Circulating endothelial cells in oncology: pitfalls and promises.

Adequate blood supply is a prerequisite in the pathogenesis of solid malignancies. As a result, depriving a tumour from its oxygen and nutrients, either by preventing the formation of new vessels, or by disrupting vessels already present in the tumour, appears to be an effective treatment modality in oncology. Given the mechanism by which these agents exert their anti-tumour activity together with the crucial role of tumour vasculature in the pathogenesis of tumours, there is a great need for markers properly reflecting its impact. Circulating endothelial cells (CEC), which are thought to derive from damaged vasculature, may be such a marker. Appropriate enumeration of these cells appears to be a technical challenge. Nevertheless, first studies using validated CEC assays have shown that CEC numbers in patients with advanced malignancies are elevated compared to healthy controls making CEC a potential tool for among other establishing prognosis and therapy-induced effects. In this review, we will address the possible clinical applications of CEC detection in oncology, as well as the pitfalls encountered in this process.

Retronectin-assisted retroviral transduction of primary human T lymphocytes under good manufacturing practice conditions: tissue culture bag critically determines cell yield.

BACKGROUND: For our clinical immunogene therapy study for the treatment of renal cell carcinoma (RCC) patients, we had developed a protocol for gene transduction and expansion of human T cells in compliance with good manufacturing practice (GMP) criteria. Critical to our successful clinical-scale transductions of patient T cells was the use of Retronectin in combination with Lifecell X-foldtrade mark cell culture bags. METHODS: In our current study, we evaluated two alternative types of bags for the Retronectin-mediated retroviral transduction of human T cells: the Miltenyi DC-generation bag and the Takara CultiLife Spin bag. RESULTS: In static transductions, but not in spinoculation, the DC-generation bags and CultiLife Spin bags performed as well as Lifecell X-foldtrade mark bags in Retronectin-assisted retroviral transduction of human T cells with respect to transduction efficiency, lymphocyte subset composition and lymphocyte function. However, both types of bags performed less well than Lifecell X-foldtrade mark cell culture bags in terms of cell yield. DISCUSSION: Adjusted numbers of cells at the start of transduction should be used when using the Miltenyi or Takara bags in order to compensate for the lower cell yield following transduction.

Bone-marrow transplantation fails to halt intrathecal lymphocyte activation in multiple sclerosis.

BACKGROUND: Given the presumed key role for autoreactive lymphocytes in multiple sclerosis (MS), treatment strategies have been developed to ablate lymphocyte activity. Intrathecal lymphocyte activation can be measured by CSF-soluble(s)CD27. OBJECTIVE: To determine the effect of maximum whole-body immune ablation on two different markers that detect lymphocyte activation in CSF-oligoclonal IgG bands and levels of CSF-sCD27. DESIGN, SETTING AND PATIENTS: The study quantified sCD27 levels and assessed the presence of oligoclonal IgG bands in CSF samples of secondary progressive patients with MS treated by autologous bone-marrow transplantation. In eight individuals, CSF was taken before and 6-9 months after conditioning. CSF-sCD27 levels were compared with other MS and non-inflammatory neurological disease controls. Regarding the effect of stem-cell transplantation on CSF oligoclonal bands, the study analysed pooled data of this and four other international studies on stem-cell transplantation in MS. RESULTS: CSF-sCD27 was significantly lower after the extremely immunoablative protocol. However, levels remained elevated compared with non-inflammatory controls and stayed within the range observed in other MS controls. The joint analysis of CSF oligoclonal bands demonstrated persistence of this immune abnormality in 88% of the reported cases (n = 34). CONCLUSIONS: The persistence of CSF lymphocyte activation markers sCD27 and intrathecal oligoclonal IgG bands after maximum immunoablative treatment indicates that complete eradication of activated lymphocytes from the CNS has not been established. This is paralleled by disease progression observed in several studies on the effect of stem-cell transplantation in MS.

Phoenix-ampho outperforms PG13 as retroviral packaging cells to transduce human T cells with tumor-specific receptors: implications for clinical immunogene therapy of cancer.

We have designed a transgene that encodes a scFv(G250) chimeric receptor, which is specific for carboxyanhydrase IX (G250-ligand, G250L), a molecule overexpressed by renal cell cancer (RCC). Retroviral transduction of this transgene into primary human T lymphocytes confers these cells with specific functional responses towards G250L-positive RCC cells. In preparation of a clinical phase (I/II) study in RCC patients, we set up a protocol for gene transduction and expansion of primary human T cells. For this purpose, we directly compared two packaging cell lines, that is, the GALV-pseudotyped MLV producing cell line PG13, and the MLV-A-producing cell line Phi-NX-Ampho (a.k.a. Phoenix-A). We generated and characterized stable scFv(G250)-positive clones of both PG13 and Phoenix cells and optimized the retrovirus production conditions. Transductions of primary human T cells yielded 30-60% scFv(G250)+ T cells using PG13-derived retrovirus versus up to 90% scFv(G250)+ T cells using Phoenix-derived retrovirus. The median number of transgene integrations per scFv(G250)+ T cell differed only 1.5-fold as determined by real-time PCR (mean number of integrations per T cell 2.6 and 3.7 for PG13 and Phoenix-based transductions, respectively). In addition, T cells transduced with Phoenix-derived retrovirus showed, on a per cell basis, 10-30% higher levels of scFv(G250)-mediated TNFalpha production and cytolysis of G250L+ RCC cells than T cells transduced with PG13-derived retrovirus. The improved functional transduction efficiency together with a limited increase in the number of integrations per recipient cell, made us select Phoenix clone 58 for our clinical immunogene therapy study.

T-lymphocyte reconstitution following rigorously T-cell-depleted versus unmodified autologous stem cell transplants.

We compared the kinetics of T-cell recovery after extensive ex vivo and in vivo T-cell depleted autologous stem cell transplantation (SCT) for multiple sclerosis (MS; n=8) with unmodified SCT for hematological malignancies (HM; n=39). Both patient group showed a very protracted recovery of 'naive' CD4(+), 45R0(-) ( approximately CD45RA(+)) T-cells. Within the 'primed' CD4(+), 45R0(+) T-cells, the 'central memory' cells expressing the CD62L and CD27 markers were the slowest to recover. The repopulating T-cells were highly activated, as shown by increased expression of HLA-DR and the apoptosis marker CD95. The capability of CD4(+) and CD8(+) T-cells to produce IFN-gamma, IL-2 and TNF-alpha had reached normal ranges from 2 months post SCT onwards. Unexpectedly, the kinetics of T-cell recovery between 3 and 12 months post transplant was similar in T-depleted and unmodified SCT. Before SCT, the HM patients showed lymphopenia of all T-cell subsets, upregulated HLA-DR and CD95 expression and increased cytokine responses. We suggest that the similar kinetics of T-cell recovery in the two patient groups may be explained by the susceptibility to apoptosis of the activated CD4(+) T-cells in the autografts of the HM patients. This susceptibility to apoptosis would interfere with a swift and sustained CD4(+) T-cell regeneration post SCT.

Regression of advanced ovarian carcinoma by intraperitoneal treatment with autologous T lymphocytes retargeted by a bispecific monoclonal antibody.

BACKGROUND: The high frequency of relapse after induction chemotherapy of advanced ovarian carcinoma calls for new therapeutic approaches. Lysis of ovarian carcinoma cells can be achieved by retargeting of T lymphocytes using F(ab')2 fragments of the bispecific monoclonal antibody (MAb) OC/TR, which is directed to the CD3 molecule on T lymphocytes and to the folate receptor on ovarian carcinoma cells. PURPOSE: Our purpose was to assess in ovarian carcinoma patients the antitumor activity of in vitro-activated autologous peripheral blood T lymphocytes retargeted with OC/TR. METHODS: Patients with epithelial ovarian cancer (International Federation of Gynecology and Obstetrics stages III and IV) meeting specific criteria were eligible to enter a phase II immunotherapy trial. Before immunotherapy, the 28 patients who entered the trial underwent laparotomy to reduce their tumor load and to allow measurement of all indicator lesions. They then received two cycles of five daily intraperitoneal infusions of autologous in vitro activated peripheral blood T lymphocytes retargeted with OC/TR plus recombinant interleukin 2 (IL-2) with (n = 11) or without (n = 17) a second daily infusion of OC/TR F(ab')2 and IL-2. Response to treatment could be assessed in 26 patients following explorative laparotomy; time to progression could be assessed in 27 patients. RESULTS: Seven patients had clinical evidence of progressive disease after treatment and therefore did not undergo laparotomy. Of the 19 patients evaluated by surgery and histology, three showed complete response, one showed complete intraperitoneal response with progressive disease in retroperitoneal lymph nodes, three showed partial response, seven had stable disease, and five had progressive disease. The overall intraperitoneal response rate was 27% (95% confidence interval [CI] = 10%-44%). The complete responses seen in three patients lasted 26 months in one patient, 23 months in the second, and 18 months in the third. Two patients were not assessable for response. One of these patients had bowel perforation during catheter removal, which precluded further evaluation. The second patient was positive only by cytologic examination before immunotherapy, was tumor free at laparotomy after immunotherapy, and remained so for the entire 21 months of follow-up, as determined by cytologic examination of random biopsy specimens. The median time to disease progression in the 15 assessable patients plus those who had stable disease was 11 months (95% CI = 6-18 months). Immunotherapy-related toxic effects included mild to moderate fever, nausea, emesis, and fatigue. Anti-mouse antibodies were detectable by the end of the treatment in 21 of 25 patients tested. CONCLUSIONS: Locoregional immunotherapy of ovarian cancer with bispecific MAb-retargeted T lymphocytes can result in tumor regression. Toxicity was mild to moderate and only transient. IMPLICATIONS: Improvement in systemic antitumor responses is needed before this approach can prove useful as adjunctive treatment following induction chemotherapy in patients with minimal residual disease.

Parallel detection of transduced T lymphocytes after immunogene therapy of renal cell cancer by flow cytometry and real-time polymerase chain reaction: implications for loss of transgene expression.

We have started a phase I/II immunogene therapy study of metastatic renal cell cancer (RCC), using autologous T lymphocytes transduced ex vivo with a gene encoding a single-chain receptor based on the monoclonal antibody (mAb) G250 [scFv(G250)]. G250 recognizes carbonic anhydrase IX, which is overexpressed by RCC cells. We have developed and validated flow cytometric and real-time polymerase chain reaction (PCR) assays to quantitatively detect transduced T cells in patient blood. The flow assay was based on staining with the anti-G250 idiotype mAb NuH82 and showed a sensitivity of 0.06% scFv(G250)(1) cells within CD3(1) T cells. The real-time PCR method showed a sensitivity of 14 copies of scFv(G250) DNA per 100 ng of total DNA, which enabled detection of 0.008% scFv(G250)(1) T cells within leukocytes. Both assays were further validated for their specificity and reproducibility. When applied to blood samples from three RCC patients treated with intravenous infusions of scFv(G250)(1) T cells, the kinetics of scFv(G250)(1) T cell counts as detected by flow cytometry were similar to those detected by real-time PCR, although PCR allowed detection of transduced T cells over a longer period of time (i.e., for patient 3, 7 versus 32 days, respectively). Interestingly, follow-up studies of patient 3 demonstrated that the number of circulating scFv(G250)(1) T cells remained fairly constant during the first 7 days posttreatment, whereas the number of gene copies increased during the same period of time. These results suggest loss of scFv(G250) membrane expression on adoptive transfer, which would have important implications for the antitumor efficacy of this form of immunogene therapy.

Phase I study of subcutaneously administered recombinant human interleukin 12 in patients with advanced renal cell cancer.

A phase I study was conducted to characterize the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and pharmacokinetics of a single dose followed by three times weekly s.c. injections of recombinant human interleukin 12 (rHuIL-12). The study encompassed 28 patients with advanced renal cell carcinoma. rHuIL-12 was administered on day 1, followed by an observation period of 7 days. Starting on day 8, repeated s.c. injections were administered 3 times a week for 2 weeks. The MTD of the initial injection was evaluated at dose levels of 0.1, 0.5, and 1.0 microg/kg. DLT was observed at 1.0 microg/kg and consisted of fever, perivasculitis of the skin, and leukopenia. The MTD of the subsequent repeated injections after 1 week of rest was studied at dose levels 0.5, 1.0, and 1.25 microg/kg. DLT at 1.25 microg/kg comprised deterioration of performance status, fever, vomiting, mental depression, and leukopenia. Other notable toxicities were oral mucositis and elevation of hepatic enzymes. Fever, leukopenia, and elevation of hepatic enzymes were more severe after the initial injection than after repeated injections at the same dose level. At dose level 0.5 microg/kg, the mean area under the plasma concentration-time curve decreased from 7.4 ng/h/ml after the first injection to 3.3 ng x h/ml (P = 0.034) after repeated administrations, and at dose level 1.0 microg/kg, it ranged from 31.8 ng/h/ml to 6.0 ng x h/ml (P = 0.041). One patient had a partial response and seven had stable disease. The MTD of a single s.c. injection of rHuIL-12 was 0.5 microg/kg, and the MTD of three subsequent administrations per week was 1.0 microg/kg. In comparison with a single administration, the three times weekly administrations at the same dose level was accompanied with a milder pattern of side effects and a reduction of the area under the plasma concentration-time curve.

Immunization of carp (Cyprinus carpio) with a Vibrio anguillarum bacterin: indications for a common mucosal immune system.

Uptake and transport of formalin-killed Vibrio anguillarum bacteria were studied in the second gut segment of carp and the resulting reaction of the immune system was investigated. Within a few hours after anal administration antigenic determinants of bacteria were present in intraepithelial macrophages of the second gut segment. In gut and skin mucus and bile, immunoglobulins (Ig's) were detected, but the amount was much lower than found in serum. In mucus of the second gut segment, 4 times more Ig (per mg protein) was found than in the first segment. Upon oral or anal immunization, slightly enhanced antigen-specific Ig titers could be detected in skin mucus and bile, but only after a booster along the same route. The existence of a common mucosal immune system is discussed, with special reference to the significance of the second gut segment. After anal intubation an increase of antigen-specific Ig could also be observed in serum. Following a booster, an enhanced cal memory. After anal boosting equal levels of serum antibody were reached compared with two consecutive intramuscular injections. However, no significant antibody increase occurred in serum after oral immunization, not even when bacteria were administered daily with the food.

Humoral response and memory formation in carp after injection of Aeromonas hydrophila bacterin.

The humoral immune response of carp (Cyprinus carpio) upon a bacterial fish pathogen Aeromonas hydrophila was studied in relation to memory formation. After a single intramuscular (i.m.) injection of formalin killed A. hydrophila cells (F-Ah), maximum serum Ab (Ab) titers were observed at day 20. Distinct titers were still seen at day 360 in the groups injected with a medium or high antigen (Ag) dose (10(7) respectively 10(9) F-Ah). The effect of a second immunization with a high Ag dose was studied in fish primed 1, 3, 8 or 12 months earlier with 10(5), 10(7) or 10(9) F-Ah. The height of the secondary Ab response was positively correlated with the height of the priming Ag dose. Challenge with a low Ag dose (10(6) F-Ah) gave the best results with 10(7) F-Ah primed animals. The highest secondary responses were obtained with combinations of corresponding priming and challenge dosages. It is concluded that fish are able to form immunological memory to this bacterial Ag. However, optimal memory levels are reached after a relative long period (3-8 months).

Adoptive immuno-gene therapy of cancer with single chain antibody [scFv(Ig)] gene modified T lymphocytes.

Adoptive transfer of antigen-specific T cells has recently shown therapeutic successes in the treatment of viral infections and tumors. T cells specific for the antigen of interest can be generated in vitro, and adoptively transferred back to provide patients with large numbers of immune-competent T cells. Adoptive T cell therapy, however, is a patient-tailored treatment that unfortunately is not universally applicable to treat viral infections and tumors. We and others have demonstrated that the transfer of genes encoding antigen-specific receptors into T cells (i.e., genetic retargeting) represents an attractive alternative to induce antigen-specific immunity. Currently, we evaluate this concept in a clinical protocol to treat patients with metastatic renal cell cancer (RCC) using autologous RCC-specific gene-modified T lymphocytes.

Gallbladder sensitivity to CCK in duodenal ulcer disease, highly selective and truncal vagotomy.

BACKGROUND/AIMS: Following truncal vagotomy, a heightened contractile response of the gallbladder to cholecystokinin (CCK) has been reported in patients. We investigated whether the gallbladder responsiveness to the CCK analog cerulein is also affected in patients with a highly selective vagotomy (HSV) and in duodenal ulcer patients, since most patients had truncal vagotomy for recurrent peptic ulcer disease. MATERIALS AND METHODS: Gallbladder emptying (cholescintigraphy) and plasma cholecystokinin like immunoreactivity (CCK-LI) levels were studied during infusion of graded doses of the CCK analog cerulein. RESULTS: In duodenal ulcer patients (n = 9), patients with HSV (n = 9), patients with truncal vagotomy (n = 9) and control subjects (n = 9), infusion of stepwise increasing doses of cerulein (1-16 ng.kg-1.h-1) induced dose related changes in plasma CCK-LI. In patients with truncal vagotomy, the gallbladder contraction in response to 1, 2 and 4 ng.kg-1.h-1 of cerulein was significantly increased over controls; whereas the gallbladder contraction to cerulein in duodenal ulcer patients and patients with HSV was not significantly different from controls. CONCLUSIONS: Thus, in patients with truncal vagotomy, gallbladder contractile response to CCK is significantly enhanced, possibly due to denervation of hepatic vagal branches since gallbladder contraction after CCK infusion shows no difference between post HSV or duodenal ulcer patients and the controls.

Phase I dose-escalation study of F60008, a novel apoptosis inducer, in patients with advanced solid tumours.

Resistance of cancer cells to cytotoxic therapy can be caused by the activation of strong anti-apoptotic effectors, for example NF-kappaB. Therefore, compounds that inhibit NF-kappaB stimulation might overcome chemotherapy resistance. F60008, a semi-synthetic derivate of triptolide, is converted to triptolide in vivo and activates apoptosis in human tumour cells. We performed a phase I and pharmacological study of F60008 given intravenously as a weekly infusion for 2 weeks every 3 weeks in patients with advanced solid tumours. Twenty patients were enrolled, and a total of 35 cycles were administered. The most frequent haematological side-effect was mild grade 1-2 anaemia. Non-haematological toxicities included fatigue, nausea, vomiting, diarrhoea and constipation, all grade 1-2. Two lethal events were observed in which an increase in caspase-3 activity and overt apoptosis in monocytes and neutrophils could be seen. Pharmacokinetic studies showed high inter-individual variability and rendered F60008 a far from optimal derivate of triptolide.

Retroviral vectors for clinical immunogene therapy are stable for up to 9 years.

Recombinant retroviruses are one of the most commonly used gene transfer vehicles for therapeutic gene delivery. The stability of viral vectors upon long-term storage, anticipated to be short lived, is expected to impact timeline and financial course of clinical immunogene therapy. However, to date little is known about vector stability. Therefore, we analyzed the stability of retroviral vectors produced in culture supernatants (RTVsup) for ex vivo gene therapy upon long-term storage. We have generated RTVsups derived from two packaging cell lines, PG13 and Phoenix(Ampho). Both lines produced murine leukemia virus-derived SFG-scFv(G250)-CD4gamma vector, which were pseudotyped with the gibbon ape leukemia virus envelope and amphotropic envelope, respectively. The supernatants were stored at -80 or -196 degrees C. To date, the PG13-derived RTVsups have been evaluated over a period of 9 years (1998-2007). In addition, a clinical batch of Phoenix(Ampho)-derived RTVsup has been evaluated over a period of 5 years (2002-2007). Here, we show that both RTVsups, when stored up to 9 and 5 years, respectively, do not show any sign of decay in their capacity to functionally transduce primary human T cells. These data provide evidence that in terms of 'life expectancy' the production and storage of clinical batches of RTVsup for gene therapy warrants the corresponding professional and financial risks.

Process validation and clinical evaluation of a protocol to generate gene-modified T lymphocytes for imunogene therapy for metastatic renal cell carcinoma: GMP-controlled transduction and expansion of patient's T lymphocytes using a carboxy anhydrase IX-specific scFv transgene.

BACKGROUND: Adoptive transfer of autologous T cells that are gene-transduced to express Ag-specific receptors represents an experimental strategy to provide tumor-specific immunity to cancer patients. We studied this concept in patients with metastatic renal cell cancer (RCC) using retroviral transduction of T cells with a single-chain Ab-G250 chimeric receptor [scFv(G250)]. We describe the validation of our clinical protocol for gene transduction and expansion of human T lymphocytes. METHODS: A batch of scFv(G250) transgene-containing retrovirus was produced under conditions of good manufacturing practice (GMP). In addition to quality control and safety testing of the virus batch, extensive potency testing was performed, i.e. assessment of its functional transduction efficiency in primary human T cells. Subsequently, the clinical gene transduction and cell-expansion protocol was subjected to a series of process validations and a clinical evaluation using T cells obtained from healthy donors and three RCC patients. RESULTS: The clinical batch of scFv(G250) transgene-containing retrovirus met the quality and safety control criteria. Small-scale transductions yielded 62-92% scFv(G250)+ T cells and, at a clinical scale, 50-84% transduction efficiencies were obtained. Patient and healthy donor T cells showed similar expansion potencies, and also yielded similar levels of scFv(G250)-mediated immune functions, i.e. specific cytolysis of G250-ligand expressing RCC cells and production of IFN-gamma upon stimulation with such cells. All T cell cultures were free of replication competent retroviruses. DISCUSSION: We have shown that the validated batch of scFv(G250) transgene-containing retrovirus in combination with our GMP T-cell transduction and expansion protocol successfully generates clinically relevant numbers of functional scFv(G250) gene-modified T cells for patient treatment.

An experimental study on neural crest migration in Barbus conchonius (Cyprinidae, Teleostei), with special reference to the origin of the enteroendocrine cells.

A neural crest transplantation technique is described for fish. As in other classes of vertebrates, two pathways of neural crest migration can be distinguished: a lateroventral pathway between somites and ectoderm, and a medioventral pathway between somites and neural tube/notochord. In this paper evidence is presented for a neural crest origin of spinal ganglion cells and pigment cells, and indication for such an origin is obtained for sympathetic and enteric ganglion cells and for cells that are probably homologues to adrenomedullary and paraganglion cells in the future kidney area. The destiny of neural crest cells near the developing lateral-line sense organs is discussed. When grafted into the yolk, neural crest cells or neural tube cells appear to differentiate into 'periblast cells'; this suggests a highly activating influence of the yolk. Many neural crest cells are found around the urinary ducts and, when grafted below the notochord, even within the urinary duct epithelium. These neural crest cells do not invade the gut epithelium, even when grafted adjacent to the developing gut. Consequently enteroendocrine cells in fish are not likely to have a trunk- or rhombencephalic neural crest origin. Another possible origin of these cells will be proposed.

Enteroendocrine APUD cells in the digestive tract of larval Barbus conchonius (Teleostei, Cyprinidae).

The development of Barbus conchonius is described with special attention to the differentiation of the gut. Amine precursor uptake and decarboxylation (APUD) are present in enteroendocrine cells during development, whereas these processes are lacking in adult specimens. The first APUD cells originate on the fourth day of development in the anterior part of the gut and on the fifth day in the caudal areas. The APUD facility of the cells disappears within 2 days, and after the 6th day APUD cells can no longer be distinguished in the intestinal epithelium. The first APUD cells were obsserved when four types of enteroendocrine cells were recognized with the electron microscope. These enteroendocrine cells contain granules of different electron densities, and microtubules and cilia can be observed. Some enteroendocrine-like cells are found below the basement membrane of the intestinal epithelium, indicating a possible extra-endodermal origin. APUD cells, except melanoblasts, have not been found migrating from the neural crest in ventral direction. The origin of the enteroendocrine cells of B. conchonius is discussed.

Antigen localization in the lymphoid organs of carp (Cyprinus carpio).

A brief morphological description is given of the spleen, head kidney and trunk kidney, the three peripheral lymphoid organs of carp. An antigen-localization study was carried out using Aeromonas hydrophila (a cellular bacterial antigen) and an indirect immunofluorescence test. Examination of the lymphoid organs at various times after injection (up to 12 months) showed that antigen was at first present in splenic ellipsoids and in solitary phagocytic cells in the spleen, head and trunk kidney. Later on, the antigen was gradually concentrated in or near melano-macrophage centres in all the organs studied. By this time, it had disappeared from the splenic ellipsoids, and the number of solitary A. hydrophila-immunoreactive cells had also decreased. At a later stage, antigen was located extracellularly at the membrane of cells in and around the melano-macrophage centres, and it remained so for a full year. No antigen was detected in the lymphoid organs following a bath immunization.