Restriction of human adenovirus replication in Chinese hamster cell lines and their hybrids with human cells.

We have found that the replication of human adenovirus (Ad2) is restricted in multiple Chinese hamster cell lines including CHO and V79. The major site of restriction involves differential accumulation of late viral proteins as demonstrated by immunofluorescence assay and polyacrylamide gel electrophoresis with and without prior immunoprecipitation. Synthesis of fiber and penton base are markedly reduced, whereas others, such as the 100K polypeptide, are synthesized efficiently.

In vitro effects of 4-hydroxyperoxycyclophosphamide on human immunoregulatory T subset function.

Treatment of T cells in vitro with low concentrations of 4-hydroperoxycyclophosphamide (4-HC) is known to result in immunopotentiation of both T and B cell effector function in a manner analogous to that of cyclophosphamide administered in vivo. A previous study demonstrated that augmentation of polyclonal immunoglobulin secretion occurs following pretreatment of autologous collaborating T cells with low concentrations of 4-HC as a result of blockade of suppressor effector induction from suppressor precursor, both of which share the identical T4+,8-phenotype. The present study was undertaken to examine the effects of 4-HC on regulatory T-T interactions in mixed lymphocyte culture (MLC) responses and for allospecific cytotoxic T lymphocyte (CTL) responses.

Immortalization of human fibroblasts transformed by origin-defective simian virus 40.

Simian virus 40 (SV40)-mediated transformation of human diploid fibroblasts has provided an effective experimental system for studies of both "senescence" in cell culture and carcinogenesis. Previous interpretations may have been complicated, however, by the semipermissive virus-cell interaction. In earlier studies, we previously demonstrated that the human diploid fibroblast line HS74 can be efficiently transformed by DNA from replication-defective mutants of SV40 containing a deletion in the viral origin for DNA synthesis (SVori-).

Sequential evaluation of alpha-2b-interferon treatment in 128 patients with hairy cell leukemia.

This multicenter study reports on 128 patients with hairy cell leukemia (HCL) who were treated subcutaneously with alfa-2b interferon (Intron A, Schering Corp, Kenilworth, NJ), three times a week at a dosage of 2 megaunits/m2. Five patients (4%) had a complete response (CR) with virtual eradication of hairy cells from the bone marrow, 98 (77%) showed a partial response (PR), defined as hematologic normalization of all three blood counts associated with decreased hairy cells in the bone marrow, and nine (7%) showed a minor response (MR) that included improvement in at least one measurement of the blood count. Sixteen persons (12%) did not respond.

Enhancement of a human antibody response in vitro mediated by interaction of interferon-alpha with T lymphocytes.

This study describes the effects of human recombinant IFN-alpha 2 on antibody production in vitro. Whereas the inclusion of IFN-alpha 2 in cultures for 7 days had a relatively minor effect on pokeweed mitogen (PWM)-induced antibody production, it resulted in a dose-related enhancement of a hapten-specific primary antibody response. Comparison of PWM and IFN-induced [3H]thymidine uptake indicated that the observed IFN activation was not polyclonal.

Modification of luminol-dependent chemiluminescence reactivity of peripheral blood leukocytes from patients with lymphoreticular tumor, solid cancer, or healthy blood donors by interferon-alpha.

The effect of interferon-alpha (rIFN-alpha 2) on modulating the luminol-dependent chemiluminescence (CL) response evoked by Zymosan or phorbol myristate acetate (PMA) has been studied in heparinized whole blood as well as isolated peripheral blood leukocytes derived from cancer patients and healthy blood donors. The cancer patients, diagnosed with chronic leukemia or lymphoma or solid cancer, were under rIFN-alpha 2 therapy. The CL emission to both Zymosan or PMA was enhanced in the whole blood of the patient's group in comparison to whole blood of healthy blood donors.

Recombinant alfa interferon in renal cell carcinoma: a randomized trial of two routes of administration.

Ninety-seven patients with recurrent or metastatic renal cell carcinoma were randomized to receive recombinant interferon (IFN) alfa-2b (Intron A; Schering-Plough, Kenilworth, NJ) by either the subcutaneous (SC) or intravenous (IV) route. The SC dosage was 2 X 10(6) IU/m2 three times weekly, and the IV dose 30 X 10(6) IU/m2 for five consecutive days every 3 weeks. Dose escalation to a maximum of 10 X 10(6) IU/m2 SC and 50 X 10(6) IU/m2 IV was allowed for patients with minimal or absent toxicity.

Combination trial of subcutaneous interferon alfa-2b and oral cyclophosphamide in favorable histology, non-Hodgkin's lymphoma.

Patients with follicular non-Hodgkin's lymphoma (NHL) respond well to chemotherapy but frequently relapse and progress with conversion to more aggressive histology lymphomas. In a prior Cancer and Leukemia Group B (CALGB) trial, oral cyclophosphamide, given as a single agent, was found to be equivalent to a five-drug regimen in remission induction in patients with follicular NHL who had not received prior chemotherapy. Recently, interferon alfa-2b (Intron A; Schering Plough) has been demonstrated to elicit complete or partial responses in up to 50% of patients with nodular NHL who had received prior chemotherapy.

Identification of temperature-sensitive DNA- mutants of Chinese hamster cells affected in cellular and viral DNA synthesis.

We described a strategy which facilitates the identification of cell mutants which are restricted in DNA synthesis in a temperature-dependent manner. A collection of over 200 cell mutants temperature-sensitive for growth was isolated in established Chinese hamster cell lines (CHO and V79) by a variety of selective and nonselective techniques. Approximately 10% of these mutants were identified as ts DNA- based on differential inhibition of macromolecular synthesis at the restrictive temperature (39 degrees C) as assessed by incorporation of [3H]thymidine and [35S]methionine.

Cytogenetic evidence for clonal evolution in B-cell chronic lymphocytic leukemia.

Sequential cytogenetic studies were performed in eight of ten patients with B-cell chronic lymphocytic leukemia presenting with trisomy 12 as the sole chromosomal abnormality. Follow-up studies of peripheral blood lymphocytes revealed that the karyotypes retained the sole abnormality of trisomy 12 in five cases, trisomy 12 converted to a normal karyotype during remission in one case, additional chromosome changes (-X,14q-) along with trisomy 12 appeared in one patient and multiple chromosome changes with or without trisomy 12 appeared in the remaining patient. The findings indicate that other chromosome changes in addition to trisomy 12 may develop as a result of clonal evolution or dedifferentiation, though the possibility that in two patients these changes may be related to chemotherapy and/or irradiation could not be ruled out entirely.

Characterization of non-T effector cell subpopulations involved in production of human alpha interferon.

The phenotype of the human effector leukocyte subset involved in production of alpha interferon was examined using positive and negative selection techniques including murine monoclonal antibodies. The data suggest that the effector cell responsible for the elaboration of human alpha interferon is surface immunoglobulin positive, lacks either the E-rosette receptor or any monocyte determinants and is also negative for expression of the surface antigens identified by Leu-10 and Leu-11b monoclonal antibodies. Neither monocytes nor polymorphonuclear leukocytes were shown to play a role in regulation or production of alpha interferon.

Primary chemotherapy for localized non-Hodgkin's lymphomas with diffuse histologic characteristics. Preliminary report of a prospective study.

Thirty-three patients with diffuse non-Hodgkin's lymphoma (stages I and II) received intermediate doses of oral methotrexate followed by leucovorin calcium every four weeks, on days 1 and 8, followed on day 15 by intravenous cyclophosphamide and vincristine sulfate. Prednisone was given for four weeks on alternate courses of treatment. A total of six such four-week courses was planned.

Alpha-2 interferon therapy of hairy-cell leukemia: a multicenter study of 64 patients.

Sixty-four patients with hairy-cell leukemia (HCL) (61 had undergone prior splenectomy) were treated with alpha-2 interferon (Intron A, Schering Corp, Kenilworth, NJ) subcutaneously three times per week at a dosage of 2 X 10(6) U/m2. Three patients (5%) demonstrated a complete response (CR) with apparent eradication of hairy cells from the bone marrow, 45 patients (70%) showed a partial response (PR) defined as normalization of all three blood counts associated with decreased involvement in the bone marrow, and nine patients (14%) showed a minor response that included improvement in at least one blood count. Three patients had no response, three patients died before completing 1 month of therapy, and one patient refused further therapy after 1 month of therapy.

B cell growth factor-induced proliferation of hairy cell lymphocytes and inhibition by type I interferon in vitro.

Malignant B cells from hairy cell leukemia (HCL) patients are unable to proliferate when stimulated with standard B cell mitogens. Using chromatographically purified B cell growth factor (BCGF), HCL can be stimulated to proliferate as assessed by incorporation of tritiated thymidine [3HTdR] into DNA. Proliferation was found to be time dependent, with no detectable 3H-TdR incorporation in up to three days of culture, and significant stimulation evident at days 6 and 10.

The reproducibility of acute lymphoblastic leukemia phenotype determinations: evaluation of monoclonal antibody and conventional hematopoietic markers.

Peripheral blood and/or bone marrow lymphoblasts from 25 patients with acute lymphoblastic leukemia (ALL) were tested with a panel of monoclonal antibodies (MoAbs) and conventional hematopoietic markers by three different laboratories. The results were analysed to evaluate the reproducibility of ALL phenotype determinations. Specimens were transported between laboratories by 24-h courier service and were classified on the basis of indirect immunofluorescence MoAb reactivities as follows: B-lineage ALL (BA-1+T-MCS-2-); T-lineage ALL (T+BA-1-MCS-2-); myeloid antigen ALL (MCS-2+BA-1-CALLA-T-) and unclassified ALL (BA-1-MCS-2-CALLA-T-).

Defective DNA topoisomerase I activity in a DNAts mutant of Balb/3T3 cells.

Cell and polyomavirus DNA synthesis in ts20, a temperature-sensitive mutant derived from Balb/3T3 cells, is inhibited at an early step in chain elongation in vivo and in vitro. Virus DNA synthesized under restrictive conditions, when analyzed by gel electrophoresis and fluorography, contained a series of equally spaced bands migrating between form I and form II. If restrictive conditions were prolonged, the relative amount of these less-supercoiled topoisomers increased while the overall amount of virus DNA decreased.

Further characterization of the phenotype of ts20, a DNAts mutant of BALB/3T3 cells.

Ts20 is a temperature-sensitive mutant cell line derived from BALB/3T3 cells that is blocked at a step in DNA synthesis involving chain elongation. Following a shift from 33 degrees to 39 degrees C, mutant cells lost ability to grow or form colonies. When mutant cells were infected with polyomavirus, both cell and virus DNA synthesis were inhibited at the restrictive temperature of 39 degrees C.

Differential replication of SV40 and polyoma DNAs in Chinese hamster ovary cells.

We have investigated the ability of CHO cells to allow growth of papovaviruses by analyzing viral DNA replication after transfection using the calcium-phosphate co-precipitation technique. These analyses showed that when SV40-containing plasmids were introduced into CHO cells, viral DNA replicated to a level of approximately 1000 copies per T antigen-expressing cell, and neither late proteins nor virus progeny were produced. When polyoma (Py)-containing plasmids were transfected into CHO cells, a ten-fold higher level of Py DNA was present per T antigen-positive cell, and viral capsid proteins and progeny virus were detected, indicating that CHO cells are not equally restricted for all papovaviruses.

Phase II study of recombinant alpha-2 interferon in resistant multiple myeloma.

A multicenter phase II study of INTRON, recombinant alpha-2 interferon (Schering Corp, Kenilworth, NJ), in patients with relapsing or refractory myeloma was initiated. Patients received either intravenous therapy for two weeks followed by subcutaneous therapy or subcutaneous dosing from initiation of treatment. Of 38 evaluable patients, 19 were refractory and 19 had relapsed at entry.

T-cell depletion of bone marrow does not inhibit in vitro hematopoiesis.

One approach to overcome the problem of histoincompatibility in bone marrow transplantation is to use T cell depleted marrow from a haploidentical donor in an attempt to ameliorate graft-versus-host disease. Since the T cell requirements for normal hematopoiesis are uncertain, experiments were performed to study the effects of E rosette-T cell depletion on in vitro growth of hematopoietic progenitor cells. Marrow mononuclear cells were cultured in a modified CFU-GEMM assay before and after T cell depletion.

Clonal chromosome abnormalities in prison-acquired lymphoproliferative syndrome.

Lymph nodes from five male patients with prison-acquired lymphoproliferative syndrome (PALS), which seems to be a prodrome of acquired immune deficiency syndrome (AIDS), were examined cytogenetically. Two had clonal chromosome abnormalities, i.e.