Autocrine stimulation of interleukin 1 beta in acute myelogenous leukemia cells.

A significant increase in CD25 antigen-positive cells by IL-1 was observed in cells of a patient with M7 acute myelogenous leukemia. Basal proliferation and expression of CD25 antigen by the M7 leukemic cells were inhibited by addition of anti-IL-1 beta antibody in a dose-dependent manner, but not by rabbit anti-IL-1 alpha antibody. Culture supernatants of these leukemic cells contained IL-1 activity, which was specifically inhibited by addition of anti-IL-1 beta antibody, and Northern blot analysis detected intracellular IL-1 beta mRNA. These results indicated that autocrine secretion of IL-1 beta was involved in proliferation of some myelogenous leukemic cells.

Consecutive national surveys of ABO-incompatible blood transfusion in Japan.

BACKGROUND AND OBJECTIVES: Morbidity and mortality from ABO-incompatible transfusion persist as consequences of human error. Even so, insufficient attention has been given to improving transfusion safety within the hospital. MATERIALS AND METHODS: National surveys of ABO-incompatible blood transfusions were conducted by the Japanese Society of Blood Transfusion, with support from the Ministry of Health, Labor and Welfare. Surveys concluded in 2000 and 2005 analysed ABO-incompatible transfusion data from the previous 5 years (January 1995 to December 1999 and January 2000 to December 2004, respectively). The first survey targeted 777 hospitals and the second, 1355 hospitals. Data were collected through anonymous questionnaires. RESULTS: The first survey achieved a 77.4% response rate (578 of 777 hospitals). The second survey collected data from 251 more hospitals, but with a lower response rate (61.2%, or 829 of 1355 hospitals). The first survey analysed 166 incidents from 578 hospitals, vs. 60 incidents from 829 hospitals in the second survey. The main cause of ABO-incompatible transfusion was identification error between patient and blood product: 55% (91 of 166) in the first survey and 45% (27 of 60) in the second. Patient outcomes included nine preventable deaths from 1995 to 1999, and eight preventable deaths from 2000 to 2004. CONCLUSION: Misidentification at the bedside persists as the main cause of ABO-incompatible transfusion.

Mechanoelectrical feedback: independent role of preload and contractility in modulation of canine ventricular excitability.

Mechanoelectrical feedback, defined as changes in mechanical state that precede and alter transmembrane potential, may have potential importance in understanding the role of altered load and contractility in the initiation and modulation of ventricular arrhythmias. To assess the independent effects of preload and contractility on myocardial excitability and action potential duration, we determined the stimulus strength-interval relationship and recorded monophasic action potentials in isolated canine left ventricles contracting isovolumically. The strength-interval relationship was characterized by three parameters: threshold excitability, relative refractory period, and absolute refractory period. The effects of a threefold increase in left ventricular volume or twofold increase in contractility on these parameters were independently assessed. An increase in preload did not change threshold excitability in 11 ventricles but significantly shortened the absolute refractory period from 205 +/- 15 to 191 +/- 14 ms (P less than 0.001) (mean +/- SD). Similarly, the relative refractory period decreased from 220 +/- 18 to 208 +/- 19 ms (P less than 0.002). Comparable results were observed when contractility was increased as a result of dobutamine infusion in 10 ventricles. That is, threshold excitability was unchanged but the absolute refractory period decreased from 206 +/- 14 to 181 +/- 9 ms (P less than 0.003), and the relative refractory period decreased from 225 +/- 17 to 205 +/- 18 ms (P less than 0.003). Similar results were obtained when contractility was increased with CaCl2, indicating that contractility associated changes were independent of beta-adrenergic receptor stimulation. An increase in preload or contractility was associated with shortening of the action potential. A threefold increase in preload and twofold increase in contractility were associated with a decrease in action potential duration of 22 and 24 ms, respectively. There was a significant linear correlation between action potential duration and excitability (absolute refractory period). The similar effects of increased preload and contractility on threshold excitability and refractoriness can be explained by the action these perturbations have on the time course of repolarization. Therefore, excitability of the ventricle is sensitive to and is modulated by alteration of load or inotropic state. The similar effects of either increased preload or contractility on excitability may be mediated by a common cellular mechanism which results in a rise in intracellular free Ca2+ and secondary abbreviation of the action potential.

Immunopathological mechanisms of human T cell lymphotropic virus type 1 (HTLV-I) uveitis. Detection of HTLV-I-infected T cells in the eye and their constitutive cytokine production.

The immunopathology of human T cell lymphotropic virus type 1 (HTLV-I) uveitis was addressed by using T cell clones (TCC) established from the intraocular fluid of patients with HTLV-I uveitis. Proviral DNA of HTLV-I was identified in 55 out of 94 (59%) or 13 out of 36 (36%) TCC from the ocular fluid or the peripheral blood of these patients, respectively. Most of HTLV-I-infected TCC had a CD3+ CD4+ CD8- phenotype. HTLV-I infection on TCC was confirmed by analysis of the viral mRNA, nucleotide sequence, virus-associated proteins, and virus particles. HTLV-I-infected TCC, but not HTLV-I negative TCC, constitutively produced high amounts of IL-6 (1,336 +/- 1,050 pg/ml) and TNF-alpha (289 +/- 237 pg/ml) in the absence of any stimuli. HTLV-I-infected TCC from the ocular lesion also constitutively produced high amounts of IL-1 alpha (12,699 pg/ml), IL-2 (61 pg/ml), IL-3 (428 pg/ml), IL-8 (1,268 pg/ml), IL-10 (28 pg/ml), IFN-gamma (5,095 pg/ml), and GM-CSF (2,886 pg/ml). Hydrocortisone, a drug effective in vivo for the treatment of HTLV-I uveitis, severely depressed cytokine production in vitro in most cases. In summary, the results demonstrated direct evidence of HTLV-I infection of the eye and suggest that cytokines produced by HTLV-I-infected T cells are responsible for the intraocular inflammation in patients with HTLV-I uveitis.

Establishment of a hairy cell leukemia cell line carrying Tac antigen and phagocytic activity with B-cell characteristics.

A hairy cell leukemia cell line designated "Hair-M" was established in a suspension culture derived from the peripheral blood of an 86-year-old Japanese male with a diagnosis of hairy cell leukemia. The Hair-M cells were identified as having prominent hair-like cytoplasmic projections by examination with phase-contrast and scanning electron microscopy. These cells displayed ruffled membranes and stublike microvilli similar to those observed on the surfaces of cells in the peripheral blood of the patient. Immunologic and cytochemical studies on the Hair-M cells confirmed derivation from the clone of the patient's leukemia cells. Although the cultured Hair-M cells had definite B-cell characteristics, such as IgG kappa-chains on the surface and in cytoplasm, they also demonstrated Tac antigen, which is usually expressed on activated T-cells, and myelomonocyte antigens determined by OKM-1 and MCS-1 monoclonal antibodies. Other cell surface markers, including E(-), IgGFc(-), IgMFc(-), C3R(+), Ia-like antigen(+), OKT9(+), OKT10(+), and terminal deoxynucleotidyl transferase(-), were detected; no Epstein-Barr virus-determined nuclear antigen was detected. The karyotype of the Hair-M cells was determined to be 46XY with -11, -14, and two marker chromosomes. The Hair-M cells also had phagocytic activity to rabbit anti-human IgG serum-coated polyacrylamide gel particles.

Modulation of cell surface antigens induced by 12-O-tetradecanoyl-phorbol 13-acetate in two myeloblastic cell lines, a promyelocytic cell line, and a monoblastic cell line: detection with five monoclonal antibodies.

The modulation of cell surface antigens in 2 myeloblastic cell lines (ML-1 and KG-1), a promyelocytic cell line (HL-60), and a monoblastic cell line (THP-1-0) by the presence of 12-O-tetradecanoyl-phorbol 13-acetate [(TPA) CAS: 16561-29-8] was investigated by indirect membrane immunofluorescence with the use of three monoclonal antibodies (MoAb) (OKM-1, 63D3, and MCS-2) reacting with myeloid-monocyte antigens (expressed by cells of both granulocyte and monocyte lineages) and two MoAb (1/12/13 and MCS-1) reacting with myeloid antigens (expressed by cells of the granulocyte lineage). Functionally mature macrophage properties, such as adherence, morphologic character, and phagocytosis, were induced by the presence of TPA in each of the cell lines except for adherence in the HL-60 cells. After 3 days in culture, the expression of the OKM-1-defined antigen was markedly augmented in all 4 cell lines. The expression of the 63D3-defined antigen was also markedly augmented in the ML-1, KG-1, and THP-1-0 cells, but it was not significantly altered in the HL-60 cells. The MCS-2-defined antigen was amplified in expression in the ML-1 and HL-60 cells, but it showed minimum decrease in the KG-1 and THP-1-0 cells. The MCS-1-defined antigen expression was suppressed in ML-1, HL-60, and THP-1-0 but was enhanced in KG-1. The suppressed expression of My-1 antigen (detected by the MoAb 1/12/13) was noted in all 4 cell lines. Thus in the ML-1 cells, expression of the myeloid-monocyte antigens was augmented, whereas myeloid antigen expression was inhibited in the presence of TPA, a result that parallels antigenic expression in terminal macrophage differentiation. The trend was true, except for the 4 cell line-antigen combinations (MCS-2-defined antigen and MCS-1-defined antigen in KG-1, 63D3-defined antigen in HL-60, and MCS-2-defined antigen in THP-1-0). The heterogeneous attitude of some antigens to TPA found in these cell lines may result from the fact that they represent different points in the myeloid-monocyte differentiation scheme.

Comparison between agar and methylcellulose cultures of human leukemic cells.

A comparison was made between the agar and methylcellulose culture systems with respect to their ability to support the clonal growth of leukemic cells obtained from patients with acute myeloblastic leukemia, acute lymphoblastic leukemia, and chronic myelogenous leukemia in blastic crisis. The number of clusters and/or colonies formed and the morphology of the cells within them varied from patient to patient. Nevertheless, no significant difference between the two culture systems within given leukemic specimens was found. No significant differences were noted among three different conditioned media used as sources of colony-stimulating activity. Most of the cells within clusters and colonies were identified to be immature members of granulocyte-macrophage series or to be indistinguishable from the preculture leukemic blast cells by morphological and cell surface marker studies. Cells from myeloid crisis in chronic myelogenous leukemia grew well in the cultures, but cells from lymphoid crisis did not proliferate.

Biochemical and functional characterization of MCS-2 antigen (CD13) on myeloid leukemic cells and polymorphonuclear leukocytes.

The antigen defined by MCS-2 monoclonal antibody (mAb) was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of surface and internally labeled cells. Surface iodination revealed that MCS-2 antigen on the surfaces of acute myelogenous leukemia cells, HL-60 cells, and polymorphonuclear leukocytes (PMN) had the same molecular weight (Mr 150,000) and that their autoradiographic bands were also the same. Internal labeling of HL-60 cells with [35S]methionine followed by immunoprecipitation revealed two bands whose molecular weights were 150,000 and 130,000. HL-60 cells gave stronger bands than did PMN. The intensity of the Mr 130,000 band became weaker, when internally pulse-labeled cells were cultured in the absence of labeled methionine, suggesting that Mr 130,000 glycoprotein was a precursor protein of Mr 150,000 glycoprotein. MCS-2 mAb precipitated two bands from tunicamycin-treated HL-60 cells whose apparent molecular weights were 100,000 and 110,000. When cells were cultured with MCS-2 mAb, expression of the antigen decreased rapidly (within 10 min). The degree of suppression was more prominent in PMN than in acute myelogenous leukemia and in myelomonocytic cell lines. Reexpression of MCS-2 antigen by PMN after removal of the mAb from the culture medium was not observed, but it occurred rapidly in myelomonocytic cell lines, although it was blocked by pretreatment of the cells with cycloheximide. These findings suggested that the less-marked suppression of MCS-2 antigen expression by cell lines was due to its greater synthesis by these cells. These findings suggested that MCS-2 mAb reacted with identical molecules, which were recognized by other mAbs belonging to CD13. Furthermore, modulation of MCS-2 antigen was observed by MCS-2 mAb itself.

Monoclonal antibody MCS-2 as the marker of phorbol diester-induced myeloid differentiation in acute undifferentiated leukemia.

Leukemic cells from 32 cases of acute leukemia were cultured in vitro with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) to study their differentiative potential. Three cases of acute undifferentiated leukemia (AUL) were studied intensively. We found that culturing of leukemic cells with TPA can induce changes in cell surface antigens. In particular, MCS-2, a "pan" granulocyte/monocyte marker, was inducible in vitro in AUL and in acute myelogenous leukemia, while it was not inducible in acute lymphoblastic leukemia. BA-2 (recognizing the Mr 24,000 protein) and TA-1 (recognizing the Mr 170,000 and Mr 95,000 proteins) were also inducible in cases of AUL, acute myelocytic leukemia, and acute monoblastic leukemia, although these antigens are not limited only to leukemias of the myelomonocytic lineage. Our studies also indicate that undifferentiated cells could be induced to nonspecific esterase and sometimes to chloroacetate esterase reactivity while losing terminal deoxynucleotidyl transferase. Morphological studies in these cases revealed cytological maturation following TPA treatment. In most cases, these changes were also partially inducible by culturing cells in medium alone or with the addition of dimethyl sulfoxide but not to the extent that was demonstrated by TPA. Our studies showed that MCS-2 is a very good, specific marker of acute nonlymphocytic leukemia. A potential use for TPA to aid in the subclassification of patients with AUL is also suggested.

Expression of CD44 variant isoforms, CD44v3 and CD44v6, are associated with prognosis in nasopharyngeal carcinoma.

OBJECTIVE: The clinical and prognostic significance of CD44 variant isoform expression in nasopharyngeal carcinoma is not well known. This study aimed to clarify whether CD44 variant isoform expression serves as a prognostic factor in nasopharyngeal carcinoma. METHODS: Forty-two nasopharyngeal carcinoma patients, who underwent concurrent chemoradiotherapy as the initial treatment, were the subjects of investigation. Expression of CD44 variant isoforms, CD44v3, CD44v4, CD44v5, CD44v6 and CD44v7, in nasopharyngeal carcinoma was assessed in relation to concurrent chemoradiotherapy resistance and disease-specific survival of the patients. RESULTS AND CONCLUSION: The patients with CD44v6 high expression showed a clinically incomplete response to concurrent chemoradiotherapy at the primary site. The disease-specific survival rate was lower in patients with high expression of CD44v3 than in those with low expression. These results suggest that analysis of CD44v6 and CD44v3 expression is useful in estimating prognosis and determining effective treatment strategies in nasopharyngeal carcinoma.

Preservation of ventricular function by treatment of ventricular fibrillation with phenylephrine.

Epinephrine promotes resuscitation from ventricular fibrillation because of its peripheral vasoconstrictive effects. However, the beta-adrenergic effects of epinephrine may be detrimental because of the stimulation of myocardial oxygen demand. To test whether functional recovery from fibrillation in hearts treated with a selective alpha-adrenergic agent is greater than in hearts treated with epinephrine, ventricular fibrillation was induced in eight isolated dog hearts while coronary perfusion pressure was maintained at 30 mm Hg. In random order, epinephrine (5 micrograms/min), phenylephrine (50 micrograms/min) or no drug was infused for 5 min. The heart was then defibrillated, the drug infusion stopped and coronary perfusion pressure increased to 100 mm Hg. Coronary blood flow (ml/min per 100 g), arteriovenous oxygen difference (ml O2/dl) and myocardial oxygen consumption (ml O2/min per 100 g) measured after 4 min of ventricular fibrillation were greater with epinephrine (mean +/- SD 30.9 +/- 11.7, 17.5 +/- 1.6 and 5.4 +/- 1.9, respectively) than with phenylephrine (24.4 +/- 6.0, 15.7 +/- 2.6 and 3.8 +/- 1.1, respectively) or no drug (19.8 +/- 5.2, 12.8 +/- 1.8 and 2.6 +/- 0.7, respectively) (p less than 0.05, p less than 0.05 and p less than 0.05, respectively). The slope of the end-systolic pressure-volume relation 10 min after defibrillation and restoration of normal coronary perfusion pressure was depressed (percent of prefibrillation value) most by epinephrine infusion (72 +/- 17%, n = 6), less by no drug infusion (82 +/- 12%, n = 4) and was increased after phenylephrine infusion (143 +/- 17%, n = 6) (p less than 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of methoxamine and phenylephrine on left ventricular contractility in rabbits.

The end-systolic pressure-volume relation is employed to evaluate left ventricular contractility. In clinical studies, pharmacologic vasoconstriction is used to increase left ventricular systolic pressure to assess pressure-volume relations. However, the effect of vasoconstrictors on the ventricular contractile state is not well characterized. The effects of methoxamine and phenylephrine on systemic arterial pressure and left ventricular contractility in rabbits were studied with three protocols. In protocol 1, anesthetized rabbits (n = 10) were injected with incremental doses of methoxamine and phenylephrine intravenously. Methoxamine (4 mg) increased the mean arterial pressure by 50 +/- 12% (mean +/- SE) (n = 5, p = 0.001). Phenylephrine (0.2 mg) increased mean arterial pressure by 82 +/- 14% (n = 5, p = 0.004). In protocol 2, isolated blood-perfused hearts were injected with incremental doses of these drugs in the ascending aorta in amounts approximately equal to the concentrations injected in the intact rabbits. Methoxamine (2 mg) reduced isovolumic peak systolic left ventricular pressure by 43 +/- 9% (n = 7, p = 0.003), whereas phenylephrine (0.1 mg) increased the isovolumic pressure by 24 +/- 9% (n = 7, p less than 0.05). These responses indicated an enhanced contractile state with phenylephrine and a reduced contractile state with methoxamine. Pretreatment with propranolol blunted the effect of phenylephrine on isovolumic pressure (n = 6, p less than 0.02). In protocol 3, cross-circulation experiments allowed study of the effect of these drugs on isovolumic left ventricular pressure in the isolated heart and simultaneously on the systemic arterial pressure in the intact anesthetized rabbit (support rabbit).(ABSTRACT TRUNCATED AT 250 WORDS)

Controls of ventricular contractility assessed by pressure-volume ration, Emax.

The present study on canine left ventricles showed that Emax which we previously proposed as a good index of both ventricular contractility and its pumping capability, decreased from 2.06 to 1.38 kPa/ml (15.5 to 10.4 mmHg/ml) via the sino-aortic baroreceptor reflex. Cerebral ischaemic response increased Emax to 3.83 kPa/ml (28.8 mmHg/ml). Emax decreased to 1.17 kPa/ml (8.8 mmHg/ml) after cardiac denervation.

Mechanically induced action potential changes and arrhythmia in isolated and in situ canine hearts.

Stretch of excised myocardial tissue causes electrophysiological and potentially arrhythmogenic changes in transmembrane action potentials but corresponding data of the intact mammalian heart are lacking. The effects of increases in ventricular volume and pressure on epicardial monophasic action potentials were therefore investigated in isolated, cross circulated and in situ canine hearts. In seven isolated hearts, increases in ventricular volume and pressure resulted in (1) a linearly related decrease in action potential amplitude (r = 0.988; slope = 0.41% amplitude.ml-1; volume intercept = 17.6 ml), mainly due to a decrease in maximum diastolic potential; (2) a decrease in action potential plateau duration (at 20% repolarisation) by 19 (SD 8)%; and (3) appearance of early afterdepolarizations, reaching up to 18% of total action potential amplitude. Afterdepolarizations occurred only when ventricular outflow was obstructed at end diastole but not at end systole. In eight in situ hearts, increase in left intraventricular pressure produced by transient occlusions of the ascending aorta was also accompanied by decrease in maximum diastolic potential and action potential plateau duration, and by appearance of early afterdepolarizations. In both isolated and in situ intact ventricles, the loading induced electrophysiological changes were associated with occurrence of ectopic ventricular beats. These data show that mechanical overload produces significant electrophysiological changes in the intact canine ventricle which may lead to arrhythmia.

HIV-Nef enhances interleukin-2 production and phosphatidylinositol 3-kinase activity in a human T cell line.

OBJECTIVE: The Nef protein has a major influence on disease pathogenesis in HIV-infected individuals. The objective of the present study was to examine the effects of Nef on T lymphocyte activation and associated signalling events. DESIGN: A recombinant vaccinia expression system was used to express Nef in a human T cell line. Stimulation of these cells with anti-CD28 antibody, and either phorbol 12-myristate 13-acetate (PMA) or anti-CD3, activates signal transduction pathways and results in IL-2 production and IL-2 receptor alpha-chain (CD25) expression. Cellular responses were examined in cells expressing either Nef or an irrelevant control protein. METHODS: Activation of signalling was assessed by immunoblot analysis, or by in-vitro phosphatidylinositol 3-kinase (PI3K) assays. IL-2 production was measured by enzyme-linked immunosorbent assay, and CD25 cell surface expression was examined using flow cytometry. RESULTS: Infection of cells with recombinant vaccinia expressing HIV-nef resulted in a marked increase in the production of IL-2 when cells were activated. The enhanced IL-2 response was accompanied by an increase in the level of PI3K activity. IL-2 production remained sensitive to inhibition with the PI3K competitive inhibitor Ly294002, and to the fungal macrolide, rapamycin. In contrast, CD25 expression was not affected, and there were no measurable changes to nuclear factor kappaB (NFkappaB) activation pathways. CONCLUSION: Enhanced IL-2 production in stimulated T cells expressing HIV-Nef is associated with increased activation of PI3K-dependent signalling pathways. The results support a model in which Nef affects HIV disease progression by distorting T cell responses.

Lymphocyte activation in HIV-1 infection. II. Functional defects of CD28- T cells.

OBJECTIVES AND DESIGN: The expression of the accessory molecule CD28 was compared in various populations of T and natural killer (NK) cells from HIV-1-negative and HIV-1-positive individuals and correlated with activation using mitogens in vitro. METHODS: Multiparameter flow cytometric analysis using combinations of CD3 CD28 and other markers was performed together with absolute cell counting in peripheral blood. Blast transformation and proliferative responses were also quantitated using the Cytoronabsolute after stimulation with phytohaemagglutinin (PHA) and anti-CD3. CD28- cells were also purified to confirm the observations. RESULTS: In HIV-1-negative individuals > 90% of CD3+ T cells were CD28+ and responded to stimulation, while CD3- CD16+ CD57+ NK-like cells were CD28- and failed to respond. In HIV-1-positive individuals the expression of CD28 was greatly reduced and the proportion of CD3+CD28- T cells expanded. CD8 lymphocytosis was caused entirely by the accumulation of CD28- T cells and many of these expressed activation markers human lymphocyte antigen-DR, CD38 and CD45RO on their membrane and molecules such as TIA-1 and perforin, associated with cytolytic function, in their cytoplasm. The strong positive correlation (r = 0.66) between the lack of CD28 expression and the poor proliferation from HIV-1-positive individuals was confirmed by demonstrating that only CD28+ cells transformed into lymphoblasts and proliferated. Although the CD28- including CD3+ T cells transiently expressed CD25 (interleukin-2R alpha), they did not undergo blastogenesis or activation measured by bromodeoxyuridine uptake and died after 3-4 days in culture. These observations were confirmed in costimulation experiments with anti-CD2 and anti-CD28. CONCLUSION: In HIV-1 infection activated CD3+CD28- T cells accumulate but are unresponsive to mitogens and anti-CD28. These cells appear to represent terminally differentiated effector cells which fail to respond to further stimuli because of the absence of a CD28 second signal.

Induction and subcellular localization of metallothionein in regenerating rat liver.

A highly specific antiserum against rat liver metallothionein (MT) was raised in a Japanese white rabbit. Using this anti-MT antiserum, we found that MT was localized in the nuclei as well as in the cytoplasm of hepatocytes in newborn rats. Since it is known that these cells are growing actively, we suspected that there was a relationship between the localization of MT in cell nuclei and the cell proliferation. Therefore, the induction and subcellular localization of MT were examined in rat liver remaining after 70% removal. MT was induced in the remnant liver rapidly after the hepatectomy, its concentration being about 80-fold higher than that of the intact liver. Flow cytometric analysis revealed that MT was translocated into the nuclei from the cytoplasm of hepatocytes during liver regeneration after partial hepatectomy. The highest MT level in the nuclei was observed 24 h after hepatectomy. MT-stained positive nuclei were in S to G2M phases of the cell cycle of regenerating hepatocytes, and the nuclei in G1 phase were not stained with anti-MT antiserum. The increase in hepatic MT levels did not directly cause MT translocation into the nuclei. These results suggested that MT was a cell cycle-dependent, nuclear protein.

Epitope mapping of CD1a, CD1b, and CD1c antigens in human skin: differential localization on Langerhans cells, keratinocytes, and basement membrane zone.

CD1 antigens are classified into at least three groups, CD1a, CD1b, and CD1c. In order to delineate the localization of epitopes of CD1 antigens in human skin, we examined the immunoreactivity of fourteen different CD1 antibodies (seven CD1a, five CD1b, and two CD1c antibodies). The epitopes for CD1a, CD1b, and CD1c are differentially localized on epidermal Langerhans cells, dermal dendritic cells, keratinocytes, the luminal portion of eccrine gland ducts, and the basement membrane zone in normal human skin.

The distribution of T-cell subsets among HTLV-I carriers in Japan.

Data on T-cell subsets from 89 human T-cell lymphotropic virus-I (HTLV-I) carriers and 25 seronegative people were analyzed to identify differences in T-cell subset values among three subgroups: HTLV-I carriers with abnormal lymphocytes (Ably; n = 24), carriers without Ably (n = 65), and HTLV-I seronegatives (n = 25). Estimates of mean values were adjusted for age, sex, smoking, and alcohol drinking, as appropriate. The percentage of CD25+ T cells was elevated in carriers with Ably (mean, 16.7 +/- 1.0) compared with the seronegatives (11.4 +/- 1.4; p = 0.0002); individuals with CD25 T-cell percentages above the median for the seronegatives had a corresponding 5.4-fold risk for being a carrier with Ably. Similarly, the percentage of CD4 T cells was elevated in carriers with Ably. Conversely, the percentage of CD8 T cells was lower among both groups of HTLV-I carriers than in the seronegatives. There was a corresponding significant increase (p = 0.0004) of the CD4/CD8 ratio among carriers with Ably (1.57 +/- 0.12) compared with the seronegatives (1.22 +/- 0.12). Among subjects with CD4/CD8 ratios above the median for the seronegatives, there were 6.8- and 4.5-fold risks for being carriers with or without Ably, respectively. The percentage of CD7 was lower among carriers with Ably (75.6 +/- 1.6) than among seronegatives (78.9 +/- 1.5; p = 0.13). The percentage of beta-interleukin-2-receptor-positive T cells did not vary among the three subgroups.(ABSTRACT TRUNCATED AT 250 WORDS)

Neutralizing monoclonal antibodies against recombinant human interleukin-2.

A series of hybridoma cell lines which produce monoclonal antibodies (MAbs) against recombinant human interleukin-2 (rIL-2) have been established by fusion of murine myeloma cell line P3-NS1-1-AG4-1 and spleen cells of BALB/c mice which had been immunized with rIL-2. 48 hybridoma strains were selected by a solid-phase screening method which produced MAbs reacting with IL-2: four MAbs, L-15, L-20, L-34, and L-61, exhibited strong inhibition of the proliferating effect of rIL-2 on IL-2-dependent cell lines, NK7 and CTLL-2. L-61, the most potent MAb among them, also neutralized natural human IL-2, while the other three MAbs were unreactive. All the four MAbs were specific to human IL-2: they did not cross-react with mouse or rat IL-2. These MAbs are expected to be useful tools in the investigation of IL-2 function.