Therapy

Synthesis and cytotoxicity evaluation of thiazole derivatives obtained from 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene- 3-carbonitrile

Reactivity of 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3- carbonitrile towards thioglycolic acid resulted in thiazole derivative 1. The latter reacted with different chemical reagents to give thiazole, pyrano[2,3-d]thiazole and thiazolo[ 4,5-d]thiazole derivatives. Cytotoxicity effects of the newly synthesized products against six cancer cell lines, namely, human gastric cancer (NUGC), human colon cancer (DLD- 1), human liver cancer (HA22T and HEPG-2), human breast cancer (MCF) and nasopharyngeal carcinoma (HONE-1) as well as against a normal fibroblast cell (WI-38) were evaluated. The study showed that the 4,5,6,7 tetrahydrobenzo[ b] thiophene derivatives 6a, 7, 8a,b, 9b and 10b,c w ere t he most active compounds. Their potencies were attributed to the presence of the electron withdrawing groups.

Eliciting protective immune responses against murine myeloma challenge in lymphopenia mice through adoptive transfer of tumor antigen-specific lymphocytes and immunization of tumor vaccine secreting mIL-21

Previous studies have indicated that the cytokine interleukin (IL)-21 may induce both innate and adaptive immune responses against tumors. The goal of this study was to evaluate a new adoptive immunotherapy strategy that combined lymphocytes from mice immunized with a murine myeloma vaccine secreting murine IL-21 (mIL-21-Sp2/0) in lymphopenic mice induced by cyclophosphamide. The data indicate that effective antitumor immunity was induced in mice receiving syngeneic murine lymphocytes from the mice immunized with the mIL-21-Sp2/0. More importantly, the efficacy against the Sp2/0 cell challenge was enhanced after the lymphocytes were activated and proliferated ex vivo before administration into the lymphopenic mice. We conclude that the adoptive transfer of tumor antigen-specific lymphocytes into mice immunized with mIL-21-Sp2/0 induced protective immune responses against myeloma challenge.

Generation of BKV-Specific T Cells for Adoptive Therapy against BKV Nephropathy

Nephropathy associated with BK virus has emerged as an important cause of allograft failure in renal transplant recipients. Here we exploited a recently developed novel monocyte based solid phase T cell selection system, in which monocytes are immobilized on solid support, for antigen-specific T cell purification. The underlying hypothesis of this new method is that antigen-specific T cells recognize, bind their cognate antigens faster than non-specific T cells and are concentrated on the surface after removing the non-adherent cells by washing. Moreover, activated antigen-specific T cells proliferate more rapidly than non-specific T cells, further increasing the frequency and purity of antigen-specific T cells. Optimal selection times for BK virus-specific T cells are studied. Our data demonstrated that T cell selection can usually increase the frequency of antigen-specific T cells by > 10 fold, whereas T cell expansion following the selection boost the frequency of antigen-specific T cells by another ~10 fold. This new T cell selection system is superior to traditional stimulation method (i.e. simply mixing antigen presenting cells and lymphocytes together) in generating antigen-specific T cells. This inexpensive and simple T cell selection system can produce large quantity of highly purified BK virus-specific T cells within 1–2 weeks after initial T cell activation.

Characterization of Non-Conserved HLA-A*0201 Binding T cell Epitopes of JC Virus T Antigen

JC virus-specific CD8+ cytotoxic T lymphocytes are associated with a favorable outcome in patients with progressive multifocal leukoencephalopathy. However, very few JC virus T cell epitopes restricted to MHC class I have been defined. Of the two HLA-A*0201-restricted JCV epitopes, VP1p36 and VP1p100, studies have shown that they are conserved T cell epitopes of polyomaviruses. The cross-recognition associated to these epitopes has complicated the efforts of understanding the dynamics of immune response to JC virus. Based on the previously identified HLA-A*0201 binding T cell epitope of Simian virus 40 T antigen P281–289 (KCDDVLLLL) and BK virus T antigen P558–566 (SLQNSEFLL), T cell epitopes of JC Virus T antigen P282–290 (KCEDVFLLM) and P557–565 (SLSCSEYLL) were identified. In this report, we demonstrated that JC Virus P282–290 and P557–565 were able to stimulate T cell responses in healthy donors’ PBMCs and CD8+ cytotoxic T lymphocytes raised with both peptides could recognize and lyse their targets. Most importantly, there were no T cell cross-recognitions between JC Virus, BK Virus and SV40 virus. Therefore, JCV T-ag epitopes P282–290 and P557–565 could be better antigen epitopes compared to VP1p36 and VP1p100 to study the dynamics of cellular immune response to JCV in PML patients. In addition, as a HLA-A*0201 binding T cell epitope, both peptides could be a valuable component of immunotherapies aiming at increasing the cellular immune response against JCV for the treatment of progressive multifocal leukoencephalopathy.