Blocking of HIV-1 infection, but not HIV-1-induced syncytium formation, by a CD4 peptide derivative partly corresponding to an immunoglobulin CDR3.
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Biomedical subjects
Publications and source records attributed to K Ikuta.
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We established the continuous growth of WEHI-3B D+ cells in protein-free chemically defined F-12 medium by stepwise decreases in the concentration of fetal calf serum. This cell line, designated as WEHI-3B-Y1, has now been propagated in protein-free F-12 medium for 3 years. The population-doubling time of the cells in culture is about 24 hr. WEHI-3B-Y1 cells are immature undifferentiated cells which show positive staining for naphthol ASD chloroacetate esterase and alpha-naphthyl butyrate esterase and spontaneously exhibit a low level of differentiation to mature granulocytes and macrophages. Medium conditioned by WEHI-3B-Y1 cells stimulated the proliferation of an interleukin-3 (IL-3)-dependent FDCP-2 cell line. This conditioned medium was shown to have erythroid burst-promoting activity when assayed using normal murine bone marrow. The colony formation of WEHI-3B-Y1 cells in semi-solid agar culture was not stimulated by purified recombinant human granulocyte colony-stimulating factor (rhG-CSF). However, in the presence of human transferrin, rhG-CSF enhanced the number of colonies of WEHI-3B-Y1 cells but did not induce their differentiation. These results suggest that WEHI-3B-Y1 cells cultured in protein-free medium produced murine IL-3. In addition, human G-CSF enhanced the clonal growth but did not induce the differentiation of WEHI-3B-Y1 cells cultured in serum-free medium.
Several cell clones producing teardrop-shaped human immunodeficiency virus type 1 (HIV-1) particles were isolated from MT-4 cells that survived HIV-1 infection after extensive cell lysis. Most of the teardrop-shaped particles contained an electron-dense core structure, and the particles could replicate in MT-4 cells. No significant structural difference in the HIV-1 proteins was observed between these cell clones and the MOLT-4 cells producing intact HIV-1 particles, although their envelope structure is morphologically abnormal.
Immunofluorescence assay (IFA) has been applied for detection of antibody to human immunodeficiency virus type 1 (HIV-1). To compare the IFA with an enzyme-linked immunosorbent assay (ELISA) and particle agglutination (PA), we examined the antibody response to HIV-1 in 475 sera from AIDS, PGL and ARC patients as well as several risk groups and healthy persons by three methods. The positive results by any methods were confirmed by western blot (WB). The results by all methods were well correlated on the sera from 45 asymptomatic male homosexuals and 70 female prostitutes. There were some false positive results by ELISA in the sera from prisoners and healthy persons. Four sera from drug abusers were positive only by PA and IFA and were negative by ELISA. All were WB-inconclusive. Particle agglutination and IFA results were compared with western blot analysis on 208 ELISA-positive sera. All IFA-strongly positive sera (84%) were positive by western blot. The sera with weakly positive, negative and inconclusive results by IFA (16%) were possibly any of positive, inconclusive or negative by western blot. By PA, 200 of 208 (97%) sera were PA-positive and 1% of these sera were WB-inconclusive while the PA-negative sera were either negative or inconclusive by western blot. These results suggested that PA is a simple and sensitive method for screening of HIV-1 antibody while IFA could be a primary confirmatory test and western blot would then be used for confirming any IFA-negative or inconclusive results.
The effect of interferon-alpha (IFN-alpha) on virus replication in cells acutely infected with human immunodeficiency virus type 1 (HIV-1) and virus production from cells persistently infected with HIV-1 was studied. In both cell systems, significant suppression was observed. However, this suppression was not due to protein synthesis of the major viral proteins. Electron microscopy revealed the accumulation of intact virus particles on the cell surface of the cells treated with IFN-alpha. Thus, IFN-alpha might suppress the release stage of the particle from infected cells.
We studied the effect of mitoxantrone (MIT) on the proliferation and differentiation of murine myelomonocytic leukemia cell line WEHI-3B (D+), human myelocytic leukemia cell line HL-60 and cells from patients with newly diagnosed acute nonlymphocytic leukemia (ANLL). In a liquid culture, growth inhibition and differentiation of WEHI-3B (D+) cells to mature myeloid cells and a reinforcement tendency of the induction of nitroblue tetrazolium reducing capacity as well as of ASD chroloacetate esterase staining was observed by the treatment with MIT. Fresh ANLL cells classified as M4 were induced by MIT to undergo terminal differentiation to macrophage-like cells. Since at concentrations of WEHI-3B (D+) cells of less than 1 x 10(5)/ml induction of differentiation was observed due to MIT, it is suggested that its mechanism of action differs from that of the induction of differentiation by granulocyte colony-stimulating factor and is due to the direct action of MIT.
Human erythroid burst-promoting activity (BPA) of recombinant growth factors and crude materials, of media conditioned by omentum tissue (OMCM), and of media conditioned by the bladder carcinoma cell line (HTB9CM) was measured by three different culture methods. Using the two-stage culture method, significant activity was shown in OMCM (137%-329% of the control), HTB9CM (102%-333%), recombinant human (rh) granulocyte-macrophage colony-stimulating factor (rhGM-CSF) (179%-220%), rh interleukin 3 (rhIL-3) (232%-676%), and rh insulin-like growth factor 1 (rh IGF-1) (106%-175%), whereas there was no significant increase in the number of erythroid bursts by the same additives when the one-stage culture or the delayed erythropoietin method was employed. Linear dose-response curves were observed in the tested range of rhIL-3 and rhGM-CSF. We also observed that 1) a larger amount of rhGM-CSF was required for the optimal stimulation of erythroid burst-forming units (BFU-E) than for the optimal stimulation of granulocyte-macrophage colony-forming units (CFU-GM), and 2) even the maximum dose of rhGM-CSF increased erythroid bursts to a lesser extent than was possible by the addition of rhIL-3. The former results implies that BPA is not the major activity of GM-CSF, and the latter result, although it is not conclusive, suggests that the GM-CSF-responsive BFU-E represent only a subset population of BFU-E responsive to IL-3. The two-stage culture is a useful assay method for screening BPA in biological materials with respect to accuracy, dose responsiveness, and reproducibility.
Only one peptide of CD4 (amino acid residues 70-132) among 16 synthetic peptide fragments selectively inhibited HIV-1 replication and HIV-1-induced syncytium formation. Several smaller peptides within this region did not show any activity, except for the peptide (86-132) which showed somewhat lower activity.
A series of investigations was conducted to trace serum superoxide dismutase (SOD) activities by ELISA and localizations of hepatic tissue SOD by the indirect method using peroxidase conjugated antibody, and the diagnostic and physiological significance of SOD in 19 alcoholics was studied. The values increased significantly both in serum Cu, Zn-SOD to 136 +/- 18 ng/ml (normally 33 +/- 9 ng/ml) and in serum Mn-SOD to 859 +/- 686 ng/ml(normally 84 +/- 30 ng/ml) respectively when polyclonal antibody was used (P less than 0.001). The increase in serum Mn-SOD was higher than that in serum Cu, Zn-SOD, fluctuations of these values showed similar tendencies. Meanwhile, serum Cu, Zn-SOD (94 +/- 50 ng/ml) identified by monoclonal antibody, also, showed higher values than that of normal subjects (37 +/- 7 ng/ml) (P less than 0.001). On the other hand, localization of hepatic tissue Cu, Zn-SOD in alcoholics varied, being 63.2% in the cytoplasmic diffuse type, 42.0% in the nuclear diffuse type, 42.1% in the vacuolated membrane type, and 15.8% in the small granular type respectively. Participation of Cu, Zn-SOD in ethanol oxidation, protective roles played by cell membrane, lysosome membrane and nucleic acid of Cu, Zn-SOD to harmful free radicals was presumed. In addition, localization of hepatic tissue Mn-SOD was mostly of the cytoplasmic diffuse type (52.7%) and was extremely variable. From such results, relative or absolute reductions of hepatic tissue SOD in alcoholics was suggested to act on the development of tissue injuries acceleratingly.
The identification and clinical significance of light microscopic giant mitochondria (GM) were investigated in liver biopsy specimens of 60 alcoholics. By light microscopic examinations using the same section and neighboring sections, we suggest that light microscopic GM correspond to the crystalloid bodies (CB) detected on ultrastructural observation. The reasons are as follows: (1) difference in stainability between eosinophilic light microscopic GM and acidbasophilic mitochondria; (2) similarity in morphological features and density of the round- and cigar-shaped types at the light microscopic level to those of CB at the electron microscopic level; (3) similarity of the area occupied in the hepatic cytoplasm at both light and electron microscopic levels; (4) the crystalline structure of CB in compatible with the subtype of Mallory body (MB); (5) a description of CB has been made at the electron microscopic level, although not yet at the light microscopic level. Moreover, we clinically observed that light microscopic GM seldom appeared either in early fatty liver of cases aged 35 or less or the late macronodular liver cirrhosis stage of alcoholic liver injuries while they were frequently recognized during the acute aggravation phase of the chronic stage (GPT: p less than 0.05). Furthermore, if one was to assume that MB is a change accompanying necrosis of the liver cells, the light microscopic GM might be a change accompanying degeneration of the cytoplasmic organelles.
MT-4 cells persistently infected with human immunodeficiency virus type 1 (HIV-1) (MT-4/HIV-1) were recently isolated (K. Ikuta, C. Morita, M. Nakai, N. Yamamoto, and S. Kato, Japan. J. Cancer Res. (Gann), 79, 418-423, 1988). Mouse hybridoma cell clones producing monoclonal antibodies (MoAbs) to HIV-1 gag p24 and p18, and pol reverse transcriptase (RT) were isolated by using this MT-4/HIV-1 cell line for the screening of MoAb production by the immunofluorescence (IF) test. By indirect IF tests of acetone-fixed cells with these MoAbs, the IF intensities in MT-4/HIV-1 cells were found to be higher than those in the other HIV-1 infected cells, such as MOLT-4/HIV-1, HL-60/HIV-1, and U937/HIV-1 cells. Cell surface expression of the HIV-1 gag p24 and p18 antigens examined by IF and radioimmune techniques with these MoAbs revealed the p24 and p18 antigens to be expressed strongly on the cell surface of MT-4/HIV-1 cells and faintly on the cell surface of MOLT-4/HIV-1 cells, respectively. However, monoclonal antibody isolated in the present study failed to detect pol RT antigen on the surface of MT-4/HIV-1 cells. These results indicate that the gag p24 and p18 antigens are expressed, at least in part, on the surface of HIV-1-infected cells.
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A total of 41 antibody-secreting hybridoma cells against the HPRS24 strain of Marek's disease virus (MDV) type 2 (MDV2) have been isolated. Of these monoclonal antibodies (MAbs), 24 were found by immunofluorescence tests to react specifically with MDV2-infected cells, but not MDV type 1 (MDV1)- or herpesvirus of turkeys (HVT)-infected cells, while eight reacted with MDV1- or MDV2-infected cells and nine with MDV1-, MDV2- or HVT-infected cells. By using these MAbs, seven classes of MDV type-specific or cross-reactive polypeptides were characterized by immunoprecipitation followed by SDS-PAGE. Among them, a 28K/32K glycoprotein differed from the previously identified gA and gB. The 28K/32K glycoprotein was found on the surface of MDV2-infected cells and in the cytoplasm by an immunofluorescence test with MAbs. In addition, a cross-reactive polypeptide of 25K/29K was also detected in MDV1-infected cells with MAbs reactive with the 28K/32K glycoprotein of MDV2.
Serial passages in culture of herpesvirus of turkeys resulted in structural genomic changes at the regions common to two virus strains with loss of their protective ability against Marek's disease.
The fluorescence quenching reaction between fluorescein mercury or halogeno-fluorescein mercury compounds (fl. Hg, 2,7- or 2,4-dichloro-fl.Hg, 3',4',5',6'-tetrachloro-fl.Hg, mercurochrome) and beta-lactam antibiotics (ampicillin (AB-PC) and cephalexin (CEX] was investigated, and mercurochrome was selected for the detection of beta-lactam antibiotics; the detection limit was about 0.8 micrograms/ml. A fluorimetric assay of beta-lactam antibiotics was established by measuring the fluorescence of mercurochrome and mercurochrome-beta-lactam antibiotics solutions in weakly basic media to determine the degree of fluorescence quenching. The maximum emission wavelength of mercurochrome solution was at 544 nm with excitation at 470 nm. The calibration graphs were linear over the ranges of about 0-6 micrograms/ml beta-lactam antibiotics penicillins (AB-PC, penicillin G, sulbenicillin, amoxicillin, cyclacillin, oxacillin, hetacillin and piperacillin) and cepham antibiotics (CEX, cefazolin, cephaloglycin, cephaloridine and cefpyramide), and the relative standard deviation was 2.7% for 1.4 micrograms/ml of AB-PC (n = 5). This fluorescence quenching reaction between mercurochrome and beta-lactam antibiotics was applied in a survey of decomposition and remaining potency of beta-lactam antibiotics.
A highly sensitive spectrophotometric determination of human serum albumin (HSA) with 3',4',5',6'-tetrachlorogallein (T.Cl.Gall)-Mo(VI) complex in a Triton X-100 + polyvinyl alcohol micellar medium is proposed. This method can be used to determine up to ca. 150 micrograms/10 ml of HSA from the optical absorbance at 640 nm, and is superior in sensitivity to the other extremely sensitive spectrophotometric methods. The great sensitivity of this method results from the use of third-derivative spectrophotometry. The binding parameters of T.Cl.Gall-Mo(VI) complex to HSA are n = 77.3 and K = 1.05 x 10(4) M-1 as determined from dual double-reciprocal plots. It is suggested that the colored complex in this system may be the association complex between [HSA]m+ and [MoVI(T.Cl.Gall)2]n- involving hydrophobic interaction between HSA and T.Cl.Gall. The proposed method should also be useful for the detection and determination of some peptides (e.g. low molecular weight peptides containing basic amino acids), as well as proteins.
We tested purified recombinant hemopoietic factors for their effects on the proliferation and differentiation of murine myelomonocytic leukemia cells (WEHI-3B-Y1) in serum-free agar culture. We found that purified recombinant human G colony-stimulating factor (CSF) markedly increased the colony number of WEHI-3B-Y1 cells and differentiation-inducing activity. However, at low colony densities [( 100/dish), G-CSF did not induce the differentiation of WEHI-3B-Y1 cells. We conclude that G-CSF does not induce the differentiation of WEHI-3B-Y1 cells directly, but induce the differentiation as a result of the secondary autoinduction of differentiation. Interleukin 3 (IL-3) slightly enhanced but erythropoietin (Epo) did not alter the colony number of WEHI-3B-Y1 cells. GM-CSF or M-CSF decreased the colony number of WEHI-3B-Y1 cells. Such purified recombinant human IL-3, Epo, GM-CSF and M-CSF did not induce morphologically the distinct differentiation of WEHI-3B-Y1 cells.
Pharmacokinetic and clinical studies on a new cephalosporin antibiotic, cefodizime (THR-221, CDZM), were performed and the results obtained are summarized as follows: 1. At about 84 minutes after a bolus injection of 1 g dose of CDZM, the drug was transferred well into tissues of internal genital organs and remained there at therapeutic levels for 285 minutes. The drug was also transferred quickly and sufficiently into exudate from pelvic dead space and its levels were still kept at high levels at 6 hours after administration. 2. CDZM was given to 8 women affected with gynecologic infections. The outcome of CDZM therapies showed that the drug was effective in all 8 of patients (100%) clinically and bacteriologically. 3. Notable adverse effects or abnormal laboratory test results were not observed except for 2 patients with transient and slight elevation of transaminase levels. Based on these results, it may be concluded that CDZM is a highly effective and a very safe antibiotic for the treatment on infectious diseases in gynecologic field.