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J G Bender

Publications and source records attributed to J G Bender.

At least 37 records · Page 2Linked to original sources
PubMed1995

Immunocytochemical analysis of tumor cells in pre- and post-culture peripheral blood progenitor cell collections from breast cancer patients.

We examined peripheral blood progenitor cell (PBPC) collections and CD(34+)-selected fractions cultured in PIXY321, a fusion protein comprising analog interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) domains, for the presence of contaminating tumor cells from 14 patients with advanced-stage breast cancer. Five of the 14 (36%) pre-culture PBPC specimens contained immunocyto-chemically (ICC)-detectable tumor cells using two different cocktails of monoclonal antibodies (mAbs). After 10 days in culture with PIXY321, the CD(34+)-selected fractions showed a median 23.6-fold expansion of hematopoietic cells. No ICC-positive tumor cells were detected in any post-culture specimens. We conclude that in vitro expansion of CD(34+)-selected PBPCs with PIXY321 can expand hematopoietic cell populations apparently without risk of expanding contaminating breast cancer cell populations.

Antibodies, Monoclonal↗
PubMed1994

Sequential transplants using mobilized peripheral blood progenitor cells.

Modest success has been achieved with the use of high-dose cytotoxic therapy and bone marrow transplantation in solid tumors. Patient outcome can potentially be improved with further intensification of the therapy. The rapid hematologic recovery achieved with mobilized peripheral blood progenitor cells (PBPC) may reduce the toxicity of transplantation enabling the use of sequential courses of myeloablative therapy. We report on 42 patients with solid tumors enrolled in a tandem transplant protocol involving the use of PBPC mobilized with cyclophosphamide (4 g/m2), etoposide (1 g/m2), and granulocyte-colony-stimulating factor (G-CSF: 10 micrograms/kg/day). This regimen significantly increased the number of circulating progenitor cells; only 1-2 aphereses were sufficient to collect 2.5 x 10(8)/kg mononuclear cells, our goal for each transplant course. The median number of circulating colony-forming units (CFU) and CD34+ cells obtained for each transplant course were 70.3 x 10(4)/kg, and 11.7 x 10(6)/kg, respectively. There was a significant correlation between the numbers of CD34+ cells and CFU measured in the apheresis product (r = 0.49, P = .003). The first transplant regimen given to 38 patients consisted of thiotepa, carboplatin, and cyclophosphamide. The second transplant regimen given to 29 patients consisted of busulfan and etoposide. Hematologic recovery was comparable after each of the two transplant courses. The median time to neutrophil recovery over 0.5 x 10(9)/L and to platelet transfusion independence was 9 and 8 days, respectively. There was no difference in engraftment rates after transplant with PBPC only (n = 28 courses) compared to transplant with PBPC plus bone marrow (n = 39 courses).(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1994

Phenotypic analysis and characterization of CD34+ cells from normal human bone marrow, cord blood, peripheral blood, and mobilized peripheral blood from patients undergoing autologous stem cell transplantation.

Single- and multicolor flow cytometry were used to define progenitor subsets in normal human bone marrow and peripheral blood, cord blood, and blood following mobilization of CD34+ progenitor cells by cyclophosphamide or cyclophosphamide/etoposide/G-CSF treatment. CD34 cells were quantitated and subsets of CD34+ cells were defined by coexpression of CD33, CD13, CD10, CD19, CD45RA, and CD71. Myeloid and erythroid progenitors were quantitated by sorting single CD34+ cells into individual wells of 96-well plates containing methylcellulose, IL-3, GM-CSF, G-CSF, IL-6, and erythropoietin. Comparative studies of CD34 cells showed that the percentage of CD34+ mononuclear cells was greatest in blood samples from patients following mobilization treatment with cyclophosphamide/etoposide/G-CSF averaging 2%. By comparison, the remaining sample groups ranged from 1.68 to 0.15% CD34 cells in this order, bone marrow > cord blood > cyclophosphamide mobilized blood > peripheral blood. Comparison of CD34 cells per milliliter of bone marrow or blood showed a range of 22.4 x 10(4) to 0.65 x 10(4)/ml in the following order, bone marrow > chemotherapy/etoposide/G-CSF > cord blood > cyclophosphamide-mobilized blood. Comparative analysis of CD34 subsets from different sources showed significant differences, particularly bone marrow and blood samples. A distinct population of CD34+ CD19+ (Leu 12) CD10+ (CALLA) pre-B lymphocyte cells was defined in bone marrow with lower side and forward light scatter characteristics and was variable between donors (29.8 +/- 16.9%, mean +/- 1 SD; range, 3-54%; n = 8). This population was not found to a significant degree in blood and also expressed CD45RA (Leu 18). Coexpression studies of CD45RA and CD71 (transferrin receptor) expression on CD34+ cells defined a CD45RA- CD71+ population containing 89 +/- 6.3% (n = 4) BFU-E and a CD45RA+ CD71+ population that contained all CFU-GM (n = 4). LeuM7 (CD13) stained a larger percentage to a greater intensity than MY7 (CD13). Coexpression of CD45RA (Leu 18) and CD13 (LeuM7) defined a subset of CD13+ CD45RA+ cells enriched for CFU-GM and CFU-M with a cloning efficiency of 31%. Coexpression of CD33 (MY9) and CD13 (MY7) defined a population that was predominantly CFU-GM with a cloning efficiency of 38%. These studies define CD34+ phenotypes containing pure populations of B lymphocyte, granulocyte-macrophage, or erythroid progenitors and demonstrate the utility of multiparameter flow cytometry to define lineage-committed CD34+ cells.

Adult↗
PubMed1994

Correlation of colony-forming cells, long-term culture initiating cells and CD34+ cells in apheresis products from patients mobilized for peripheral blood progenitors with different regimens.

Peripheral blood progenitor cell (PBPC) populations used for transplantation were analyzed for the presence of CD34+ cells, colony-forming cells (initial CFC), and long-term culture initiating cells (LTC-IC) cultured on irradiated stroma for 5 weeks. Thirty-eight leukapheresis products were studied from 11 patients with breast cancer, 2 with non-Hodgkin's lymphoma and 1 with ovarian cancer harvested during recovery from either cyclophosphamide (CY) chemotherapy or cyclophosphamide-VP16 with G-CSF (CY-VP-G). CY-VP-G products had a threefold higher median number of mononuclear cells collected, a fivefold higher median concentration of CD34 and LTC-IC and a threefold higher concentration of initial-CFC when compared with CY products. CY-VP-G products had a significantly higher ratio of CFU-GM to BFU-E than the CY-mobilized products. Significant correlations of r = 0.89 and r = 0.68 were observed when comparing CD34 and CFC in products from CY or CY-VP-G patients, respectively. Analysis of the regression lines indicated that slopes of these regression lines were significantly different with a ratio of CD34 to initial CFC of 15:1 in the CY-VP-G products versus 5.2:1 with the CY products. These data indicate a higher cloning efficiency of the CD34+ population in the products from CY-mobilized patients. Significant correlations of r = 0.9 (CY) and r = 0.53 (CY-VP-G) were observed when the initial CD34 concentration and the LTC-IC were compared. Comparison of initial CFC with LTC-IC also showed significant correlations (r = 0.94, CY; r = 0.58, CY-VP-G) in samples from both patient groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Expansion of primitive human hematopoietic progenitors in a perfusion bioreactor system with IL-3, IL-6, and stem cell factor.

Present methods for long-term hematopoietic culture (LTHC) employ a static culture environment which is not well-characterized. Primitive long-term culture-initiating cell (LTC-IC) numbers have been shown to decline in conventional static human LTHC, even with exogenous cytokine combinations. We have expanded human hematopoietic cells from umbilical cord blood on a preformed marrow stroma with synergistic cytokine combinations in a novel perfusion bioreactor system, which continuously maintained culture conditions within desired ranges. Interleukin-3 (IL-3) and interleukin-6 (IL-6) in perfusion culture resulted in rapid 7-day expansion of granulocyte-macrophage colony forming units (CFU-GM, 11-fold), erythroid burst-forming units (BFU-E, 2.5-fold), and granulocyte-erythroid-macrophage colony forming units (CFU-Mix, 2.4-fold), compared to 6-fold, 1.4-fold, and no expansion, respectively, in static cultures. Addition of stem cell factor (SCF) to IL-3/IL-6 in static culture increased the extent of CFU-GM expansion (to 9-fold), but did not result in BFU-E or CFU-Mix expansion. In perfusion cultures with IL-3/IL-6/SCF, much greater expansions of CFU-GM (18-fold) and CFU-Mix (5.3-fold) were obtained. More importantly, expansion of LTC-IC (nearly 3-fold in two of three experiments) was only obtained with IL-3/IL-6/SCF and perfusion. The ability to expand hematopoietic cells while maintaining or expanding primitive progenitors has potential clinical applications in bone marrow transplantation and gene therapy.

Cell Count↗
PubMed1993

CD34+ progenitors and colony-forming units-granulocyte macrophage are recruited during large-volume leukapheresis and concentrated by counterflow centrifugal elutriation.

The recruitment of mononuclear cells (MNCs), colony-forming units-granulocyte macrophage (CFU-GM), lymphocyte subpopulations, and CD34+ progenitor cells was studied during large-volume (15-25 L blood processed) peripheral blood stem cell (PBSC) harvests. Normal donors (n = 13) underwent a 4-hour leukapheresis designed to maximize PBSC yield (blood flow rate, 85 mL/min). Mean (+/- SD) volume processed was 17.7 +/- 0.4 L, and yield was 2.4 +/- 0.7 x 10(10) white cells containing 99 percent MNCs and 1.3 mL red cells per L of blood processed. Postapheresis hematocrit, platelets, and MNCs were reduced from preapheresis values by 7, 35, and 23 percent, respectively (p < 0.05). In nine donors, the component was collected as four 1-hour samples, and culturing of CFU-GM and flow cytometric analysis of lymphocyte subpopulations and CD34+/HLA-DR+ cells were done in individual samples. Total CFU-GM were 2.4 +/- 1.4 x 10(6) (3.0 +/- 1.8 x 10(4) CFU-GM/kg) and lymphocytes were 20.8 x 10(9), with 75 percent CD3+ T cells, 10 percent CD19/CD20+ B cells, and 17 percent natural killer cells. A more than twofold increase in CFU-GM and CD34+ cells was noted over the course of the 4-hour procedure (p < 0.05). In four donors, the leukapheresis component underwent counterflow centrifugal elutriation (CCE), which separated it into four fractions in an attempt to concentrate CD34+ and CFU-GM progenitors and to deplete T-lymphocytes on a large scale. There was a 1.8-, 4.6-, 3.9-, and 0.32-fold increase in CFU-GM in the four fractions relative to the unseparated component.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Expansion of neutrophil precursors and progenitors in suspension cultures of CD34+ cells enriched from human bone marrow.

The growth and differentiation of selected bone marrow CD34+ cells stimulated with hematopoietic growth factors in lipid cultures were evaluated to determine whether cell types that may be useful for reducing the neutropenia associated with high-dose chemotherapy (HDC) can be produced and quantitated in vitro. CD34+ cells enriched from bone marrow were cultured for up to 5 weeks in interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) with or without stem cell factor (SCF) (also termed c-kit ligand). The mixture of IL-3, GM-CSF and G-CSF resulted in an 18-fold increase in cells after 10 to 12 days of culture and a 94-fold increase after 21 days. A 3-fold increase in colony-forming unit granulocyte-macrophage (CFU-GM) was observed after 10 days of culture. The addition of SCF during the first 10 days of culture further augmented the proliferation of cell numbers to 24-fold and colony-forming cells (CFC) to 8-fold after 10 days while cell numbers increased 130-fold after 21 days. Two-color flow cytometry defined phenotypes expressing CD11b and CD15 that represented maturation stages of neutrophils. Maturation of neutrophils in these cultures could be followed by the initial appearance after 3 to 7 days of a CD15+CD11b- phenotype representing promyelocytes, which gave rise after 2 to 3 weeks to a CD15+CD11b+ phenotype representing more mature neutrophil forms (metamyelocytes to segmented neutrophils). In contrast to normal neutrophil development, only a small fraction (10 to 15%) of the culture-derived neutrophils expressed CD16. These data define the kinetics and differentiation of neutrophils and neutrophil precursors from selected CD34+ cells in liquid cultures.

Antigens, CD↗
PubMed1992

Beneficial effects of reduced oxygen tension and perfusion in long-term hematopoietic cultures.

Growth of hematopoietic stem and progenitor cells found in the MNC fraction of human cord blood was evaluated under atmospheres containing reduced (5%) and normal (20%) oxygen tension. Reduced oxygen tension increased total cell numbers by as much as 5-fold in cord blood suspension cultures, but this effect was less pronounced in cultures containing an irradiated bone marrow stromal cell layer. However, reduced oxygen tension resulted in a substantial increase in both the number and frequency of colony-forming cells observed in both types of LTHC studied. Under low oxygen, CFU-C progenitor cell numbers were as much as 10-fold higher. Finally, reduced oxygen tension slowed the rate of irradiated stromal layer degeneration, as judged by cell counts and microscopic examination. These results indicate that low oxygen, which better approximates the in vivo environment, enhances the growth and maintenance of human stromal and progenitor cells in vitro. These low oxygen findings were then applied to a murine model LTHC perfusion system. In this system, irradiated 3T3 stromal layer integrity was improved under low oxygen and was substantially further improved with continuous medium perfusion. Cell counts and flow cytometry analysis indicated that the total cell production and the production of immature cells from murine bone marrow MNC on irradiated 3T3 cells were significantly enhanced under low oxygen with perfusion. After three weeks of culture, a 24-fold higher number of Thy1.2lo F4/80- MAC1- cells (indicative of murine stem and progenitor cells) was observed in the perfusion system as compared with static culture under ambient oxygen.

Animals↗
PubMed1992

Effects of synergistic cytokine combinations, low oxygen, and irradiated stroma on the expansion of human cord blood progenitors.

Expansion of hematopoietic progenitor cells in the mononuclear cell (MNC) fraction of human cord blood was evaluated under atmospheres containing reduced (5%) and normal (20%) oxygen tensions. Cells were cultured with synergistic cytokine combinations in suspension (without stroma) and on irradiated bone marrow stroma. Addition of interleukin (IL)-3 and IL-6 (IL-3/IL-6) provided a greater expansion of both total and progenitor cells than IL-1 and IL-3 (IL-1/IL-3). IL-3/IL-6 maintained a higher level of progenitors throughout the 8-week culture period, whereas progenitors disappeared earlier from cultures with IL-1/IL-3. This indicates that an earlier cell type was affected by IL-3/IL-6, and/or that IL-3/IL-6 favored self-renewal while IL-1/IL-3 induced differentiation. Reduced oxygen tension enhanced the productivity of these long-term hematopoietic cultures (LTHC) under all conditions tested. In suspension cultures, reduced oxygen increased cumulative total cell production by 125% and 167%, and cumulative progenitor production by 68% and 21%, with IL-1/IL-3 and IL-3/IL-6, respectively. The presence of irradiated stroma increased cumulative progenitor cell production almost threefold in cultures without cytokines. In cultures with cytokines, the beneficial effect of stroma was less significant, but was greater under 20% O2 than 5% O2. Cultures under 5% O2 provided more progenitors and often maintained progenitors for 1 to 2 weeks longer than those under 20% O2. To quantitate more precisely the shift in cell populations induced by IL-3/IL-6 and stroma in cultures under 5% O2, flow cytometry analysis was used. By week 3, the addition of IL-3/IL-6 stimulated a 15-fold and 25-fold expansion of promyelocytes (CD15+CD11b-) in suspension and stromal cultures, respectively. Addition of IL-3/IL-6 also increased mature granulocyte (CD15hiCD11b+) and monocyte (CD15loCD11b+) numbers, while no effect was seen on T-(CD3+) or B- (CD19+) lymphocytes. Endogenous production of IL-6 was significantly higher under 5% O2 in both suspension and stromal cultures, and IL-6 production was increased threefold by the addition of IL-1/IL-3. Very little IL-1 beta was produced in these cultures, and endogenous IL-3 and tumor necrosis factor (TNF)-alpha were undetectable by enzyme-linked immunosorbent assay (ELISA) analysis.

Cell Division↗
PubMed1992

Defining a therapeutic dose of peripheral blood stem cells.

Peripheral blood stem cells (PBSC) are now used extensively to provide rapid and durable hematopoietic reconstitution following supralethal myeloablative therapies. A major clinical issue is the quantitation of the cells responsible for reconstitution. We review here published reports of transplants using the measurement of mononuclear cells and granulocyte-macrophage colony-forming units (CFU-GM) to quantitate PBSC. In addition, we present data from three institutions where hematopoietic recovery is correlated with doses of CFU-GM or CD34+ cells. These data suggest doses of 20 x 10(4) CFU-GM or 2 x 10(6) CD34+ cells/kg body weight that provide rapid engraftment of neutrophils and platelets.

Antigens, CD↗
PubMed1992

Functional characterization of mouse granulocytes and macrophages produced in vitro from bone marrow progenitors stimulated with interleukin 3 (IL-3) or granulocyte-macrophage colony-stimulating factor (GM-CSF).

Bone marrow from C3H/ouj mice was depleted to < 1% of CD11b+ granulocytes and macrophages using paramagnetic beads coated with sheep anti-rat antibodies. CD11b- cells, enriched three- to fourfold in colony-forming cells, were stimulated in liquid culture with interleukin 3 (IL-3) or granulocyte-macrophage colony-stimulating factor (GM-CSF). Cultures stimulated with IL-3 or GM-CSF increased cell numbers fourfold at 7 days, with the CD11b+ population increasing to 63% +/- 9% (n = 5) with IL-3 or 96% +/- 1% (n = 4) cells with GM-CSF. Functional responsiveness of the granulocytes and macrophages was assessed by flow cytometry in an oxidative burst assay using dichlorofluorescein (DCF) and a quantitative phagocytosis assay using opsonized fluorescent beads. Granulocytes and macrophages, identified by light scatter characteristics and allophycocyanine staining of CD11b, were assayed simultaneously with granulocytes from fresh mouse bone marrow and peripheral blood. GM-CSF-generated CD11b+ cells had higher oxidative responses than similar populations produced in response to IL-3. The oxidative burst of these in vitro generated CD11b+ populations was similar to the equivalent fresh bone marrow population. Oxidative burst responses of peripheral blood phagocytic cells could not be adequately measured in this system. Peripheral blood CD11b+ cells were the most phagocytic, followed by GM-CSF-stimulated CD11b+ cells; IL-3-stimulated and bone marrow CD11b+ cells were the least phagocytic. These data demonstrate that functional granulocytes can be produced in vitro using growth factors and that GM-CSF produces a more responsive cell than IL-3.

Animals↗
PubMed1992

Characterization of chemotherapy mobilized peripheral blood progenitor cells for use in autologous stem cell transplantation.

Twenty patients were treated with chemotherapy to mobilize progenitors into the blood. Peripheral blood stem cells were quantitated in peripheral blood or leukapheresis products using colony assays and flow cytometric measurement of CD34+ cells. In four patients where complete sets of serial samples were obtained, the appearance of CD34+ cells preceded the increase in CFU-GM by 24-48 h. Peak levels of CD34+ cells ranged from 0.6-5% and coincided with the peak increase in CFU-GM. Mobilized CD34+ cells contained subsets expressing CD33, CD13, CD45RA, CD38, HLA-DR, CD61 and CD41. Subsets of CD34+ cells expressing CD33, CD13, or CD45RA represent committed myeloid progenitors. In contrast to bone marrow CD34+ cells, few mobilized CD34+ cells expressed CD71, CD7, CD19 or CD10. Prompt engraftment of granulocytes greater than 500 x 10(6)/l at a median of 13 days and platelets greater than 50 x 10(9)/l at a median of 15 days was observed in patients reconstituted with mobilized cells. These data indicate that CD34+ cells mobilized during recovery from chemotherapy are predominantly myeloid in phenotype and contain few actively proliferating cells or cells with lymphoid phenotypes.

Antigens, CD↗