Ex-vivo expansion of CFU-GM and BFU-E in unselected PBMC cultures with Flt3L is enhanced by autologous plasma

BACKGROUND

Previous ex-vivo expansion studies in our laboratory, comparing unselected and CD34(+)-selected PBMC, have shown no advantage for CD34(+) cell selection, in terms of the expansion achieved. Our goal was to develop procedures for consistent generation of large numbers of hematopoietic progenitor and post-progenitor cells from unselected PBMC.

METHODS

Unselected PBMC, collected from cancer patients undergoing apheresis prior to high-dose chemotherapy and autologous stem cell rescue, were expanded ex vivo in static cultures, without a stromal layer, in the presence of Flt3 ligand (Flt3L), a recombinant GM-CSF/IL-3 fusion protein (PIXY321), G-CSF and GM-CSF for 10 days.

RESULTS

The addition of 2% autologous plasma to this cytokine combination enhanced expansion of total cell numbers (3.2 fold versus 1.9 fold; p < 0.01), colony-forming units granulocyte-macrophage (CFU-GM) (22.0 fold versus 8.1 fold, p < 0.01) and burst-forming units erythroid (BFU-E) (17.6 fold versus 7.0 fold, 0.01 < p < 0.02). The optimal seeding density for a given specimen was inversely related to the frequency of CD34(+) cells in the sample. CFU-GM expansion with the Flt3L-containing cytokine cocktail was equivalent to that obtained with IL-3, IL-6, G-CSF and SCF, whether or not the cultures were supplemented with autologous plasma. In plasma-free cultures, BFU-E expansion was significantly higher with IL-3, IL-6, G-CSF and SCF than with Flt3L, PIXY321, G-CSF and GM-CSF. In the presence of autologous plasma, however BFU-E expansion was higher in the Flt3L-containing media. In comparison studies, autologous plasma suppressed BFU-E expansion in SCF-containing cultures. Consistent with our colony assay results, dual-parameter flow cytometric analysis of the expanded cell population revealed that supplementation with autologous plasma yielded a significant increase in the numbers of myeloid progenitors in Flt3L-containing cultures.

DISCUSSION

Unselected PBMC from cancer patients can be effectively expanded ex vivo in Flt3L, PIXY321, G-CSF and GM-CSF, supplemented with autologous plasma, yielding high numbers of myeloid and erythroid progenitors.

Survival of CD23-positive (CD23+) mantle cell lymphoma (MCL) compared to classic CD23-negative (CD23-) MCL: Biologic correlates and clinical outcomes in a 10-year analysis

8039

Background: MCL has been historically classified as CD23-, but CD23+ immunophenotype (IP) is identified in a significant minority of patients (pts). It is unclear whether clinicopathologic or survival differences exist between CD23- and CD23+ MCLs. Methods: MCL diagnosis was based on morphology, IP with associated cyclinD1-positivity and/or t(11;14). We identified MCL pts treated at our institution from 1997–2006. We investigated IP (CD23 by flow cytometric analysis), pt characteristics, prognostic factors, and survival. Results: We identified 54 pts (16F/38M), of whom 89% had stage IV disease, IPI = 3 in 57%, 38% elevated LDH, 26% high B2- microglobulin, 30% bulky disease (= 7cm), and 39% with peripheral blood involvement. Thirty-three pts (61%) had CD23- disease, 14 (26%) CD23+ MCL, and 7 (13%) had variable CD23 expression (CD23+/CD23- varied in tissue sites). The only clinicopathologic differences between CD23- and CD23+ pts were increased incidence of extranodal disease (besides marrow or gastrointestinal [GI]) in the former (58% vs. 21%, respectively; p=0.029; most commonly lung or CNS disease); while splenomegaly was more common in the latter (71% vs. 42%; p=0.11). Ki67 staining was not predictive of CD23 status or survival among either IP. Treatment was overall similar in both CD23 groups. Table 1 shows survival for all pts and CD23- pts compared to CD23+ MCL. Cox regression prognostic analysis among all pts (n=54) showed that IPI = 3, bulky disease, and high B2-microglobulin were associated with inferior event-free survival (EFS), while CD23+ MCL and stem cell transplant in first remission were associated with improved EFS (all <0.05). IPI = 3, bulky disease, and presence of extranodal disease besides marrow/GI were associated with inferior overall survival. Conclusions: Over 25% of MCLs are CD23+. CD23+ MCL is associated with a more indolent course and improved outcomes compared with ‘classic‘ CD23- MCL.

No significant financial relationships to disclose.

[Table: see text]

Treg depletion with denileukin difititox (DD) enhances lymphocytosis and eosinphilia in patients treated with high-dose IL-2 (HDIL-2) for metastatic renal cell cancer (MRCC)

14627

Background: CD4+CD25+ T cells (Treg) play a suppressive role in immune regulation. DD is an IL-2 receptor specific cytotoxin. We postulated depletion of Treg with DD may enhance immune effector cell populations during HDIL-2 tx, including eosinophilia which was reported to be involved in immune response to neoplasm (Mattes et al. J Exp Med 197: 387, 2003). Methods: Seven pts (5 male, median age 58 yrs) with MRCC were tx’d with HDIL-2 and DD in different schedules to determine safety and effect on immune response as manifested by changes in Treg, lymphocyte, and peak eosinophil counts. Pts were tx’d with IL-2 600,000 IU/kg Q8H on days (d) 1–5 and 15–19. Three (group A) and 2 (group B) pts were given 6 and 9 ug/kg daily on d 8–10 respectively, while 2 (group C) pts received 9 ug/kg of DD on d -4- -2. Four (group D) pts with metastatic melanoma who received HDIL-2 as above but without DD were included as controls. Flow cytometry was done on days -4, 1,8,10,15 for group C and on days 1, 8, 10, 15, 22 for groups A, B, and D. CBC was obtained within 24 hours of flow cytometry. Results: After DD Treg increased in group A (mean change in absolute T-reg count of 16%) and decreased in groups B and C (34.5 and 20% respectively) compared to baseline. Group C trended toward a greater lymphocytosis at day 8 compared to all other groups (mean increase of 8.6 vs. 3.3 K/ul p = 0.059). A higher peak level of eosinophilia was noted in group C compared with groups A, B and D combined (mean increase of 9.9 vs. 3.0 k/ul p = 0.03). Group C demonstrated a higher mean % change in absolute number of CD8+ T-cells between onset of therapy and Day 8 compared to groups A, B, D combined (increase of 1095% vs. 496% respectively, p = 0.35). Toxicity was similar to that expected with HDIL-2. Conclusions: Administration of DD in conjunction with HDIL-2 was associated with a decrease in Treg that may be schedule and dose dependent. The results suggest an enhanced immune stimulatory effect as manifested by lymphocytosis and peak eosinophilia and CD8+ T-cells in group C. Despite small pt numbers, results suggest that pre-treatment with DD may confer an advantage. It is too early to know if laboratory results correlate to clinical benefit.

[Table: see text]

Estrogen and progesterone receptors in gynecomastia

The etiology of gynecomastia is unknown. There seems to be no increased incidence of malignancies in patients with idiopathic gynecomastia; however, patients with Klinefelter syndrome exhibit an increased incidence of malignancy. The authors reviewed the results of 34 patients with gynecomastia diagnosed in adolescence who, following initial evaluation, had a mastectomy. The estrogen and progesterone receptors were analyzed in these patients. Three of the patients were diagnosed with Klinefelter syndrome. These three patients exhibited elevated amounts of estrogen and progesterone receptors. None of the patients who were not diagnosed with this syndrome demonstrated significant elevation of their estrogen or progesterone receptors. The presence of elevated estrogen and progesterone receptors in patients with Klinefelter syndrome provides a potential mechanism by which these patients may develop breast neoplasms. The absence of elevated estrogen and progesterone receptors in patients with idiopathic gynecomastia may serve to clarify why these patients' disease rarely degenerates into malignancy.

Treatment of autoimmune disease by intense immunosuppressive conditioning and autologous hematopoietic stem cell transplantation

Multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis are immune-mediated diseases that are responsive to suppression or modulation of the immune system. For patients with severe disease, immunosuppression may be intensified to the point of myelosuppression or hematopoietic ablation. Hematopoiesis and immunity may then be rapidly reconstituted by reinfusion of CD34(+) progenitor cells. In 10 patients with these autoimmune diseases, autologous hematopoietic stem cells were collected from bone marrow or mobilized from peripheral blood with either granulocyte colony-stimulating factor (G-CSF) or cyclophosphamide and G-CSF. Stem cells were enriched ex vivo using CD34(+) selection and reinfused after either myelosuppressive conditioning with cyclophosphamide (200 mg/kg), methylprednisolone (4 g) and antithymocyte globulin (ATG; 90 mg/kg) or myeloablative conditioning with total body irradiation (1,200 cGy), methylprednisolone (4 g), and cyclophosphamide (120 mg/kg). Six patients with multiple sclerosis, 2 with systemic lupus erythematosus, and 2 with rheumatoid arthritis have undergone hematopoietic stem cell transplantation. Mean time to engraftment of an absolute neutrophil count greater than 500/microL (0.5 x 10(9)/L) and a nontransfused platelet count greater than 20,000/microL (20 x 10(9)/L) occurred on day 10 and 14, respectively. Regimen-related nonhematopoietic toxicity was minimal. All patients improved and/or had stabilization of disease with a follow-up of 5 to 17 months (median, 11 months). We conclude that intense immunosuppressive conditioning and autologous T-cell-depleted hematopoietic transplantation was safely used to treat these 10 patients with severe autoimmune disease. Although durability of response is as yet unknown, all patients have demonstrated stabilization or improvement.

Detection of HIV-RNA-positive monocytes in peripheral blood of HIV-positive patients by simultaneous flow cytometric analysis of intracellular HIV RNA and cellular immunophenotype

Determinations of plasma HIV viral RNA copy numbers help to define the kinetics of HIV-1 infection in vivo and to monitor antiretroviral therapy. However, questions remain regarding the identity of various infected cell types contributing to this free virus pool and to the in vivo lifecycle of HIV during disease progression. Characterization of a novel fluorescence in situ hybridization (FISH) assay employing a pool of labeled oligonucleotide probes directed against HIV RNA was done followed by coupling of the FISH assay with simultaneous surface immunophenotyping to address these questions. In vitro characterizations of this assay using tumor necrosis factor-alpha stimulated and unstimulated ACH-2 cells demonstrated the ability to detect < 5% HIV RNA positive cells with a sensitivity of < 30 RNA copies per cell. Peripheral blood mononuclear cells from 39 HIV-seropositive patients on no, single, combination, or triple drug therapy and 8 HIV-seronegative patients were examined. The majority of HIV-positive patients (24/39) harbored monocytes positive for HIV RNA and a significantly higher fraction of patients with high plasma viral load carried positive monocytes (13/16) than did patients in the low plasma viral load group (11/23). These results demonstrate the effectiveness of a novel FISH assay for identifying and monitoring HIV-infected cell populations in the peripheral blood of HIV-positive patients. In addition, monocytes are a major source of cellular HIV virus in the peripheral blood of HIV patients, even with progression of disease.

T cell-depleted autologous hematopoietic stem cell transplantation for multiple sclerosis: report on the first three patients

Multiple sclerosis (MS) is a disease of the central nervous system characterized by immune-mediated destruction of myelin. In patients with progressive deterioration, we have intensified immunosuppression to the point of myeloablation. Subsequently, a new hematopoietic and immune system is generated by infusion of CD34-positive hematopoietic stem cells (HSC). Three patients with clinical MS and a decline of their Kurtzke extended disability status scale (EDSS) by 1.5 points over the 12 months preceding enrollment and a Kurtzke EDSS of 8.0 at the time of enrollment were treated with hematopoietic stem cell (HSC) transplantation using a myeloablative conditioning regimen of cyclophosphamide (120 mg/kg), methylprednisolone (4 g) and total body irradiation (1200 cGy). Reconstitution of hematopoiesis was achieved with CD34-enriched stem cells. The average time of follow-up is 8 months (range 6-10 months). Despite withdrawal of all immunosuppressive medications, functional improvements have occurred in all three patients. We conclude that T cell-depleted hematopoietic stem cell transplantation can be performed safely in patients with severe and debilitating multiple sclerosis. Stem cell transplantation has resulted in modest neurologic improvements for the first time since onset of progressive disease although no significant changes in EDSS or NRS scales are evident at this time.

In vitro production of megakaryocytes from PIXY321 versus GM-CSF-mobilized peripheral blood progenitor cells

The generation of megakaryocytes (MK) from cultured peripheral blood progenitor cells (PBSC), harvested via apheresis, from 18 female breast cancer patients treated with either PIXY321 or GM-CSF was compared. Nonadherent mononuclear cells (MNC) were cultured in liquid suspension with 50 U/ml thrombopoietin (TPO) and 2.5% autologous heparinized plasma for 12 days. Flow cytometric analysis was used to measure the percentage of CD34+ on day 1 and CD41+ cells on day 12. The frequency of CD34+ cells was greater in GM-CSF-mobilized samples than in PIXY321-mobilized samples, and MK/MNC yields correlated directly with the number of CD34+ cells seeded, PIXY321-mobilized samples produced more MKs per CD34+ cell than GM-CSF-mobilized samples. Overall, there was no significant difference in the MK/MNC yield between PIXY321- and GM-CSF-mobilized samples. Cyclophosphamide (CY) increased the frequency of CD34+ cells and the corresponding MK/MNC yield for both cytokines, but had no effect on the MK/CD34+ yield. Compared to GM-CSF, PIXY321 mobilization resulted in increased CD34+ cell commitment to the MK lineage.

DNA ploidy in nonmelanoma skin cancer

BACKGROUND

Patients with head and neck squamous cell carcinoma die of locoregional recurrence and those with basal cell carcinoma suffer cosmetic and functional changes from its treatment. Prognostic factors are based upon tumor characteristics and host factors. Flow cytometry can assist with prognostic characterization of nonmelanoma skin cancer.

METHODS

Specimens from 40 sequential patients with head and neck nonmelanoma skin cancers were prospectively obtained at the time of surgery. The patients were followed for four years for local recurrence and metastasis to regional lymph nodes. Samples were prepared from frozen specimens using a modification of the Vindelov procedure.

RESULTS

DNA aneuploidy or tetraploidy and histology of well differentiated squamous cell carcinoma were significantly associated with metastasis to regional lymph nodes. Direct extension of tumor below the adipose tissue was associated with an S-phase greater than 4.1 and a proliferative fraction greater than 5.5. No tumors recurred at the site of surgical resection.

CONCLUSIONS

The measurement of DNA ploidy of well differentiated squamous cell carcinoma, and proliferative capacity or S-phase of both basal cell and squamous cell carcinomas assists in predicting the biologic proclivity for locoregional invasion or metastasis of nonmelanoma skin cancer. Identification of aggressive tumors at the time of surgery may offer the opportunity for prevention of lethal metastasis by using adjunctive therapy.

Phase I/II study of combined granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor administration for the mobilization of hematopoietic progenitor cells

PURPOSE

To study the toxicity and efficacy of combined granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) administration for mobilization of hematopoietic progenitor cells (HPCs).

MATERIALS AND METHODS

Cohorts of a minimum of five patients each were treated subcutaneously as follows: G-CSF 5 micrograms/kg on days 1 to 12 and GM-CSF at .5, 1, or 5 micrograms/kg on days 7 to 12 (cohorts 1, 2, and 3); GM-CSF 5 micrograms/kg on days 1 to 12 and G-CSF 5 micrograms/kg on days 7 to 12 (cohort 4); and G-CSF and GM-CSF 5 micrograms/kg each on days 1 to 12 (cohort 5). Ten-liter aphereses were performed on days 1 (baseline, pre-CSF), 5, 7, 11, and 13. Colony assays for granulocyte-macrophage colony-forming units (CFU-GM) and erythroid burst-forming units (BFU-E) were performed on each harvest.

RESULTS

The principal toxicities were myalgias, bone pain, fever, nausea, and mild thrombocytopenia, but none was dose-limiting. Four days of treatment with either G-CSF or GM-CSF resulted in dramatic and sustained increases in the numbers of CFU-GM per kilogram collected per harvest that represented 35.6 +/- 8.9- and 33.7 +/- 13.0-fold increases over baseline, respectively. This increment was attributable both to increased numbers of mononuclear cells collected per 10-L apheresis and to increased concentrations of progenitors within each collection. The administration of G-CSF to patients already receiving GM-CSF (cohort 4) caused the HPC content to surge to nearly 80-fold the baseline (P = .024); the reverse sequence, ie, the addition of GM-CSF to G-CSF, was less effective. The CFU-GM content of the baseline aphereses correlated with the maximal mobilization achieved (r = .74, P = .001).

CONCLUSION

Combined G-CSF and GM-CSF administration effectively and predictably mobilizes HPCs and facilitates apheresis.

Detection of CD4+ T cells harboring human immunodeficiency virus type 1 DNA by flow cytometry using simultaneous immunophenotyping and PCR-driven in situ hybridization: evidence of epitope masking of the CD4 cell surface molecule in vivo

Human immunodeficiency virus type 1 (HIV-1) infection of T cells and cells of the monocyte/macrophage lineage requires a specific interaction between the CD4 antigen expressed on the cell surface and the HIV-1 external envelope glycoprotein (gp120). To study the association between HIV-1 infection and modulation of cell surface expression of the CD4 molecule in vivo, we examined the CD4+ T cells harboring proviral DNA obtained from HIV-1-infected individuals who had received no antiretroviral therapy for at least 90 days. Simultaneous immunophenotyping of CD4 cell surface expression and PCR-driven in situ hybridization for HIV-1 DNA were used to resolve the CD4+ T cells into distinct populations predicted upon the presence or absence of proviral DNA. Among the HIV-1-infected study subjects, the percentage of CD4+ T cells harboring proviral DNA ranged from 17.3 to 55.5%, with a mean of 40.5%. Cell surface fluorescent staining with anti-CD4 antibody directed against a non-gp120 binding site-related epitope (L120) or a conformation-dependent epitope of the gp120 binding site (Leu 3A) demonstrated either an equivalent or a 1.5- to 3-fold-lower cell surface staining intensity for the HIV-1 DNA-positive subpopulation relative to the HIV-1 DNA-negative subpopulation, respectively. These data suggest that masking or alteration of specific epitopes on the CD4 molecule occurs after viral infection.

Abnormal flow cytometry profiles in patients with interstitial cystitis

Flow cytometry was performed on bladder cells from patients with interstitial cystitis and control patients. Cells were processed in standard fashion for flow cytometry with propidium iodide staining and analysis was restricted to samples with sufficient cells for cytokeratin gating and acceptable coefficients of variation. Of 14 interstitial cystitis patients 4 (29%) demonstrated aneuploid deoxyribonucleic acid (DNA) profiles as evidenced by a discrete peak with a DNA index of 1.2 or greater in the cytokeratin positive population. The aneuploid peak accounted for up to 54% of the cytokeratin positive population in these samples. No such aneuploid DNA profiles were evident in specimens obtained from control patients. A significant DNA tetraploid population, as evidenced by a 4C (G2) peak greater than 20%, was observed in 6 of 14 interstitial cystitis patients (43%) and 8 of 11 controls (72%). Manual counting of the per cent of binucleated cytokeratin positive cells in the cytokeratin stained population and nuclear preparations of several samples for flow analysis indicate that apparent DNA tetraploidy in the interstitial cystitis and control patients is due to an abundance of binucleated cells. Aneuploid DNA profiles on barbotage specimens from interstitial cystitis patients may reflect a real karyotypic abnormality or altered chromosome complement (true aneuploidy), abnormal chromatin structure or abnormal cytoplasmic binding of the propidium iodide stain. This finding may signal an underlying abnormality of the epithelial cell population in some patients with the clinical diagnosis of interstitial cystitis.

Leukocyte adhesion molecules as biocompatibility markers for hemodialysis membranes

Comparative flow cytometric measurement was used to evaluate the significance of leukocyte adhesion molecule (LAM) activity changes during hemodialysis (HD) with different cellulosic and non cellulosic membranes. Six hemodialysis patients (men) who were in a maintenance program for more than 6 months were treated consecutively with five different dialyzers (cuprophan, hemophan, 2 types of cellulose acetate, and polysulfone). During each study HD, blood was sampled from the arterial line at 0, 15, and 60 min and from the venous port at 3 min to harvest leukocytes immediately after the first cell-membrane contact. After whole blood lysis preparation, leukocytes were incubated with fluorescent antibodies to label LAM CD 11A/18 (LFA-1), CD 11B/18 (Mac-1), CD 11C/18 (p150/95), and CD 54 (ICAM-1) (Becton-Dickinson, San Jose, CA). Data were acquired for the granulocyte, monocyte, and lymphocyte population based on forward and 90 degrees scatter light measurements. Accuracy of gating was verified by CD 14/45 staining for all samples. Baseline integrin expression for the selected populations before biomaterial contact was found to be heterogeneous for different patients, but underwent changes for the same patient during HD treatment. The fluorescent intensity corresponding to specific integrins was characterized by different patterns of up/down regulation with maximal deviations occurring at 3 min. Fluorescent intensity of the granulocyte and monocyte populations sampled at 15 min was 40-50% lower as compared with those sampled immediately after the first biomaterial contact. Based on the basal fluorescence levels and values recorded after the first biomaterial contact and those at 15 min, two coefficients were generated to compare membrane properties.

Detection of HIV-1 DNA and messenger RNA in individual cells by PCR-driven in situ hybridization and flow cytometry

Human immunodeficiency virus type-1 (HIV-1) DNA and messenger RNA sequences in both cell lines and blood obtained directly from HIV-1-infected patients were amplified by polymerase chain reaction and hybridized to fluorescein-labeled probes in situ, and the individually labeled cells were analyzed by flow cytometry. After flow cytometric analysis, heterogeneous cell populations were reproducibly resolved into HIV-1-positive and -negative distributions. Fluorescence microscopy showed that the cellular morphology was preserved and intracellular localization of amplified product DNA was maintained. Retention of nonspecific probe was not observed. Analysis of proviral DNA and viral messenger RNA in cells in the blood of HIV-1-infected patients showed that the HIV-1 genome persists in a large reservoir of latently infected cells. With the use of this technique it is now possible to detect single-copy DNA or low-abundance messenger RNA rapidly and reproducibly in a minor subpopulation of cells in suspension at single-cell resolution and to sort those cells for further characterization.

Flow cytometric detection of herpes simplex virus type 2 infected and transformed cells by immunoenzymatic and by indirect immunofluorescence staining

The glucose oxidase antiglucose oxidase (GAG) immunoenzymatic staining procedure has been used to detect herpes simplex virus (HSV) antigens microscopically. In this study, the GAG procedure was adapted to cells in suspension, and its potential usefulness in flow cytometry was examined. HSV-2 infected monkey kidney and HSV-2 transformed mouse cells were stained using antisera to HSV-2 or to an HSV-2 specific protein with a molecular weight of 38 Kd, respectively, with the GAG procedure. Flow cytometric analysis of the GAG stained cells was then performed by the measurement of scattered light intensity in the angular intervals 1 degree-2 degrees, 2.5 degrees-19 degrees, and 3 degrees-6 degrees. The greatest scattered light intensity decrement caused by staining occurred in the 3 degrees-6 degrees angular interval, as predicted by previous work. In infected cells, which stain intensely by immunofluorescence, the difference between positively and negatively stained cells was adequate for detecting infected cells using the GAG method; however, this was not the case for the lightly staining transformed cells. The indirect immunofluorescence method of analysis of the same populations was superior to the scattered light method of analysis of the GAG stained infected and transformed cells.