Synthesis and anti-HIV activity of 1,3,4,5-tetrahydro-2H-1,4-benzodiazepin-2-one (TBO) derivatives. Truncated 4,5,6,7-tetrahydro-5-methylimidazo[4,5,1-jk][1,4]benzodiazepin-2( 1H)-on es (TIBO) analogues.

4,5,6,7-Tetrahydro-5-methylimidazo[4,5,1-jk][1,4]benzodiazepin-2(1 H)-ones (TIBO), 1, have been shown to significantly inhibit HIV-1 replication, as reported in detail in our prior publications. Since our earlier reports, we have modified the TIBO structures 1 by removing the 5-membered ring of 1, generating 1,3,4,5-tetrahydro-2H-1,4-benzodiazepin-2-ones (TBO), 4, a bicyclic series of compounds. Although compounds 4 possess modest activity when compared to TIBO analogues 1, they clearly demonstrated significant anti-HIV-1 activity.

Peripheral blood CD34+ cells differ from bone marrow CD34+ cells in Thy-1 expression and cell cycle status in nonhuman primates mobilized or not mobilized with granulocyte colony-stimulating factor and/or stem cell factor.

Granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) have been shown to stimulate the circulation of hematopoietic progenitor cells in both mice and nonhuman primates. We evaluated the immunophenotype and cell cycle status of CD34+ cells isolated from the bone marrow (BM) and leukapheresis product of cytokine-mobilized nonhuman primates. CD34+ cells were isolated from rhesus macaques that had received no cytokine therapy, 100 micrograms/kg/d G-CSF, 200 micrograms/kg/d SCF, or a combination of both 100 micrograms/kg/d G-CSF and 200 micrograms/kg/d SCF as a subcutaneous injection for 5 days. BM was aspirated before (day 0) and on the last day (day 5) of cytokine administration. On days 4 and 5, peripheral blood (PB) mononuclear cells were collected using a novel method of leukapheresis. Threefold more PB mononuclear cells were collected from animals receiving G-CSF alone or G-CSF and SCF than from animals that had received either SCF alone or no cytokine therapy. CD34+ cells were positively selected using an immunoadsorptive system from the BM, PB, and/or leukapheresis product. Threefold and 10-fold more CD34+ cells were isolated from the leukapheresis product of animals receiving G-CSF or G-CSF and SCF, respectively, than from animals receiving no cytokine therapy or SCF alone. The isolated CD34+ cells were immunophenotyped using CD34-allophycocyanin, CD38-fluorescein isothiocyanate, and Thy-1-phycoerythrin. These cells were later stained with 4', 6-diamidino-2-phenylindole for simultaneous DNA analysis and immunophenotyping. BM-derived CD34+ cells did not differ significantly in cell cycle status and Thy-1 or CD38 phenotype before or after G-CSF and/or SCF administration. Similarly, CD34+ cells isolated from the leukapheresis product did not differ significantly in immunophenotype or cell cycle status before or after G-CSF and/or SCF administration. However, there were consistent differences in both immunophenotype and cell cycle status between BM- and PB-derived CD34+ cells. CD34+ cells isolated from the PB consistently had a smaller percentage of cells in the S+G2/M phase of the cell cycle and had a higher percentage of cells expressing Thy-1 than did CD34+ cells isolated from the BM. A greater proportion of PB-derived CD34+ cells were in the S+G2/M phase of the cell cycle after culture in media supplemented with interleukin-6 and SCF, However, culturing decreased the proportion of CD34+ cells expressing Thy-1.

Efficacy of pentastarch in granulocyte collection by centrifugal leukapheresis.

The efficacy of 6% hydroxyethyl starch (hetastarch, HS) in enhancing granulocyte harvest by centrifugal leukapheresis has been described by a simple equation which predicts the granulocyte collection efficiency (GCE) based on an intrinsic donor variable, the erythrocyte sedimentation rate (ESR): GCE(%) = 1.3 ESR (mm/hr) + 45. Ten percent low molecular weight hydroxyethyl starch (pentastarch, PS) has been reported to be as effective as HS with potentially fewer adverse donor reactions (ADR). The derivation of an analogous equation for PS under conditions previously reported for HS may quantify PS efficacy and allow comparison to HS. We prospectively measured the in vitro and the in vivo effects of PS on the donor ESR in 53 granulocyte collections from 44 donors using the model CS-3000 Plus blood cell separator (CS). We then correlated the findings with the GCE of each procedure and derived an equation which expresses GCE in terms of baseline donor ESR. The in vitro addition of PS increased the donor ESR 2.4-fold, but its administration to a donor during a collection procedure did not appreciably change the ESR. Higher baseline donor ESR was more likely to result in more efficient cell collections: GCE (%) = 0.8 ESR (mm/hr) + 20; (r = 0.37). For granulocyte harvests using the CS and PS as the sedimenting agent 1) baseline donor ESR affects granulocyte harvests, but the poor correlation does not allow an accurate prediction of GCE and cell yield from the baseline donor ESR; 2) in comparison with HS (results from a previous study), PS may be less effective in vitro and not effective in vivo in elevating ESR, and may be less effective in enhancing granulocyte harvest; and 3) the parameters (slope, y-intercept, correlation coefficient) which define the linear relationship between baseline donor ESR and GCE may serve collectively as a quantitative measure of the effectiveness of different hydroxyethyl starch agents in enhancing granulocyte harvests. These parameters may be helpful in rapidly assessing the clinical efficacy of new, potentially useful hydroxyethyl starch agents prior to initiating a randomized, controlled clinical trial.

Peripheral blood stem cell collection using the small volume collection chamber in the Fenwal CS-3000 Plus blood cell separator.

Optimal methods for peripheral blood stem cell (PBSC) collection should yield a small volume product containing minimal platelets and a large number of mononuclear cells (MNC). The Fenwal CS-3000 Plus blood cell separator was modified in an attempt to meet these objectives. Modifications of the CS-3000 Plus included use of the small volume collection chamber (SVCC), increasing the interface/offset detector setting to 150 and decreasing the centrifuge speed to 1400 rpm. Thirty-eight patients undergoing 224 PBSC collections were studied. Mobilization methods included 4 g/m2 cyclophosphamide (CY), CY + 250 micrograms/m2 subcutaneous granulocyte-macrophage colony-stimulating factor (GM-CSF) or GM-CSF alone. The median collection volume was 58 ml containing a median of 21 ml of red blood cells. Platelet collection efficiency was < 4.4% and the median number of extracted platelets was 0.6 x 10(11)/apheresis. Median reduction in the platelet count post-apheresis was 15%. MNC purity was 95.5% and MNC collection efficiency was 61%. Yield of MNC was 1 x 10(8)/kg/apheresis. Collected progenitor cells correlated with both the WBC and MNC content of the apheresis product. The modified CS-3000 Plus with the SVCC is effective for PBSC collection following three different mobilization regimens and is, therefore, recommended for routine collection of PBSC.

Automated processing of human bone marrow can result in a population of mononuclear cells capable of achieving engraftment following transplantation.

A concentrate of mononuclear bone marrow cells is often desired for ex vivo treatment with pharmacologic agents, monoclonal antibodies, cytokines, and other agents prior to transplantation. A method has been developed for automated separation of mononuclear cells from large volumes of harvested bone marrow. A programmable instrument originally designed for clinical ex vivo cell separation and the plasma-pheresis of patients and blood donors was adapted to permit rapid preparation, in a closed sterile system, of a bone marrow product enriched with mononuclear cells. A mean (+/- SEM) of 53 +/- 30 percent of the original mononuclear cells was recovered in a volume of 125 +/- 42 mL containing 82 +/- 12 percent mononuclear cells. This technique removed 95 +/- 9 percent of the red cells in the original marrow. No density gradient materials or sedimenting agents were employed in this process. Of 36 marrows processed by this technique, 19 autologous (6 of which were purged with 4-hydroperoxycyclophosphamide) and 7 allogeneic marrows have been transplanted, with all evaluable patients achieving a neutrophil count of 0.5 x 10(9) per L in a mean (+/- SEM) of 21 +/- 6 days.

Peripheral blood mononuclear cell collection from patients undergoing adoptive immunotherapy or peripheral blood-derived stem cell transplantation and from healthy donors.

The demand for collection of mononuclear cells from the peripheral blood of patients for therapeutic purposes is rapidly increasing. Automated blood cell separators are usually designed for collection of blood components from healthy donors. We reviewed safety and efficiency of collection data of a new procedure for the Fenwal CS 3000 blood cell separator in 125 collections from normal donors and 101 collections from patients after IL-2 pretreatment or chemotherapy. The new procedure set red blood cell spillovers to occur at 3.5 minute intervals, using procedure 1 with the interface detector set at 1,000 and the standard granulocyte and collection chambers. Despite significant anemia and thrombocytopenia in a large number of patients no serious procedure-related side effects occurred. The lymphocyte yield was 4.74 +/- 1.6 x 10(9) per 5 liters of blood processed in normal donors and 24.2 +/- 12.0 x 10(9) per 10 liters of blood processed after IL-2 treatment. After chemotherapy the lymphocyte yield was 4.5 +/- 3.1 x 10(9) per 10 liters of blood processed; the collection efficiency was found to be significantly lower in this group. The main problem was the platelet loss of 35.6 +/- 12% of the initial count in normal donors, 40.3 +/- 14.1% after IL-2 treatment, and 42.1 +/- 18.0% after chemotherapy. The platelet loss is, however, closely related to the preapheresis platelet count; patients with thrombocytopenia lose fewer platelets than normal donors. Therefore the procedure was found to be safe for patients with a platelet count as low as 20/nl. This report provides a basis for safe, effective mononuclear cell collection from patients with very abnormal peripheral blood counts.

Automated isolation of mononuclear cells using the Fenwal CS3000 blood cell separator.

We describe a method for in vitro isolation of mononuclear cells from peripheral blood or bone marrow using a Fenwal CS3000 Apheresis device without employing density gradients or sedimenting agents. The automatic processing program requires minimal operator intervention and no subjective operator decisions. A mean of 67% of starting mononuclear cells were recovered in a 100 ml product having 95% mononuclear cells and less than 1% of the original red blood cells. The average processing time was 35 minutes.

Technical aspects of lymphokine-activated killer cell production.

Adoptive immunotherapy is a novel approach to treating patients with cancer, utilizing as therapy a patient's own peripheral blood lymphocytes that have been activated by incubation with interleukin-2 (IL-2). These cells develop the ability to mediate tumor regression in vivo and are referred to as lymphokine-activated killer (LAK) cells. The production of LAK cells is a complex and labor-intensive process. Lymphocytes are collected by continuous-flow centrifugation, purified on Ficoll-Hypaque (FH) density gradients, incubated in vitro with IL-2, and then harvested for infusion into the patient. An automated approach to LAK cell generation has been developed using the Fenwal CS-3000 cell separator and polyolefin PL-732 blood storage bags. Lymphocyte concentrates (LC) containing 6.5 x 10(9) mononuclear cells per pack were obtained using standard leukapheresis techniques. Disposable apheresis kits were then modified to allow the LC to be pumped into the separation chamber along with a counter-centrifugal flow of saline, removing the platelets and plasma by elutriation. The remaining cells were underlaid with FH, displacing the lymphocytes into a collection bag, where they were washed and concentrated. Mean leukocyte recovery was 59.2% (99.9% lymphocytes, n = 14). The final product contained 6.7% of the initial platelets and had a hematocrit of less than 1%.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of an automated closed system for generation of human lymphokine-activated killer (LAK) cells for use in adoptive immunotherapy.

Immunotherapy utilizing the adoptive transfer of lymphokine-activated killer (LAK) cells in conjunction with recombinant interleukin-2 (IL-2) can mediate tumor regression in some patients with advanced cancer. The activation of large numbers of LAK cells was performed in roller bottles in a research laboratory setting and required meticulous aseptic technique, at least one skilled technician per patient and one laminar flow hood per patient. To reduce the complexity and expense of LAK cell generation for human immunotherapy trials we have developed a closed-system automated procedure using a continuous flow blood cell separator. PBL were obtained by standard apheresis techniques. Platelets and plasma were elutriated using countercentrifugal flow of saline in the cell separator machine. The washed PBL were underlaid with Ficoll-Hypaque (FH) in the original separation bag. Lymphocytes were then flushed into a collection bag where they were concentrated and washed with 2 liters of saline. Mean recovery from the automated FH technique was 54.6 +/- 4.3% compared to 62.3 +/- 4.0% using manual methods in 50 ml tubes (P greater than 0.05). Cells were diluted in the collection bag with RPMI 1640 +/- 2% human AB serum and could be dispensed in an automated fashion to polyolefin bags via a sample port with 1000-1500 U/ml IL-2. After 3-4 days of culture in 5% CO2 at 37 degrees C, activated cells from the bags were harvested and washed in a closed system using the continuous flow cell separator. Cell yield from the harvest was 79.2 +/- 5.4% in the automated system compared to 64.9 +/- 5.0% in the standard procedure using manual harvest of roller bottles (P less than 0.01). Lytic capacity of the cells against fresh human tumor in a 4 h 51Cr release assay was equivalent in cells processed either by the automated or the conventional manual method. The advantages of a closed system include decreased potential for microbial contamination and reduced labor and capital equipment costs. This technique may be easily adapted for use with other cell collection and culture systems.

Use of a continuous-flow cell separator in density gradient isolation of lymphocytes.

A continuous-flow technique was developed to isolate and concentrate lymphocytes over Ficoll-Hypaque (FH) density gradients using an automated cell separator (Model CS-3000, Fenwal). Lymphocyte concentrates (LC) containing 6.51 X 10(9) mononuclear cells were obtained by standard leukapheresis techniques. Disposable apheresis kits were modified to allow the LC to be pumped into a separation chamber along with a counter-centrifugal flow of saline, removing the platelets and plasma by elutriation. The remaining cells were underlaid with 300 ml of FH, displacing the lymphocytes into a collection bag, where they were washed and concentrated. Mean leukocyte recovery was 59.2 percent (99.9% lymphocytes, n = 14). The final product contained 6.7 percent of the initial platelets and had a hematocrit of less than 1 percent. In paired studies using split leukocyte concentrates (n = 15), lymphocyte recovery obtained by the automated apheresis technique compared favorably with that obtained by standard manual FH gradients (59.8 +/- 3.4% versus 67.3 +/- 4.2%, p greater than 0.05) and platelet contamination was significantly reduced (2.7 +/- 0.5% versus 26.6 +/- 5.7% residual platelets, p less than 0.001). Equivalent lymphokine-activated killer (LAK) activity was generated from cells isolated by both manual and automated techniques. An automated continuous-flow cell separator can be used for rapid FH isolation of large numbers of lymphocytes, providing a sterile product suitable for human use.

A technique to reduce lymphocyte contamination of plateletapheresis products collected with a centrifugal blood cell separator.

It is desirable to minimize the contamination of plateletapheresis products by lymphocytes because of the role these cells may play in febrile nonhemolytic transfusion reactions, alloimmunization, platelet deterioration during storage and also to reduce donor lymphocyte loss. This study attempted to determine whether lymphocyte contamination could be reduced by rapidly depleting plasma from the separation chamber at selected intervals during plateletapheresis with a blood cell separator (CS-3000, Fenwal). Donors who provided platelet components with more than 0.10 X 10(9) lymphocytes without rapid depletion underwent a second plateletapheresis procedure in which the rapid depletion technique was used. The plasma pump was reprogrammed to remove rapidly 12 ml of plasma from the separation chamber (pump speed 48 ml/min) immediately after the plasma pump reversal. All other collection techniques were identical for all procedures. Significantly fewer lymphocytes were collected in those procedures in which rapid depletion was used (mean, 0.187 X 10(9] than when it was not used (mean, 0.331 X 10(9] (p = 0.001, n = 30). There was no effect on platelet yield, efficiency of platelet collection, processing time, or total collection time. This procedure provides a product that should be considered for routine use.