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Y Kawade

Publications and source records attributed to Y Kawade.

At least 37 records · Page 2Linked to original sources
PubMed1987

Synergistic antiproliferative effect of interferon-beta in combination with bleomycin or neocarzinostatin on HeLa cells in culture: additive effect when combined with adriamycin or mitomycin C.

Human fibroblast interferon (IFN)-beta was administered in combination with the free radical-generating antiproliferative agents bleomycin (BLM), neocarzinostatin (NCS), adriamycin (ADM), and mitomycin C (MMC) to HeLa cells in culture. IFN showed a true synergistic antiproliferative activity in the presence of BLM or NCS. These effects were observed regardless of the ratio of IFN to BLM or NCS concentrations. However, the effect of IFN in the presence of ADM or MMC was additive. The possibility that IFN-beta potentiates the antiproliferative effects of these free radical-generating agents in a different manner is also discussed.

Antineoplastic Agents↗
PubMed1987

Studies on the expression of spontaneous and induced interferons in mouse peritoneal macrophages by means of monoclonal antibodies to mouse interferons.

Monoclonal antibodies (MAbs) to mouse interferons (MuIFN) have been used to characterize the interferon-like activities spontaneously expressed in mouse peritoneal macrophages freshly explanted from normal pathogen-free mice. Injection of mice with MAbs to MuIFN-alpha or -beta resulted in a significant increase of vesicular stomatitis virus (VSV) multiplication in peritoneal macrophages. Addition of these MAbs to freshly explanted mouse macrophages accelerated the decay of the antiviral state to VSV during the 'ageing' in vitro of these macrophage cultures. Furthermore, these MAbs to MuIFN-alpha or -beta markedly inhibited the transfer of the antiviral state from freshly explanted peritoneal cells or macrophages to syngeneic macrophages 'aged' in vitro permissive for virus replication. These effects were not observed using a non-neutralizing antibody to MuIFN-alpha, nor with a MAb to MuIFN-gamma. In all experiments sheep polyclonal antibodies to MuIFN-alpha/beta were more effective than the corresponding amount of MAbs to MuIFN-alpha or -beta. A mixture of both these MAbs was more effective than either alone. Interferons produced after stimulation of peritoneal macrophages with Newcastle disease virus (NDV) and of total peritoneal cells with lipopolysaccharides (LPS) have also been characterized by means of MAbs to IFNs. The results of neutralization studies with these antibodies indicated that MuIFN-beta was the major component of peritoneal cell IFN (induced by both NDV and LPS) and MuIFN-alpha was a minor component (13 to 17%). These data indicate that both MuIFN-alpha and -beta, but not MuIFN-gamma, are spontaneously present in/on mouse peritoneal macrophages and are produced after stimulation with NDV or LPS.

Animals↗
PubMed1987

Interferon-alpha enhances the production of leukotriene B4 in murine peritoneal macrophages stimulated by opsonized zymosan.

Murine peritoneal macrophages pretreated with interferon (IFN)-alpha and then stimulated by opsonized zymosan produced two to three times more LTB4 than untreated macrophages. However, PGE2 production was not changed by IFN-alpha. Meanwhile, IFN-gamma did not affect the production of LTB4 and PGE2. From the results it is considered that IFN-alpha can modulate inflammation or host defence through the production of LTB4.

Animals↗
PubMed1986

Purification and characterization of recombinant murine immune interferon.

The recombinant murine immune interferon (rMu-IFN-gamma) was purified to homogeneity from Escherichia coli harboring the expression vector of murine IFN-gamma. The purified rMu-IFN-gamma showed an Mr of 15 000 in SDS-polyacrylamide gel electrophoresis. Results of amino acid analysis, amino- and carboxyl-terminal analyses and peptide mapping of rMu-IFN-gamma suggest that it has the complete protein sequence predicted on the basis of cDNA except for lack of four amino acid residues from the mature carboxyl-terminus.

Amino Acid Sequence↗
PubMed1986

Contrasting effect of alpha/beta- and gamma-interferons on expression of macrophage Ia antigens.

IFN-gamma is known to induce the expression of Ia antigens on macrophages. We found that murine IFN-alpha and -beta blocked the effects of IFN-gamma in a dose-dependent manner. The antagonistic effect of IFN-alpha and -beta was observed even when macrophages were prestimulated with IFN-gamma. These inhibitory effects of IFN-alpha or -beta were blocked by their respective antibodies. The block exerted by IFN-alpha/beta was similar whether Ia levels were monitored by immunofluorescence with anti-Ia mAb, or by stimulation of freshly sensitized, alloreactive T lymphoblasts. Adherent macrophage-rich populations from newborn mice were incapable of expressing Ia antigens following stimulation with IFN-gamma, and would inhibit the response of adult macrophages to this lymphokine. Addition of anti-IFN-beta mAb, but not anti-IFN-alpha allowed newborns' macrophages to express Ia in response to IFN-gamma, and ablated the suppressive activity toward adult cells. These results indicate that IFN-alpha and -beta, which can be produced in the course of self-defense responses and during ontogeny, may contribute to the down-regulation of macrophage Ia expression.

Animals↗
PubMed1986

Purification of natural human interferon-gamma by antibody affinity chromatography: analysis of constituent protein species in the dimers.

A simple procedure for purifying human interferon-gamma from leukocytes was established, based on monoclonal antibody affinity chromatography. The recovery of interferon activity was essentially quantitative, and the specific activity of the product was (4-12) x 10(7) international units/mg protein. SDS-polyacrylamide gel electrophoresis reproducibly revealed four components associated with interferon activity (and no other proteins): two major ones with molecular weights (MW) of 24,000-25,000 (25K) and 19,000-20,000 (20K), a minor one with MW 14,000-15,000 (15K) (these three bands were doublets), and a still less prominent one(s) with MV 40,000-48,000. Gel filtration in neutral solution indicated that all the 25K, 20K, and 15K species exist as oligomers, probably dimers. By means of experiments using a cleavable crosslinking reagent, the dimers were shown to comprise both homo-and heterodimers. Gel filtration in alkali (the condition used during purification) indicated that the molecules are largely in a monomeric state. Thus, the molecules once dissociated in alkali appear to reassociate at random upon neutralization; this process takes place without being accompanied by inactivation.

Amino Acid Sequence↗
PubMed1986

A monoclonal antibody with broad reactivity to human interferon-alpha subtypes useful for purification of leukocyte-derived interferon.

A monoclonal antibody to human interferon-alpha, termed HT-1 antibody, with a broad reactivity to various subtypes of interferon-alpha was prepared. It bound and neutralized all of the four subtypes of E. coli-derived human recombinant interferon-alpha (alpha 1, alpha 2, alpha 4, and alpha 6) tested; it also neutralized human natural leukocyte interferon but only partially. Human interferon-beta and -gamma were not bound. The antibody conjugated to Sepharose beads retained over 90% of human leukocyte interferon induced by Sendai virus. The bound interferon was recovered by acid elution in good yields and in almost pure form (specific activity was about 2 X 10(8) international units/mg protein). The purified interferon showed, in SDS-polyacrylamide gel electrophoresis, an activity profile with major peaks in a mol. wt. range of 17,000-22,000, which completely agreed with the profile shown by polyclonal antibody-purified interferon. Such purified leukocyte interferon-alpha preparations containing most of the naturally occurring subtypes can be useful for clinical and other purposes.

Animals↗
PubMed1985

SV40 vector with early gene replacement efficient in transducing exogenous DNA into mammalian cells.

An early replacement SV40 vector, SV40-Mu beta, was constructed by replacing part of the early genes of the virus with mouse interferon-beta (IFN-beta) cDNA. Upon transfection of COS-7 cells with this DNA, transducing viral particles were produced, which could infect various cells and cause efficient production of mouse IFN-beta. The viral stock contained no detectable wild-type SV40. The IFN production after the virus infection was very high in monkey kidney cells, but less so in human epithelial cells, and low in mouse, pig, hamster cells and in human lymphocytes. The efficiency of introduction of the DNA to monkey kidney cells was compared with that by the calcium phosphate precipitation method, and the viral vector was found to be more efficient by a factor of several tens to hundreds.

Animals↗
PubMed1985

Synthesis and secretion of biologically active mouse interferon-beta using a Bacillus subtilis alpha-amylase secretion vector.

Mouse interferon-beta (IFN-beta) cDNA, whose signal sequence had been removed by BAL 31 digestion, was introduced into a Bacillus subtilis secretion vector constructed by using the promoter and signal sequence of the B. subtilis alpha-amylase gene. The resultant chimeric plasmids were transferred into B. subtilis 207-25. Four kanamycin-resistant transformants were selected by both colony hybridization and a new immunoblot method for secretory proteins. They secrete the proteins which cross-react with sheep anti-mouse IFN-beta serum into the culture medium. One of them expressed a high IFN-beta activity as assayed by the L cell and vesicular stomatitis virus system, while the other three showed weak or little IFN activities. Based on our previous study [Ohmura et al., Nucl. Acids Res. 12 (1984) 5307-5319], it was suggested that the secreted IFN molecules are hybrid proteins in which the NH2-terminal region consists of part of the alpha-amylase signal peptide. Nucleotide sequence analysis revealed that plasmid pTUB502, which expressed high IFN activity, is joined to the mouse IFN-beta gene from the codon position 6 of its mature protein. The other three plasmids, pTUB506, pTUB509, and pTUB519, contain the mouse IFN-beta gene from the codon positions 3, 1, and -5, respectively. The NH2-terminal region of the mouse IFN-beta seems to be closely related to its biological activity.

Animals↗
PubMed1985

Cellular mechanisms in in vivo production of gamma interferon induced by lipopolysaccharide in mice infected with Mycobacterium bovis BCG.

Infection of mice with Mycobacterium bovis BCG sensitizes them for immune induction of interferon (IFN)-gamma by specific antigen. These mice were found also to respond to lipopolysaccharide (LPS) and concanavalin A (Con A) with high level production of IFN-gamma in the circulation, which was not observed in control mice. In this study, we compared the IFN-gamma response to LPS with that to Con A in an attempt to clarify the cellular mechanisms responsible for in vivo LPS-induced IFN-gamma production. Consequently, (i) the responses to LPS and Con A differed in the kinetics, that to LPS having a longer lag period. (ii) Spleen cells taken from infected mice produced little IFN-gamma in response to LPS, but they showed a higher IFN-gamma response to Con A than those from control mice. (iii) By treating infected mice with immunosuppressive drugs or antibodies to T and natural killer cells before challenge with the inducers, it was indicated that different cellular systems are involved in the IFN-gamma responses to LPS and to Con A.

Animals↗
PubMed1985

Neutralization of activity of effector protein by monoclonal antibody: formulation of antibody dose-dependence of neutralization for an equilibrium system of antibody, effector, and its cellular receptor.

Binding of an antibody to an effector protein will not necessarily inactivate it totally. In order to incorporate this into mathematical expressions of neutralization reaction between a monoclonal antibody and an effector which acts on cells through receptor binding, a static equilibrium system was considered that consists of effector, receptor and antibody, allowing formation of the ternary complex. A formula was derived for the antibody dose-dependence of neutralization, which was qualitatively similar to that found experimentally for monoclonal antibodies to interferon. According to the formula, the extent of neutralization, N, will approach a saturation value N infinity at high antibody concentrations, instead of increasing indefinitely, as is the case with conventional antibodies; the value N infinity is determined by the degree of reduction, upon antibody binding, of the effector's affinity to the receptor (and/or by the ability of antibody to inhibit the effector action subsequent to receptor binding). On the other hand, experimental data in the region of small N's will allow one to estimate the effector-antibody association constant.

Antibodies, Monoclonal↗
PubMed1985

The nature of neutralization reaction between effector protein and monoclonal antibody: a quantitative study of neutralization characteristics of anti-interferon antibodies.

Several monoclonal antibodies to human interferon-alpha and beta were examined quantitatively for neutralization of antigenically homogeneous interferons. The extent of neutralization increased with antibody concentration in each case with a rate considerably lower than in the case of conventional (polyclonal) antibodies, and there often appeared to be a limit to the maximum interferon titre that can be neutralized, even using very high antibody concentrations (there were no such limits with conventional antibodies). This suggests that the interferon in a 1:1 interferon-antibody complex in general retains some activity, to the degree characteristic of that antibody; namely, each monoclonal antibody is considered to have a characteristic efficacy of neutralization, rather than being either neutralizing or non-neutralizing in an all-or-one fashion. The antibody dose-dependence curves were interpreted to be governed by two independent parameters of the antibody: the efficacy of neutralization and the affinity. The former is reflected by the maximum interferon titre neutralizable by high antibody doses and the latter by the minimum antibody dose that can effect detectable neutralization. Thus, quantitative neutralization tests of monoclonal antibodies to an effector protein would give useful information for classifying them as to their affinities and as to whether the epitopes they recognize are important for the biological activity of the effector.

Antibodies, Monoclonal↗
PubMed1984

Antigenicity of mouse interferons induced in vitro and in vivo by poly(I).poly(C).

Various mouse IFNs induced by poly(I).poly(C) or poly(ICLC) were analyzed for the antigenic types by neutralization tests using anti-IFN-alpha and anti-IFN-beta antibodies. The IFN samples included IFNs produced by L cells, by spleen cells in vitro and ex vivo, and in plasma of mice injected with the inducers. L-cell IFN was estimated to consist of IFN-beta and IFN-alpha at a ratio of about 80:20. Spleen IFNs also consisted of both IFN species, but IFN-alpha was the major component. Blood IFN samples obtained 1-4 h after injection of poly(I).poly(C) or poly(ICLC) consisted of the two molecular species, whereas the samples 8 and 24 h after injection contained only IFN-alpha. High levels of IFN activity (IFN-alpha) persisted much longer in the circulation of mice injected with poly(ICLC) than in mice injected with poly(I).poly(C).

Animals↗
PubMed1984

Neutralization of interferon by antibody: appraisals of methods of determining and expressing the neutralization titer.

Basic problems in the quantitation of interferon (IFN) neutralization by antibody were considered. Commonly used experimental methods were examined, and the "constant antibody method" (the IFN dose-response [e.g., cytopathic effect] curve is depicted in the presence of fixed concentrations of antibody) was found to be the most convenient and informative; the "constant IFN method" which is widely used is in principle equivalent, but not suitable for tests of IFN of mixed antigenic types and for monoclonal antibodies. As previously proposed (J. IFN Res. 1, 61, 1980), the antibody titer is defined not by neutralization of a fixed absolute amount of IFN (such as 10 international units), but by the IFN titer reduction factor, namely as the reciprocal of antibody dilution that neutralizes 10 experimental units (EU)/ml of IFN to 1 EU/ml. This definition was found satisfactory for many antibodies to human and mouse IFNs, in that the value for given antibody did not change with changes in IFN sensitivity of the assay system, whereas the titer based on the absolute amount of IFN neutralized did. In other words, a given antibody will neutralize a larger amount of IFN when assayed in a system with a lower IFN sensitivity. A simplified model of neutralization reaction was described that provided a theoretical background for this observation. The model also allowed some inferences to be made about the relationship of the titer to the affinity and IFN-binding capacity of the antibody.

Animals↗