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Yasuharu Nishimura

Publications and source records attributed to Yasuharu Nishimura.

At least 37 records · Page 2Linked to original sources
PubMed2005

Therapeutic effect of alpha-galactosylceramide-loaded dendritic cells genetically engineered to express SLC/CCL21 along with tumor antigen against peritoneally disseminated tumor cells.

The close cooperation of both innate and acquired immunity is essential for the induction of truly effective antitumor immunity. We tested a strategy to enhance the cross-talk between NKT cells and conventional antigen-specific T cells with the use of alpha GalCer-loaded dendritic cells genetically engineered to express antigen plus chemokine, attracting both conventional T cells and NKT cells. DC genetically engineered to express a model antigen, OVA, along with SLC/CCL21 or monokine induced by IFN-gamma/CXCL9, had been generated using a method based on in vitro differentiation of DC from mouse ES cells. The ES-DC were loaded with alpha-GalCer and transferred to mice bearing MO4, an OVA-expressing melanoma, and their capacity to evoke antitumor immunity was evaluated. In vivo transfer of either OVA-expressing ES-DC, stimulating OVA-reactive T cells, or alpha-GalCer-loaded non-transfectant ES-DC, stimulating NKT cells, elicited a significant but limited degree of protection against the i.p. disseminated MO4. A more potent antitumor effect was observed when alpha-GalCer was loaded to ES-DC expressing OVA before in vivo transfer, and the effect was abrogated by the administration of anti-CD8, anti-NK1.1 or anti-asialo GM1 antibody. alpha-GalCer-loaded double transfectant ES-DC expressing SLC along with OVA induced the most potent antitumor immunity. Thus, alpha-GalCer-loaded ES-DC expressing tumor-associated antigen along with SLC can stimulate multiple subsets of effector cells to induce a potent therapeutic effect against peritoneally disseminated tumor cells. The present study suggests a novel way to use alpha-GalCer in immunotherapy for peritoneally

Animals↗
PubMed2005

Usefulness of the novel oncofetal antigen glypican-3 for diagnosis of hepatocellular carcinoma and melanoma.

Glypican-3 (GPC3) mRNA and protein are expressed in >80% of human hepatocellular carcinomas (HCC) but not in normal tissues except for placenta and fetal liver. The oncofetal antigen GPC3 is a glycosylphosphatidyl inositol-anchored membrane protein and may be secreted. It is a novel tumor marker for human HCC: GPC3 protein was present in sera from 40-50% of HCC patients, but was not detected in sera from patients with liver cirrhosis or chronic hepatitis, or in sera from healthy individuals. alpha-Fetoprotein (AFP) and PIVKA-II (protein induced by vitamin K absence or antagonist-II), are well known major tumor markers for HCC. Generally, AFP shows high positivity for HCC but also high false-positivity in detection assays. Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) is a recently described marker of HCC. Detection of AFP-L3 shows a much higher specificity than AFP, but a lower sensitivity. On the other hand, detection of PIVKA-II shows a lower false-positivity, but is not always sensitive enough to detect low levels secreted by small HCCs. There was no correlation between the three tumor markers, AFP, PIVKA-II, and GPC3 in terms of their presence in HCC cells. All three tumor markers showed similar positivity in patients with HCC, detecting 80% of patients with the disease. GPC3 is also a novel tumor marker for the diagnosis of human melanoma, especially in the early stages of the disease. Expression of GPC3 mRNA and protein was evident in tumor cells from >80% of patients with melanoma and melanocytic nevus, which is a common benign lesion. GPC3 protein was detected in sera from 40% (36/91) of melanoma patients, but not in sera from those with large congenital melanocytic nevus, or from healthy donors. Surprisingly, we detected serum GPC3 even in patients with stage 0, in situ melanoma. The positive detection rate of serum GPC3 at stage 0, I, and II (44.4%, 40.0%, 47.6%, respectively) was significantly higher than that of 5-S-cysteinyldopa, a well known tumor marker for melanoma (0.0%, 8.0%, and 10.0%, respectively). Interestingly, GPC3 was highly immunogenic in mice and elicited effective anti-tumor immunity with no evidence of autoimmunity. Thus, GPC3 is useful for diagnosis of HCC and melanoma and may also have a role in immunotherapy or tumor prevention. However, studies in humans are warranted.

Animals↗
PubMed2004

Mouse homologue of a novel human oncofetal antigen, glypican-3, evokes T-cell-mediated tumor rejection without autoimmune reactions in mice.

PURPOSE AND EXPERIMENTAL DESIGN: We recently identified glypican-3 (GPC3) overexpressed specifically in human hepatocellular carcinoma, as based on cDNA microarray analysis of 23,040 genes, and we reported that GPC3 is a novel tumor marker for human hepatocellular carcinoma and melanoma. GPC3, expressed in almost all hepatocellular carcinomas and melanomas, but not in normal tissues except for placenta or fetal liver, is a candidate of ideal tumor antigen for immunotherapy. In this study, we attempted to identify a mouse GPC3 epitope for CTLs in BALB/c mice, and for this, we set up a preclinical study to investigate the usefulness of GPC3 as a target for cancer immunotherapy in vivo. RESULTS: We identified a mouse GPC3-derived and Kd- restricted CTL epitope peptide in BALB/c mice. Inoculation of this GPC3 peptide-specific CTL into s.c. Colon26 cancer cells transfected with mouse GPC3 gene (C26/GPC3) led to rejection of the tumor in vivo, and i.v. inoculation of these CTLs into sublethally irradiated mice markedly inhibited growth of an established s.c. tumor. Inoculation of bone marrow-derived dendritic cells pulsed with this peptide prevented the growth of s.c. and splenic C26/GPC3 accompanied with massive infiltration of CD8+ T cells into tumors. Evidence of autoimmune reactions was never observed in surviving mice that had rejected tumor cell challenges. CONCLUSIONS: We found the novel oncofetal protein GPC3 to be highly immunogenic in mice and elicited effective antitumor immunity with no evidence of autoimmunity. GPC3 is useful not only for diagnosis of hepatocellular carcinoma and melanoma but also for possible immunotherapy or prevention of these tumors.

Adenocarcinoma↗
PubMed2004

Identification of glypican-3 as a novel tumor marker for melanoma.

PURPOSE: We reported recently the novel tumor marker glypican-3 (GPC3) for hepatocellular carcinoma. In the present study, we investigated the expression of GPC3 in human melanoma cell lines and tissues and asked whether GPC3 could be a novel tumor marker for melanoma. EXPERIMENTAL DESIGN: Expression of GPC3 mRNA and protein was investigated in human melanoma cell lines and tissues using reverse transcription-PCR and immunohistochemical analysis. Secreted GPC3 protein was quantified using ELISA in culture supernatants of melanoma cell lines and in sera from 91 patients with melanoma and 28 disease-free patients after surgical removal of primary melanoma. All of the subjects were Japanese nationals. RESULTS: In >80% of melanoma and melanocytic nevus, there was evident expression of GPC3 mRNA and protein. Furthermore, GPC3 protein was evidenced in sera of 39.6% (36 of 91) of melanoma patients but not in sera from subjects with large congenital melanocytic nevus (0 of 5) and from healthy donors (0 of 60). Twenty-seven of 36 serum GPC3-positive patients were negative for both serum 5-S-cysteinyldopa and melanoma-inhibitory activity, well-known tumor markers for melanoma. The positive rate of serum GPC3 (39.6%) was significantly higher than that of 5-S-cysteinyldopa (26.7%) and of melanoma-inhibitory activity (20.9%). Surprisingly, we detected serum GPC3 even in patients with stage 0 in situ melanoma. The positive rate of serum GPC3 at stage 0, I, and II (44.4%, 40.0%, and 47.6%) was significantly higher than that of 5-S-cysteinyldopa (0.0%, 8.0%, and 10.0%). Also observed was the disappearance of GPC3 protein in sera from 11 patients after surgical removal of the melanoma. CONCLUSIONS: GPC3 is apparently a novel tumor marker useful for the diagnosis of melanoma, especially in early stages of the disorder.

Adult↗
PubMed2004

Proliferation potential-related protein, an ideal esophageal cancer antigen for immunotherapy, identified using complementary DNA microarray analysis.

PURPOSE: To establish effective antitumor immunotherapy for esophageal cancer, we tried to identify an useful target antigen of esophageal cancer. EXPERIMENTAL DESIGN: We did cDNA microarray analysis to find a novel candidate antigen, proliferation potential-related protein (PP-RP). We examined cytotoxicity against tumor cells in vitro and in vivo of CTLs specific to PP-RP established from esophageal cancer patients. RESULTS: In 26 esophageal cancer tissues, an average of relative ratio of the expression of the PP-RP mRNA in cancer cells versus adjacent normal esophageal tissues was 396.2. Immunohistochemical analysis revealed that, in 20 of the 22 esophageal cancer tissues, PP-RP protein was strongly expressed only in the cancer cells and not so in normal esophageal epithelial cells. PP-RP protein contains 10 epitopes recognized by HLA-A24-restricted CTLs. These CTLs, generated from HLA-A24-positive esophageal cancer patients, had cytotoxic activity against cancer cell lines positive for both PP-RP and HLA-A24. Furthermore, adoptive transfer of the PP-RP-specific CTL line inhibited the growth of a human esophageal cancer cell line engrafted in nude mice. CONCLUSIONS: The expression of PP-RP in esophageal cancer cells was significantly higher than in normal cells, and the CTLs recognizing PP-RP killed tumor cells in vitro and also showed tumor rejection effects in a xenograft model. Therefore, PP-RP may prove to be an ideal tumor antigen useful for diagnosis and immunotherapy for patients with esophageal cancer. cDNA microarray analysis is a useful method to identify ideal tumor-associated antigens.

Adult↗
PubMed2004

Identification of a novel human cancer/testis antigen, KM-HN-1, recognized by cellular and humoral immune responses.

PURPOSE: We used serologic screening of a cDNA expression library of human testis to identify novel cancer/testis antigens that elicit both humoral and cellular immune responses in cancer patients. EXPERIMENTAL DESIGN AND RESULTS: We identified a novel gene designated KM-HN-1 the expression of which is testis-specific among normal tissues; it contains coiled coil domains and a leucine zipper motif and encodes a putative protein consisting of 833 amino acids. KM-HN-1 expression was observed in various cancer tissues and cancer cell lines at both mRNA and protein levels. Immunofluorescence staining of an esophageal cancer cell line revealed that KM-HN-1 protein was present exclusively in the nucleus during mitosis. Recombinant KM-HN-1 protein was produced, and used for ELISA to quantitate levels of IgG antibody specific to KM-HN-1. Higher levels of IgG antibodies specific to KM-HN-1 were detected in many types and numbers of cancer patients but not in healthy donors. The CTL lines specific to KM-HN-1, generated from HLA-A*2402-positive healthy donors and cancer patients, killed human leukocyte antigen (HLA)-A24-positive cancer cells expressing KM-HN-1 but not cell lines that did not express either KM-HN-1 or HLA-A24. CONCLUSIONS: We identified a novel cancer/testis antigen, KM-HN-1, which elicited humoral immune responses in patients with various types of cancer. Furthermore, KM-HN-1-specific CTLs could be generated from both healthy donors and cancer patients, which indicated that KM-HN-1 can be a candidate for an ideal target for cancer immunotherapy.

Amino Acid Motifs↗
PubMed2004

B-Raf contributes to sustained extracellular signal-regulated kinase activation associated with interleukin-2 production stimulated through the T cell receptor.

A T cell receptor (TCR) recognizes and responds to an antigenic peptide in the context of major histocompatibility complex-encoded molecules. This provokes T cells to produce interleukin-2 (IL-2) through extracellular signal-regulated kinase (ERK) activation. We investigated the roles of B-Raf in TCR-mediated IL-2 production coupled with ERK activation in the Jurkat human T cell line. We found that TCR cross-linking could induce up-regulation of both B-Raf and Raf-1 activities, but Raf-1 activity was decreased rapidly. On the other hand, TCR-stimulated kinase activity of B-Raf was sustained. Expression of a dominant-negative mutant of B-Raf abrogated sustained but not transient TCR-mediated MEK/ERK activation. The inhibition of sustained ERK activation by either expression of a dominant-negative B-Raf or treatment with a MEK inhibitor resulted in a decrease of the TCR-stimulated nuclear factor of activated T cells (NFAT) activity and IL-2 production. Collectively, our data provide the first direct evidence that B-Raf is a positive regulator of TCR-mediated sustained ERK activation, which is required for NFAT activation and the full production of IL-2.

Animals↗
PubMed2004

Detection of the novel autoantibody (anti-UACA antibody) in patients with Graves' disease.

Uveal autoantigen with coiled coil domains and ankyrin repeats (UACA) is an autoantigen in patients with panuveitis such as Vogt-Koyanagi-Harada disease. The prevalence of IgG anti-UACA antibodies in patients with uveitis is significantly higher than healthy controls, suggesting its potential role as an autoantigen. Originally, UACA was cloned from dog thyroid tissue following TSH stimulation. So, we presumed UACA could be a novel autoantigen in autoimmune thyroid diseases. We measured serum anti-UACA antibody titer using ELISA in patients with autoimmune thyroid diseases (Graves' disease, Hashimoto's thyroiditis, subacute thyroiditis, and silent thyroiditis). The prevalence of anti-UACA antibodies in Graves' disease group was significantly higher than that in healthy group (15% vs. 0%). Moreover, the prevalence of anti-UACA antibodies in Graves' ophthalmopathy was significantly higher than that in Graves' patients without ophthalmopathy (29% vs. 11%). Especially, 75% of severe ocular myopathy cases showed high UACA titer. Immunohistochemical analysis revealed that UACA protein is expressed in eye muscles as well as human thyroid follicular cells. Taken together, UACA is a novel candidate for eye muscle autoantigens in thyroid-associated ophthalmopathy.

Adult↗
PubMed2004

Comparison of frequency of interferon-gamma-positive CD4+ T cells before and after percutaneous coronary intervention and the effect of statin therapy in patients with stable angina pectoris.

We investigated the effect of statin therapy on T-cell activation in patients who underwent percutaneous coronary intervention by using flow cytometric analysis. The increased frequency of interferon-gamma-positive CD4(+) T cells after percutaneous coronary intervention was significant in the group treated without statins but not in the group treated with statins.

Aged↗
PubMed2004

Enhanced priming of antigen-specific CTLs in vivo by embryonic stem cell-derived dendritic cells expressing chemokine along with antigenic protein: application to antitumor vaccination.

Dendritic cell (DC)-based immunotherapy is regarded as a promising means for anti-cancer therapy. The efficiency of T cell-priming in vivo by transferred DCs should depend on their encounter with T cells. In the present study, we attempted to improve the capacity of DCs to prime T cells in vivo by genetic modification to express chemokine with a T cell-attracting property. For genetic modification of DCs, we used a recently established method to generate DCs from mouse embryonic stem cells. We generated double-transfectant DCs expressing a chemokine along with a model Ag (OVA) by sequential transfection of embryonic stem cells, and then induced differentiation to DCs. We comparatively evaluated the effect of three kinds of chemokines; secondary lymphoid tissue chemokine (SLC), monokine induced by IFN-gamma (Mig), and lymphotactin (Lptn). All three types of double transfectant DCs primed OVA-specific CTLs in vivo more efficiently than did DCs expressing only OVA, and the coexpression of SLC or Lptn was more effective than that of Mig. Immunization with DCs expressing OVA plus SLC or Mig provided protection from OVA-expressing tumor cells more potently than did immunization with OVA alone, and SLC was more effective than Mig. In contrast, coexpression of Lptn gave no additive effect on protection from the tumor. Collectively, among the three chemokines, expression of SLC was the most effective in enhancing antitumor immunity by transferred DCs in vivo. The findings provide useful information for the development of a potent DC-based cellular immunotherapy.

Animals↗
PubMed2004

Degenerate recognition and response of human CD4+ Th cell clones: implications for basic and applied immunology.

It was once considered that the T cell response is an all or nothing type event, but recent studies have clearly indicated that T cells show many different types of activation in recognition of altered ligands for T cell receptors (TCR). In this review, we summarize our recent findings on the response of human CD4+ helper T (Th) cell clones to altered peptide ligands (APL); peptides carrying single or multiple residue substitutions in antigenic peptides. The extensive analyses revealed that TCR-antagonism and partial agonism are frequently observed by the stimulation with APLs substituted at particular amino acid residues of antigenic peptides. We observed unique partially agonistic APLs inducing prolongation of T cell survival without cell proliferation. Superagonistic APLs stimulated enhanced proliferation and production of cytokines in Th cell clones reactive to tumor-associated antigens. The other APL induced enhanced production of interleukin-12 by antigen presenting cells and subsequent enhancement of IFN-gamma production by T cells reactive to allergens. By utilizing an HLA-DR-restricted T cell epitope library generated by mutated invariant chain genes, it was revealed that human Th cell clones recognize a more diverse array of peptides with multiple and simultaneous amino acid substitutions in an antigenic peptide. APLs also induced altered intracellular signaling events including intracellular calcium increase and phosphorylation of signaling molecules. This information provides basic knowledge regarding the characteristics of antigen recognition by human Th cells and the subsequent activation, and a novel method for manipulation of human Th cell responses by APLs, as a possible candidate for antigen-specific immuno-potentiating or immunosuppressive therapy.

Amino Acid Substitution↗
PubMed2003

Identification of naturally processed helper T-cell epitopes from prostate-specific membrane antigen using peptide-based in vitro stimulation.

PURPOSE: There is growing evidence that CD4(+) helper T lymphocytes (HTLs) play an essential role in the induction and long-term maintenance of antitumor CTL responses. Thus, approaches to develop effective T-cell-based immunotherapy should focus in the stimulation of both CTLs and HTLs reactive against tumor-associated antigens. The present studies were performed with the purpose of identifying HTL epitopes for prostate-specific membrane antigen (PSMA) for the optimization of vaccines for prostate cancer. EXPERIMENTAL DESIGN: Synthetic peptides from regions of the PSMA sequence that were predicted to serve as HTL epitopes were prepared with use of computer-based algorithms and tested for their capacity to trigger in vitro HTL responses in lymphocytes from normal volunteers. RESULTS: Our results show that 4 peptides from PSMA were effective in eliciting HTL responses. Moreover, HTL reactive to 3 of the 4 peptides were capable of reacting with naturally processed antigen in the form of freeze/thaw lysates or apoptotic cells produced from PSMA-positive LNCaP tumor cell lines. CONCLUSIONS: Human HTLs are capable of effectively recognizing epitopes derived from PSMA. The information presented here should facilitate the design of improved vaccination strategies for prostate cancer.

Animals↗
PubMed2003

Glypican-3, overexpressed specifically in human hepatocellular carcinoma, is a novel tumor marker.

With the global pandemic of hepatitis B and C infections, the incidence of Hepatocellular carcinoma (HCC) is rapidly increasing world wide. We identified glypican-3 (GPC3), a novel oncofetal gene over-expressed specifically in human HCC, as based on data of cDNA microarrays. As GPC3 is a GPI-anchored membrane protein and could be secreted, we attempted to detect secreted GPC3 protein in sera from HCC patients using Western blotting and ELISA. GPC3 protein was positive in sera of 40.0% (16/40) of HCC patients, and negative in sera from subjects with liver cirrhosis (LC) (0/13), chronic hepatitis (CH) (0/34), and healthy donors (0/60). All subjects were Japanese. Although 12 of 40 HCC patients were negative for both alpha-fetoprotein (AFP) and PIVKA-II well known tumor markers of HCC, four of these were GPC3-positive in the sera. We also observed vanishing GPC3 protein in the sera of three patients after the surgical treatment for HCC. On the other hand, immunohistochemical analysis revealed that HCC expressed GPC3 protein in all 14 HCC patients tested. In conclusion, GPC3, as defined in this study was shown to be a useful tumor marker for cancer-diagnosis for large numbers of patients with HCC.

Adult↗
PubMed2003

Preference toward a T-helper type 1 response in patients with coronary spastic angina.

BACKGROUND: Coronary artery spasm plays an important role in the pathogenesis of ischemic heart diseases such as unstable angina (UA) and acute myocardial infarction. Nitric oxide (NO) plays an important role in coronary artery spasm. We previously reported a deficiency in NO activity in the spasm arteries of patients with coronary spastic angina (CSA). Others have reported that NO influences the immune response. Therefore, we investigated the balance between T-helper type 1 (Th1) and 2 (Th2) responses in patients with CSA by evaluating the frequencies of interferon (IFN)-gamma-producing T cells and interleukin (IL)-4-producing T cells in the peripheral blood of such patients. METHODS AND RESULTS: Peripheral blood mononuclear cells were collected from 50 consecutive patients with CSA, 23 consecutive patients with UA, 36 patients with stable angina (SA), and 21 patients with chest pain syndrome (CPS). Cytokine-producing CD4+ T cells were quantified by 3-color flow cytometry after stimulation with phorbol myristate acetate and ionomycin. UA and CSA were associated with a significant increase in the frequency of CD4+ T cells that produced IFN-gamma, whereas these conditions caused no significant difference in the frequency of CD4+ T cells that produced IL-4. Culturing with an NO donor compound for 24 hours before stimulation inhibited the increase in the frequency of CD4+ T cells that produced IFN-gamma. CONCLUSIONS: We demonstrated that there was a preference toward the Th1-type response in patients with CSA and that T cells showed a reduced Th1-type response after being treated with NO.

Adult↗