Septal extension graft use in the treatment of alar collapse.

OBJECTIVE: In our study, we showed that the septal extension graft (SEG) technique, which we applied for nasal projection in rhinoplasty surgery, increases the tension of the lateral cartilage (LC) and alar structures. We also demonstrated that nasal congestion could be treated by applying this technique in patients with nasal obstruction due to bilateral dynamic alar collapse. PATIENTS AND METHODS: This study was conducted retrospectively on 23 patients with nasal obstruction due to alar collapse. Bilateral dynamic nasal collapse and (+) Cottle test was present in all patients. Nasal lateral wall tissue was also found flaccid on nasal palpation and collapsed to the extent of obstruction on deep inspiration. Standard septal extension graft (SEG) and tongue-in-groove techniques were applied to all patients. RESULTS: Septal cartilage was used for SEG in all patients. No complaints of nasal obstruction on deep inspiration were noted by the patients at six months postoperative follow-up, and Cottle tests were negative. The patients' mean respiratory score was 152 postoperatively, compared to 66.5 preoperatively. This difference was statistically significant using the Wilcoxon signed ranks test (p<0.001). In evaluating postoperative cosmetic appearance due to nasal tip projection (NTP) and cephalic rotation changes, 16 men and four women reported that it was better, while two men felt that there was no change. One woman reported that her cosmetic appearance was worse than before; a revision surgery was performed for her at seven months postoperatively. CONCLUSIONS: This method is effective for patients with bilateral nasal collapse and thick-short columella. With the applied surgery, the caudal edge of the LC diverges from the septum, alar region tension and resistance increase, the columella increases in length, nasal projection increases, and the vestibule cross-sectional area is enlarged. In this way, a significant increase in nasal vestibular volume was obtained.

Applied surgical methods and outcomes in crooked nose rhinoplasty.

OBJECTIVE: In this retrospective and multicentric study, we investigated applied surgical methods in rhinoplasty for crooked nose deformity. PATIENTS AND METHODS: The retrospective data for 300 crooked nose deformity cases (191 males and 109 females) were used in our study. Classification of the initial deformities was performed as (1) I-shaped crooked nose deformity, (2) C-shaped crooked nose deformity, (3) Reverse C-shaped crooked nose deformity, and (4) S-shaped crooked nose deformity. As an operation technique, L-strut septoplasty was performed. The applied surgical methods in rhinoplasty to correct the crooked nose are evaluated and classified. RESULTS: Our results showed that initial deformities in crooked nose patients were I-shaped crooked nose deformity (34%), C-shaped crooked nose deformity (28%), Reverse C-shaped crooked nose deformity (21.3%), and S-shaped crooked nose deformity (16.7%). L-strut septoplasty was performed, and the results of the applied methods to correct the crooked nose were evaluated and classified. It was noticed that more than one procedure was applied to each case: (1) double-side lateral osteotomy (86.6%), (2) wedge bone resection on one side of the osteotomy (7.3%), (3) single-side lateral osteotomy (6%), (4) symmetric spreader grafts (56%), (5) asymmetric spreader grafts (10.6%), (6) shaving of the transverse wing of dorsal septum (8%), (7) correction of deviated dorsal septum (16.3%), (8) displaced anterior nasal spine (12.6%), (9) clocking suture (dorsal septal rotation suture) (9%), (10) dorsal septal scoring and splinting graft (8.3%), and equalizing lateral cruses (12.6%). CONCLUSIONS: I-shaped and C-shaped crooked nose deformities were mainly detected in crooked nose deformity patients. Correcting the crooked nose, double-side lateral osteotomy, and symmetric spreader grafts were the most applied techniques to correct the crooked nose. Other rhinoplasty techniques were also applied to these patients; more than one technique was needed.

Do products containing menthol exacerbate allergic rhinitis? A narrative review.

The aim of this paper is to review whether products containing menthol exacerbate allergic rhinitis. A literature survey was performed on PubMed, Google and Google Scholar concerning allergic rhinitis (AR). Allergic rhinitis is an inflammatory condition of the nasal mucosa characterized by wheeze, congestion, nasal pruritus and discharge, or any combination thereof. Menthol is a naturally occurring phytochemical, with the formula C10H20O. The L-isomeric form creates the typical odor of peppermints and causes a sensation of coolness when applied to the skin or mucosae. Inhaling menthol vapor is known to affect the respiratory system in a number of different ways. The cooling agent, menthol, is also recognized as a trigger for asthma, AR and urticaria. The menthol molecule stimulates the TRPM8 receptor and may stimulate histamine release in a dose-dependent manner from RBL-2H3 cell cultures. The addition of menthol to products produces symptomatic relief in some patients by providing an impression of freer nasal air flow. It does this by stimulating cold receptors on branches of the fifth cranial nerve. Menthol is capable of provoking allergic hypersensitivity reactions and disorders, including asthma, AR and urticaria. It may also trigger an anaphylactic response. The use of menthol-containing products is best avoided in cases where an allergic disorder exists.

Is G. cambogia a promising treatment? Effects on cultured nasal epithelial cells.

OBJECTIVE: The purpose of this study is to assess the effects of applying Garcinia cambogia to cultured human nasal epithelial cells. MATERIALS AND METHODS: A cell culture was set up consisting of human primary nasal epithelial cells harvested during septorhinoplasty from volunteers. The cells came from individuals with no history of rhinosinusitis. One assay for assessing cytotoxicity in cell culture utilizes MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). This method allows visualization of fragmented DNA, condensation of nuclei and changes to the external cellular membrane or cytoskeleton. Our study employed this method. Nasal epithelial cells at 37°C were exposed in culture to G. cambogia for a period of 24 hours. Afterwards an MTT assay was used in conjunction with confocal microscopy to assess evidence of toxicity. The proliferative capability of the nasal epithelial cells was also evaluated by inducing a scratch injury to cultured cells followed by light microscopic examination. RESULTS: Testing for cytotoxicity in this manner indicates that G. cambogia does not appear harmful to cultured nasal epithelial cells when applied directly. The cells exposed to this plant extract were still fully viable 24 hours afterwards. There was no increase in viability at the level of statistical significance. It was noted, however, that proliferation did increase slightly within the exposure period. The MTT assay and confocal microscopy confirm these findings. Under confocal microscopic examination, a compact morphology with unaltered nuclear and cytoskeletal appearances was observed. Thus, there is no evidence suggesting viability is impaired or that cytotoxicity occurs. Ordinary light microscopic examination showed the area denuded of cells had become re-covered completely within 24 hours in the cultures where G. cambogia had been applied. The result suggests that exposure to G. cambogia has no significant effect in terms of stimulating or inhibiting cellular proliferation. CONCLUSIONS: G. cambogia may offer clinical benefit as a supplementary topical treatment for inflammation of the nose and sinuses, as seen in chronic and acute rhinosinusitis, or nasal polyps. The plant appears to increase nasal epitheliocytic proliferation slightly, as revealed by the MTT assay. There were no indications of a cytotoxic effect on epithelial cells of the nose.

The superiority of Dexpanthenol or Vaseline as excipient in nasal formulations.

OBJECTIVE: Dexpanthenol is an ingredient in multiple topical pharmaceutical preparations thanks to its high penetration and localized concentration. It is included in many ointments or lotions for dermatological use, assisting in healing and reducing pruritus. Vaseline is a synthetic product obtained by distilling crude oil. It is commercially available in several grades. The study presented here examined how topically applied agents (dexpanthenol or vaseline) affect nasal epithelial cells in culture. In particular, the study aimed to identify any alterations to epithelial cells which might indicate toxicity. MATERIALS AND METHODS: The nasal epithelial cells used were sourced from mucosal tissue fragments left over the following septorhinoplasty on five patients not suffering from rhinosinusitis. The first step was to dissect the mucosal fragments into smaller pieces on a sterilized Petri dish. These fragments were then placed into the DMEM-F12 cell culture medium, which had been freshly prepared. The dexpanthenol and vaseline were diluted in dimethylsulfoxide (DMSO) to a concentration of 5 mg/mL. The cells in the wells were exposed to varying concentrations of dexpanthenol or vaseline. The actual concentration of the test reagent to which the epithelial cells were exposed ranged from 0.15 mg/mL to 5 mg/mL. The exposure period was 24 hours. The cells were finally examined using a Leica SP5II confocal microscope. The features sought were DNA fragmentation, condensation of the nuclei, changes in the outer membrane, or cytoskeletal abnormality. These features, if present, indicate cytotoxicity. RESULTS: The viability of the cultured nasal epithelial cells was unaltered by a 24-hour exposure to dexpanthenol, nor was the cellular proliferation rate affected at the level of statistical significance. There was evidence of a cytotoxic effect from exposing nasal epithelial cells to vaseline in liquid form for 24 hours. There was a reduction in cellular viability in the plates where the highest dose of vaseline (5 mg/mL) was used. Cellular viability was not affected significantly at any of the doses below 5 mg/mL. CONCLUSIONS: The absence of cytotoxic effects from the application of dexpanthenol to the nasal mucosa indicates that this agent may be safely used within the nose. The cytotoxic effects of liquid vaseline observed in this trial (condensed nuclear chromatin, loss of cellular volume) indicate that this agent may be harmful when used intranasally. For patients who require nasal packing due to nose bleeds or following endoscopic sinus surgical procedures, dexpanthenol should be preferred to vaseline from the point of view of maximizing healing of a nasal injury.

The intranasal trigeminal system: roles in rhinitis (allergic and non-allergic).

The aim of this paper is to review intranasal trigeminal system and associated reflexes. The literature survey was performed on PubMed, ProQuest Central database of Kirikkale University and Google Scholar. The intranasal trigeminal system and associated reflexes play an important role in humans in both health and disease, including in rhinitis of non-allergic and mixed type. The intranasal trigeminal nerve provides sensory perception to the lining of the nose, supplying information on how patent the nasal airway is and responding to various chemical signals. The reflexes known to exist within the intranasal trigeminal system are nasobronchial reflex, trigemino-cardiac reflex, nasogastric reflex, and nasal cycle. The intranasal trigeminal system and its reflexes play a vital role in normal human physiology. Alterations in how this system operates may underlie multiple forms of rhinitis and more research is needed to fully understand the mechanisms involved.

Mechanisms and solutions for nasal drug delivery - a narrative review.

The aim of this paper is to review mechanisms and solutions for nasal drug delivery. Literature survey was performed via PubMed, Google Scholar, Google, and ProQuest Central database of Kirikkale University. The nasal lining presents a large area of endothelium of variable permeability and with a rich vascular supply. Advantages of this route include eliminating first-pass metabolism and being easily accessible. The nasal route enables some agents which are otherwise difficult to administer to enter the systemic circulation, for example, low molecular mass compounds with high polarity, peptides, or proteins. There are three principal factors that influence the extent to which drugs can be absorbed through the nasal lining, namely the physico-chemical characteristics of the drug molecule itself, the action of the mucociliary system within the nose, and the presence of any factors increasing nasal absorption. A key factor limiting the use of the intranasal route of administration is insufficient absorption through the nasal mucosa. A number of drugs in development cannot be administered intranasally because their bioavailability following nasal administration is too low. There has been considerable research focus on methods to enhance absorption via the nasal mucosa. In this chapter, we review the literature related to this problem and discuss potential solutions.

Good manufacturing practice and clinical-grade human embryonic stem cell lines.

Human embryonic stem cell (hESC) lines, after directed differentiation, hold the greatest potential for cell transplantation treatment in many severe diseases. Good manufacturing practice (GMP) quality, defined by both the European Medicines Agency and the Food and Drug Administration, is a requirement for clinical-grade cells, offering optimal defined quality and safety in cell transplantation. Using animal substance-free culture media, feeder cells or feeder-free matrix in derivation, passaging, expansion and cryopreservation procedures, immune reactions against animal proteins in the cells, and infection risk caused by animal microbes can be avoided. It is also possible to apply GMP to animal components if no better options are available. In recent production of GMP-quality hESC lines, feeder cells had been cultured in fetal bovine serum, and the medium supplemented with an animal protein containing a serum replacement component. Using embryos cultured in a GMP laboratory, isolating the inner cell mass mechanically, deriving lines on human feeder cells originally cultured in xeno-free medium in a GMP laboratory, and using xeno-free media for derivation and culture of hESC lines themselves, GMP-quality xeno-free hESC lines could be established today. Human serum is a xeno-free component available today, but many chemically defined media are under development.

Differentiation of human embryonic stem cells into osteogenic or hematopoietic lineages: a dose-dependent effect of osterix over-expression.

Enhanced differentiation of human embryonic stem cells (HESCs), induced by genetic modification could potentially generate a vast number of diverse cell types. Such genetic modifications have frequently been achieved by over-expression of individual regulatory proteins. However, careful evaluation of the expression levels is critical, since this might have important implications for the differentiation potential of HESCs. To date, attempts to promote osteogenesis by means of gene transfer into HESCs using the early bone "master" transcription factor osterix (Osx) have not been reported. In this study, we attained HESC subpopulations expressing two significantly different levels of Osx, following lentiviral gene transfer. Both subpopulations exhibited spontaneous differentiation and reduced expression of markers characteristic of the pluripotent phenotype, such as SSEA3, Tra1-60, and Nanog, In order to promote bone differentiation, the cells were treated with ascorbic acid, beta-glycerophosphate and dexamethasone. The high level of Osx, compared to endogenous levels found in primary human osteoblasts, did not enhance osteogenic differentiation, and did not up-regulate collagen I expression. We show that the high Osx levels instead induced the commitment towards the hematopoietic-endothelial lineage-by up-regulating the expression of CD34 and Gata1. However, low levels of Osx up-regulated collagen I, bone sialoprotein and osteocalcin. Conversely, forced high level expression of the homeobox transcription factor HoxB4, a known regulator for early hematopoiesis, promoted osteogenesis in HESCs, while low levels of HoxB4 lead to hematopoietic gene expression.

Lentiviral-mediated HoxB4 expression in human embryonic stem cells initiates early hematopoiesis in a dose-dependent manner but does not promote myeloid differentiation.

The variation of HoxB4 expression levels might be a key regulatory mechanism in the differentiation of human embryonic stem cell (hESC)-derived hematopoietic stem cells (HSCs). In this study, hESCs ectopically expressing high and low levels of HoxB4 were obtained using lentiviral gene transfer. Quantification throughout differentiation revealed a steady increase in transcription levels from our constructs. The effects of the two expression levels of HoxB4 were compared regarding the differentiation potential into HSCs. High levels of HoxB4 expression correlated to an improved yield of cells expressing CD34, CD38, the stem cell leukemia gene, and vascular epithelium-cadherin. However, no improvement in myeloid cell maturation was observed, as determined by colony formation assays. In contrast, hESCs with low HoxB4 levels did not show any elevated hematopoietic development. In addition, we found that the total population of HoxB4-expressing cells, on both levels, decreased in developing embryoid bodies. Notably, a high HoxB4 expression in hESCs also seemed to interfere with the formation of germ layers after xenografting into immunodeficient mice. These data suggest that HoxB4-induced effects on hESC-derived HSCs are concentration-dependent during in vitro development and reduce proliferation of other cell types in vitro and in vivo. The application of the transcription factor HoxB4 during early hematopoiesis from hESCs might provide new means for regenerative medicine, allowing efficient differentiation and engraftment of genetically modified hESC clones. Our study highlights the importance of HoxB4 dosage and points to the need for experimental systems allowing controlled gene expression. Disclosure of potential conflicts of interest is found at the end of this article.

Retroviral gene transfer into primary human natural killer cells.

Modulation of intracellular signaling pathways or receptor expression in natural killer (NK) cells by genetic manipulation is an attractive possibility in studies of NK cell specificity and function. Moreover, feasible applications of these genetic manipulations in the context of gene and NK cell therapy regimens may be considered. However, efficient gene modification of primary NK cells has been largely hampered by the absence of an efficient gene-transfer protocol.A retrovirus-based easy-to-use transduction protocol that can insert the gene of interest permanently into primary NK cells would be an important tool to advance our studies in NK cell biology and NK cell-mediated therapies. We have recently described a protocol for efficient expansion of NK cells under good manufacturing practice (GMP) conditions from the healthy donors and from patients with hematological malignancies. As the active division of cells is a prerequisite for efficient retroviral insertion, the high rate of expansion in this protocol provides more efficient transduction by retroviral vectors. We hereby present this simple and efficient retroviral vector-based gene-transfer protocol for such ex vivo cultured primary human NK cells.

Anti-myeloma activity of endogenous and adoptively transferred activated natural killer cells in experimental multiple myeloma model.

OBJECTIVE: Despite advances in autologous stem cell transplantation and chemotherapy, multiple myeloma (MM) remains an incurable disease. Due to the role of natural killer (NK) cells in host resistance against several tumors, it is of interest to explore the anti-MM activity of NK cells. For this reason, we aimed to determine if NK cells provide anti-MM activity following interleukin-2 (IL-2) administration, and if ex vivo activated and intravenously administered NK cells prolong survival in MM-bearing C57BL/KaLwRij mice. METHODS: The anti-MM effect of IL-2 was tested by intraperitoneal injection into the 5T33MM-inoculated mice. Subsequently, in vivo effector cell depletions were performed by administration of anti-NK1.1 or anti-CD8 monoclonal antibodies. Finally, magnetically separated and activated NK cells from splenocytes of C57BL/KaLwRij mice were adoptively transferred to tumor-bearing mice in conjunction with IL-2 treatment. RESULTS: IL-2 administration into MM-bearing mice significantly prolonged their survival. This effect was diminished by in vivo depletion of NK cells. Adoptive transfer of activated NK cells showed a significant in vivo anti-MM effect that was dependent on cell dose. Biodistribution of the marked adoptively transferred NK cells correlated with MM cells' homing sites. CONCLUSION: These data suggest that activated NK cells have a promising potential in adoptive immunotherapy for MM.

Long-term follow-up of gene-marked CD34+ cells after autologous stem cell transplantation for multiple myeloma.

Gene marking can be used to investigate if progenitor cells harvested from patients are contaminated with tumorigenic cells. It can also provide information about the contribution of hematopoietic stem cells to long-term engraftment and about long-term transgene expression from integrated retroviral vectors. In order to study autologous-infused cell contribution to relapse as well as the long-term persistence of the transgene in hematopoietic cells following autologous bone marrow (BM) transplantation for multiple myeloma, we genetically marked autologous CD34+ enriched BM or peripheral blood cell grafts of eight myeloma patients using retroviral vectors. Six patients were subsequently transplanted with the marked graft and followed with regular time points of analysis. Briefly, mononuclear cells were harvested by leukapheresis during 2-4 consecutive days following priming with granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF. The CD34+ cells separated on Cellpro ceprate avidin-biotin columns were exposed to the G1Na vector coding for neomycin resistance gene at a ratio of five vector particles per cell at three consecutive time points achieving an average transduction efficacy of 2% (0.43-5.1%). The patients were transplanted with a mixture of transduced cells and un-manipulated graft. Vector integration and transgene expression were analyzed by colony assays and polymerase chain reaction. The transgene could be detected for up to 5 years post-transplant in normal BM cells, even in remission following relapse and no side effects related to retroviral gene transfer were observed. There were no marked myeloma cells observed in the patients either in remission or in relapsing disease, which indicates that contribution of infused cells to relapse is unlikely.

Evaluation of ex vivo expanded human NK cells on antileukemia activity in SCID-beige mice.

The possibility of using natural killer (NK) cells in treatment of human hematological malignancies has increased in recent years. One factor contributing to this is the introduction of new methods for ex vivo generation of enriched populations of clinical grade NK cells. The objective of the present study was to evaluate the safety and efficacy of human ex vivo expanded clinical grade NK cells against K562 leukemia cells in severe combined immunodeficiency disease (SCID)-beige mice. Irradiated SCID-beige mice were injected intravenously (i.v.) with K562 leukemia cells. Following leukemia cell injection, mice were injected with ex vivo expanded human NK cells. NK cells were followed in vivo and mice monitored for survival from leukemia. Administration of these ex vivo expanded clinical grade NK cells was safe and prevented leukemia development. In conclusion, these results imply possibilities for the use of this NK cell preparation in treatment trials of human hematological malignancies and possibly other forms of cancer.

The derivation of clinical-grade human embryonic stem cell lines.

The pluripotent nature of human embryonic stem cells (hESC) has attracted great interest in using them as a source of cells or tissue in cell therapy. However, in order to be used in regenerative medicine, the pluripotent hESC lines should be established and propagated according to good manufacturing practice quality requirements. The cultures should be animal substance free in order to exclude the risk of infections and immunogenity. They should also be genetically and epigenetically normal. The detailed molecular mechanisms of their pluripotency are still not defined. Using human feeder cells, a medium containing only human proteins, the mechanical isolation of the inner cell mass and mechanical passaging of hESC, is a safe option until a functional defined medium containing physiological concentrations of regulatory factors is available.

Gap junctions promote the bystander effect of herpes simplex virus thymidine kinase in vivo.

Transfer of the herpes simplex thymidine kinase gene (HSVtk) into tumor cells followed by the administration of ganciclovir (GCV) provides a potential strategy for the treatment of some malignancies. During GCV treatment, not only the cells that express the HSVtk gene are killed but also frequently neighboring tumor cells that are not genetically altered. This has been called the "bystander effect." Although the mechanism of the bystander effect in vivo remains elusive, our results suggest that gap junction formation between neighboring cells is an important contributing factor. The C6 rat glioma cell line, which exhibits a low level of intercellular communication by gap junctions and connexin43 (Cx43)-transfected clones of this cell line forming gap junctions from a moderate level (Cx43-12 and Cx43-14) to a high level (Cx43-13), were transduced with HSVtk. Transduced and nontransduced cells were mixed in various concentrations and then cultured in vitro or injected s.c. into C.B-17/SCID-beige mice followed by i.p. injections of GCV. Cx43-transfected clones showed a significant increase of the bystander effect compared with the less coupled C6 parental cell line. In 11 of 12 mice injected with cells of Cx43-transfected clones, no tumors were seen at the inoculation site when a mixture of 50% HSVtk-negative and HSVtk-positive cells was used. Moreover, in mice injected with cells of clone Cx43-13, which exhibits the highest intercellular communication, tumors were frequently undetectable at the inoculation site when using mixtures of 75% HSVtk-negative and 25% HSVtk-positive cells, and even mixtures containing 5% HSVtk-positive cells of Cx43-transfected clones showed tumor size reduction. All animals in control groups (n = 26) developed large tumors at every injection site. These results demonstrate that gap junctions are an important component in mediating the bystander effect in vivo.

Targeting IL-2 to the endoplasmic reticulum confines autocrine growth stimulation to NK-92 cells.

OBJECTIVE: Anti-tumor effects mediated by adoptively transferred natural killer (NK) cells are dependent on the presence of interleukin-2 (IL-2). IL-2 is considered to be a survival factor for NK cells and an enhancer of their cytotoxic potential. However, systemic administration of IL-2 is frequently impeded by undesirable side effects, such as high toxicity and nonlocalized administration. Genetic modification of NK cells expressing IL-2 in a localized and controlled manner could be a powerful tool for overcoming these obstacles. METHODS: Consequently, we have cloned the IL-2 gene using PCR and designed constructs that target IL-2 to specific subcellular compartments. The IL-2-dependent NK-92 cell line was used to verify the functionality of the subcellularly targeted IL-2 constructs. RESULTS: IL-2 targeted specifically to the endoplasmic reticulum (ER) was sufficient to support growth of NK-92 cells. In such cell lines, IL-2 was verified to be localized to the ER. IL-2 was not detected in the supernatant and growth of non-IL-2-modified NK-92 cells was not supported during coculturing experiments. IL-2-transduced NK-92 cell lines showed comparable functional activity and cytotoxicity to parental NK-92 cells. CONCLUSION: We demonstrate the ability of ER-retained IL-2 to provide autocrine growth stimulation to NK-92 cells, without secretion of the cytokine to the extracellular compartment. Therapy with IL-2 gene-modified autoactivating NK cells may avoid side effects imposed by exogenously administered IL-2.

Efficient gene transfer into primary human natural killer cells by retroviral transduction.

OBJECTIVE: To optimize retroviral gene transfer into primary human natural killer (NK) cells. MATERIALS AND METHODS: NK cells from healthy donors were expanded ex vivo for a period of 21 days. Retroviral transductions were carried out by replacing culture media with retrovirus-containing supernatant during 2-hour incubations on days 3, 4, 5, 6, 10, 15, or 20. In some experiments, NK cells were transduced on 2 consecutive days (days 5 and 6). Green fluorescent protein served as a marker for detection of transduced cells. RESULTS: NK cells showed a median of 27.2% transduction efficiency after a single transduction round (transduction on day 5) and a median of 47.1% transduction efficiency after two rounds of transduction (transduction on days 5 and 6), 24 hours after exposure to retrovirus-containing supernatants. On day 21 after initial culture, 51.9% of NK cells were transduced after a single transduction round (transduction on day 5) and 75.4% after two rounds of transduction (transduction on days 5 and 6). Gene transfer did not change the function or phenotype of NK cells as determined by phenotypical analysis, nor did the proliferative ability or cytotoxic function change. CONCLUSION: The results show that NK cells can successfully be transduced with retroviral vectors, without any detectable changes in phenotype or function. This may open up new possibilities in the studies of NK cell biology and the development of NK cells for immunotherapy regimens.

A murine model of acute myeloid leukemia with Evi1 overexpression and autocrine stimulation by an intracellular form of GM-CSF in DA-3 cells.

The poor treatment response of acute myeloid leukemia (AML) overexpressing high-risk oncogenes such as EVI1, demands specific animal models for new treatment evaluations. Evi1 is a common site of activating integrations in murine leukemia virus (MLV)-induced AML and in retroviral and lentiviral gene-modified HCS. Still, a model of overt AML induced by Evi1 has not been generated. Cell lines from MLV-induced AML are growth factor-dependent and non-transplantable. Hence, for the leukemia maintenance in the infected animals, a growth factor source such as chronic immune response has been suggested. We have investigated whether these leukemias are transplantable if provided with growth factors. We show that the Evi1(+)DA-3 cells modified to express an intracellular form of GM-CSF, acquired growth factor independence and transplantability and caused an overt leukemia in syngeneic hosts, without increasing serum GM-CSF levels. We propose this as a general approach for modeling different forms of high-risk human AML using similar cell lines.

Expansion of natural killer (NK) and natural killer-like T (NKT)-cell populations derived from patients with B-chronic lymphocytic leukemia (B-CLL): a potential source for cellular immunotherapy.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia in the Western world. It is currently an incurable disease, making new treatment options such as immunotherapy desirable. Monoclonal antibodies (Mabs) to surface antigens of the tumor cell is one option. Administration of cytotoxic cells such as natural killer (NK) and natural killer-like T (NKT) cells expanded in vitro might be a useful treatment modality alone or in combination with MAbs. A limiting step in the development of successful cellular immunotherapy has been the availability of appropriate cytotoxic cells. Here, we report the feasibility of expanding populations of the human killer cells, CD3-CD56+ NK and CD3+CD56+ NKT cells, from peripheral blood mononuclear cells (PBMCs) of B-CLL patients. The influence of tumor B cells on the in vitro expansion of killer cells was assessed by depleting B cells from PBMCs by microbead separation before culture. The 21-day cultures from both B-cell- and non-B-cell-depleted PBMC showed a marked expansion of NK cells, and also of T cells, among which almost half had the NKT phenotype. Depletion of B cells before culture did not change the expansion rates of NK and NKT cells significantly. In patients with progressive B-CLL, NK cell expansion capacity was improved after fludarabine treatment when compared to samples obtained before treatment. Repeated samples of PBMCs from individual untreated patients with both indolent and progressive disease cultured under identical conditions gave similar NK cell expansion rates. Expanded killer cell populations had cytotoxic function against the NK-sensitive target K562 cell line and expressed high levels of Granzyme B. From our studies, we conclude that NK cells as well as NKT cells from the peripheral blood of B-CLL patients can be expanded, and that these cells have cytotoxic capacity.