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Biomedical subjects

L L Sensenbrenner

Publications and source records attributed to L L Sensenbrenner.

At least 19 recordsLinked to original sources
PubMed2001

Durable treatment-free remission after high-dose cyclophosphamide therapy for previously untreated severe aplastic anemia.

BACKGROUND: Severe aplastic anemia is a life-threatening bone marrow failure disorder. High-dose cyclophosphamide therapy followed by allogeneic bone marrow transplantation cures the disease. However, it requires a suitable donor and carries the risk for graft-versus-host disease. A small pilot study demonstrated that high-dose cyclophosphamide therapy without bone marrow transplantation leads to durable, treatment-free complete remission. OBJECTIVE: To confirm the safety and efficacy of high-dose cyclophosphamide therapy alone in patients with severe aplastic anemia. DESIGN: Uncontrolled clinical trial. SETTING: Three tertiary care hospitals. PATIENTS: 19 patients with untreated severe aplastic anemia. INTERVENTION: Cyclophosphamide, 50 mg/kg of body weight per day for 4 consecutive days. MEASUREMENTS: Probability of response and overall survival were measured. Complete remission was defined as normal blood count for age and sex. Partial remission was defined as independence from transfusion and an absolute neutrophil count greater than 0.5 x 10(9) cells/L without growth factor support. Nonresponders were patients who remained transfusion dependent or died. Relapse was defined as no longer meeting criteria for partial or complete remission. RESULTS: The median time to an absolute neutrophil count of 0.5 x 10(9) cells/L was 49 days. The probability of survival was 84% (95% CI, 59% to 95%) at 24 months. The probability of achieving treatment-free remission was 73% (CI, 51% to 91%) at 24 months, and the probability of achieving complete remission was 65% (CI, 39% to 89%) at 50 months. No responding patients have had relapse or have developed secondary clonal disorders. CONCLUSIONS: High-dose cyclophosphamide therapy without bone marrow transplantation produces durable treatment-free remission in severe aplastic anemia. This approach deserves further study in patients with severe aplastic anemia who are not suitable candidates for allogeneic bone marrow transplantation.

Adolescent↗
PubMed2001

Pulmonary T cell repertoire in patients with graft-versus-host disease following blood and marrow transplantation.

Pulmonary inflammation is one of the risk factors associated with blood and marrow transplantation (BMT). To determine the potential role of T cells in pulmonary complications after transplantation, we analyzed the T-cell repertoire expressed in bronchoalveolar lavage fluids from eleven patients with graft-versus-host disease following BMT. A reverse transcriptase-polymerase chain reaction was used to amplify rearranged TCR transcripts in unfractionated, CD4+, and CD8+ T cells from bronchoalveolar lavage fluids. The relative expression of TCR variable (V) gene families and the diversity of junctional region lengths associated with different AV and BV gene families were analyzed. Nearly all TCR AV and BV gene families were detected in bronchoalveolar lavage cells from BMT recipients. Oligoclonal patterns of TCR junctional region lengths were observed in unfractionated, CD4+, and CD8+ bronchoalveolar T cells. The oligoclonal expansion of bronchoalveolar T cells in patients was confirmed by DNA sequencing. TCRV gene expression is almost completely restored in the lungs of BMT recipients as early as two weeks after transplantation. Increased oligoclonality among TCR gene families suggests either an incomplete restoration of TCR diversity or an antigen-driven expansion of T cells in the lungs of BMT recipients with graft-versus-host disease, not necessarily related to pulmonary infection.

Adult↗
PubMed1996

Complete remission in severe aplastic anemia after high-dose cyclophosphamide without bone marrow transplantation.

Severe aplastic anemia (SAA) can be successfully treated with allogeneic bone marrow transplantation (BMT) or immunosuppressive therapy. However, the majority of patients with SAA are not eligible for BMT because they lack an HLA-identical sibling. Conventional immunosuppressive therapy also has major limitations; many of its remissions are incomplete and relapse or secondary clonal disease is common. Cyclophosphamide is a potent immunosuppressive agent that is used in all BMT conditioning regimens for patients with SAA. Preliminary evidence suggested that high-dose cyclophosphamide, even without BMT, may be beneficial to patients with SAA. Therefore, 10 patients with SAA and lacking an HLA-identical sibling were treated with high-dose cyclophosphamide (45 mg/kg/d) for 4 consecutive days with or without cyclosporine. A complete response (hemoglobin level, > 13 g/dL; absolute neutrophil count, > 1.5 x 10(9)/L, and platelet count > 125 x 10(9)/L) was achieved in 7 of the 10 patients. One of the complete responders died from the acquired immunodeficiency syndrome 44 months after treatment with high-dose cyclophosphamide. The 6 remaining patients are alive and in continuous complete remission, with a median follow-up of 10.8 years (range, 7.3 to 17.8 years). The median time to last platelet transfusion and time to 0.5 x 10(9) neutrophils/L were 85 and 95 days, respectively. None of the complete responders has relapsed or developed a clonal disease. These results suggest that high-dose cyclophosphamide, even without BMT, may be more effective than conventional immunosuppressive therapy in restoring normal hematopoiesis and preventing relapse or secondary clonal disorders. Hence, further studies confirming the efficacy of this approach in SAA are indicated.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Sinus disease in the bone marrow transplant population: incidence, risk factors, and complications.

BACKGROUND: Fever associated with sinus disease in the immunocompromised bone marrow transplant recipient requires prompt evaluation and therapy. Very little is known about the incidence, risk factors, and sequelae of nonsurgically treated sinus disease in this population. METHODS: A retrospective review of 107 consecutive allogeneic and autologous bone marrow transplant recipients from August 1987 to July 1989 was performed to determine (1) the overall incidence of sinus disease; (2) factors that influence the development of sinus disease; and (3) the sequelae of sinus disease treated nonsurgically. RESULTS: Overall 33 (31%) of 107 bone marrow transplant recipients had sinus disease defined as a radiographic abnormality with clinical symptoms. Eleven (10%) of 107 recipients had preexisting sinus disease. Sinus disease developed in 22 (21%) of 107 recipients after bone marrow transplantation. Sinus abnormalities were significantly higher among allografted bone marrow transplant recipients than among autografted recipients (p = 0.027). The diagnosis, stage of disease, cytoreductive regimen, or graft-vs.-host disease were not different between recipients in whom sinus disease did and did not develop. There were no deaths as a result of sinus complications. CONCLUSIONS: Sinus disease developed in 21% of the studied population after bone marrow transplantation. Allogeneic recipients had a higher incidence of sinus disease than autologous recipients. There were no deaths attributed to sinus complications. All sinus disease in this bone marrow transplant population was treated medically. No patient required surgical intervention either before or after bone marrow transplantation.

Adult↗
PubMed1995

Prevention of hemorrhagic cystitis following allogeneic bone marrow transplant preparative regimens with cyclophosphamide and busulfan: role of continuous bladder irrigation.

High dose cyclophosphamide and/or busulfan conditioning treatment of recipients of bone marrow transplants proved to be highly effective but associated with substantial and sometimes life threatening hemorrhagic cystitis. To prevent this complication, a prophylactic continuous bladder irrigation program was instituted in patients receiving cyclophosphamide and/or busulfan in preparation for bone marrow transplantation. Retrospective analysis of 199 patients who underwent allogeneic bone marrow transplantation revealed that continuous bladder irrigation significantly decreased the frequency of hemorrhagic cystitis in patients receiving busulfan and cyclophosphamide (continuous bladder irrigation 23% versus no bladder irrigation 53%, p < 0.004). There was no difference in the frequency of hemorrhagic cystitis between the different preparative regimens in patients who underwent continuous bladder irrigation. There was no relationship between the incidence of hemorrhagic cystitis and the severity of graft-versus-host disease or the time to engraftment. The duration of hemorrhagic cystitis and overall survival rates were similar in both groups, and there was no increase in complications related to catheterization. In general, continuous bladder irrigation was well tolerated, decreased the incidence of hemorrhagic cystitis and may be useful in bone marrow transplant patients.

Adolescent↗
PubMed1995

Anti-CD3-activated splenocytes enhance survival in lethally irradiated mice after transplant of syngeneic hematopoietic stem cells.

Although cytokines produced by activated T cells may accelerate immunohematopoietic reconstitution after autologous bone marrow transplantation (ABMT), there is no direct evidence that infusion of anti-CD3 mAb-activated T cells can accelerate engraftment by hematopoietic stem cells. This study tests the ability of anti-CD3-activated murine splenocytes (ASC) to enhance the rescue of lethally irradiated (9 Gy) BDF1 mice by transplant of a limiting dose of fresh unmanipulated syngeneic splenocytes (SC). A minority (14.8%, 10-25%) of mice could be rescued with 5 x 10(5) SC after 9 Gy total-body irradiation (TBI). When 10(6) or 10(7) ASC were added to 5 x 10(5) SC, survival increased to 50% in those that received 5 x 10(5) SC + 10(6) ASC (not significant [NS]) and to 81.4% (77.7-88.0%) in those that received 5 x 10(5) SC + 10(7) ASC (p < 0.001). Furthermore, adding a fixed dose of 10(7) ASC to increasing doses of SC (10(5), 5 x 10(5), and 10(6)) enhanced survival at the different doses of SC. ASC alone did not rescue mice. CD3+ cells were the predominant population (77.6 +/- 6.7%) in the ASC inoculum, while NK cells remained low (1.2 +/- 0.9%). Colony-forming unit-spleen (CFU-S) yield after injection of SC showed dose dependence, whereas injection of 10 x 10(6) ASC alone failed to show any CFU-S yield in 23 of 25 recipient spleens. These results show that ASC enhanced survival of mice rescued with limiting doses of SC and that this effect was ASC dose-dependent but not dependent on the addition of extra stem cells.

Animals↗
PubMed1994

Prospective comparative trial of autologous versus allogeneic bone marrow transplantation in patients with non-Hodgkin's lymphoma.

A prospective comparative trial of allogeneic versus autologous bone marrow transplant (BMT) was conducted. Sixty-six consecutive patients (median age, 41; range, 15 to 60; female:male ratio = 21:45) entered this clinical trial. Priority for allogeneic BMT was given to patients who were 55 or younger and had a major histocompatibility complex-matched or 1-antigen-disparate sibling donor. Autologous BMT was offered to all other patients whose age was 60 or younger. Patients who had no sibling donor and who had BM involvement at the time of evaluation were not eligible. Thirty-one patients received an allograft, and 35 patients received an autograft. Thirteen patients received a BM graft purged with 4-hydroperoxycyclophosphamide because of previous BM involvement. Patients who had previous radiation to the thoracic and/or abdominal areas of more than 20 Gy received a preparative regimen consisting of cyclophosphamide (1,800 mg/m2/d for 4 days), VP-16 (200 mg/m2 every 12 hours for 8 doses), and 1,3-bis(2-chloroethyl)-1-nitrosourea (600 mg/m2 as 1 dose). Other patients received cyclophosphamide 1,800 mg/m2/d for 4 days followed by total body irradiation of 12 Gy administered as a single daily fraction over 4 days. With a median follow-up of 14 months, the progression-free survival (PFS) for autograft and allograft recipients was 24% +/- 8% (+/- SE) and 47% +/- 9%, respectively, (P = .21). However, the probability of disease progression was significantly higher in the autologous group (69% +/- 9%) than in the allogeneic group (20% +/- 10%; P = .001). When other confounding prognostic factors were adjusted in the multivariate analysis, chemosensitive disease and allograft were found to have a significant favorable influence on probability of disease progression (P = .03 and .003), but only chemosensitive disease had a significant influence on the PFS (P < .002). Our results suggest the existence of graft-versus-lymphoma effect and also support the rationale of using immunotherapy after autologous BMT. Allogeneic BMT should be preferable to autologous BMT in younger patients with lymphoma.

Adolescent↗
PubMed1994

Successful treatment of human Waldenström's macroglobulinemia with combination biological and chemotherapy agents.

The immunomodulating effects and antitumor activity of two biological agents, bryostatin 1 (Bryo1) and alpha-interferon, were tested in vitro and in vivo either alone or prior to chemotherapy agents, against a Waldenström's macroglobulinemia tumor line (WSU-WM). Bryol caused a decrease in the expression of CD10, CD19, IgM, Leu10, and CD22 and a temporary growth inhibition as measured by cell cycle analysis. alpha-Interferon did not show any major effects. In vivo, severe combined immunodeficient mice were used to test the activity of the agents against WSU-WM. Bryo1 (i.p.) was given either alone or sequentially with doxorubicin (i.v.), vincristine (i.v.), melphalan (i.v.), and alpha-interferon (i.v.). Bryo1 given 24 h before vincristine or melphalan resulted in the highest tumor growth inhibition, tumor growth delay, and tumor cell kill. Two of five mice receiving Bryo1/vincristine combination were free of tumors > 200 days after treatment and were considered cured. In light of our findings, we recommend that Bryo1 be considered for clinical investigation in human B-cell tumors and might best be given combined with other chemotherapy agents used in the treatment of that disease. Whether Bryo1 is acting as a differentiating agent or as a direct anti-Waldenström's macroglobulinemia tumor agent, remains unclear.

Animals↗
PubMed1994

Preclinical studies using immobilized OKT3 to activate human T cells for adoptive immunotherapy: optimal conditions for the proliferation and induction of non-MHC-restricted cytotoxicity.

In order to obtain large numbers of T cells for adoptive immunotherapy after bone marrow transplantation (BMT), we optimized conditions for long-term proliferation of T cells that exhibit non-MHC-restricted cytotoxicity using immobilized anti-CD3 (OKT3) activation and culture in IL-2. Proliferation and cytotoxicity directed at Daudi, K562, and B cell lines were used to determine (1) the optimal concentration of IL-2 and the optimal time of exposure to immobilized OKT3 for maintaining growth and cytotoxicity, (2) the starting populations that can be used, (3) the T cell subsets that mediate cytotoxicity, and (4) the optimal medium and concentration of serum for maintaining growth and cytotoxicity. Peripheral blood lymphocytes (PBL) activated with OKT3 would proliferate and mediate cytotoxicity at IL-2 doses as low as 30 IU/ml. Increasing the IL-2 concentrations beyond 600 IU/ml did not augment the proliferative or cytotoxic responses of PBL. A 24-hr incubation on OKT3 was sufficient to activate PBL. Increasing the incubation time on OKT3 from 24 to 72 hr did not significantly enhance cytotoxicity. Comparisons between PBL and purified T cells (E-rosette) indicated that either cell population could be activated with OKT3 in the presence of IL-2 to proliferate and mediate non-MHC-restricted cytotoxicity. Purified populations of CD4+ or CD8+ T cells demonstrated equivalent proliferation and cytotoxicity when activated using IL-2 and OKT3. With equal concentrations of human or fetal bovine serum, RPMI 1640 and X-Vivo 10 were comparable for supporting proliferation and cytotoxicity. These conditions are being used to activate and expand T cells for clinical trials that involve infusing activated T cells into recipients after autologous BMT.

Blood Physiological Phenomena↗
PubMed1994

Allogeneic bone marrow transplantation in patients with myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) represent an acquired group of clonal disorders of the pleuripotent stem cells, resulting in progressive life-threatening cytopenias or transformation into acute leukemias. A major issue of using alloBMT in MDS is the criteria used for patient selection. Therapeutic trials of lesser intensity such as differentiating agents, and cytokines could be the preferable choice for patients with good prognostic features. On the other hand, patients with poor prognostic features may urgently need to establish a normal hematopoiesis through allogeneic bone marrow transplantation (alloBMT). Important prognostic indicators in MDS include FAB classification, presence of abnormal localization of immature precursors, degree of cytopenias and cytogenetic abnormalities. We used a novel preparative regimen--"BAC" consisting of the consecutive administration of 1 mg/kg of busulfan every 6 hours for 16 doses followed by 2 g/M2 of cytosine arabinoside (ara-C) given every 12 hours for four doses, and finally 60 mg/kg of cyclophosphamide daily for 2 days. Thirty two patients transplanted had a median age of 33 years. Nine of the patients had either RA or RARS, 21 had RAEB or RAEB-T and 2 were unclassified MDS. Twenty two of our patients had chromosomal abnormalities while 10 had a normal karyotype analysis. Nine of the 32 patients had documented leukemic transformation and received induction therapy prior to BMT. The median time from diagnosis to BMT was 5.6 months, ranging from 1.3 to 30.2 months. Nineteen out of 32 patients are alive without disease, with a median follow up of 24 months. The actuarial event-free survival for the entire group is 52%. Two patients have relapsed with an actuarial relapse rate of 12%. Only significant favorable prognostic indicator for the event-free survival was in the recipient of a genotypically matched graft (76%) compared to recipients of a non-genotypic graft (23%) (p = 0.02). "BAC" is a unique preparative regimen for alloBMT in MDS with excellent results.

Bone Marrow Transplantation↗
PubMed1994

Graft failure in children receiving HLA-mismatched marrow transplants with busulfan-containing regimens.

Identifying risk factors that lead to graft failure may reduce morbidity and mortality after bone marrow transplantation (BMT) for hematologic malignancies. We evaluated engraftment of all patients with acute myelogenous leukemia (AML), chronic myelogenous leukemia (CML) and myelodysplastic syndrome (MDS) receiving an unmanipulated marrow allogeneic BMT at the Detroit Medical Center from 1987 to 1992 using a busulfan, cyclophosphamide +/- cytarabine preparative regimen. Three of 118 patients had graft failure (2.5%; (95% confidence interval (CI) 0.7%, 6.4%). Graft failure was high in patients < or = 15 years with 3 of 12 patients with failure (25.0%) compared with 0 of 106 patients > 15 years (p = 0.002). Failure to engraft was not seen in HLA-identical (related or unrelated) donor transplants (0 of 103) whereas 3 of 15 HLA-mismatched donors failed (p = 0.003). Patient diagnosis, locus of HLA-mismatch, cytarabine in the preparative regimen, marrow cell dose and the relative reactive index (RRI) were not significant factors. Altered busulfan kinetics secondary to young age was probably not a major factor since 8 of 8 HLA-identical donor transplants engrafted in children. These findings demonstrate that patients receiving an unmanipulated marrow graft using busulfan-containing regimens were at a high risk for graft failure only if they were < or = 15 years of age and had an HLA-mismatched donor. More immunosuppressive preparative regimens, possibly including total body irradiation, should be considered to prevent potential graft failure in children.

Adolescent↗
PubMed1994

Phase I study of alpha-interferon augmentation of cyclosporine-induced graft versus host disease in recipients of autologous bone marrow transplantation.

To explore the augmentation of cyclosporin-induced graft-versus-host disease (GVHD) in autologous bone marrow transplantation (BMT), we conducted a phase I dose escalation trial of interferon (IFN)-alpha 2a. A dose of either 1 or 3 x 10(6) units of IFN-alpha 2a was given by daily sc injection starting on day 0 of BMT and continuing for 28 days. Cyclosporine (CYA) was also started on day 0 of BMT at a dose of 1 mg/kg/day for 28 days. We enrolled 22 patients (median age 43 years, range 19-55 years, male/female ratio = 9/13) which included 11 patients with lymphoma, 5 patients with Hodgkin's disease, 4 patients with AML and 1 patient each with acute lymphoblastic leukemia (ALL) and myeloma. Patients were divided into four groups: two control groups received either CYA or IFN-alpha 2a alone and the other two groups received IFN-alpha 2a at a dose of either 1 x 10(6) or 3 x 10(6) units/day sc concomitantly with CYA for 28 days. IFN-alpha 2a treatment was terminated early in 5 patients: 2 patients receiving IFN-alpha 2a at a dose of 3 x 10(6) units/day developed intractable fatigue, nausea and vomiting and 3 other patients had life-threatening transplant-related complications not related to IFN-alpha 2a (1 patient receiving 3 x 10(6) units/day, and 2 receiving 1 x 10(6) units/day). These patients were considered not evaluable. Of the 17 evaluable patients, all 13 who received IFN-alpha 2a developed GVHD regardless of whether they received CYA whereas only 2 of the 4 patients who received CYA alone developed detectable GVHD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Constitutive and mitogen-stimulated cytokine mRNA expression by peripheral blood mononuclear cells from most autologous and allogeneic bone marrow transplant recipients is intact.

The immunodeficiency that occurs after human bone marrow transplantation (BMT) leaves BMT recipients susceptible to fatal infections. Although cytokines are critical for coordinating immune responses and immune reconstitution after BMT, there are still gaps in our knowledge about the expression of mRNA for cytokines in peripheral blood mononuclear cells (PBMC) after BMT. Therefore, we systematically studied cytokine gene expression by PBMC from 11 allogeneic and four autologous BMT recipients from 111 to 837 days after BMT and compared the results with PBMC from seven normal controls tested in parallel. PBMC were examined for mRNA expression for IL-2r alpha, IL-2, IL-3, IL-4, IL-6, and IL-7 using reverse transcription polymerase chain reaction (RT/PCR). PBMC from 11 allogeneic recipients constitutively expressed mRNA for IL-2r alpha in 2 of 11 and IL-2 in 1 of 9 samples tested whereas the same PBMC constitutively expressed mRNA for IL-3 in 8 of 11, IL-4 in 3 of 7, IL-6 in 6 of 7 and IL-7 in 3 of 6 samples tested. After PHA/PMA stimulation, PBMC from the same recipients frequently expressed mRNA for IL-2r alpha in 9 of 11, IL-2 in 8 of 9, IL-4 in 3 of 7 and IL-6 in 7 of 7. PBMC from four autologous recipients (two short-term and two long-term) frequently constitutively expressed mRNA for IL-2r alpha (3 of 4) IL-2 (3 of 4), and IL-3 (4 of 4). Stimulation of PBMC from the autologous recipients did not alter cytokine expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia, Aplastic↗
PubMed1993

Differential effects of bryostatin 1 on human non-Hodgkin's B-lymphoma cell lines.

Bryostatin 1 (Bryo1), a macrocyclic lactone and a protein kinase C activator, is extracted and purified from the marine bryozoan Bugula neritina. In this study we describe its effect on morphology, surface immunophenotype, acid phosphatase (AcP), tartrate-resistant acid phosphatase (TRAP), proliferation and cell cycle of non-Hodgkin's B-lymphoma cell lines representing four differentiation stages. Except for the WSU-BL, a high-grade SCNCL, all other cell lines showed obvious changes in their morphology when treated with 200 nM Bryo1. Phenotypically, a dramatic decrease of CD10 and induction of CD11c and BL7 on some cell lines consistent with further B-cell differentiation was seen. The lines in control cultures showed variable expression of AcP and TRAP. Following treatment with Bryo1, there was a general increase in AcP expression except in WSU-BL line. WSU-FSCCL and WSU-DLCL were TRAP-negative but became TRAP-positive when treated with Bryo1. Cell growth and cycle analysis during treatment of different cell lines revealed evidence of strong, moderate, or no growth inhibition by Bryo1 compared with control cultures. Our results indicate that Bryo1 shows differentiation effects on low-grade FSCCL, intermediate-grade FLCL and high-grade DLCL, and stimulatory or no effect on high-grade SCNCL. Since Bryo1 does not have tumor-promoting activity, it has a potential therapeutic role as a B-cell differentiating agent.

Acid Phosphatase↗
PubMed1993

Bryostatin 1-induced modulation of the acute lymphoblastic leukemia cell line Reh.

We have previously reported that the phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA) induces further differentiation of the human acute lymphoblastic leukemia cell line Reh to a monocytoid B lymphocyte stage. In the present study, we investigated the differentiating capacity of another protein kinase C (PKC) activator, bryostatin 1 (bryo). Reh cells were treated in vitro with TPA, bryo, or interferon-alpha (IFN-alpha) for a period of 5 days during which cells were analyzed for changes in growth patterns, morphology, cytochemistry, and surface phenotype. Bryo caused a dose-dependent growth inhibition of Reh cells. Morphologically, the treated cells expressed monocytoid features with development of filopodia and numerous vacuoles indicating phagocytic activity. Bryo induced similar phenotypic changes to TPA, including induction of CD11c, increased expression of CD22 and down-regulation of CD10 and CD19. Enzymatically, bryo, like TPA, induced tartrate-sensitive acid phosphatase expression but failed to induce periodic acid Schiff (PAS) and nonspecific esterase (NSE). Bryo inhibited the TPA action on NSE and CD10. IFN-alpha showed additive growth inhibitory and phenotypic effects to bryo. Collectively, our findings indicate that bryo is capable of inducing further differentiation of the Reh cells along the B cell lineage similar to those of TPA.

Acid Phosphatase↗
PubMed1993

Bryostatin 1-induced hairy cell features on chronic lymphocytic leukemia cells in vitro.

The phorbol esters induce differentiation of chronic lymphocytic leukemia (CLL) cells. Clinical use of this observation has been hampered by the fact that phorbol esters are also tumor promoters. In this study we demonstrate that another protein kinase C activator, without tumor promoting activity, has similar effects on CLL cells. Fresh leukemic cells from the peripheral blood of 13 patients with CLL were isolated and cultured in the absence (control) or presence of Bryostatin 1 or 12-0-tetradecanoylphorbol 13-acetate (TPA). Aliquots of cells were then analyzed after 24, 72 and 120 hours for morphological changes, acid phosphatase (ACP) and the co-expression of two hairy cell-associated surface antigens, CD22 and CD11c, by flow cytometry. Bryostatin 1 induced changes in shape and morphology similar to TPA, with adherence and increase in cell size, abundant cytoplasm and irregular cytoplasmic membrane. Both agents induced a statistically significant increase in the expression of CD22 and CD11c compared with control (p < 0.0008). There was no significant difference between the two agents in the degree of expression of these two markers. Both agents also induced ACP that was tartrate resistant (TRAP). These changes indicate that Bryostatin is as effective as TPA in inducing further differentiation of CLL cells to a hairy cell stage.

Acid Phosphatase↗
PubMed1993

Coactivation with anti-CD28 monoclonal antibody enhances anti-CD3 monoclonal antibody-induced proliferation and IL-2 synthesis in T cells from autologous bone marrow transplant recipients.

Recent studies show that costimulation of T cells with anti-CD28 Mab (anti-CD28) enhances anti-CD3 Mab (anti-CD3)-induced proliferative responses and cytokine production. This study determines if coactivation with anti-CD3 and anti-CD28 corrects defects in proliferation and IL-2 secretion in peripheral blood lymphocytes (PBL) from bone marrow transplant (BMT) recipients. PBL or T cells from 5 of 16 autologous and 5 of 22 allogeneic recipients increased their anti-CD3-induced proliferation responses by > 50% after coactivation. In short-term (< 180 days after BMT) autologous recipients, the group mean response increased after anti-CD3 activation from 62,900 to 97,800 cpm after coactivation. In long-term (> 180 day after BMT) autologous recipients, the group mean response after anti-CD3 activation increased from 62,600 to 78,400 cpm after coactivation. The long-term autologous recipient group had costimulated responses from PBL that were significantly higher than the paired anti-CD3-induced responses (p < 0.01); in contrast, such differences were not seen in allogeneic recipient groups. After anti-CD3 stimulation, the mean response of 88,000 cpm for PBL from short-term allogeneic recipients and the mean response of 83,600 cpm for PBL from long-term allogeneic recipients were higher than those in PBL from autologous recipients were higher than those in PBL from autologous recipient groups. The amount of IL-2 secreted by T cells from three autologous and three allogeneic recipients was enhanced 0.9-25-fold by coactivation. Coactivation of PBL from selected recipients increased proliferation into the normal range and increased IL-2 secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗