Optimized adoptive T-cell therapy for the treatment of residual mantle cell lymphoma

Mantle cell lymphoma (MCL) is an aggressive B-cell neoplasm with few patients achieving long-term survival with current treatment regimens. High-dose therapy is effective in reducing the tumor burden; however, patients eventually relapse due to minimal residual disease. Having demonstrated efficacy in other malignancies, the effectiveness of dendritic cell-based immunotherapy for minimal residual MCL was examined. We demonstrated that dendritic cells (DC) primed with MCL antigens stimulated the activation of MCL-specific T cells that recognized and destroyed both MCL cell lines and primary MCL in vitro. In addition, in vivo studies demonstrated that adoptively transferred MCL-specific T cells were able to significantly inhibit tumor growth in mice with minimal residual MCL. Subsequently, when combined with CHOP chemotherapy, adoptive T-cell therapy was able to significantly extend the survival of the mice by further reducing the tumor burden. These results clearly show that MCL-specific cellular immunotherapy is effective in treating minimal residual MCL, paving the way for future clinical studies.     

The role of virus-specific adoptive T-cell therapy in hematopoietic transplantation

Viral infections are amongst the most significant complications following hematopoietic transplantation and occur principally because of a lack of virus-specific T cells. Drug treatments are often suboptimal because of toxicity, limited viral sensitivity, or the potential for the development of resistance. Adoptive immunotherapy to restore virus-specific cellular immunity is clearly an attractive alternative and the pioneering work of the previous decade established that cellular products could be clinically effective. However, the techniques used in these early studies are expensive and relatively difficult to produce to GMP-compliant standards. This is major limitation to their wider application. This review concentrates on more recent studies detailing direct selection methodologies that are more suited to clinical scalability and more readily assessable in prospective randomised studies. We will also consider strategies that allow multiple pathogens to be targeted concurrently, and strategies that aim to extend the benefits of these technologies to transplant recipients whose donors are seronegative for these viruses and currently are most vulnerable to viral reactivations.     

Synergistic antitumor activity of cyclophosphamide and ABPP in the treatment of established and advanced tumors in murine tumor models

Summary We have previously shown that the in vivo administration of ABPP, an interferon inducing pyrimidinone, generates activated killer cells that can lyse fresh tumor cells in vitro in 4-h ⁵¹chromium release assays. The administration of this agent however has no effect on established tumor. In this communication we show that ABPP, when used in combination with low or moderate doses of cyclophosphamide, can be quite effective against early established (day 3) tumor as well as against advanced, grossly visible (day 8–10) tumor in both the i.p. and pulmonary metastasis model. The synergistic antitumor activity of this cheoimmunotherapeutic regimen was very strong against immunogenic tumors but rather weak against nonimmunogenic tumors. Two treatment cycles were significantly more effective than one and multiple cycles even cured the majority of mice with established i.p. tumor. These experiments demonstrate the potential of chemoimmunotherapeutic regimens and highlight the efficacy of multiple treatment cycles.     

Expression and regulation of interferon gamma-inducible proteasomal subunits LMP7 and LMP10 in the bovine corpus luteum

The proteasome is a large, polymeric protease complex responsible for intracellular protein degradation and generation of peptides that bind to class I major histocompatibility complex (MHC) molecules. Interferon gamma (INFgamma) induces expression of alternative proteasomal subunits that affect intracellular protein degradation, thereby changing the types of peptides that bind to class I MHC molecules. These alterations in class I MHC peptides can influence whether cells and tissues are tolerated by the immune system. Expression of two INFgamma-inducible proteasomal subunits, LMP7 and LMP10, in bovine luteal tissue was examined in this study. Northern analysis revealed the presence of mRNA encoding LMP7 and LMP10 in luteal tissue. Steady-state amounts of LMP7 mRNA did not change during the estrous cycle, but LMP10 mRNA was low in early corpus luteum (CL) and elevated in midcycle and late CL. Tumor necrosis factor alpha alone and in the presence of LH and/or prostaglandin F2alpha elevated steady-state amounts of LMP10 mRNA but did not affect LMP7 mRNA in cultured luteal cells. Immunohistochemistry revealed the presence of LMP10 primarily in small luteal cells. Numbers of LMP10-positive cells were lower in early CL than in midcycle and late CL. The finding that INFgamma-inducible proteasomal subunits are expressed in luteal tissue when the CL is fully functional was unexpected and suggests that proteasomes in luteal cells may generate peptides capable of stimulating a class I MHC-dependent inflammatory response.     

Interaction of monocytes with vascular endothelial cells synergistically induces interferon gamma-inducible protein 10 expression through activation of specific cell surface molecules and cytokines

To further understand the regulatory mechanisms involved in the process of angiogenesis, the present study was designed to determine the expression and regulation of interferon gamma-inducible protein 10 (IP-10) in peripheral blood monocytes and human umbilical vein endothelial cells (HUVECs). We found that the interaction of monocytes with HUVECs resulted in synergistic increases in IP-10 expression and secretion, which consequently inhibited endothelial tube formation in vitro. Induction of IP-10 was mediated via specific cell surface molecules, as indicated by the finding that IP-10 secretion was significantly inhibited by anti-CD40 ligand antibody, and to a lesser extent by anti-CD40 antibody. Furthermore, we examined the effects of soluble mediators, such as inflammatory and immune cytokines on IP-10 secretion. Addition of interleukin (IL)-1, as well as interferon gamma, induced a marked augmentation of IP-10 secretion by unstimulated monocytes, unstimulated HUVECs, and co-cultures of the two cell types. In contrast, IL-10, recognized as an anti-inflammatory cytokine, significantly inhibited IP-10 secretion by co-cultures. Our results suggest that the interaction of monocytes with endothelial cells results in synergistic increases in IP-10 expression and secretion, which contribute to the regulation of angiogenesis and initiation of inflammatory vascular diseases.     

Synergistic effect of TPA and T-cell mitogens in nonmammalian vertebrates

Summary The phorbol ester, 12-0-tetradecanoyl-phorbol-13-acetate (TPA) was used as a comitogen with the plant lectins phytohemagglutinin (PHA) and concanavalin A (ConA) in short-term cultures of whole blood from nonmammalian vertebrates. Stimulation with TPA in addition to standard mitogens resulted in a synergistic effect, consistently yielding more metaphases than cultures stimulated with either PHA, ConA, or TPA alone and is successful with blood samples as small as 0.1 ml. The increased mitotic index makes it possible to use different banding procedures for systematic studies. Also, because the amount of blood needed is so small, this procedure, unlike other published techniques, does not require the destruction of smaller animals to do chromosome studies. This work was supported in part by National Institute of Environmental Health Science Grant 5-T32-ES07015-08 to the Environmental Toxicology Center at the University of Wisconsin-Madison.     

GMP production of anti-tumor cytotoxic T-cell lines for adoptive T-cell therapy in patients with solid neoplasia

BACKGROUND: The adoptive transfer of ex vivo-induced tumor-specific T-cell lines provides a promising approach for cancer immunotherapy. We have demonstrated previously the feasibility of inducing in vitro long-term anti-tumor cytotoxic T-cell (CTL) lines directed against different types of solid tumors derived from both autologous and allogeneic PBMC. We have now investigated the possibility of producing large amounts of autologous anti-tumor CTL, in compliance with good manufacturing practices, for in vivo use. METHODS: Four patients with advanced solid tumors (two sarcoma, one renal cell cancer and one ovarian cancer), who had received several lines of anticancer therapy, were enrolled. For anti-tumor CTL induction, patient-derived CD8-enriched PBMC were stimulated with DC pulsed with apoptotic autologous tumor cells (TC) as the source of tumor Ag. CTL were then restimulated in the presence of TC and expanded in an Ag-independent way. RESULTS: Large amounts of anti-tumor CTL (range 14-20 x 10(9)), which displayed high levels of cytotoxic activity against autologous TC, were obtained in all patients by means of two-three rounds of tumor-specific stimulation and two rounds of Ag-independent expansion, even when a very low number of viable TC was available. More than 90% of effector cells were CD3(+) CD8(+) T cells, while CD4(+) T lymphocytes and/or NK cells were less than 10%. DISCUSSION: Our results demonstrate the feasibility of obtaining large quantities of anti-tumor specific CTL suitable for adoptive immunotherapy approaches.     

Interleukin-15 rescues tolerant CD8+ T cells for use in adoptive immunotherapy of established tumors

CD8+ T cells can mediate eradication of established tumors, and strategies to amplify tumor-reactive T-cell numbers by immunization or ex vivo expansion followed by adoptive transfer are currently being explored in individuals with cancer. Generating effective CD8+ T cell-mediated responses to tumors is often impeded by T-cell tolerance to relevant tumor antigens, as most of these antigens are also expressed in normal tissues. We examined whether such tolerant T cells could be rescued and functionally restored for use in therapy of established tumors. We used a transgenic T-cell receptor (TCR) mouse model in which peripheral CD8+ T cells specific for a candidate tumor antigen also expressed in liver are tolerant, failing to proliferate or secrete interleukin (IL)-2 in response to antigen. Molecular and cellular analysis showed that these tolerant T cells expressed the IL-15 receptor alpha chain, and could be induced to proliferate in vitro in response to exogenous IL-15. Such proliferation abrogated tolerance and the rescued cells became effective in treating leukemia. Therefore, high-affinity CD8+ T cells are not necessarily deleted by encounter with self-antigen in the periphery, and can potentially be rescued and expanded for use in tumor immunotherapy.     

Synergistic antitumor effect of interferon and anti-idiotype monoclonal antibody in murine lymphoma

Both IFN-alpha and anti-idiotype monoclonal antibody therapy have significant antitumor activity in vivo in a murine B cell lymphoma model. Combination therapy with syngeneic anti-idiotype antibody of the IgG2a or IgG2b isotype (a single i.p. injection of 100 micrograms) and recombinant human hybrid interferon-alpha A/D (10(4) to 10(6) U three times weekly for 3 wk) synergistically increased median survival time in mice challenged with a lethal dose of tumor cells compared with the sum of the median survival times of the two individual treatments. IFN-alpha has direct antiproliferative activity against 38C13 in vitro and enhances in vitro macrophage anti-idiotype antibody-specific cytolysis for IgG2a, IgG2b, and IgG1 isotypes.     

Regulation of blastocyst migration,apposition, and initial adhesion by a chemokine,interferon gamma-inducible protein 10 kDa (IP-10), during early gestation

For a pregnancy to be established, initial apposition and adhesion of the blastocyst to maternal endometrium must occur in a coordinated manner; however, a key factor(s) that mediates the trophoblast cell migration and attachment to the apical surface of the endometrium has not been identified. In this study, we examined the effect of an endometrial chemokine, interferon-gamma-inducible protein 10 kDa (IP-10), on conceptus migration to the endometrial epithelium. We first studied endometrial IP-10 mRNA expression, which was localized in the subepithelial stromal region, and detected the protein in the uterine flushing media during early pregnancy. Expression of IP-10 mRNA by the endometrium of cyclic animals was stimulated by the addition of a conceptus factor interferon-tau (IFN-tau). Immunofluorescent analysis revealed that IP-10 receptor, CXCR3, was localized in the trophoblast cells, to which biotinylated-recombinant caprine IP-10 (rcIP-10) bound. Chemotaxis assay indicated that rcIP-10 stimulated the migration of trophoblast cells, and the effects of rcIP-10 were neutralized by the pretreatment with an anti-IP-10 antibody. Adhesive activity of trophoblast cells to fibronectin was promoted by rcIP-10, and the effect was inhibited by the use of anti-IP-10 antibody. Further adhesion experiments demonstrated that binding of trophoblast cells to fibronectin was completely inhibited by a peptide of the Arg-Gly-Asp (RGD) sequence, which binds to integrins alpha5beta1, alphaVbeta1, alphaVbeta3, and alphaVbeta5, whereas non-binding peptide containing Arg-Gly-Glu (RGE) had minimal effects. More importantly, rcIP-10 promoted the adhesion of trophoblast cells to primary cells isolated from endometrial epithelium. Furthermore, rcIP-10 stimulated the expression of integrin alpha5, alphaV, and beta3 subunit mRNA in trophoblast cells. These findings suggest that endometrial IP-10 regulates the establishment of apical interactions between trophoblast and epithelial cells during early gestation.     

Eradication of established tumors in mice by a combination antibody-based therapy

Tumor-cell apoptosis is the basis of many cancer therapies, and tumor-specific T cells are the principal effectors of successful antitumor immunotherapies. Here we show that induction of tumor-cell apoptosis by an agonistic monoclonal antibody to DR5, the apoptosis-inducing receptor for TNF-related apoptosis-inducing ligand (TRAIL), combined with T-cell activation by agonistic monoclonal antibodies to the costimulatory molecules CD40 and CD137, potently and rapidly stimulated tumor-specific effector CD8+ T cells capable of eradicating preestablished tumors. Primary fibrosarcomas initiated with the carcinogen 3-methylcholanthrene (MCA), multiorgan metastases and a primary tumor containing as many as 90% tumor cells resistant to DR5-specific monoclonal antibody were rejected without apparent toxicity or induction of autoimmunity. This combination therapy of three monoclonal antibodies (trimAb) rapidly induced tumor-specific CD8+ T cells producing interferon (IFN)-gamma in the tumor-draining lymph node, consistent with a crucial requirement for CD8+ T cells and IFN-gamma in the tumor rejection process. These results in mice indicate that a rational monoclonal antibody-based therapy that both causes tumor-cell apoptosis through DR5 and activates T cells may be an effective strategy for cancer immunotherapy in humans.     

Adeno-associated virus type 2-mediated gene transfer: role of cellular T-cell protein tyrosine phosphatase in transgene expression in established cell lines in vitro and transgenic mice in vivo

The use of adeno-associated virus type 2 (AAV) vectors has gained attention as a potentially useful alternative to the more commonly used retrovirus and adenovirus vectors for human gene therapy. However, the transduction efficiency of AAV vectors varies greatly in different cells and tissues in vitro and in vivo. We have documented that a cellular protein that binds the immunosuppressant drug FK506, termed the FK506-binding protein (FKBP52), interacts with the single-stranded D sequence within the AAV inverted terminal repeats, inhibits viral second-strand DNA synthesis, and consequently limits high-efficiency transgene expression (K. Qing, J. Hansen, K. A. Weigel-Kelley, M. Tan, S. Zhou, and A. Srivastava, J. Virol., 75: 8968-8976, 2001). FKBP52 can be phosphorylated at both tyrosine and serine/threonine residues, but only the phosphorylated forms of FKBP52 interact with the D sequence. Furthermore, the tyrosine-phosphorylated FKBP52 inhibits AAV second-strand DNA synthesis by greater than 90%, and the serine/threonine-phosphorylated FKBP52 causes approximately 40% inhibition, whereas the dephosphorylated FKBP52 has no effect on AAV second-strand DNA synthesis. In the present study, we have identified that the tyrosine-phosphorylated form of FKBP52 is a substrate for the cellular T-cell protein tyrosine phosphatase (TC-PTP). Deliberate overexpression of the murine wild-type (wt) TC-PTP gene, but not that of a cysteine-to-serine (C-S) mutant, caused tyrosine dephosphorylation of FKBP52, leading to efficient viral second-strand DNA synthesis and resulting in a significant increase in AAV-mediated transduction efficiency in HeLa cells in vitro. Both wt and C-S mutant TC-PTP expression cassettes were also used to generate transgenic mice. Primitive hematopoietic stem/progenitor cells from wt TC-PTP-transgenic mice, but not from C-S mutant TC-PTP-transgenic mice, could be successfully transduced by recombinant AAV vectors. These studies corroborate the fact that tyrosine phosphorylation of the cellular FKBP52 protein strongly influences AAV transduction efficiency, which may have important implications in the optimal use of AAV vectors in human gene therapy.     

IL-12 and IL-10 expression synergize to induce the immune-mediated eradication of established colon and mammary tumors and lung metastasis

Preclinical studies demonstrated that certain cytokines are potentially useful for the induction of antitumor immune responses. However, their administration in clinical settings was only marginally useful and evoked serious toxicity. In this study, we demonstrate that the combination of autologous inactivated tumor cells expressing IL-12 and IL-10 induced tumor remission in 50-70% of mice harboring large established colon or mammary tumors and spontaneous lung metastases, with the consequent establishment of an antitumor immune memory. Mice treatment with tumor cells expressing IL-12 was only marginally effective, while expression of IL-10 was not effective at all. Administration of the combined immunotherapy stimulated the recruitment of a strong inflammatory infiltrate that correlated with local, increased expression levels of the chemokines MIP-2, MCP-1, IFN-gamma-inducible protein-10, and TCA-3 and the overexpression of IFN-gamma, but not IL-4. The combined immunotherapy was also therapeutically effective on established lung metastases from both colon and mammary tumors. The antitumor effect of the combined immunotherapy was mainly dependent on CD8+ cells although CD4+ T cells also played a role. The production of IFN-gamma and IL-4 by spleen cells and the development of tumor-specific IgG1 and IgG2a Abs indicate that each cytokine stimulated its own Th pathway and that both arms were actively engaged in the antitumor effect. This study provides the first evidence of a synergistic antitumor effect of IL-12 and IL-10 suggesting that a Th1 and a Th2 cytokine can be effectively combined as a novel rational approach for cancer immunotherapy.     

Cellular basis of immunologic interactions in adoptive T cell therapy of established metastases from a syngeneic murine sarcoma

The adoptive transfer of specifically sensitized T lymphocytes can effectively mediate the regression of established local and metastatic tumors. Previous experiments using the weakly immunogenic MCA 105 sarcoma indicated that cellular interactions between transferred L3T4+ helper and Lyt-2+ cytotoxic immune T cells were necessary for mediating tumor regression. In this study, the kinetics of T-T cell interactions were analyzed by in vivo depletion of T cell subsets with mAb. The anti-tumor efficacy of transferred immune cells was abrogated by in vivo administration of either L3T4 or Lyt-2 mAb on the day of cellular therapy. However, if mAb were given 3 days after the transfer of immune cells, depletion of Lyt-2+ but not L3T4+ cells abrogated anti-tumor efficacy. T cell depletion on day 6 after transfer of immune cells had no adverse effect on tumor regression, indicating the period required for T cell reactivity in vivo. Furthermore, depletion of Ia+ cells by in vivo mAb treatment abrogated the anti-tumor efficacy of immune cells. It is thus hypothesized that there are two distinct but sequential phases of in vivo T cell interactions leading to the regression of established tumors after adoptive immunotherapy. An initial "helper/inducer" phase apparently requires the interaction of L3T4+ immune cells and the tumor Ag involving Ia+ cells. The inducement of L3T4+ cell activation is to provide helper function via the secretion of IL-2. The second phase designated as an "effector phase" involves differentiation of immune Lyt-2+ cells under the influence of IL-2 secreted during the helper/inducer phase for generation of mature Lyt-2+ effector cells. To further support the hypothesis of a two-phase process we have examined the phenotype and kinetics of tumor regression mediated by effector cells generated by secondary in vitro sensitization (IVS). Although the IVS cells were generated from fresh MCA 105 immune spleen cells, their anti-tumor efficacy was mediated solely by Lyt-2+ lymphocytes. Kinetic studies revealed that the in vivo requirement of IVS Lyt-2+ effector cells to mediate tumor regression was less than 3 days, and the anti-tumor reactivity of these cells was not affected by in vivo depletion of Ia+ cells. Thus, the IVS reaction is likely representative of the in vivo counterpart of the helper/inducer phase leading to the generation of mature Lyt-2+ immune effector cells. Tumor regression after transfer of Lyt-2+ cells generated in IVS therefore required a relatively shorter period of time than that required after the transfer of fresh noncultured MCA 105 immune spleen cells.     

Optimized combination therapy using bortezomib, TRAIL and TLR agonists in established breast tumors

TNF-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family of cytokines, which can induce apoptosis in various tumor cells by engaging the receptors, DR4 and DR5. Bortezomib (Velcade) is a proteasome inhibitor that has been approved for patients with multiple myeloma. There is some experimental evidence in preclinical models that bortezomib can enhance the susceptibility of tumors to TRAIL-induced apoptosis. In this study, we investigated the effects of TRAIL-induced death using an agonistic antibody to the TRAIL receptor DR5 (α-DR5) in combination with bortezomib administered to mice previously injected with breast cancer cells (TUBO). This combination had some beneficial therapeutic effect, which was significantly enhanced by the co-administration of a Toll-like receptor 9 agonist (CpG). In contrast, single agent treatments had little effect on tumor growth. In addition, we evaluated the effect of combination with α-DR5, bortezomib, and CpG in the prevention/treatment of spontaneous mammary tumors in Balb-neuT mice. In this model, which is more difficult to treat, we observed dramatic antitumor effects of α-DR5, bortezomib and CpG combination therapy. Since such a mouse model more accurately reflects the immunological tolerance that exists in human cancer, our results strongly suggest that these combination strategies could be directly applied to the therapy for cancer patients.     

Candida albicans abrogates the expression of interferon-gamma-inducible protein-10 in human keratinocytes

Candida albicans is the predominant causative agent of human cutaneous candidiasis. Epidermal keratinocytes play an important role in the cutaneous immune response through the production of cytokines and chemokines, including IFN-gamma-inducible protein 10 (IP-10). Here, we investigated the influence of C. albicans infection on IP-10 production by normal human epidermal keratinocytes (NHEK) in vitro. Our results showed that IFN-gamma-stimulated NHEK showed enhanced IP-10 mRNA and protein expression; this expression was downregulated by C. albicans infection. Candida tropicalis also impaired IFN-gamma-induced IP-10 expression, but Candida glabrata did not. Heat-killed C. albicans did not impair IFN-gamma-induced IP-10 expression. We found that coincubation of NHEK with live C. albicans without cell-to-fungi contact impaired IFN-gamma-induced IP-10 mRNA and protein expression in NHEK, suggesting the role of soluble factors derived from live C. albicans in this impairment. Enzyme-linked immunosorbent assay analysis revealed that C. albicans and C. tropicalis could produce marked levels of prostaglandin (PG) E(2), while C. glabrata produced low levels of this prostaglandin. Treatment with E-series prostaglandin receptor antagonists, AH6809 and AH23848, restored IFN-gamma-induced IP-10 expression in C. albicans-infected NHEK. Thus, Candida-derived PGE(2) may impair IFN-gamma-induced IP-10 expression in human keratinocytes and may play a role in the pathogenesis of cutaneous candidiasis.