Expression and modulation of progesterone induced blocking factor (PIBF) and innate immune factors in human leukemia cell lines by progesterone and mifepristone.

Progesterone (P), required for successful pregnancy, influences autoimmune, infectious, and malignant diseases via adaptive and innate immune effects. P induces NK inhibitor progesterone induced blocking factor (PIBF) in CD8+ T cells. PIBF isoforms could permit solid tumor immune escape. Expression and modulation of PIBF and innate immune proteins by P in leukemia cells and leukocyte subpopulations have not been reported. Ten T, seven myeloid, six B, five epithelial, fibroblast BG9, G-CSF mobilized CD34+ stem cells, and peripheral blood mononuclear cells were screened for PIBF mRNA by RT-PCR, and protein by immunohistochemistry in SRIK-NKL, MOT, U937, HL60, R-CLL, MD-E, 729pH6neo, SRIH-B(ATL), SRIK-B(T-PLL), and MeWo. Cell lines expressing PIBF and exemplifying myeloid/monoblast, natural killer/T, and B lineages were cultured with and without 0.5 - 5 microM P or 0.5 - 0.05 microM mifepristone (RU486) for 24 h. Subsequently they were examined for changes in the expression of mRNA by RT-PCR and protein by immunohistochemistry for PIBF and some innate immune factors. All cells expressed PIBF mRNA; protein only in four (SRIK-NKL, U937, SRIK-B(T-PLL) and HL60) out of 10 cell lines tested. P increased and RU486 decreased PIBF in U937, SRIK-B(T-PLL) and SRIK-NKL. P upregulated TLR-4 in U937, and HNP1 - 3, LL-37, IRAK-2, and IRAK-4 in multiple lines and RU486 down regulated these. PIBF may be used by some leukemias to evade immune surveillance and is a potential therapeutic target. P may impact infection and autoimmunity via effects on LPS receptor, TLR signaling, and antimicrobial peptides.

Expression of mRNA and proteins for toll-like receptors, associated molecules, defensins and LL-37 by SRIK-NKL, a CD8+ NK/T cell line.

Natural killer (NK) cells, innate lymphocyte effectors, kill virus-infected host and tumor cells in non-MHC, non-TCR restricted fashion, unlike T cells. The role of NK cells in recognition and killing of pathogens remains unknown. Expression of the ten human pathogen associated molecular pattern or toll-like receptors (TLR's), associated molecules, and antimicrobial peptides alpha, beta defensins, and LL-37 by NK cells has not been investigated previously. We report our CD8+ NK/T cell line SRIK-NKL, derived from leukemic phase of acute lymphoblastic lymphoma, expresses mRNA and protein for 8/10 TLR's, associated proteins for signaling, defensins, cathelicidin/LL-37, and responds to live bacteria by cell proliferation and increased IFN-gamma, TNF-alpha, TNF-beta, and MIP-1alpha production.

Soluble Fas and soluble Fas ligand proteins in human milk: possible significance in the development of immunological tolerance.

Human milk contains a complex uncharacterized, immune system able to exert actions both locally and systemically. This study reports the results of an ELISA-based quantitation of soluble Fas and soluble Fas ligand in human milk which may modulate the Fas/FasL system that is critical for the expression of immune tolerance and apoptosis. Production of Fas/FasL mRNAs by milk cells was also examined using RT-PCR. Fas is ubiquitously expressed in various cells and when bound by its ligand FasL, present predominantly on activated T- and NK cells, Fas-expressing cells are killed. A large amount of soluble Fas (1746-4320 pg/ml) is detected in colostrum, transitional milk and the mature milk of mothers delivering prematurely or at full-term, whereas FasL is present only in the range 123-310 pg/ml. Milk cells are positive for Fas mRNA, but negative for FasL mRNA. An excess of soluble Fas in human milk may bind to FasL preventing apoptosis and preserving epithelial barriers, and may represent an additional new mechanism whereby human milk favours immune tolerance and normal gastrointestinal development.

Hepatocyte growth factor in human milk and reproductive tract fluids.

PROBLEM: Despite evidence indicating a role for hepatocyte growth factor (HGF) in gastrointestinal and reproductive physiology, the concentration and distribution of HGF in human breast milk (BM) and reproductive tract fluids remain unknown. METHOD OF STUDY: Using enzyme-linked immunosorbent assay (ELISA), the HGF concentrations were determined in human oviductal fluid (hOF), follicular fluid (FF), amniotic fluid (AF), seminal plasma (SP), and colostrum/milk samples, and expression of HGF mRNA by milk cells and AF cells were examined by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: HGF is present at nearly 70-fold normal serum (0.85+/-0.15 ng/mL) concentration in FF (n = 3; x = 57+/-16 ng/mL) and AF (n = 17; x = 57+/-26 ng/mL), and is also present in hOF (n = 3; x = 4.8+/-2.3 ng/mL) and CVL (n = 8; x = 0.7+/-1.1 ng/mL) varying throughout the menstrual cycle. HGF is found at 3-times serum concentration in BM (n = 24; x = 2.3+/-1.3 ng/mL) with no significant difference between premature and full term or stage of lactation (colostrum, transitional, mature milk). HGF mRNA was detected in BM cells but not in AF cells. CONCLUSIONS: HGF is present in sufficient amounts to profoundly affect gastrointestinal maturation in the fetus via swallowed AF and neonate via BM, and helps to explain the increased rate of necrotizing enterocolitis (NEC) in infants of premature rupture of membrane (PROM)-complicated pregnancies, and the decreased rate in breast fed neonates. HGF in FF may be necessary for the development and maturation of the oocyte. HGF in hOF, SP, and cervicovaginal lavage (CVL) is likely to enhances epithelial cell integrity and the mucosal barrier. Thus, HGF is widely available in the reproductive tract with functions that remain to be fully elucidated.

Delta9 tetrahydrocannabinol and cannabidiol alter cytokine production by human immune cells.

Marijuana, a widely abused drug in the US, and its derivatives (cannabinoids) have been used in AIDS and cancer patients for treatment of intractable nausea and cachexia. Yet, objective investigations of the effect of cannabinoids on the human immune system are few. We investigated the effect of delta9 tetrahydrocannabinol (THC) and cannabidiol (CBD) on cytokine production in vitro by human leukemic T, B, eosinophilic and CD8+ NK cell lines as models. THC decreased constitutive production of IL-8, MIP-1alpha, MIP-1beta, and RANTES and phorbol ester stimulated production of TNF-alpha, GM-CSF and IFN-gamma by NK cells. It inhibited MIP-1beta in HTLV-1 positive B-cells but tripled IL-8, MIP-1alpha and MIP-1beta in B-cells and MIP-1beta in eosinophilic cells but doubled IL-8. Both cannabinoids strongly inhibited IL-10 production by HUT-78 T-cells. Results indicate that THC and nonpsychotropic CBD have complex lineage and derivative specific effects on cytokines consistent with previous animal studies. These effects while of potential benefits in some inflammatory/autoimmune diseases may worsen HIV infection, tumorigenesis and allergic inflammation in the lung.

The clinical value of digene hybrid capture HPV DNA testing in a referral-based population with abnormal pap smears.

PURPOSE OF INVESTIGATION: The hybrid capture human papillomavirus (HPV) DNA assay is offered by the manufacturer to assist clinicians with patients with ASCUS pap smear results to assess the risk factor and to potentially direct follow-up of these patients. In our practice, a gynecologic oncology practice that has a referral based population with abnormal pap smears, our purpose was to evaluate the patients referred with all grades of abnormal cervical cytology. METHODS: One hundred consecutive patients who were referred for evaluation of abnormal cervical cytology: atypical squamous cells of undetermined significance (ASCUS); low-grade squamous intraepithelial lesion (LGSIL); high-grade squamous intraepithelial lesion (HGSIL); or squamous cell carcinoma (SCC) were evaluated by repeat pap smear, hybrid capture HPV DNA analysis and colposcopy. Colposcopic findings were recorded, and if appropriate, cervical biopsies were performed. Hybrid capture results were correlated with histologic and cytologic findings. Using histopathologic diagnosis as the reference standard, the sensitivity and positive predictive value of pap smear and high risk HPV were calculated. The Kappa test was used to correlate colposcopic and histopathologic findings. RESULTS: Repeat pap smears at the time of initial consultation demonstrated 25 patients with normal results, 39 with LGSIL, 30 with HGSIL, 1 SCC and 5 ASCUS. Seventy-eight patients underwent cervical biopsy. Colposcopic findings correlated significantly with histopathologic findings (p<0.0001). Forty-four percent of patients tested positive for HPV DNA: 40 patients with high risk HPV, three patients with low risk HPV, and one patient with both high risk and low risk HPV. Sixteen of 39 patients (41%) with LGSIL on pap smear tested positive for high risk HPV; 37% of patients in this group required cervical conization because cervical biopsies demonstrated moderate/severe dysplasia. The diagnosis of moderate/severe dysplasia significantly correlated with the presence of high risk HPV [OR 78.9 (8.31-389.30)]. There was no significant correlation between the HPV DNA signal strengths and the histologic grade of dysplasia. The sensitivity and the positive predictive value of pap smear alone in identifying moderate/severe dysplasia was 62% and 96%, respectively. The combination of HGSIL pap smears and high risk HPV increased the sensitivity but not the positive predictive value for the detection of moderate/severe dysplasia to 77.7% and 95%, respectively (P=NS). CONCLUSIONS: Although in this setting, the use of hybrid capture DNA testing did not significantly improve the sensitivity or positive predictive value of the diagnosis of HGSIL cytology when compared to cytologically indicated plus colposcopically directed cervical biopsies in this population of women at high risk for the presence of disease, the combination of HGSIL pap smears and high-risk HPV did result in a clinically important increase in the diagnosis of moderate/severe dysplasia.

Cytokines of the human reproductive tract.

PROBLEM: How is it possible that the female genital tract immunologically does not reject spermatooa not the preimplantation and nidating embryo? METHODS: Four fluids of the human reproductive tract, i.e., human oviductal fluid (hOF), follicular fluid (FF), amniotic fluid (AF), and seminal plasma (SP) were investigated by specific ELISA for 18 cytokines. The concentrations, presence or absence of these compounds were evaluated for their possible role in the immunology of the reproductive process. RESULTS: Stem cell factor and IL-11 were detected in all reproductive tract fluids examined whereas large amounts of IL-1 beta and IL-1RA was found in AF and hOF. Follicular fluid revealed IL-2. HOF contained IL 2, IL-6, IL-8, TNF-alpha, MIP-1 alpha, IFN-gamma, and high levels of IL-1 beta, IL-10, IL-1RA, and sIL-2R. Amniotic fluid contained sIL-2R, IL-8, IL-1 beta, IL-1RA, IL-6, TNF-alpha, and MIP-1 alpha. No IL-12 or IL-13 was detected in hOF follicular fluid or amniotic fluid. Almost no free TGF-beta 1 or TGF-beta 2 was found in any reproductive tract fluid except seminal plasma. Seminal plasma contained large quantities of free TGF-beta 1 (9,220 +/- 3,635 pg/mL) in addition to large quantities of latent TGF-beta 2 (2,933 +/- 2,169 pg/mL) and TGF-beta 1 (71,000 +/- 3,240 pg/mL). Furthermore, considerable concentrations of IL-8 (1900 +/- 374 pg/mL) and sIL-2R (350 mu/mL) exist in seminal plasma. CONCLUSIONS: HOF contains a high level of IL-10 (588 +/- 304 pg/mL), a powerful immune suppressor which probably plays a role in regulating immune responses in the fallopian tube and possibly in the endometrial cavity. Our observations suggest that seminal plasma with its huge content of TGF beta provides immune protection for sperm. Unfortunately, such high concentrations of TGF beta may also inhibit an immune defense in any organ in which semen is deposited.

Phenotype, genotype and cytokine production in acute leukemia involving progenitors of dendritic Langerhans' cells.

To date no hematopoietic progenitors of dendritic Langerhans' cells (DLC), which represent an highly efficient class of antigen presenting cells, have been identified or the cytokines they elaborate have been defined. Here we describe an acute leukemia patient whose blasts (90-96% in peripheral blood and bone marrow) had a phenotype consistent with putative progenitors of DLC. The patient was treated with ara-C and VP-16 but did not achieve remission. The blasts had lobulated nuclei, no cytoplasmic vacuolation or Auer rods and were weakly positive for acid phosphatase and non-specific esterase and negative for PAS, granzyme A, dipeptidyl aminopeptidase IV, ATPase/ADPase and lysozyme production. The blasts were positive for CD1a, CD4, CD16, CD35, HLADR, HLADQ, CD11b, CD11c, CD14, CD33, CD34, CD11a, CD71, CD19, CD25, IL-2R beta and negative for CD2, CD7, CD8, CD10, CD22, CD56, CD57, surface or cytoplasmic CD3, TCR delta and TCR beta, HTLV-1p19 and P-glycoprotein. On liquid culture with or without 5 x 10(-9) M 12-O-tetradecanoylphorbol-13-acetate (TPA) for 3 days, the blasts formed aggregates of proliferating and elongating cells on the wall of the flasks with a decline in CD34, numerous dendritic processes appeared on the cells and there was strong positivity for ATPase/ADPase, but no other changes in phenotype. No macrophages were observed, indicating derivation from separate DLCs. Cytogenetic analysis showed chromosomal abnormalities and electron microscopy showed Birbeck granules. Southern blotting of DNA showed rearrangement of one allele for both JH and TCR beta but no HTLV-1 related sequences. Culture supernatants from blasts cultured with or without TPA showed the production of large amounts of IL-8, IL-6, TNF-alpha, MIP-1 alpha, IL-10 and interferon gamma and modest amounts of IL-1 alpha, GM-CSF and stem cell factor. The presence not only of CD1a, HLADR, HLADQ and many other characteristics including Birbeck granules, but also differentiation along the lines of DLC with appearance of dendritic processes on the cells and expression of ATPase/ADPase activity, indicate that the leukemic blasts in our patient represented a leukemic counterpart of normal progenitors of DLC and the leukemia a new entity which could possibly be classified as AML-M8. Lastly, many pro-inflammatory cytokines produced by DLC could contribute to inflammation and IL-10 to immunosuppression.

Soluble interleukin-2 receptor, soluble CD8 and soluble intercellular adhesion molecule-1 levels in hematologic malignancies.

Plasma levels of soluble interleukin-2 receptor (sIL-2R), soluble CD8 (sCD8) and soluble intercellular adhesion molecule 1 (sICAM-1) were determined by ELISA assays in about 100 patients with hairy cell leukemia (HCL), acute myelomonocytic leukemia (AMMoL), acute myelocytic leukemia (AML), chronic lymphocytic leukemia (CLL), prolymphocytic leukemia (PLL), acute lymphoblastic leukemia (ALL), adult T-cell leukemia (ATL), and mycosis fungoides (MF). Additionally, cultured AML, ALL, and CLL cells grown with and without 12-0-tetra-decanoyl-phorbol-13-acetate (TPA) were tested for IL-2R (CD25) expression by indirect immunofluorescence. Supernatants of these cultures were also tested for sIL-2R by ELISA. Elevated sIL-2R levels were found in HCL patients at initial diagnosis and relapse, in AMMoL, in AML, in the accelerated and non-accelerated phases of B-CLL, in PLL, in non-T/non-B ALL, in B-ALL in mixed lineage ALL, in T-CLL, in T-ALL, and in active MF. Reduced levels of sIL-2R were encountered in HCL patients in remission, in pre-T-ALL, and in MF patients in remission. Also, in non-accelerated CLL sIL-2R levels were less elevated than in later stages of the disease. In T-CLL, sIL-2R was only slightly elevated. Thus, we believe sIL-2R could prove to be a useful marker of disease stage, subtype, and prognosis in several hematologic malignancies. The cultures with and without TPA suggested that the undetermined source of sIL-2R in HCL, ALL and AML could indeed be the malignant cells but perhaps not so in the case of B-CLL. Plasma sCD8 was found to be below normal control levels in HCL, and lowest in relapsing cases. In addition, sCD8 levels were below normal in pre-T-ALL, and in MF. Levels in the non-accelerated phase of B-CLL approximated those of controls. Elevated levels of sCD8 were observed in AML, AMMoL, accelerated stage B-CLL, PLL, non-T/non-B ALL, B-ALL, mixed lineage ALL, T-ALL, T-CLL, and ATL. Thus, in a few instances, sCD8 may also correlate with disease subtype, as well as stage. Although sICAM-1 levels were elevated in all leukemias, its levels in CLL did not appear to be related to disease activity. Whether this is true or not for other leukemias would require additional work on sICAM-1 levels and its relationship to disease activity and prognosis.

Constitutive production of interleukin-8 (IL-8) by normal and malignant human B-cells and other cell types.

The culture supernatants from 43 human cell lines obtained during log phase and from purified normal peripheral blood B-lymphocytes cultured at 10(6) cells ml-1 for 48 h in RPMI 1640-5% fetal calf serum were examined for interleukin-8 (IL-8) using Elisa kits. Constitutive IL-8 production was found for 14/15 B-cell lines (5 derived from normal persons and 2 from AML patients, 1 pre-B-ALL, 2 CLL with trisomy 12, 2 HTLV-I+, 1 HTLV-II+, 1/2 Burkitt lymphoma), 4/16 T-cell lines (3/6 HTLV-I+, 1 HTLV-II+, 0/9 T-ALL), myeloid line HL-60, monocytoid line U937, 3/3 ovarian carcinoma, 1/1 endometriosis, 2/2 normal fibroblast, 0/2 C-ALL, 0/1 pre-erythroid line K562, as well as for normal B-lymphocytes. Later, cells examined by indirect immunofluorescence using IL-8 antibodies gave a positive reaction. DNA from 4 IL-8 producing and 3 non-producing cell lines, when probed with IL-8 cDNA gave the same 3.5 kb EcoRI fragment indicating similarities of the IL-8 gene in these cells. Two B-cell lines examined showed the expression of 1.8 kb IL-8 mRNA. These results indicate IL-8 production by a greater variety of cells than previously believed which open possibilities for new IL-8-mediated immune functions by such cells as B-cells.

Human T-cell leukemia virus type I or a related retrovirus in patients with mycosis fungoides/Sézary syndrome and Kaposi's sarcoma.

Antibodies reactive with human T-cell leukemia virus type I (HTLV-I) proteins p19, p24, gp46, p56, and gp68 were detected in four of 27 patients with mycosis fungoides/Sézary syndrome (MF/SS) and one patient with Kaposi's sarcoma using radioimmunoprecipitation and Western blot analysis. Seroreactivity patterns to HTLV-I proteins of MF/SS sera were indeterminate or limited in comparison with sera of patients with adult T-cell leukemia/lymphoma. HTLV-I gag- and tax/rex-specific DNA was demonstrated in peripheral blood from three of the MF/SS patients and from the patient with Kaposi's sarcoma by the polymerase chain reaction. HTLV-I-specific DNA sequences were not detected in a cohort of seven seronegative MF/SS patients. The frequency of HTLV-I infection was four of 27 or 14.8% among the MF/SS patients, which is several hundredfold higher than in normal blood donors. The present data suggest a possible association of HTLV-I or a related retrovirus with mycosis fungoides/Sézary syndrome and Kaposi's sarcoma.

Examination of HTLV-I ELISA-positive leukemia/lymphoma patients by western blotting gave mostly negative or indeterminate reaction.

We used enzyme-linked immunosorbant assay (ELISA) and Western blotting, with "purified" human T-cell leukemia virus I (HTLV-I), to test for HTLV-I antibodies in 2583 plasma samples from 1053 leukemia/lymphoma patients treated at Roswell Park Memorial Institute, mostly between 1972 and 1984, and in 110 sera samples from normal healthy persons. The results demonstrate that ELISA and Western blot assay have limitations for HTLV-I antibody detection in an adult T-cell leukemia/lymphoma (ATL) nonendemic population. This conclusion is based on the many false reactives obtained by ELISA, and weak and indeterminate reaction (mostly p19 band) on Western blotting. All moderate to strongly HTLV-I ELISA-positive samples tested were negative for human immunodeficiency virus (HIV) antibodies. Although 6/27 mycosis fungoides (MF) patients tested gave mostly a weak reaction on HTLV-I ELISA, 3/6 MF patients gave multiple bands (p19, p31, p36, gp46) on Western blotting and three samples from one patient gave the same p31, p36, and gp46 bands. This may suggest involvement of some HTLV-I-related virus in MF. These results also indicate that prevalence of HTLV-I infection in leukemia/lymphoma patients was rare, if it exists at all, since, despite the reactivity of some sera with HTLV-I-suspected antigens, none of the samples satisfy the USPHS criteria for positivity which is based on the detection of antibodies to gag protein p24 and to an env gene product gp46 or gp61/68.

Diisopropylfluorophosphate binding proteins (serine hydrolases) from normal and leukemic hematopoietic cells.

Normal and leukemic hematopoietic cell lysates were labeled with [3H]-diisopropylfluorosorophosphate ([3H]-DFP), an active site inhibitor of serine hydrolases. The labeled proteins in the lysates were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by counting of gel segments for radioactivity. The results indicate the presence of distinct [3H]-DFP binding patterns for different normal and leukemic hematopoietic cells; significantly lower labeling in normal or leukemic lymphoid cells compared to myeloid or monocytoid cells; lower labeling in acute myeloblastic leukemia (FAB-M1) as compared to acute myelomonocytic leukemia (FAB-M4), chronic myelomonocytic leukemia or monocytes and an increase in [3H]-DFP binding with cell maturation along granulocytic series. Thus, these patterns could be useful in discriminating acute lymphoblastic leukemia from myeloid/monocytoid types of leukemia and for following maturation of myeloid cells, and perhaps for studying functional or maturation defects in hematopoietic cells in other pathological conditions.

Polyamine changes during senescence and tumorogenesis in plants.

Putrescine, spermidine, spermine and two unknowns designated as A and B were detected in first seedling leaves of barley (Hordeum vulgare L. var. Wolfe). The levels of these polyamines in first seedling leaves from 4-day-old barley plants grown in darkness or in light were comparable and did not change significantly after exposure of dark grown plants to light for 24 h. No significant consistent changes in the amounts of above polyamines, except perhaps decline in spermidine, were noted during senescence of intact or excised first seedling leaves of barley and this spermidine decline was suppressed during retardation of senescence of excised leaves by 10 mg/l kinetin in the dark. In addition, putrescine, spermidine, spermine, cadaverine and diaminopropane (0.2 mM, 1 mM, 10 mM) had no effect on senescence of excised barley leaves in the dark and both spermine and spermidine induced bleaching of the leaves in the light. Both spermine and spermidine (approx. 10 mM) inhibited RNase and DNase activities but stimulated phosphodiesterase activity (assayed with bis-p-nitrophenyl phosphate as substrate) in crude soluble extracts from barley leaves. Purified snake venom phosphodiesterase activity assayed with RNA as substrate was, however, stimulated by 300-400% by 7-14 mM spermine or spermidine indicating similar possibilities for barley phosphodiesterase. These results together with the presence of multiple species of these enzymes and a decline in net soluble RNase and DNase activities during senescence in barley leaves reported previously, make it unlikely that inhibition of RNase activity in vitro by polyamines could be correlated with their effect on senescence. Putrescine, spermidine and spermine were detected in normal and crown gall tumor tissue cultures of tobacco (Nicotiana tabacum var Wisconsin 38) and in tobacco mosaic virus (TMV)-infected freshly excised pith tissue from tobacco which represented non-proliferating tissue. The level of all three polyamines was several-fold higher in cultured tissues compared to the non-dividing freshly excised pith tissue and the tumor cultures had several-fold higher spermidine and putrescine respectively compared to normal tissue cultures. These results indicate high levels of polyamines in growing tissues but no consistent pivotal changes in polyamines during senescence. The results also do not support polyamines being natural anti-senescent compounds in plants or that their anti-senescent compounds effect could result from inhibition of RNase activity.

Human T-cell leukemia virus I provirus and antibodies in a captive gorilla with non-Hodgkin's lymphoma.

Antibodies reactive against human T-cell leukemia virus I (HTLV-I) were detected by indirect immunofluorescence assay using MT-2 as target cells, enzyme linked immunosorbent assay screen and competition assay, and Western blot analysis in three sera (one collected in 1979) from a captive gorilla which developed diffuse histiocytic lymphoma in 1983. The sera from four other healthy gorillas housed separately were HTLV-I antibody negative. All sera were negative for HTLV-III antibodies by enzyme linked immunosorbent assay. Southern blot analysis of DNA from lymphoma tissue after digestion with BamHI and using complete HTLV-I genome probe gave one 10-kilobase fragment and a characteristic 1.05-kilobase internal fragment detected in all known HTLV-I isolates. These results indicate that the gorilla was infected with HTLV-I or a closely related simian virus several years before the development of lymphoma.

Immunoglobulin chain gene rearrangements in a t(4;11) acute leukaemia with monocytoid blasts.

We report a case of acute leukaemia with the t(4;11) chromosomal translocation which, at initial diagnosis, had L-1 lymphoblasts that were positive for terminal deoxynucleotidyl transferase (TdT) and HLA-DR but negative for myeloid cytochemical markers. At last relapse the patient had mostly monocytoid blasts which were not TdT negative but were positive for HLA-DR, weakly positive for Sudan Black B (SB), periodic acid Schiff's (PAS), naphthol AS-D acetate esterase (NSE), chloroacetate esterase (CAE) and negative for acid phosphatase (AP) and nitroblue tetrazolium (NBT) reduction. Treatment with 12-o-tetradecanoylphorbol-13-acetate (TPA) in vitro induced differentiation to macrophage-like cells that were strongly positive for SB, PAS, NSE, AP, CAE and NBT reduction, indicating a latent monocyte-like phenotype. Thus the leukaemic cell clone or a precursor clone with the t(4;11) translocation manifested a lymphoid phenotype at initial diagnosis and a monocytoid phenotype at relapse. Immunoglobulin gene analysis of the monocytoid relapse blasts revealed rearrangements of the heavy chain gene alleles and germline light chain genes. Thus, the leukaemia clone with the t(4;11) chromosomal translocation could be a bipotential cell with heavy chain gene rearrangements occurring in a primitive cell which may retain the ability to differentiate along the myeloid-monocytoid lineage in response to the appropriate stimulus. Alternatively, these characteristics may result from a transformation associated event.

Fragmentation of DNA and chromatin during senescence in barley leaves.

DNA or chromatin from young (7 day) first seedling leaves of barley showed only one component which migrated little into 1% agarose gels on electrophoresis. However, DNA or chromatin from senescent (17-, 19-, and 23-day-old) leaves showed additional dispersed components migrating throughout the length of the gel which increased with age. These low molecular weight components increased even more on autodigestion of chromatin from senescent leaves by its associated DNase or by digestion of DNA from senescent leaves with partially purified chromatin DNase. DNA or chromatin from young leaves also produced gel pattern similar to old leaves on digestion with partially purified chromatin DNase from old barley leaves. Thus, fragmentation of DNA and chromatin by chromatin associated DNase, previously shown to increase 4000% on aging, occurs during senescence in barley leaves.