Effect of infusion of monoclonal antibodies to tumour necrosis factor-receptor super family 25 on graft rejection in allo-immune mice receiving autologous marrow transplantation
IMMUNOLOGY
Authors: Gorczynski, Reginald M.; Sadozai, Hassan; Zhu, Fang; Khatri, Ismat
Abstract
Significant barriers to transplantation exist for individuals who are pre-sensitized to donor antigen and have high titres of donor-reactive antibody. We report the effect of autologous bone marrow transplantation (BMTx) after myeloablation in pre-sensitized mice along with the use of monoclonal antibodies (mAbs) to tumour necrosis factor-receptor super family 25 (TNFRSF25), expressed on regulatory T (Treg) cells. C57BL/6 mice, which had been sensitized earlier with BALB/c skin allografts, received secondary BALB/c grafts after the primary grafts had been rejected. Subsequently, recipient mice underwent myeloablation with cyclophosphamide and busulphan and were injected with T-cell-depleted bone marrow from CD45.1 congenic donors (BMTx). Recipient mice underwent immunosuppressive treatment with rapamycin. A subgroup of mice was also treated with mAbs to TNFRSF25. Control mice were pre-sensitized mice that received cyclophosphamide and busulphan followed by rapamycin. BMTx-treated mice had significantly prolonged skin graft survival versus control mice. These mice also showed attenuated donor-specific mixed lymphocyte co-culture responses relative to controls, increased splenic Treg cells and markedly diminished serum anti-donor IgG. Infusion of anti-TNFRSF25 mAbs further augmented graft survival and increased graft-infiltrating Treg cells. These mAbs also expanded murine and human Treg cells in vitro with the capacity to attenuate mixed lymphocyte co-cultures using fresh peripheral blood mononuclear cells. Overall, this study delineates the roles of autologous BMTx and anti-TNFRSF25 mAbs in expanding Treg cells and attenuating alloimmune responses in pre-sensitized mice.
Attenuated expression of DFFB is a hallmark of oligodendrogliomas with 1p-allelic loss
MOLECULAR CANCER
Authors: McDonald, J. Matthew; Dunmire, Valerie; Taylor, Ellen; Sawaya, Raymond; Bruner, Janet; Fuller, Gregory N.; Aldape, Kenneth; Zhang, Wei
Abstract
Allelic loss of chromosome Ip is frequently observed in oligodendroglioma. We screened 177 oligodendroglial tumors for Ip deletions and found 6 tumors with localized Ip36 deletions. Several apoptosis regulation genes have been mapped to this region, including Tumor Protein 73 ( p73), DNA Fragmentation Factor subunits alpha ( DFFA) and beta ( DFFB), and Tumor Necrosis Factor Receptor Superfamily Members 9 and 25 ( TNFRSF9, TNFRSF25). We compared expression levels of these 5 genes in pairs of Ip-loss and Ip-intact tumors using quantitative reverse-transcriptase PCR ( QRTPCR) to test if Ip deletions had an effect on expression. Only the DFFB gene demonstrated decreased expression in all tumor pairs tested. Mutational analysis did not reveal DFFB mutations in 12 tested samples. However, it is possible that DFFB haploinsufficiency from Ip allelic loss is a contributing factor in oligodendroglioma development.