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Biomedical subjects

Y Moroi

Publications and source records attributed to Y Moroi.

At least 19 recordsLinked to original sources

Ultraviolet-B irradiation alters cytokine production by immune lymphocytes in herpes simplex virus-infected mice.

Previous studies from our laboratories have shown that UV-B irradiation at the site of an intradermal infection of herpes simplex virus (HSV) resulted in a higher incidence of zosteriform lesions and suppressed cellular immune responses to HSV in mice. In order to determine whether the production of T-cell-derived cytokine (IFN-gamma, IL-2 and IL-4) by immune cells from irradiated mice is also suppressed, we examined the production of cytokines by lymph node cells and spleen cells taken from UV-B irradiated, HSV type 1 (HSV-1)-infected mice. UV-B irradiation (120 mJ/cm2) prior to HSV-1 infection was found to markedly suppress IFN-gamma production compared to that of the non-irradiated control. IL-4 production was enhanced compared to IL-2 in the UV-B irradiated mice. These results suggest that alteration(s) in the cytokine production profile may therefore be involved in the development of severe skin lesions caused by HSV infection in UV-B irradiated mice.

Animals

Chromosome abnormalities in peripheral lymphocytes from patients with progressive systemic sclerosis.

Chromosomal abnormalities in cultured peripheral lymphocytes from 14 progressive systemic sclerosis (PSS) patients and 15 normal subjects were examined. No increase was observed in the frequency of chromosome aberrations in PSS patients who had not received any medical treatment. Those who had received medication showed an increased frequency of dicentrics (0.3%) although the frequency was not significantly higher than that for normal subjects. It is not clear, however, whether the increase was due to the hypersensitivity of PSS patients to agents used for therapeutic purposes.

Adult

Augmentation of in vitro cytolytic activity of LAK cells with heated ATL-derived cell lines.

Three adult T-cell leukemia/lymphoma-derived cell lines, MT-2, MJ, and HUT102, were investigated to determine how they responded to hyperthermia, lymphokine-activated killer (LAK) cells, or a combination of both in vitro. All three cell lines showed a similar sensitivity to LAK cells, but revealed varying degrees of sensitivity to hyperthermia (MT-2 < MJ < HUT102) by 51Cr release assay. Hyperthermia did not cause immediate cell death as determined by the trypan blue exclusion test, but did cause substantial decreases in the numbers of heated cells within 2 days. The density of the cells began to increase thereafter, which was consistent with the results of the experiments labeling the cells with 3H-TdR after hyperthermia. When the cells were heated at 39-43 degrees C for 1-3 hr and then interacted with various LAK cell/ATL cell (E/T) ratios at 37 degrees C for 4 hr, total cytolysis of the cells increased in a synergistic and/or additive manner over that of the cells without hyperthermia. Prolonged incubation of the cells at high temperature did not necessarily cause a large increase in the interaction of LAK cells after hyperthermia. This augmentation of cytolysis by LAK cells after hyperthermia was not seen in normal peripheral lymphocytes. These results suggest that the combination therapy of hyperthermia and LAK cells may be more specific, useful, and effective for treating malignant lymphoma.

Cytotoxicity, Immunologic

Induction of interleukin 2-responsiveness in thymocytes of the transgenic mice carrying lck-transgene.

The role of lck gene in T cell proliferation and differentiation was investigated with transgenic mice carrying human lck cDNA whose expression was regulated by the promoter of mouse H-2Kb and the enhancer element of mouse IgH. RNase protection assay revealed that the lck transgene was expressed in the thymus and spleen, whereas immunoblot analysis demonstrated that amounts of p56lck in freshly isolated lymphoid organs were almost equal between transgenic mice and negative littermates. Cell-surface marker analyses of the thymocytes and peripheral lymphocytes revealed no remarkable difference between both groups. Notable finding is that the thymocytes from transgenic mice showed a significant proliferative response to the stimulation with IL-2, but not the thymocytes from negative littermates. Further analysis revealed that CD4+8- single positive thymocytes proliferated in response to IL-2. While surface expression levels of IL-2R alpha and IL-2R beta of these CD4+8- thymocytes from transgenic and control mice were almost equal before stimulation with IL-2, the expression of IL-2R beta was induced only in transgenic thymocytes after stimulation with IL-2. Immunoblot analysis demonstrated that the expression of p56lck of transgenic thymocytes was not down-regulated at 4 hr after stimulation with IL-2, whereas p56lck of control ones were not detectable any more at 4 hr after stimulation with IL-2. Moreover, in vitro kinase assay substantiated such unchanged expression of p56lck in the thymocytes from transgenic mice: the kinase activities of p56lck did not decrease in thymocytes from transgenic mice after stimulation with IL-2, while kinase activities of control ones were significantly down-regulated by stimulation of IL-2. These results suggested that a significant proliferative response found in the thymocytes from lck-transgenic mice after the stimulation with IL-2 was caused by a constitutive expression of p56lck in these thymocytes even after the stimulation. Our findings, therefore, support a possibility that p56lck may play a role in the IL-2R-mediated signaling system in CD4+8- thymocytes.

Animals

The effect of p56lck, a lymphocyte specific protein tyrosine kinase, on the syncytium formation induced by human immunodeficiency virus envelope glycoprotein.

A human CD4+ T cell line, Jurkat, was transfected with a constructed plasmid, which has the envelope gene of the human immunodeficiency virus (HIV) under the transcriptional control of the human metallothionein IIA promoter, and these transfected cells were then cloned. JME2, one of the cloned cell lines, expressing the envelope glycoprotein after induction with metal ions, showed the ability to form syncytia involving other CD4+ cells not expressing the HIV envelope protein. When several CD4+ cell lines were examined for their susceptibility to syncytium formation by JME2 cells, the p56lck-expressing cell lines were found to be more susceptible to syncytium formation than the p56lck-non-expressing cell lines. To substantiate the role of p56lck in the syncytium formation, a CD4+, p56lck-non-expressing monocytoid cell line, U937 clone 2, was transfected with an lck-expressing construct. Using such transfectant cell clones, it was demonstrated that p56lck-positive cells are markedly more susceptible to the syncytium formation than p56lck-negative cells, implying a regulatory role for p56lck in syncytium formation mediated by the HIV envelope and CD4 molecule. Moreover, it was suggested, in the experiments using CD45 cross-linking or a protein tyrosine kinase inhibitor, genistein, that p56lck affects syncytium formation through its protein tyrosine kinase activity. A putative mechanism by which p56lck affects the syncytium formation is also discussed.

CD4 Antigens

Responses of B16 melanoma cell lines, F1 and F10, to hyperthermia, lymphokine-activated killer cells and a combination of both in vitro.

The cytolytic and/or cytostatic effects of hyperthermia, lymphokine-activated killer cells (LAK cells) and the combination of both were assayed using F1 and F10 B16 melanoma cell lines. F10 cells with a high metastatic potential showed a greater sensitivity to hyperthermia than F1 cells which have low metastatic potential. The F10 cells were lysed to a lesser extent by LAK cells than the F1-B16 cells. When the cell lines were subjected to hyperthermia at 43 degrees C for 3 h and then interacted with LAK cells, the maximum cytolysis reached almost 100%. When the interaction with LAK cells was followed by hyperthermia at 43 degrees C, the total release of 51Cr from the cell lines was 75-85%. The extent of 51Cr release from the B16 melanoma cell lines was inversely correlated with the survival rate as calculated by the plating efficiency of the incubated cells. The survival rate of mice intravenously injected with B16-F10 cells and subjected to hyperthermia at 41 degrees C for 3 h in vitro increased compared to that of controls. This was further increased by the simultaneous administration of LAK cells.

Animals

Aqueous solubility and acidity constants of cholic, deoxycholic, chenodeoxycholic, and ursodeoxycholic acids.

Cholic acid, deoxycholic acid, chenodeoxycholic acid, and ursodeoxycholic acid were purified by a foam fractionation method. Using thermogravimetric analysis, the attached water molecule was found to be completely removed from solids of the latter three at 100 degrees C, while cholic acid still had one water molecule of crystallization per two cholic acid molecules at that temperature. The acidity constants of the acids were accurately determined from aqueous solubility measurements at different pH values and at 15, 25, 35, and 45 degrees C. The enthalpy change of dissolution from temperature dependence of solubility as undissociated acid monomer was much less than those of common ionic surfactants. This results from a smaller entropy increase on dissolution due to the hardly flexible hydrophobic structure of these bile acids.

Calibration

Transient myopia with severe chemosis associated with exacerbation of disease activity in systemic lupus erythematosus.

A 46-year-old woman with systemic lupus erythematosus (SLE) developed bilateral transient myopia and periorbital edema with severe chemosis. Her myopia was ascribed to a refractive abnormality that was caused by curvature change and anterior displacement of the lenses and the ciliary bodies due to anterior ocular edema. The conditions were not associated with systemic edema or abnormality in the fundi and responded well to the systemic administration of corticosteroid. The course of the ocular symptoms paralleled changes of serum CH50 and anti-dsDNA antibody levels. Thus it was concluded that her ocular symptoms were closely related to activity of her SLE and may be considered a feature of SLE.

Antibodies, Antinuclear

Accumulation of p60lck in HTLV-I-transformed T cell lines detected by an anti-lck monoclonal antibody, MOL 171.

The lck gene encodes a protein tyrosine kinase of nonreceptor type, p56lck, whose expression occurs almost exclusively in T lymphocytes. MOL 171, an anti-p56lck monoclonal antibody, was produced by using a 25-amino-acid synthetic polypeptide as the antigen, its structure corresponding to the N-terminal region deduced from the lck cDNA sequence. Immunoblot analysis with MOL 171 showed the accumulation of 60 kD form of Lck protein, p60lck, and the decrease of p56lck in human T cell leukemia virus type I (HTLV-I)-transformed T cell lines. Another anti-Lck monoclonal antibody, MOL 294, raised by using a synthetic peptide corresponding to the C-terminal region deduced from the lck cDNA sequence, also detected the accumulation of p60lck in those HTLV-I-transformed T cell lines. The appearance of p60lck with the decrease of p56lck in normal T lymphocytes after stimulation suggested the origin of p60lck in HTLV-I-transformed T cells.

Antibodies, Monoclonal

Two differential pathways from double-negative to double-positive thymocytes.

Murine thymocytes are divided into four major populations on the basis of expression of CD4 and CD8 antigens. The bulk of evidence favours the view that CD4-CD8- cells can develop into CD4-CD8+ and CD4+CD8- cells via the CD4+CD8+ stage in the thymus. However, CD4-CD8+ and CD4+CD8- thymocyte subsets contain not only CD3+ mature cells but also CD3- immature cells, which seem to be intermediate cells between CD4-CD8- and CD4+CD8+ cells. Here we demonstrate mouse strain differences in the proportion of immature single-positive thymocyte subsets in thymus at the steady or developing state. In C3H mice, immature CD4+CD8- is dominant in proportion over CD4-CD8+ in foetal thymus and in donor-derived thymocytes at an early stage of bone marrow transplantation. On the other hand, immature CD4-CD8+ is dominant over CD4+CD8- during T-cell development in the case of B10.BR mice. An intermediate pattern was shown in the case of F1 mice. Both of these immature single-positive subsets gave rise to double-positive cells after 24 hr culture. These results suggest that there exist two distinct differential pathways; one is from CD4-CD8- cells to CD4+CD8+ cells via CD4-CD8+ cells, and another is via CD4+CD8- cells, and that an application of the 'CD8 pathway' or 'CD4 pathway' seems to be genetically destined by BM-derived cells but not by thymic stromal cells.

Animals

[Clinical assessment of pulmonary hypertension in collagen diseases].

The occurrence of pulmonary hypertension (PH) has been reported in association with collagen diseases. Because of its grave consequences it is of greatest importance to make an early diagnosis of PH and initiate adequate treatment. For this purpose we have carried out right heart catheterization study to determine pulmonary arterial pressure (PAP), pulmonary vascular resistance (PVR), and cardiac index in thirty-four consecutive patients with collagen diseases including cases of mixed connective tissue disease (MCTD). We also compared the hemodynamic data with clinical pictures and the results of non-invasive cardiopulmonary tests which were done before catheterization study. Pulmonary hypertension as defined by the mean PAP of greater than 20 mmHg was observed in 11 of the 34 cases. PH was observed in five of 6 cases with MCTD and six of 17 cases with PSS including 2 cases with overlapping SLE and PM. The frequencies of positive anti-nRNP antibody, serositis, Raynaud's phenomenon and muscle involvement were significantly higher in cases with PH than in cases without PH. Catheterization study was most useful for diagnosis of cases with mean PAP of less than 25 mmHg, whereas echocardiographic study identified all cases with mean PAP of greater than 25 mmHg. No significant correlation was observed between mean PAP and vital capacity, total lung capacity or diffusion capacity measured as the percent of predicted normal values, which suggests that vascular abnormalities play a more significant role in the pathogenesis of PH than pulmonary fibrosis in collagen diseases.

Adult

Isolation and characterization of a complementary DNA expressing human U1 small nuclear ribonucleoprotein C polypeptide.

A cloned complementary DNA, termed pS2, was isolated from a human fibroblast cDNA library in the bacteriophage expression vector lambda gt11 after screening with a patient's serum containing a high titer of anti-ribonucleoprotein (RNP) antibodies. A reasonable amount of cro-beta-galactosidase fusion protein (pS2EX) was obtained through subcloning of the pS2 insert into a plasmid expression vector pEX-2. Antibody against pS2EX (anti-pS2EX) was purified from this patient's serum by Sepharose 4B conjugated with pS2EX. Immunofluorescent staining of HeLa cells with anti-pS2EX antibody exhibited a typical speckled pattern in the interphase nuclei. In the immunoblot analysis, the anti-pS2EX antibody recognized the 22 kDa protein. Using immunoprecipitation of cell lysate and subsequent RNA analysis, anti-pS2EX antibody was shown to precipitate U1 RNP only. The reactivities of various anti-RNP sera to pS2EX correlated well with the positive reaction to C polypeptide in the immunoblot. These findings indicate that pS2 is a cDNA for C polypeptide of U1 snRNP. In the Northern blot using human RNA and radiolabeled pS2, a single band about 800 base was observed. The nucleotide sequence of pS2 showed no significant homologies to known proteins.

Amino Acid Sequence

2-dimensional flow cytometric analysis of peripheral blood T lymphocytes from patients with systemic lupus erythematosus: preferential expression of HLA-DR antigen on the surface of Leu 2a+ cells.

2-dimensional flow cytometric analysis of the peripheral blood T lymphocytes from 20 patients with systemic lupus erythematosus showed a significant increase in the percentage of Leu 2a+ 15- cytotoxic subset irrespective of disease activity compared to 35 age and sex matched healthy individuals. The percentage of Leu 2a+ HLA-DR + cells also increased significantly in both patients with active and inactive disease compared to the controls. In contrast, both the relative and absolute number of Leu 3a+ 8+ cell (suppressor/inducer T cell) showed a significant reduction in active and inactive disease if compared to controls. All of these changes were more drastic in the patients with active disease.

Adult

Interstitial lung disease in dermatomyositis: clinicopathological study.

We studied 14 cases of polymyositis-dermatomyositis (PM-DM) and found roentgenographic evidence of interstitial lung disease in 9 patients with DM (64.3%). Serum anti-Jo-1 antibody was demonstrated in only one case. Histologically, interstitial pneumonitis and fibrosis were noted in all cases. Deposition of immunoglobulins along the alveolar interstitium was not found in any case. Response to corticosteroid therapy was poor, and 6 cases (67%) succumbed to respiratory failure and died. We conclude that interstitial lung disease in DM occurs more frequently than previously reported and may be an important prognostic factor.

Adult

Electrophysiological and pharmacological studies on the mechanisms of ventricular tachycardia.

Employing electrophysiological and pharmacological methods, the mechanisms of recurrent ventricular tachycardia were studied in 31 patients, 18 with old myocardial infarction and 13 with idiopathic ventricular tachycardia. In the cases of ventricular tachycardia with old myocardial infraction, the initiation and termination of the tachycardia could be achieved by programmed electrical stimulation in 13 out of 18 patients. Endocardial mapping showed that the earliest excitation site during tachycardia was at the border zone of infarction, where the diastolic fragmented activity was detected. Programmed electrical stimulation sometimes provoked more than two kinds of QRS morphology of tachycardia in the same patient. Class IA antiarrhythmic agents were effective in terminating tachycardia. These data suggest that there are multiple reentrant pathways consisting of partially depressed fast fibers at the border zone of infarction. In the cases with idiopathic ventricular tachycardia, the induction and termination of tachycardia was effected by electrical stimulation in 8 out of 13 patients. For the termination of tachycardia, long overdrive pacing was sometimes necessary. The diastolic fragmented activity could not be detected by endocardial mapping. A class IV drug such as verapamil was more effective for the termination of tachycardia than class I drugs, and there were repetitive short runs of ventricular extrasystole observed until the final termination. These data support the reentrant pathways containing slow with enhanced automaticity as the circuit of idiopathic ventricular tachycardia.

Adolescent