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Biomedical subjects

K Saijo

Publications and source records attributed to K Saijo.

At least 19 recordsLinked to original sources
PubMed2005

Microwave tumour coagulation plus in situ treatment with cytokine-microparticles: induction of potent anti-residual tumour immunity.

After local microwave coagulation and subsequent intra-tumoural injection of microparticles encapsulating interleukin-2 and granulocyte-macrophage colony-stimulating factor, the anti-tumour efficacy against subcutaneous Lewis lung carcinoma in syngeneic mice was evaluated. This treatment elicited a potent systemic anti-tumour immunity that protected treated mice from re-challenge with the same tumour cells and caused the distal tumours in a bilateral tumour model to be rejected. Cytotoxicity assay indicated that both T- and natural killer cells acted as the effector cells in the anti-tumour immunity. These data highlight the feasibility of microwave-pre-treated in situ cancer vaccination for clinical use.

Animals↗
PubMed2003

Clinical course and immune response of a renal cell carcinoma patient to adoptive transfer of autologous cytotoxic T lymphocytes.

The cytotoxic T lymphocyte (CTL) is a promising candidate for an effector cell in adoptive immunotherapy for renal cell carcinoma (RCC). Here we report the clinical course and in vivo immune responses of a RCC patient with bulky retroperitoneal lymph node (RPLN) metastases who received adoptive autologous CTL therapy. A 56-year-old woman diagnosed with RCC with multiple RPLN metastases underwent unilateral nephrectomy. Autologous RCC cells were primary-cultured from surgical specimens. Before addition of peripheral blood mononuclear cells (PBMC) for CTL induction, subconfluent RCC cells were irradiated with 50 Gy. The PBMCs were then cultured on RCC cells in the induction medium supplemented with four kinds of interleukins. The induced CTLs showed the potent killing activity against autologous RCC cells in a typical MHC-class I-restricted manner. The patient received three courses of CTL therapy with a total of 10.2 x 10(9) cells, and the RPLN mass decreased markedly in size after the second course. Eosinophilia and enhanced CTL inducibility from peripheral blood were observed after CTL administrations. The patient was progression free without further treatment; however, she developed rapidly progressive glomerulonephritis more than 1 year after the last treatment. The patient died of newly developed metastases 27 months after the start of CTL therapy. At autopsy, viable RCC cells were found in multiple metastatic sites. However, only diffuse fibrous tissue was observed in the responding RPLN mass. Apparent histological divergence was observed between primary and metastatic sites.

Carcinoma, Renal Cell↗
PubMed2001

Cytokine-independent Jak3 activation upon T cell receptor (TCR) stimulation through direct association of Jak3 and the TCR complex.

Jak3 is responsible for growth signals by various cytokines such as interleukin (IL)-2, IL-4, and IL-7 through association with the common gamma chain (gammac) in lymphocytes. We found that T cells from Jak3-deficient mice exhibit impairment of not only cytokine signaling but also early activation signals and that Jak3 is phosphorylated upon T cell receptor (TCR) stimulation. TCR-mediated phosphorylation of Jak3 is independent of IL-2 receptor/gammac but is dependent on Lck and ZAP-70. Jak3 was found to be assembled with the TCR complex, particularly through direct association with CD3zeta via its JH4 region, which is a different region from that for gammac association. These results suggest that Jak3 plays a role not only in cell growth but also in T cell activation and represents cross-talk of a signaling molecule between TCR and growth signals.

Animals↗
PubMed2000

Tumor formation suppressed in gammadeltaT knock-out mice.

Tumor formation was examined in mice in which the beta-chain gene of alphabetaT was knocked out (alphabetaT-KO mice) or the delta-chain gene of gammadeltaT was knocked out (gammadeltaT-KO mice). Development of Hepa 1-6 cell hepatoma was observed in six of six alphabetaT-KO mice, in four of six wild-type mice, and in only one of six gammadeltaT-KO mice. These results imply that gammadeltaT cells play a role in suppression of killer cell activity in tumor-bearing mice.

Animals↗
PubMed2000

The B-cell-specific Src-family kinase Blk is dispensable for B-cell development and activation.

The B-cell lymphocyte kinase (Blk) is a src-family protein tyrosine kinase specifically expressed in B-lineage cells of mice. The early onset of Blk expression during B-cell development in the bone marrow and the high expression levels of Blk in mature B cells suggest a possible important role of Blk in B-cell physiology. To study the in vivo function of Blk, mice homozygous for the targeted disruption of the blk gene were generated. In homozygous mutant mice, neither blk mRNA nor Blk protein is expressed. Despite the absence of Blk, the development, in vitro activation, and humoral immune responses of B cells to T-cell-dependent and -independent antigens are unaltered. These data are consistent with functional redundancy of Blk in B-cell development and immune responses.

Animals↗
PubMed1999

Ablation of a specific cell population by the replacement of a uniquely expressed gene with a toxin gene.

The transgenic expression of a toxin gene or a thymidine kinase gene under the control of cell type-specific promoter/enhancer has been shown to be useful for removing a specific cell population in mice. However, this approach requires extensive analysis of the control elements for gene expression in the preparation of the transgenic constructs, and furthermore, the toxin gene might be expressed ectopically because of random integration, resulting in aberrant depletion of unrelated cells. To avoid such difficulties with the transgenic approach, we established a method for the specific depletion of a cell population by replacing a uniquely expressed gene in the population with the diphtheria toxin gene by using homologous recombination. The NKR-P1 gene, a specific cell surface marker of natural killer (NK) cells, was selected as the target gene for depleting NK cells. In chimeric mice reconstituted with embryonic stem cells in which the NKR-P1 gene was replaced by the toxin gene, NKR-P1(+) cells were almost completely depleted, and NK cell function was abrogated in the embryonic stem cell-derived lymphoid cells. Other cell lineages developed normally. These results show that all NK cells express NKR-P1, that NKR-P1(+) cells do not influence the development of T and B cells, and further, that this technology of cell targeting is a fast and powerful method of generating mice lacking any chosen cell population.

Animals↗
PubMed1999

Ig-alpha cytoplasmic truncation renders immature B cells more sensitive to antigen contact.

To study the function of Ig-alpha in the selection of autoreactive B cells, we have analyzed mb-1 cytoplasmic truncation mutant mice (mb-1delta(c)/delta(c)), which coexpress transgenes encoding hen egg lysozyme (HEL) and HEL-specific immunoglobulin. We demonstrate that in the presence of soluble HEL (sHEL) and dependent on the mb-1delta(c) mutation, most immature B cells bearing the HEL-specific Ig transgene undergo rearrangements of endogenous kappa light chains, resulting in loss of HEL specificity. Moreover, immature B cells from Ig-alpha mutant mice respond to BCR cross-linking with an exaggerated and prolonged calcium response and induction of protein tyrosine phosphorylation. Our data imply a negative signaling role for Ig-alpha in immature B cells.

Animals↗
PubMed1999

Reduction of end-stage malignant glioma by injection with autologous cytotoxic T lymphocytes.

Autologous cytotoxic T lymphocytes (CTL) against primary-cultured malignant gliomas were generated from peripheral blood mononuclear cells in vitro in 4 patients. Activities of the CTL were highly specific to the corresponding autologous glioma and were inhibited, in one patient, with antibodies against CD3, CD8 and MHC-class I molecules. When the CTL were injected 3 times into the primary-tumor-resected cavity via an Ommaya tube, reduction of the recurrent tumors with magnetic resonance imaging (MRI)-measured volumes exceeding 45 cm3 was observed in 3 patients. In a patient with glioblastoma multiforme (GBM), the tumor volume (estimated, 130 cm3) was rapidly reduced to 1/3, although re-recurrence of the tumor followed 40 days later. A slight but distinct rapid reduction of the tumor volume was observed in another GBM patient and in an anaplastic astrocytoma patient; essentially no change was observed in a further GBM patient. These results suggest that adoptive immunotherapy with autologous CTL will be clinically effective against end-stage malignant gliomas.

Adult↗
PubMed1999

Autologous high-killing cytotoxic T lymphocytes against human lung cancer are induced using interleukin (IL)-1beta, IL-2, IL-4, and IL-6: possible involvement of dendritic cells.

Although CTLs bear main immune responses in human tumors, stable CTL clones against human lung cancer have rarely been generated. Our previous study demonstrated efficient autologous CTL induction in human gastric cancer and glioblastoma by cytokine combination of interleukin (IL)-1beta (167 IU/ml), IL-2 (67 IU/ml), IL-4 (67 IU/ml), and IL-6 (134 IU/ml). In this study, we demonstrated successful induction of autologous stable CTLs in five of six patients with lung adenocarcinoma from mixed-lymphocyte tumor culture using this cytokine combination. All CTLs revealed potent and specific killing activity against autologous target cells (over 75% in CD8+ CTLs and over 50% in CD4+ CTLs at an E:T ratio of 10 for 24 h). Using a series of antibodies, CD8+ CTLs showed to recognize tumor-specific antigens of lung cancer cells through HLA class I. In the separate experiments, failure of CTL induction from monocyte-depleted peripheral blood mononuclear cells and appearance of cells with characteristics of dendritic cells from adherent peripheral blood mononuclear cells in the culture of the same concentration of IL-1beta, IL-4, and IL-6 indicated that CTLs can be efficiently generated by this cytokine combination via possible dendritic cell induction. This is the first study of an efficient and reproducible in vitro CTL induction against human lung cancer.

Adenocarcinoma↗
PubMed1998

Csk controls antigen receptor-mediated development and selection of T-lineage cells.

The development and function of alphabetaT lymphocytes depend on signals derived from pre-T and alphabetaT cell receptors (preTCR and alphabetaTCR) (reviewed in refs 1, 2). The engagement of these receptors leads to the activation of Lck and Fyn, which are protein tyrosine kinases (PTKs) of the Src family. It remains unclear to what extent the activation of Src-family PTKs can direct the differentiation steps triggered by preTCR and alphabetaTCR. Here we show that the inactivation of the negative regulator of Src-family PTKs, carboxy-terminal Src kinase (Csk), in immature thymocytes abrogates the requirement for preTCR, alphabetaTCR and major histocompatibility complex (MHC) class II for the development of CD4+ 8+ double-positive and CD4+ single-positive thymocytes as well as peripheral CD4 alphabetaT-lineage cells. These data show that Csk and its substrates are required to establish preTCR/alphabetaTCR-mediated control over the development of alphabetaT cells.

Animals↗
PubMed1998

In vitro induction of HLA-A2402-restricted and carcinoembryonic-antigen-specific cytotoxic T lymphocytes on fixed autologous peripheral blood cells.

HLA-A2402-restricted and carcinoembryonic-antigen(CEA)-specific cytotoxic T lymphocytes (CTL) were induced by culturing human peripheral blood mononuclear cells (PBMC) on formalin-fixed autologous adhesive PBMC that had been loaded with CEA-bound latex beads. The CTL killed the CEA-producing HLA-type matched cancer cells, but not the non-producers of CEA, at an effector/target ratio of 10 within 24 h. On the basis of available HLA-A24-binding peptides, we have also attempted to identify the epitope peptide recognized by the CTL. The peptide CEA652(9), TYACFVSNL, stimulated the CTL most strongly when pulsed on HLA-A2402-expressing target cells. The other nine peptides so far tested were also active, but less efficient in their effect on CTL. The CTL failed to kill target cells pulsed with the HLA-A2-binding CEA peptide, CAP-1. The CTL were also generated on the fixed adherent cells previously pulsed with the peptide CEA652(9). Cytotoxic activity of the CTL was inhibited by monoclonal antibodies against CD3, CD8, and MHC class I molecules. These results suggest that human autologous CTL will be inducible on the autologous fixed PBMC without use of the cultured target cancer cells if tumor antigenic protein is available.

Adenocarcinoma↗
PubMed1998

A novel human glassy-cell carcinoma cell line producing IL-6 and IL-8 from uterine cervix.

A novel human cell line, TOM-2, was established from a rare uterine cervical cancer, glassy cell carcinoma (GCC). TOM-2 is the second established GCC cell line so far reported. The cells were intermediately or poorly differentiated with dysplastic nuclei and polygonal shape and secreted two tumor markers and cytokines, i.e., CA-125 and SCC, interleukin (1L)-1alpha, -6, and -8, and TNF-alpha. Growth of TOM-2 was so strongly dependent on population density that it was not possible to determine the plating efficiency. In mass culture, the following characteristics were observed: doubling time, 83 h; mode of chromosome number, 79; human papillomavirus type 18 DNA, detectable; tumorigenicity, easily transplantable into subcutis of nude mice; chemosensitivity in vitro, considerably sensitive to Cisplatin and 5-FU but not to 9 other antineoplastic agents. This novel cell line will be useful for developing new therapeutic strategies for the rare cancer, GCC.

Adult↗
PubMed1998

Essential role of IL-7 receptor alpha in the formation of Peyer's patch anlage.

We investigated the role of IL-7 receptor alpha (IL-7Ralpha) signal in the formation of Peyer's patch (PP) anlage. Although pan-lymphopenia is a common phenotype of rag2-/- and il7ralpha-/- mice, a close inspection revealed nodules corresponding to PP in the adult rag2-/- but not in the il7ralpha-/- mouse. In our previous study, three histologically distinct steps in the formation of PP were identified. The first is the appearance of VCAM-1 + spots in the intestine, which probably represents an initial stage of the formation of the PP anlage. Accumulation of cells bearing IL-7Ralpha, CD4 or Ia in this region then follows and eventually entry of mature lymphocytes expressing CD3 or B220 occurs just before birth. Based on this criterion, we next investigated which of these events is defective in mice with severe combined immunodeficiency. Formation of VCAM-1 + spots and cluster formation of IL-7Ralpha+ cells proceed normally in the rag2-/- mouse which completely lacks mature lymphocytes. In contrast, no VCAM-1+ spots were detected in the embryonic nor neonatal il7ralpha-/- mice, suggesting that IL-7Ralpha signal is involved in the early phase of PP anlage formation. The same defect was found in the jak3-/- mouse. In addition to the appearance of VCAM1+ spots, the clustering of IL-7Ralpha+ cells was absent in the jak3-/- mouse, though IL-7Ralpha+ cells are found to scatter over the intestine. These results indicate that IL-7Ralpha is an essential signal for an early step of PP anlage formation, without which the subsequent processes cannot be initiated.

Animals↗
PubMed1998

High rate of induction of human autologous cytotoxic T lymphocytes against renal carcinoma cells cultured with an interleukin cocktail.

A high rate of induction (9 of 10 cases) of human autologous cytotoxic T lymphocytes (CTL) was achieved in vitro from peripheral blood mononuclear cells of renal carcinoma patients by applying an interleukin (IL)-cocktail consisting of IL-1, -2, -4, and -6. The CTL specifically lysed their own target carcinoma cells within 24 h but did not kill neighboring autologous normal kidney cells or allogeneic renal cancer cell lines. In the case of TUHR4TKB, for which autologous CTL were not induced, no expression of MHC class-I molecules was observed on the surface of these carcinoma cells, although they were sensitive to autologous natural killer cells. The results imply that adoptive immunotherapy for metastasized renal carcinoma will be feasible with autologous CTL in combination with natural killer cells.

Cell Survival↗
PubMed1997

Premature aging syndrome with osteosarcoma, cataracts, diabetes mellitus, osteoporosis, erythroid macrocytosis, severe growth and developmental deficiency.

We describe a premature aging disorder in a 15-year-old girl with severe growth and developmental deficiency. Her clinical findings included osteosarcoma, nuclear and subcapsular cataracts, insulin-resistant diabetes mellitus, osteoporosis, epilepsy, foot ulcers, erythroid macrocytosis, and unusual facial appearance. Hyaluronic acid levels in serum and urine were normal. Cultured skin fibroblasts had a normal potential for in vitro growth. This finding represents a new and unique premature aging syndrome.

Abnormalities, Multiple↗
PubMed1997

Crucial role of Jak3 in negative selection of self-reactive T cells.

Jak3 mediates growth signals through cytokine receptors such as interleukin-2 (IL-2), IL-4, and IL-7, and its deficiency results in autosomal recessive SCID in mice and humans. In spite of the severely reduced number of lymphocytes in Jak3-deficient mice, the differentiation profile of thymocytes was normal and mature T cells accumulated in the periphery with age. However, we found that self-reactive T cells were not deleted in the thymus and the peripheral tissues in Jak3-deficient mice. All peripheral T cells were in the activation state and thus were unable to be activated further, as demonstrated by the failure of eliciting Ca2+ response upon T cell receptor (TCR) stimulation. From the analysis of TCR-transgenic Jak3-deficient mice, only self-reactive T cells appeared to be in the activated state and anergic. These findings demonstrate a crucial function of Jak3 in the negative selection of autoreactive T cells and the maintenance of functional peripheral T cells.

Animals↗
PubMed1996

Dynamic Small-Angle X-ray Scattering System using an Imaging Plate.

A synchrotron-radiation dynamic small-angle X-ray scattering (Synchrotron Radiation-DSAXS) system using an imaging plate has been developed at the Photon Factory, National Laboratory for High Energy Physics, Japan, in collaboration with the Department of Polymer Chemistry, Kyoto University, Japan, for studying the dynamic response of mesoscopic structures in polymers to applied mechanical stimuli. Small-angle X-ray scattering patterns of 100 x 100 mm(2) have been successively recorded on a 400 x 200 mm(2) stage-mounted imaging plate with a minimum time interval of 0.5 s. X-ray data are simultaneously obtained with stress and strain measurements on specimens subjected to a mechanical deformation. The performance of the DSAXS system is demonstrated along with some experimental results concerning the dynamic deformation of a b.c.c. lattice with paracrystalline distortion in a co-polymer having spherical microdomains under a large oscillatory shear deformation.

Journal Article↗