The role of cytokines in graft-versus-host reactions and disease.

CD4+ and CD8+ T lymphocytes are responsible for the initiation of graft-versus-host disease (GVHD) which limits the efficacy of human allogeneic bone marrow transplantation. Activated T cells are a rich source of cytokines in vitro, and many of these same molecules are also found in graft-versus-host reactions (GVHR) and GVHD. However, T cells are not the only source of these soluble mediators. Cytokines control the actions of many cell types both in vitro and in vivo, so these soluble factors can easily influence the actions of both the engrafted hematopoietic cells and the host's cells. The complex manner in which cells and cytokines interact in GVHR and GVHD is reviewed here. We speculate that cytokine cascades play major roles in many aspects of GVHR and GVHD.     

Cellular and vaccine therapeutic approaches for gliomas

Despite new additions to the standard of care therapy for high grade primary malignant brain tumors, the prognosis for patients with this disease is still poor. A small contingent of clinical researchers are focusing their efforts on testing the safety, feasibility and efficacy of experimental active and passive immunotherapy approaches for gliomas and are primarily conducting Phase I and II clinical trials. Few trials have advanced to the Phase III arena. Here we provide an overview of the cellular therapies and vaccine trials currently open for patient accrual obtained from a search of . The search was refined with terms that would identify the Phase I, II and III immunotherapy trials open for adult glioma patient accrual in the United States. From the list, those that are currently open for patient accrual are discussed in this review. A variety of adoptive immunotherapy trials using ex vivo activated effector cell preparations, cell-based and non-cell-based vaccines, and several combination passive and active immunotherapy approaches are discussed.     

Effects of interleukin 4 upon human tumoricidal cells obtained from patients bearing solid tumors

The use of human interleukin 4 (IL4) in the generation of tumoricidal effector cells derived from cancer patients undergoing either interleukin 2/lymphokine activated killer cells (IL2/LAK) therapy or tumor derived activated cell (TDAC) therapy was examined in the present study. Human IL4 alone did not generate LAK cells from patients undergoing IL2/LAK therapy when cultured in media containing 2% AB serum (five out of six patients). However, when the serum free medium, Aim V, was used, IL4 did generate LAK cells (eight out of nine patients), although not as cytotoxic as those activated with IL2. When cells were cultured in both IL2 and IL4 during the generation of LAK cells (3-7 days), better cell recoveries were frequently observed. The cytolytic activity of these cells against Daudi target cells was slightly reduced when compared to that response induced by IL2. This inhibition of LAK activity by IL4 was dose dependent with 1,000 U/ml IL4 producing maximal effects. This form of inhibition did not correlate with any phenotypic differences between those cells cultured in IL2 and those cells cultured in IL2 plus IL4. The IL4 mediated inhibition was also observed when the cells were cultured in Aim V medium which contains indomethacin. This inhibition induced by IL4 could not be overcome by using supra-optimal IL2. In addition to its effect during the generation of IL2 induced LAK cells, IL4 also appeared to reduce the cytolytic activity of pre-activated mature LAK cells. These results suggest that IL4 has a complex role in regulating the actions of LAK cells induced by lymphokines. When IL4 was used with IL2 during the first 5 weeks of growth of TDAC, an enhanced growth was observed when compared to the growth of TDAC when only one lymphokine was used. Besides the growth enhancement of TDAC, a better cytolytic response was observed when both lymphokines were used together. Thus, for the best growth of TDAC both IL2 and IL4 are required.     

Macrophage colony stimulating factor: not just for macrophages anymore! A gateway into complex biologies

Macrophage colony stimulating factor (M-CSF, also called colony stimulating factor-1) has traditionally been viewed as a growth/differentiation factor for monocytes, macrophages, and some female-specific tumors. As a result of alternative mRNA splicing and post-translational processing, several forms of M-CSF protein are produced: a secreted glycoprotein, a longer secreted form containing proteoglycan, and a short membrane-bound isoform. These different forms of M-CSF all initiate cell signaling in cells bearing the M-CSF receptor, called c-fms. Here we review the biology of M-CSF, which has important roles in bone physiology, the intestinal tract, cancer metastases to the bone, macrophage-mediated tumor cell killing and tumor immunity. Although this review concentrates mostly on the membrane form of human M-CSF (mM-CSF), the biology of the soluble forms and the M-CSF receptor will also be discussed for comparative purposes. The mechanisms of the biological effects of the membrane-bound M-CSF reveal that this cytokine is unexpectedly involved in many complex molecular events. Recent experiments suggest that a tumor vaccine based on membrane-bound M-CSF-transduced tumor cells, combined with anti-angiogenic therapy, should be evaluated further for use in clinical trials.     

Ginger's (Zingiber officinale Roscoe) inhibition of rat colonic adenocarcinoma cells proliferation and angiogenesis in vitro

Ginger's (Zingiber officinale Roscoe) natural bioactives, specifically ginger extract and 6‐gingerol, were measured for their in vitro inhibition of two key aspects of colon cancer biology – cancer cell proliferation and angiogenic potential of endothelial cell tubule formation. Ginger extract was obtained via column distillation, while the 6‐gingerol was purchased from Calbiochem. Antiproliferation activity was assessed through tritiated thymidine ([³H]Tdr) incorporation studies of YYT colon cancer cells; the anti‐angiogenic ability of gingerol was assessed by a Matrigel assays using MS1 endothelial cells. These selected ginger bioactives had: 1) a direct effect on YYT rat cancer cell proliferation (6–1.5% ginger extract; 100–4 µM 6‐gingerol); 2) an indirect effect on MS1 endothelial cell function either at the level of endothelial cell proliferation or through inhibition of MS1 endothelial cell tube formation (100–0.8 µM). Compound 6‐gingerol was most effective at lower doses in inhibiting endothelial cell tube formation. These in vitro studies show that 6‐gingerol has two types of antitumor effects: 1) direct colon cancer cell growth suppression, and 2) inhibition of the blood supply of the tumor via angiogenesis. Further research is warranted to test 6‐gingerol in animal studies as a potential anticancer plant bioactive in the complementary treatment of cancer. Copyright © 2008 John Wiley & Sons, Ltd.     

Intrapleural injection of transforming growth factor-beta antibody inhibits pleural fibrosis in empyema

STUDY OBJECTIVES: Transforming growth factor (TGF)-beta is a cytokine that has been demonstrated to be an important modulator of inflammation and angiogenesis, as well as a potent stimulator of pleural fluid production and fibrosis. We previously demonstrated that rising levels of pleural fluid TGF-beta(1) correlate with pleural fibrosis in experimental empyema in rabbits. In this study, our hypothesis is that neutralization of TGF-beta with an intrapleural injection of a monoclonal antibody to TGF-beta will decrease pleural fibrosis in empyema. DESIGN: Prospective, randomized, blinded study. SETTING: Animal research laboratory. SUBJECTS: Nineteen rabbits. INTERVENTIONS: An empyema was induced in 19 rabbits by intrapleural injection of Pasteurella multocida. A panspecific monoclonal antibody to TGF-beta was injected into the pleural space on 2 subsequent concurrent days in nine rabbits. Ten rabbits received intrapleural injections of bacteria alone and served as controls. All animals were then killed on day 6. Immunohistochemistry, using the antibody to TGF-beta, was performed on pleural tissue specimens from the control rabbits. MEASUREMENTS AND RESULTS: Immunohistochemistry revealed localization of TGF-beta to macrophages in the exudative material and the visceral pleura. After injection of the antibody to TGF-beta, the amount of purulent, exudative material in the pleural space of the nine experimental animals was markedly decreased at autopsy on day 6, relative to control animals. All markers of empyema and pleural fibrosis were also significantly decreased in the rabbits receiving intrapleural anti-TGF-beta. CONCLUSIONS: TGF-beta localizes to macrophages in experimental empyema. Early intrapleural injection of an antibody to TGF-beta inhibits empyema formation and significantly decreases pleural fibrosis in experimental empyema.     

Macrophages can recognize and kill tumor cells bearing the membrane isoform of macrophage colony-stimulating factor

NBXFO hybridoma cells produced both the membrane and secreted isoforms of macrophage colony-stimulating factor (M-CSF). Murine bone marrow cells stimulated by the secreted form of M-CSF (sM-CSF) became Mac1+, Mac2+, Mac3+, and F4/80+ macrophages that inhibited the growth of NBXFO cells, but not L1210 or P815 tumor cells. In cytotoxicity studies, M- CSF activated macrophages and freshly isolated macrophages killed NBXFO cells in the presence of polymyxin B, eliminating the possibility that contaminating lipopolysaccharide (LPS) was responsible for the delivery of the cytotoxic signal. Retroviral-mediated transfection of T9 glioma cells with the gene for the membrane isoform of M-CSF (mM-CSF), but not for the secreted isoform of M-CSF, transferred the ability of macrophages to kill these transfected T9 cells in a mM-CSF dose- dependent manner. Macrophage-mediated killing of the mM-CSF transfected clone was blocked by using a 100-fold excess of recombinant M-CSF. Catalase, superoxide dismutase, and the nitric oxide inhibitor, N-omega- nitro-arginine methyl ester (NAME), did not effect macrophage cytotoxicity against the mM-CSF transfectant T9 clones. T9 parental cells when cultured in the presence of an equal number of the mM-CSF transfectant cells were not killed, indicating specific target cell cytotoxicity by the macrophages. Electron microscopy showed that macrophages were capable of phagocytosizing mM-CSF bearing T9 tumor cells and NBXFO hybridoma cells; this suggested a possible mechanism of this cytotoxicity. This study indicates that mM-CSF provides the necessary binding and triggering molecules through which macrophages can initiate direct tumor cell cytotoxicity.