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Biomedical subjects

M Taniguchi

Publications and source records attributed to M Taniguchi.

At least 721 records · Page 40Linked to original sources
PubMed1985

Detection of antigen-specific suppressor T cell factor by sandwich radioimmunoassay using two monoclonal antibodies with different specificities.

We established a sandwich radioimmunoassay using two monoclonal antibodies specific for the distinct allotypic determinants on heavy and light chains of antigen-specific suppressor T cell factors (TsF). By use of this assay system, we confirmed our previous findings that the allotypic determinants (Ct) detected by BALB/c anti-CB-20 (7C5 and 7D1) were shared in various TsF with different antigen specificities, and also that the genes coding for the Ct determinants were indicated to be located on the right side of the Igh-V gene cluster, because the assay system equally detected either KLH-TsF or OVA-TsF from Ighb mice, such as C57BL/6, CB-20 and BAB-14, but not from BALB/c or C3H with other Igh allotypes. Furthermore, the radioimmunoassay, when used with two different anti-Ct (7C5 and 7D1), preferentially detected the extracted form of TsF, whereas the secreted TsF was easily detected by the combination of anti-Ct (7D1) and anti-I-Jb. In fact, the assay system defined two types of Ts hybridomas: one producing TsF in cytoplasm or on the membrane but not secreting and another secreting in the culture supernates. We also demonstrated that materials bound to the plate coated with anti-Ct antibody that had been incubated with different concentrations of cell-free extracts exhibited the dose-dependent suppression of antibody responses.

Animals↗
PubMed1985

Heterogeneous expression of melanoma-associated antigens and HLA antigens by primary and multiple metastatic lesions removed from patients with melanoma.

Indirect immunofluorescence staining with a large battery of monoclonal antibodies of primary and autologous metastatic lesions removed from seven patients with melanoma has detected heterogeneity in the expression of various types of melanoma-associated antigens (MAAs), of distinct determinants of the high molecular weight melanoma-associated antigen (HMW-MAA), of the two subunits of Class I HLA antigens, and of the gene products of the HLA-D region. Among the 10 MAAs tested, the HMW-MAA had the highest frequency and the Mr 87,000 MAA the lowest. Furthermore, the HMW-MAA displayed the lowest heterogeneity. These findings, in conjunction with the restricted tissue distribution of the HMW-MAA, its lack of susceptibility to antibody-mediated modulation, and the high affinity of the available anti-HMW-MAA monoclonal antibodies, indicate that this antigen may be a useful marker for radioimaging and immunotherapy in patients with melanoma. The common acute lymphoblastic leukemia antigen was detected only in five lesions. Class I HLA antigens were detected in a larger number of lesions than HLA-DR antigens, which had a significantly higher frequency than HLA-DQ antigens. The degree of antigenic heterogeneity did not appear to correlate with the histopathological features of the lesions and/or with the clinical course of the disease. The results of the present study indicate that immunodiagnostic and immunotherapeutic approaches to melanoma should rely on the use of combinations of monoclonal antibodies to distinct MAAs.

Animals↗
PubMed1985

Novel mechanisms of specific suppression of anti-hapten antibody response mediated by monoclonal anti-carrier antibody.

The cellular mechanisms of the antibody-induced suppression of immune responses were analyzed in the keyhole limpet hemocyanin (KLH) system. Some of the monoclonal anti-KLH antibodies, like KLH-specific suppressor T cell factor (KLH-TsF), were demonstrated to suppress the anti-2,4-dinitrophenyl IgG but not IgM plaque-forming cell responses in a KLH-specific and H-2-restricted manner. The anti-KLH antibodies with suppressive activity reacted with, and in turn, stimulated the suppressor hybridoma (34S-281) with the anti-idiotypic receptor complementary to the idiotypic KLH-TsF of the inducer type. Moreover, because the suppressive activity of the anti-KLH antibody was completely abolished by the treatment of responding spleen cells with anti-Lyt-2 and complement, it was apparent that the suppressive antibody activated suppressor T cell pathways. The isotype or affinity of antibodies is not related to the suppressive activity, because suppressive and nonsuppressive antibodies possess a similar affinity belonging to the same Ig isotypes. It also has been demonstrated that the Fc portion is not the functional site, because the F(ab')2 fragment still has the activity. The antibody specificity is found to be important for determining whether the antibody is suppressive or not. In fact, anti-KLH 26, but not other antibodies without activity, recognizes the particular KLH epitope seen by KLH-TsF, and exclusively interacts with the anti-idiotypic suppressor T cells. Thus, the anti-idiotypic suppressor T cell receives signals both from the suppressive anti-KLH antibody and from KLH-TsF, and transmits the antibody-induced suppressor signals to the effector-suppressor pathway. The size of the repertoire of anti-idiotypic suppressor T cells involved in the suppression seems to be very limited, because only four out of 120 monoclonal anti-KLH antibodies were found to have suppressor activity. The possible mechanisms of the cell interaction mediated by the suppressive antibody are discussed.

Animals↗
PubMed1985

[Augmentation of resistance against metastatic tumor cells after local administration of PSK].

Local administration of PSK augmented the generation of cytotoxic lymphocytes and the induction of resistance against metastatic tumor. Augmented generation of cytotoxic lymphocytes may be ascribed to local effects of PSK in the lymph nodes, since this is mediated by Lyt-1+2+ cells. Local administration of PSK increased the threshold number of metastatic tumors eliminated by hosts. This finding seems to be important in relation to augmentation of resistance against metastasis or local implantation with a limited number of tumor cells.

Adjuvants, Immunologic↗
PubMed1985

Mechanisms of in vivo generation of cytotoxic activity against syngeneic tumours. I. Local differentiation of mature cytotoxic T lymphocytes in the rejection of tumours.

Mature cytotoxic T lymphocytes (CTL) were detected in the peritoneal cavity of syngeneic mice immunized intraperitoneally (i.p.) with mitomycin C (MC)-treated EL-4 or X5563 cells, but were not found in their spleens or lymph nodes. Mature CTL appeared among PE cells after transfer of spleen cells from those immune mice, along with MC-treated tumour cells, to the peritoneal cavity of syngeneic mice. These results lead us to the hypothesis that immature CTL primed in the spleen and lymph nodes may migrate to the site of tumour inoculation and differentiate into mature CTL after antigenic or non-specific stimulation at that site. Inability of primed CTL to differentiate to mature CTL in the spleen might be explained by the effect of splenic suppressor cells, since mature CTL became detectable in the spleen of immune mice by treatment with cyclophosphamide.

Animals↗
PubMed1985

Recognition of alloantigen by cytotoxic T cell precursors is independent of the function of Ia+ cells.

The relationship between the requirement for Ia+ accessory cells (IaAC) and the differentiation of the precursor of CTL (PCTL) in the primary in vitro induction of allogeneic CTL was studied. The following observations were made PCTL can complete the antigen recognition step in the absence of IaAC. This process probably does not involve cell division. The sensitized PCTL require additional signals, which are provided through an IaAC-dependent process to differentiate into the effector CTL. IaAC from any of the responder, the stimulator, or even the third-party strains can fulfill the requirement. However, IaAC of the responder strain failed to generate the helper signal in the absence of allogeneic antigens. The cellular events taking place in the induction of CTL are discussed.

Animals↗
PubMed1984

Reaction of S-(2-amino-2-carboxyethylsulfonyl)-L-cysteine with thiosulfate: synthesis of L-alanine sulfodisulfane and application to the determination of thiosulfate.

A new reaction of S-(2-amino-2-carboxyethylsulfonyl)-L-cysteine (ACESC) with thiosulfate is described. The reaction proceeded quantitatively in formic or acetic acid solutions, yielding equimolar amounts of L-alanine sulfodisulfane (2-amino-2-carboxyethyl sulfodisulfane) and L-alanine 3-sulfinic acid. L-Alanine sulfodisulfane was obtained as pure monosodium salt; the yield was 92% of the theoretical. A new method is described for the determination of thiosulfate. The method is based on the quantitative reaction between ACESC and thiosulfate, and L-alanine sulfodisulfane, one of the reaction products, was determined using acid ninhydrin reagent 2 of M. K. Gaitonde (1967, Biochem. J. 104, 627-633). The recovery was over 95%. When samples contained sulfite in addition to thiosulfate, S-sulfo-L-cysteine (T. Ubuka et al., 1982, Anal. Biochem. 126, 273-277) was produced in addition to L-alanine sulfodisulfane by the treatment with ACESC. Both products were separated by a small Dowex 1 column and determined with the acid ninhydrin reagent 2. The recoveries were over 95%. The new method was applied to the thiosulfate sulfurtransferase reaction, in which thiosulfate, a substrate, and sulfite, a product, were determined separately.

Chemical Phenomena↗
PubMed1984

Functional roles of two polypeptide chains that compose an antigen-specific suppressor T cell factor.

The functional roles of the two polypeptide chains that compose the T cell suppressor factor (TsF) that mediates the antigen-specific and genetically restricted suppressor function were studied by using the heavy or light chains isolated from the conventional TsF or the 11S and 13S mRNA translation products of TsF. Either the heavy or the light chain of mRNA translation products reconstitutes the active TsF that suppresses the antibody response in an antigen-specific and genetically restricted manner when it is combined with the isolated heavy or light chain from the conventional TsF. As a consequence, the antigen-binding heavy chain mediates the antigen specificity of TsF. On the other hand, the I-J-positive light chain works as an element to determine the genetic restriction specificity. Thus, the identity of the histocompatibility between the I-J haplotypes on the light chain and the responding cell is essential for the functional expression of TsF. No genetic preference, however, was observed, in the association of the heavy and light chains of TsF.

Animals↗
PubMed1984

Depression of macrophage functions and T-cell-mediated immunity to listeria infection in tumor-bearing mice and its prevention by PSK.

The effect of PSK on the depressed bactericidal activity of macrophages and delayed-type hypersensitivity (DTH) to Listeria monocytogenes in BALB/c mice bearing transplantable Meth A fibrosarcoma was studied. In tumor-bearing mice pretreated with PSK, L. monocytogenes was cleared rapidly from the circulating blood and bacterial growth in the liver was inhibited effectively in the early phase of infection. This resistance to the infection could be transferred with adherent peritoneal exudate cells (PEC) but not with nonadherent or adherent spleen cells of PSK-treated mice. In the early phase of infection, tumor-bearing mice developed a lower level of DTH to L. monocytogenes than nongrafted control mice. However, the control levels of DTH could be obtained by pretreatment with PSK in tumor-bearing mice. These results suggest that the restoration of DTH to L. monocytogenes by pretreatment with PSK may be attributable to the restoration of the depressed immunological responsiveness to the normal levels in tumor-bearing mice.

Animals↗
PubMed1984

Epitope-specific regulation. IV. In vitro studies with suppressor T cells induced by carrier/hapten-carrier immunization.

Sequential immunization with a carrier molecule and a new epitope (hapten) conjugated to the carrier (carrier/hapten-carrier immunization) induces specific suppression for IgG antibody production to the new epitope (hapten) on the carrier. Once induced, this "epitope-specific" suppression persists and specifically suppresses subsequent in vivo IgG antibody responses to the hapten presented on the same or on an unrelated carrier molecule. In vitro studies presented here characterize the surface markers and specificity of suppressor T cells generated in carrier/hapten-carrier-immunized animals. Thus we show (1) that spleen cells from these donors suppress in vitro IgG anti-hapten antibody production by cocultured hapten-primed spleen cells; (2) that some but not all of the suppressor cells carry surface Lyt-2; (3) that at least some of the suppressor cells have receptors for the inducing hapten (DNP); and (4) that, unlike the suppression obtained in vivo, the in vitro suppression extends to IgG responses to unrelated carrier protein epitopes presented in association with the inducing hapten.

Animals↗
PubMed1984

Syngeneic monoclonal antibodies against melanoma antigens with species specificity and interspecies cross-reactivity.

The species-specific and the interspecies cross-reactive melanoma antigenic determinants are defined by the monoclonal antibodies raised by syngeneic immunizations. The two types of monoclonal antibodies (M562 or M622 and M2590) were obtained by the fusion of P3U1 murine myeloma cell lines and spleen cells of C57BL/6 mice hyperimmunized with MMC-treated syngeneic B16 melanoma cells. The M2590 antibody recognizes the cross-species melanoma determinant commonly shared among at least mouse, hamster, and human, while the M562 or M622 antibody reacts with the mouse (B16) melanoma antigenic determinant. The immunochemical and physiochemical characteristics of the melanoma antigens on SDS-PAGE analyses show that these two characteristic determinants are present on the same molecule (molecular weight of 31,000) of a glycoprotein. Furthermore, the interspecies cross-reactive melanoma antigenic determinants are possibly composed of the sugar moiety, whereas the species-specific determinants seem to be proteinaceous in nature.

Animals↗
PubMed1984

Transduction of effector-suppressor T cells by an antigen-specific suppressor T cell factor and Lyt-1+,2+,3+ T cells.

The cellular consequences in the suppression of IgG antibody formation initiated by an antigen-specific suppressor T cell factor (TsF) were investigated. The initial step of the suppression is the production of TsF by Lyt-2+,3+ T cells (Tsi) which activates Lyt-1+,2+,3+ acceptor T cells in the nylon wool-adherent T cell population. The activated Lyt-1+,2+,3+ T cells further generate a new effector-suppressor T cell ( Tse ) that belongs to the Lyt-2+,3+ T cell subset in the culture of nylon-adherent T cells with antigen. The Tse thus induced directly suppresses the responses mounted by B cells and nylon column-purified helper T cells in the absence of TsF. The origin of Tse was further examined by utilizing Lyt congeneic mice. The result indicates that Lyt-1+,2+,3+ acceptor T cells themselves do not differentiate into Lyt-2+,3+ Tse with losing Lyt-1 phenotype but facilitate the transduction of Tse from a preexisting precursor pool. These cellular interactions strongly suggest that Lyt-1+,2+,3+ T cells play a decisive role in an amplification of immunoregulation.

Animals↗
PubMed1984

Entrance of cholera enterotoxin subunits into thymus cells.

Analysis of the staining of cholera enterotoxin on the surface of cells with specific antibodies against each subunit of cholera enterotoxin, using a fluorescence-activated cell sorter and electron microscopy, showed that not only subunit A but also subunit B penetrates the cell membrane. The detection of subunits inside the cell was facilitated by the use of saponin, an agent that increases membrane permeability.

Animals↗