Doug Redelman

Publications (35)184.14 Total impact

• Article: Delineation of antigen-specific and antigen-nonspecific CD8(+) memory T-cell responses after cytokine-based cancer immunotherapy.

  Julia K Tietze, Danice E C Wilkins, Gail D Sckisel, Myriam N Bouchlaka, Kory L Alderson, Jonathan M Weiss, Erik Ames, Kevin W Bruhn, Noah Craft, Robert H Wiltrout, Dan L Longo, Lewis L Lanier, Bruce R Blazar, Doug Redelman, William J Murphy
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  ABSTRACT: Memory T cells exhibit tremendous antigen specificity within the immune system and accumulate with age. Our studies reveal an antigen-independent expansion of memory, but not naive, CD8(+) T cells after several immunotherapeutic regimens for cancer resulting in a distinctive phenotype. Signaling through T-cell receptors (TCRs) or CD3 in both mouse and human memory CD8(+) T cells markedly up-regulated programmed death-1 (PD-1) and CD25 (IL-2 receptor α chain), and led to antigen-specific tumor cell killing. In contrast, exposure to cytokine alone in vitro or with immunotherapy in vivo did not up-regulate these markers but resulted in expanded memory CD8(+) T cells expressing NKG2D, granzyme B, and possessing broadly lytic capabilities. Blockade of NKG2D in mice also resulted in significantly diminished antitumor effects after immunotherapy. Treatment of TCR-transgenic mice bearing nonantigen expressing tumors with immunotherapy still resulted in significant antitumor effects. Human melanoma tissue biopsies obtained from patients after topically applied immunodulatory treatment resulted in increased numbers of these CD8(+) CD25(-) cells within the tumor site. These findings demonstrate that memory CD8(+) T cells can express differential phenotypes indicative of adaptive or innate effectors based on the nature of the stimuli in a process conserved across species.
  Blood 01/2012; 119(13):3073-83. · 9.90 Impact Factor
• Article: Mechanical disruption of tumors by iron particles and magnetic field application results in increased anti-tumor immune responses.

  Myriam N Bouchlaka, Gail D Sckisel, Danice Wilkins, Emanual Maverakis, Arta M Monjazeb, Maxwell Fung, Lisbeth Welniak, Doug Redelman, Alan Fuchs, Cahit A Evrensel, William J Murphy
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  ABSTRACT: The primary tumor represents a potential source of antigens for priming immune responses for disseminated disease. Current means of debulking tumors involves the use of cytoreductive conditioning that impairs immune cells or removal by surgery. We hypothesized that activation of the immune system could occur through the localized release of tumor antigens and induction of tumor death due to physical disruption of tumor architecture and destruction of the primary tumor in situ. This was accomplished by intratumor injection of magneto-rheological fluid (MRF) consisting of iron microparticles, in Balb/c mice bearing orthotopic 4T1 breast cancer, followed by local application of a magnetic field resulting in immediate coalescence of the particles, tumor cell death, slower growth of primary tumors as well as decreased tumor progression in distant sites and metastatic spread. This treatment was associated with increased activation of DCs in the draining lymph nodes and recruitment of both DCs and CD8(+)T cells to the tumor. The particles remained within the tumor and no toxicities were observed. The immune induction observed was significantly greater compared to cryoablation. Further anti-tumor effects were observed when MRF/magnet therapy was combined with systemic low dose immunotherapy. Thus, mechanical disruption of the primary tumor with MRF/magnetic field application represents a novel means to induce systemic immune activation in cancer.
  PLoS ONE 01/2012; 7(10):e48049. · 4.09 Impact Factor
• Article: Mouse NK cell-mediated rejection of bone marrow allografts exhibits patterns consistent with Ly49 subset licensing.

  Kai Sun, Maite Alvarez, Erik Ames, Isabel Barao, Mingyi Chen, Dan L Longo, Doug Redelman, William J Murphy
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  ABSTRACT: Natural killer (NK) cells can mediate the rejection of bone marrow allografts and exist as subsets based on expression of inhibitory/activating receptors that can bind MHC. In vitro data have shown that NK subsets bearing Ly49 receptors for self-MHC class I have intrinsically higher effector function, supporting the hypothesis that NK cells undergo a host MHC-dependent functional education. These subsets also play a role in bone marrow cell (BMC) allograft rejection. Thus far, little in vivo evidence for this preferential licensing across mouse strains with different MHC haplotypes has been shown. We assessed the intrinsic response potential of the different Ly49(+) subsets in BMC rejection by using β2-microglobulin deficient (β2m(-/-)) mice as donors. Using congenic and allogeneic mice as recipients and depleting the different Ly49 subsets, we found that NK subsets bearing Ly49s, which bind "self-MHC" were found to be the dominant subset responsible for β2m(-/-) BMC rejection. This provides in vivo evidence for host MHC class I-dependent functional education. Interestingly, all H2(d) strain mice regardless of background were able to resist significantly greater amounts of β2m(-/-), but not wild-type BMC than H2(b) mice, providing evidence that the rheostat hypothesis regarding Ly49 affinities for MHC and NK-cell function impacts BMC rejection capability.
  Blood 12/2011; 119(6):1590-8. · 9.90 Impact Factor
• Article: Hydrodynamic delivery of human IL-15 cDNA increases murine natural killer cell recovery after syngeneic bone marrow transplantation.

  Isabel Barao, Maite Alvarez, Doug Redelman, Jonathan M Weiss, John R Ortaldo, Robert H Wiltrout, William J Murphy
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  ABSTRACT: Immune deficiency immediately following bone marrow transplantation (BMT) increases susceptibility to opportunistic infections as well as tumor relapse. Natural Killer (NK) cells play important roles in the resistance to virally infected and transformed cells. Interleukin (IL)-15 has been shown to be essential for NK cell development and survival. We administered human (h) IL-15 cDNA (pIL-15) via hydrodynamic delivery to murine recipients undergoing congenic BMT to determine its effects on NK cell reconstitution. Hydrodynamic pIL-15 delivery resulted in high levels of hIL-15 protein in the serum that lasted for several days and then quickly declined. The appearance of hIL-15 was followed by a significant increase of mature donor-derived NK cells within the bone marrow, spleens, and livers of the treated recipients. No accumulation of immature NK cell progenitors was observed. The NK cells from IL-15-treated recipients displayed an activated phenotype and were lytically active toward tumor targets in vitro to a similar degree as did those cells from recipients treated with control plasmid. This suggests that the predominant effect of IL-15 was a quantitative increase in total NK cell numbers and not qualitative changes in NK cell functions. No toxicities or adverse effects were observed. Studies performed in transplanted mice bearing renal carcinoma tumors demonstrated that this mode of hIL-15 gene delivery resulted in increased antitumor responses. These results support the use of cytokine gene transfer-based regimens as a platform to augment NK cell recovery after BMT.
  Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 09/2011; 17(12):1754-64. · 3.15 Impact Factor
• Article: Mouse Ly49G2+ NK cells dominate early responses during both immune reconstitution and activation independently of MHC.

  Isabel Barao, Maite Alvarez, Erik Ames, Mark T Orr, Heather E Stefanski, Bruce R Blazar, Lewis L Lanier, Stephen K Anderson, Doug Redelman, William J Murphy
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  ABSTRACT: Natural killer (NK) cell subsets can be defined by the differential expression of inhibitory receptors for MHC class I molecules. Early after congenic HSCT, we found that Ly49G2(high) single-positive NK cells repopulated, displayed an activated phenotype, and were highly cytolytic. Over time, this subset was replaced with NK cells with a normal pattern of Ly49 expression. Treatment of mice with IL-2 also resulted in the rapid expansion of these Ly49G2(high) single-positive NK cells. Only the Ly49g (Klra7) Pro1 transcript was highly induced in both HSCT- and IL-2-treated recipients. MHC-independent expansion of the Ly49G2(+) subset was also observed after Listeria monocytogenes or mouse cytomegalovirus infection. Our data indicate that during reconstitution after HSCT and various activation stimuli, Ly49G2(+) NK cells represent the "first-responder" NK cells, which occur independently of NK-cell licensing via Ly49-MHC interactions. These data suggest that the inhibitory Ly49G2 receptor represents an activation marker on mouse NK cells under various conditions.
  Blood 04/2011; 117(26):7032-41. · 9.90 Impact Factor
• Article: Serum response factor-dependent MicroRNAs regulate gastrointestinal smooth muscle cell phenotypes.

  Chanjae Park, Grant W Hennig, Kenton M Sanders, Jonathan H Cho, William J Hatton, Doug Redelman, Jong Kun Park, Sean M Ward, Joseph M Miano, Wei Yan, Seungil Ro
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  ABSTRACT: Smooth muscle cells (SMCs) change phenotypes under various pathophysiological conditions. These changes are largely controlled by the serum response factor (SRF), a transcription factor that binds to CC (A/T)6 GG (CArG) boxes in SM contractile genes. MicroRNAs (miRNA) regulate transitions among SMC phenotypes. The SMC miRNA transcriptome (SMC miRNAome) and its regulation by SRF have not been determined. We performed massively parallel sequencing to identify gastrointestinal (GI) SMC miRNA transcriptomes in mice and humans. SMC miRNA transcriptomes were mapped to identify all CArG boxes, which were confirmed by SRF knockdown and microarrays. Quantitative polymerase chain reaction was used to identify SMC-phenotypic miRNAs in differentiated and proliferating SMCs. Bioinformatics and target validation analysis showed regulation of SMC phenotype by SRF-dependent, SMC-phenotype miRNAs. We cloned and identified GI miRNA transcriptomes using genome-wide analyses of mouse and human cells. The SM miRNAome consisted of hundreds of unique miRNAs that were highly conserved among both species. We mapped miRNAs CArG boxes and found that many had an SRF-dependent signature in the SM miRNAome. The SM miRNAs CArG boxes had several distinct features. We also identified approximately 100 SMC-phenotypic miRNAs that were induced in differentiated or proliferative SMC phenotypes. We showed that SRF-dependent, SMC-phenotypic miRNAs bind and regulate Srf and its cofactors, myocadin (Myocd) and member of ETS oncogene family Elk1. The GI SMC phenotypes are controlled by SRF-dependent, SMC-phenotypic miRNAs that regulate expression of SRF, MYOCD, and ELK1.
  Gastroenterology 04/2011; 141(1):164-75. · 11.68 Impact Factor
• Article: Kitlow stem cells cause resistance to Kit/platelet-derived growth factor alpha inhibitors in murine gastrointestinal stromal tumors.

  Michael R Bardsley, Viktor J Horváth, David T Asuzu, Andrea Lorincz, Doug Redelman, Yujiro Hayashi, Laura N Popko, David L Young, Gwen A Lomberk, Raul A Urrutia, Gianrico Farrugia, Brian P Rubin, Tamas Ordog
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  ABSTRACT: Gastrointestinal stromal tumors (GIST) are related to interstitial cells of Cajal (ICC) and often contain activating stem cell factor receptor (Kit) or platelet-derived growth factor receptor alpha (Pdgfra) mutations. Kit/Pdgfra inhibitors such as imatinib mesylate have increased progression-free survival in metastatic GIST but are not curative. In mouse models we investigated whether Kit(low) ICC progenitors could represent an inherently Kit/Pdgfra inhibitor-resistant reservoir for GIST. Isolated Kit(low)Cd44(+)Cd34(+) cells were characterized after serial cloning. The tumorigenic potential of spontaneously transformed cells was investigated in nude mice. The Kit(low)Cd44(+)Cd34(+) cells' responsiveness to Kit activation and blockade was studied by enumerating them in Kit(K641E) mice (a GIST model), in mice with defective Kit signaling, and pharmacologically. Single isolated Kit(low)Cd44(+)Cd34(+) cells were clonogenic and capable of self-renewal and differentiation into ICC. In nude mice, spontaneously transformed cells formed malignant tumors expressing GIST markers. The Kit(low)Cd44(+)Cd34(+) cells were resistant to in vitro Kit blockade, including by imatinib, and occurred in normal numbers in mice with reduced Kit signaling. In Kit(K641E) mice, the mutant ICC stem cells were grossly hyperplastic but remained imatinib-resistant. In contrast, the cancer stem, cell-targeting drug salinomycin blocked the proliferation of Kit(low)Cd44(+)Cd34(+) cells and increased their sensitivity to imatinib. Kit(low)Cd44(+)Cd34(+) progenitors are true stem cells for normal and hyperplastic ICC and give rise to GIST. Resistance to Kit/Pdgfra inhibitors is inherent in GIST and is caused by the native ICC stem cells' lack of dependence on Kit for survival, which is maintained after the acquisition of oncogenic Kit mutation. Cancer stem cell drugs may target these cells.
  Gastroenterology 09/2010; 139(3):942-52. · 11.68 Impact Factor
• Article: Immunotherapy following hematopoietic stem cell transplantation: potential for synergistic effects.

  Myriam N Bouchlaka, Doug Redelman, William J Murphy
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  ABSTRACT: Hematopoietic stem cell transplantation (HSCT) is a particularly important treatment for hematologic malignancies. Unfortunately, following allogeneic HSCT, graft-versus-host disease, immunosuppression and susceptibility to opportunistic infections remain among the most substantial problems restricting the efficacy and use of this procedure, particularly for cancer. Adoptive immunotherapy and/or manipulation of the graft offer ways to attack residual cancer as well as other transplant-related complications. Recent exciting discoveries have demonstrated that HSCT could be expanded to solid tissue cancers with profound effects on the effectiveness of adoptive immunotherapy. This review will provide a background regarding HSCT, discuss the complications that make it such a complex treatment procedure following up with current immunotherapeutic strategies and discuss emerging approaches in applying immunotherapy in HSCT for cancer.
  Immunotherapy 05/2010; 2(3):399-418. · 1.85 Impact Factor
• Article: The triterpenoid CDDO-Me delays murine acute graft-versus-host disease with the preservation of graft-versus-tumor effects after allogeneic bone marrow transplantation.

  Minghui Li, Kai Sun, Doug Redelman, Lisbeth A Welniak, William J Murphy
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  ABSTRACT: The occurrence of acute graft-versus-host disease (aGVHD) and tumor relapse represent the two major obstacles impeding the efficacy of allogeneic bone marrow transplantation (BMT) in cancer. We have previously shown that the synthetic triterpenoid 2-cyano-3, 12-dioxooleana-1, 9-dien-28-oic acid (CDDO) can inhibit murine early aGVHD, but antitumor effects were not assessed. In the current study, we found that a new derivative of CDDO, CDDO-Me, had an increased ability to inhibit allogeneic T cell responses and induce cell death of alloreactive T cells in vitro. Administration of CDDO-Me to mice following allogeneic BMT resulted in significant and increased protection from lethal aGVHD compared to CDDO. This correlated with reduced TNF-alpha production, reduced donor T cell proliferation, and decreased adhesion molecule (alpha(4)beta(7) integrin) expression on the donor T cells. CDDO-Me was also superior to CDDO in inhibiting leukemia growth in vitro. When CDDO-Me was administered following an allogeneic BMT to leukemia-bearing mice, significant increases in survival were observed. These findings suggest that CDDO-Me is superior to CDDO in delaying aGVHD, while preserving or possibly even augmenting GVT effects.
  Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 03/2010; 16(6):739-50. · 3.15 Impact Factor
• Article: A model to study the phenotypic changes of interstitial cells of Cajal in gastrointestinal diseases.

  Seungil Ro, Chanjae Park, Jingling Jin, Huili Zheng, Peter J Blair, Doug Redelman, Sean M Ward, Wei Yan, Kenton M Sanders
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  ABSTRACT: Interstitial cells of Cajal (ICC) express the receptor tyrosine kinase, KIT, the receptor for stem cell factor. In the gastrointestinal (GI) tract, ICC are pacemaker cells that generate spontaneous electrical slow waves, and mediate inputs from motor neurons. Absence or loss of ICC are associated with GI motility disorders, including those consequent of diabetes. Studies of ICC have been hampered by the low density of these cells and difficulties in recognizing these cells in cell dispersions. Kit(+/copGFP) mice harboring a copepod super green fluorescent protein (copGFP) complementary DNA, inserted at the Kit locus, were generated. copGFP(+) ICC from GI muscles were analyzed using confocal microscopy and flow cytometry. copGFP(+) ICC from the jejunum were purified by a fluorescence-activated cell sorter and validated by cell-specific markers. Kit(+/copGFP) mice were crossbred with diabetic Lep(+/ob) mice to generate compound Kit(+/copGFP);Lep(ob/ob) mutant mice. copGFP(+) ICC from compound transgenic mice were analyzed by confocal microscopy. copGFP in Kit(+/copGFP) mice colocalized with KIT immunofluorescence and thus was predominantly found in ICC. In other smooth muscles, mast cells were also labeled, but these cells were relatively rare in the murine GI tract. copGFP(+) cells from jejunal muscles were Kit(+) and free of contaminating cell-specific markers. Kit(+/copGFP);Lep(ob/ob) mice displayed ICC networks that were dramatically disrupted during the development of diabetes. Kit(+/copGFP) mice offer a powerful new model to study the function and genetic regulation of ICC phenotypes. Isolation of ICC from animal models will help determine the causes and responses of ICC to therapeutic agents.
  Gastroenterology 11/2009; 138(3):1068-78.e1-2. · 11.68 Impact Factor
• Article: Lipid‐dependent cytotoxicity by the lipase PLRP2 and by PLRP2‐positive cytotoxic T lymphocytes (CTLs)

  Bryce N. Alves, Kristen Marshall, David L. Tamang, Jeffrey Leong, Doug Redelman, Viki Elliott, Mark E. Lowe, Dorothy Hudig
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  ABSTRACT: IL-4 induces a lipase, pancreatic lipase related protein 2 (PLRP2), in cytotoxic T lymphocytes (CTLs). Because PLRP2 in semen can mediate lipid-dependent toxicity to sperm, we questioned whether CTL-derived PLRP2 could support similar cytotoxicity toward tumor cells. Recombinant PLRP2 was toxic to P815 tumor cells in 48 h when lipid and another protein, colipase, were present. However, PLRP2-positive CTLs (induced with many lots of IL-4) were unable to mediate lipid-dependent cytotoxicity. Notably, CTLs induced with only one lot of IL-4 had lipid-dependent cytotoxicity. The exceptional lot of IL-4 was effective in multiple experiments at inducing lipid-dependent cytotoxicity. The lipid-dependent cytotoxicity it induced was determined to be perforin-independent. CTLs induced with IL-4 that was unable to induce lipid-dependent cytotoxicity had mRNA for PLRP2 but not mRNA for colipase. Therefore, we added exogenous colipase to the CTL assays but still cytotoxicity was unchanged. We conclude (1) that lipid-dependent cytotoxicity, promoted by the lipase PLRP2 and colipase, will kill tumor cells and (2) that more than PLRP2 alone is required for lipid-dependent cytotoxicity mediated by CTLs. Copyright © 2009 John Wiley & Sons, Ltd.
  Cell Biochemistry and Function 06/2009; 27(5):296 - 308. · 1.77 Impact Factor
• Article: Lipid-dependent cytotoxicity by the lipase PLRP2 and by PLRP2-positive cytotoxic T lymphocytes (CTLs).

  Bryce N Alves, Kristen Marshall, David L Tamang, Jeffrey Leong, Doug Redelman, Viki Elliott, Mark E Lowe, Dorothy Hudig
  [show abstract] [hide abstract]
  ABSTRACT: IL-4 induces a lipase, pancreatic lipase related protein 2 (PLRP2), in cytotoxic T lymphocytes (CTLs). Because PLRP2 in semen can mediate lipid-dependent toxicity to sperm, we questioned whether CTL-derived PLRP2 could support similar cytotoxicity toward tumor cells. Recombinant PLRP2 was toxic to P815 tumor cells in 48 h when lipid and another protein, colipase, were present. However, PLRP2-positive CTLs (induced with many lots of IL-4) were unable to mediate lipid-dependent cytotoxicity. Notably, CTLs induced with only one lot of IL-4 had lipid-dependent cytotoxicity. The exceptional lot of IL-4 was effective in multiple experiments at inducing lipid-dependent cytotoxicity. The lipid-dependent cytotoxicity it induced was determined to be perforin-independent. CTLs induced with IL-4 that was unable to induce lipid-dependent cytotoxicity had mRNA for PLRP2 but not mRNA for colipase. Therefore, we added exogenous colipase to the CTL assays but still cytotoxicity was unchanged. We conclude (1) that lipid-dependent cytotoxicity, promoted by the lipase PLRP2 and colipase, will kill tumor cells and (2) that more than PLRP2 alone is required for lipid-dependent cytotoxicity mediated by CTLs.
  Cell Biochemistry and Function 06/2009; 27(5):296-308. · 1.77 Impact Factor
• Article: Pancreatic lipase-related protein 2 (PLRP2) induction by IL-4 in cytotoxic T lymphocytes (CTLs) and reevaluation of the negative effects of its gene ablation on cytotoxicity.

  Bryce N Alves, Jeff Leong, David L Tamang, Viki Elliott, Jillian Edelnant, Doug Redelman, Cherie A Singer, Andrew R Kuhn, Rita Miller, Mark E Lowe, Dorothy Hudig
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  ABSTRACT: Pancreatic lipase-related protein 2 (PLRP2) is induced by IL-4 in vitro in cytotoxic T lymphocyte (CTL) clones and CTLs from immunized wild-type (WT) PLRP2(+/+) are more cytotoxic than PLRP2(-/-) CTLs, suggesting to previous investigators that the lipase PLRP2 might support CTL functions. Here, we further evaluate PLRP2 in CTLs. We found that PLRP2 was optimally induced in splenocytes by 3.5 x 10(-8) M IL-4 by day 6 after activation and was restricted to CD8(+) T cells. PLRP2 mRNA was detected inconsistently (and at low levels) after activation in the presence of IL-2. Cytotoxicity in 4 h (51)Cr assays of WT CTLs was approximately 3-fold the activity of PLRP2(-/-) CTLs cultured with IL-4 and, with IL-2, was unexpectedly approximately 2 fold the activity of PLRP2(-/-) CTLs. Thus, PLRP2 gene ablation affected short-term (perforin-dependent) cytotoxicity, even under the IL-2 conditions. Other variables failed to account for the reduced cytotoxicity. Granzyme B levels, activation markers, and CD8(+) T cell frequencies were similar for WT vs. PLRP2(-/-) CTLs (with either cytokine). Addition of rPLRP2 to IL-4 induced PLRP2(-/-) CTLs (or to cytotoxic granule extracts) failed to increase lysis, suggesting that the missing mediator is more than released PLRP2. Cytotoxicity of WT and PLRP2(-/-) CTLs was similar in 2-day tumor survival assays with IL-4, which can be mediated by perforin-independent mechanisms. We conclude that extracellular PLRP2 lipase is unable to directly augment the cytotoxicity that was lost by PLRP2 ablation and that after reevaluation, the question of what is PLRP2's role in CD8 T cells is still unanswered.
  Journal of leukocyte biology 06/2009; 86(3):701-12. · 4.99 Impact Factor
• Article: Regulation of perforin lysis: implications for protein disulfide isomerase proteins.

  David L Tamang, Bryce N Alves, Viki Elliott, Doug Redelman, Renu Wadhwa, Stephanie A Fraser, Dorothy Hudig
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  ABSTRACT: Perforin, a membrane-permeabilizing protein, is important to T cell cytotoxic action. Perforin has potential to damage the T cell in the endoplasmic reticulum (ER), is sequestered in granules, and later is exocytosed to kill cells. In the ER and after exocytosis, calcium and pH favor perforin activity. We found a novel perforin inhibitor associated with cytotoxic T cell granules and termed it Cytotoxic Regulatory Protein 2 (CxRP2). CxRP2 blocked lysis by granule extracts, recombinant perforin and T cells. Its effects lasted for hours. CxRP2 was calcium stable and refractory to inhibitors of granzyme and cathepsin proteases. Through mass spectrometric analysis of active 50-100 kDa proteins, we identified CxRP2 candidates. Protein disulfide isomerase A3 was the strongest candidate but was unavailable for testing; however, protein disulfide isomerase A1 had CxRP2 activity. Our results indicate that protein disulfide isomerases, in the ER or elsewhere, may protect T cells from their own perforin.
  Cellular Immunology 02/2009; 255(1-2):82-92. · 1.97 Impact Factor
• Article: Progenitors of interstitial cells of cajal in the postnatal murine stomach.

  Andrea Lorincz, Doug Redelman, Viktor J Horváth, Michael R Bardsley, Hui Chen, Tamás Ordög
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  ABSTRACT: Maintaining the integrity of networks of interstitial cells of Cajal (ICC) is essential to preserve orderly contractile activity and neuroregulation in the gastrointestinal tract and to restore these functions after tissue damage or surgeries. Maintenance of ICC requires insulin-dependent or insulin-like growth factor I (IGF-I)-dependent production of membrane-bound stem cell factor (SCF) and may involve regeneration from local progenitors. Our goal was to identify ICC precursors in postnatal murine gastric muscles. We used flow cytometry and immunohistochemistry to examine freshly dissected and cultured muscles for cells expressing CD34, an adhesion molecule expressed by stromal tumors; CD44, which occurs on mesenchymal stem cells; and receptors for SCF (Kit), insulin (Insr), and IGF-I (Igf1r). Slow waves were studied by intracellular recording. In gastric muscles, we identified rare, Kit(low)CD44(+)CD34(+)Insr(+)Igf1r(+) cells resembling common embryonic precursors of ICC and smooth muscle. These putative progenitors were absent from organotypic cultures lacking mature ICC (Kit(+)CD44(+)CD34(-)Insr(-)Igf1r(-)) due to prolonged insulin/IGF-I deprivation but were rescued by IGF-I that also prevented ICC loss. Soluble SCF failed to prevent the loss of mature ICC but dramatically expanded the putative progenitors, which supported robust slow wave activity despite retaining an immature, Kit(+)CD44(+)CD34(+)Insr(+)Igf1r(+) phenotype. Differentiation of these cells into mature, network-forming ICC required IGF-I. Conversely, restoration of ICC networks by IGF-I after prolonged insulin and IGF-I deprivation required the survival of the presumed progenitors. Kit(low)CD44(+)CD34(+)Insr(+)Igf1r(+) cells may be local progenitors for gastric ICC and stromal tumors. Loss of these cells may contribute to gastrointestinal dysmotilities.
  Gastroenterology 04/2008; 134(4):1083-93. · 11.68 Impact Factor
• Article: Regulatory and conventional CD4+ T cells show differential effects correlating with PD-1 and B7-H1 expression after immunotherapy.

  Kory L Alderson, Qing Zhou, Vanessa Berner, Danice E C Wilkins, Jonathan M Weiss, Bruce R Blazar, Lisbeth A Welniak, Robert H Wiltrout, Doug Redelman, William J Murphy
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  ABSTRACT: Recently, our laboratory reported that secondary CD8+ T cell-mediated antitumor responses were impaired following successful initial antitumor responses using various immunotherapeutic approaches. Although immunotherapy stimulated significant increases in CD8+ T cell numbers, the number of CD4+ T cells remained unchanged. The current investigation revealed a marked differential expansion of CD4+ T cell subsets. Successful immunotherapy surprisingly resulted in an expansion of CD4+Foxp3+ regulatory T (Treg) cells concurrent with a reduction of conventional CD4+ T (Tconv) cells, despite the marked antitumor responses. Following immunotherapy, we observed differential up-regulation of PD-1 on the surface of CD4+Foxp3+ Treg cells and CD4+Foxp3- Tconv cells. Interestingly, it was the ligand for PD-1, B7-H1 (PDL-1), that correlated with Tconv cell loss after treatment. Furthermore, IFN-gamma knockout (IFN-gamma-/-) and IFN-gamma receptor knockout (IFN-gammaR-/-) animals lost up-regulation of surface B7-H1 even though PD-1 expression of Tconv cells was not changed, and this correlated with CD4+ Tconv cell increases. These results suggest that subset-specific expansion may contribute to marked shifts in the composition of the T cell compartment, potentially influencing the effectiveness of some immunotherapeutic approaches that rely on IFN-gamma.
  The Journal of Immunology 04/2008; 180(5):2981-8. · 5.79 Impact Factor
• Article: Low dose IL-15 induces snap arming of CD44(low) T lymphocytes in the absence of antigen.

  David L Tamang, Bryce N Alves, Viki Elliott, Stephanie A Fraser, Doug Redelman, Dorothy Hudig
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  ABSTRACT: It is widely accepted that naïve T cells require two signals, antigen recognition and co-simulation, to become cytotoxic over the course of 3-5days. However, we observed that freshly isolated murine splenocytes without exposure to antigen become cytotoxic within 24h after culture with IL-15. IL-15 is a cytokine that promotes homeostatic proliferation, maintenance and activation of memory T cells. The induced cytotoxicity, measured by anti-CD3 redirected (51)Cr release, represented the combined activity of T cells regardless of their antigen specificity, and proceeded even when CD44(hi) (memory-associated phenotype) CD8(+) T cells were depleted. Cytotoxic capacity was perforin-dependent and occurred without detectable up-regulation of granzyme B or cell division. After induction, the phenotypic markers for the memory subset and for activation remained unchanged from the expression of resting T cells. Our work suggests that T cells may gain cytotoxic potential earlier than currently thought and even without TCR stimulation.
  Cellular Immunology 03/2008; 251(2):93-101. · 1.97 Impact Factor
• Article: Neuroendocrine hormones such as growth hormone and prolactin are integral members of the immunological cytokine network.

  Doug Redelman, Lisbeth A Welniak, Dennis Taub, William J Murphy
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  ABSTRACT: Neuroendocrine hormones such as growth hormone (GH) and prolactin (PRL) have been demonstrated to accelerate the recovery of the immune response after chemotherapy and bone marrow transplantation and to enhance the restoration of immunity in individuals infected with HIV and in normal individuals with compromised immune systems associated with aging. As the mechanism of action of these hormones has been elucidated, it has become clear that they are integral members of the immunological cytokine/chemokine network and share regulatory mechanisms with a wide variety of cytokines and chemokines. The members of this cytokine network induce and can be regulated by members of the suppressor of cytokine signaling (SOCS) family of intracellular proteins. In order to take advantage of the potential beneficial effects of hormones such as GH or PRL, it is essential to take into consideration the overall cytokine network and the regulatory effects of SOCS proteins.
  Cellular Immunology 03/2008; 252(1-2):111-21. · 1.97 Impact Factor
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  Available from: physiology.org

  Article: Differential gene expression in functional classes of interstitial cells of Cajal in murine small intestine.

  Hui Chen, Tamás Ordög, Junwei Chen, David L Young, Michael R Bardsley, Doug Redelman, Sean M Ward, Kenton M Sanders
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  ABSTRACT: Interstitial cells of Cajal (ICC) have important functions in regulation of motor activity in the gastrointestinal tract. In murine small intestine, ICC are gathered in the regions of the myenteric plexus (ICC-MY) and the deep muscular plexus (ICC-DMP). These two classes of ICC have different physiological functions. ICC-MY are pacemaker cells and generate the slow-wave electrical rhythmicity of gastrointestinal organs. ICC-DMP form synaptic connections with the varicose nerve terminals of enteric motor neurons and are involved in reception and transduction of motor neurotransmission. Gene expression underlying specific functions of ICC classes is incompletely understood. In the present study, we used recently developed highly selective techniques to isolate the two functional ICC classes from enzymatically dispersed intestinal muscles by fluorescence-activated cell sorting. The transcriptomes of ICC-MY and ICC-DMP were investigated using oligonucleotide microarray analysis. Differential expression of functional groups of genes defined by standard gene ontology terms was also studied. There were substantial numbers of genes expressed more abundantly in ICC than in the tunica muscularis, and we also detected marked phenotypic differences between ICC-MY and ICC-DMP. Notably, genes related to cell junction, process guidance, and vesicle trafficking were upregulated in ICC. Consistent with their specific functions, metabolic and Ca(2+) transport genes were relatively upregulated in ICC-MY, whereas genes for signaling proteins involved in transduction of neurotransmitter functions were relatively upregulated in ICC-DMP. Our results may lead to the identification of novel biomarkers for ICC and provide directions for further studies designed to understand ICC function in health and disease.
  Physiological Genomics 12/2007; 31(3):492-509. · 2.73 Impact Factor
• Article: The mouse mammary carcinoma 4T1: characterization of the cellular landscape of primary tumours and metastatic tumour foci.

  Sally A DuPré, Doug Redelman, Kenneth W Hunter
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  ABSTRACT: The murine mammary carcinoma 4T1 causes a leukemoid reaction with profound granulocytosis coincident with the production of tumour-derived growth factors. Here, we study the evolving cellular landscape of primary tumours and metastatic tumour foci and correlate haematopoietic cell infiltration with the production of tumour-derived chemokines. Flow cytometric analysis of enzyme digested primary tumours at different times after transplantation revealed a progressively increasing CD45(+) haematopoietic cell infiltrate consisting predominantly of CD11b(+) myeloid cells. Most of these cells had an F4/80(+)/CD11c(+) phenotype, many of which also stained Gr-1(+). Smaller numbers of Gr-1(+)CD11b(+) granulocytes and lymphoid cells were also identified. Progressive increases in Gr-1(+) granulocytes were observed in enzymatic digests of livers and lungs with metastatic tumour foci. Cultured 4T1 tumour cells expressed mRNA transcripts for the myeloid cell chemokines RANTES, MCP-1 and KC, and enzymatically digested cells from primary 4T1 tumours partially depleted of CD45(+) cells expressed transcripts for these chemokines and also MIP-1alpha and MIP-1beta. These data demonstrate that 4T1 tumour-bearing mice have mixed myeloid cell infiltrates of primary tumours and granulocytic infiltrates of metastatic organs. This pathologic presentation correlated with the expression of tumour-derived chemokines.
  International Journal of Experimental Pathology 11/2007; 88(5):351-60. · 2.57 Impact Factor