Biomedical subjects

Mitsuo Honda

Publications and source records attributed to Mitsuo Honda.

41 records · Page 3Linked to original sources

PubMed2002

Increased expression of cyclooxygenase-2 in local lesions of endometriosis patients.

PROBLEM: Human endometrial glands contain the highest levels of cyclooxygenase (COX), although whether it is COX-1 and/or COX-2 has not been previously determined. Overexpression of COX-2 may result in the pathogenesis of endometriosis. METHOD OF STUDY: Tissue sections were obtained from 28 premenopausal women undergoing laparotomy or laparoscopic surgery for benign conditions. Endometrium, ectopic endometriosis tissue and peritoneum were obtained at the time of surgery. Informed consents were obtained from all the patients participating in this study. Immunohistochemistry was performed on consecutive sections of paraffin-embedded tissue using anti-COX-2 antibody. Expressions of COX-2 mRNA in endometrium, ectopic endometriosis tissue, and peritoneum were quantitavely determined by competitive reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In the uterus, COX-2 was localized in the endometrial epithelium. Eutopic endometrial surface epithelium contains more COX-2 than does glandular epithelium. We observed more frequent and denser COX-2 staining in the ectopic endometriosis implants when compared with eutopic endometrium. Level of COX-2 mRNA in endometriosis was increased up to five times that of eutopic endometria. CONCLUSION: Hyper activation of COX-2 with abnormal prostaglandin generation is considered to contribute to the pathophysiology of endometriosis and disease progression.

Adult↗

PubMed2002

Effects of human interleukin-18 and interleukin-12 treatment on human lymphocyte engraftment in NOD-scid mouse.

NOD/LtSz-prkdc(scid)/prkdc(scid) (non-obese diabetic-severe combine immunodeficiency; NOD-scid) mice grafted with human peripheral blood lymphoid cells have been used as an in vivo humanized mouse model in various studies. However, cytotoxic human T cells are induced in this model during immune responses, which gives misleading results. To assist in grafting of human lymphocytes without the induction of cytotoxic human T cells, we investigated the effects of T helper type 1 (Th1) and Th2 cytokines on human lymphocyte grafting and migration, as well as the production of immunoglobulin deposited in glomeruli and human immunodeficiency virus-1 (HIV-1) infection using NOD-scid mice. Administration of interleukin-18 (IL-18) and IL-12 enhanced the grafting of human CD4+ and CD8+ T cells in the mice, whereas co-administration prevented grafting due to interferon-gamma-dependent apoptosis. Immunoglobulin A (IgA) deposits were observed in mice treated with IL-18 alone, but not in those given phosphate-buffered saline, IL-12 alone, or IL-18 + IL-12. A high rate of HIV infection was also observed in the IL-18-treated group. Together, these results indicate that IL-18 may be effective for the grafting and migration of CD4+ and CD8+ T cells, except for the induction of apoptosis and regulation of class-switching IgA. IL-18-administered NOD-scid mice provide a useful small humanized model for the study of HIV infection and IgA nephropathy.

Animals↗

PubMed2002

Dynamics of gamma interferon, interleukin-12 (IL-12), IL-10, and transforming growth factor beta mRNA expression in primary Mycobacterium bovis BCG infection in guinea pigs measured by a real-time fluorogenic reverse transcription-PCR assay.

The guinea pig has been utilized as a model for studying infectious diseases because its reactions closely resemble those of humans biologically and immunologically. However, the cytokine responses in this animal remain to be studied. Initially, we established a quantitative assay using a real-time reverse transcription-PCR (RT-PCR) to measure guinea pig gamma interferon (IFN-gamma), interleukin-12 (IL-12), IL-10, and transforming growth factor beta (TGF-beta) mRNA. By preparing primer-fluorogenic probe sets for these cytokines and standard RNA templates corresponding to the target sequence of each cytokine, we obtained linear standard curves essential for quantitative determination. In guinea pigs immunized by intradermal (i.d.) vaccination with the Tokyo strain of Mycobacterium bovis BCG (0.1 mg) or else hyperimmunized with the same vaccine (10 mg) given intravenously (i.v.), peripheral blood mononuclear cells (PBMCs) at 4 weeks showed an increase in IFN-gamma mRNA expression in the latter but not the former animals. However, at week 10, IFN-gamma mRNA expression was markedly elevated in PBMCs, spleen cells, and cells in bronchoalveolar lavage fluid in both the i.d.- and the i.v.-immunized animals, the level of expression being 10 times higher in the latter. In contrast, the expression levels of IL-12 mRNA in PBMCs, spleen cells, and BAL cells were not enhanced in either group at 10 weeks postimmunization. The expression of IL-10 and TGF-beta increased slightly only in PBMCs. Regardless of differences in the levels of cytokine responses, the magnitudes of the purified protein derivative of tuberculin-specific delayed-type hypersensitivity (DTH) skin reactions for the two groups did not differ significantly at 8 weeks postvaccination. In this study, we quantitatively measured IL-10, IL-12, TGF-beta, and IFN-gamma mRNA in BCG-immunized guinea pigs and showed that the level of IFN-gamma mRNA expression does not necessarily reflect the magnitude of the DTH response, suggesting that there may be an intricate relationship between protective immunity, the level of IFN-gamma, and the DTH response. Thus, our quantitative assay would be of use for the development of vaccines using guinea pig models.

Animals↗

PubMed2002

Selective expansion of perforin-positive CD8+ T cells by immature dendritic cells infected with live Bacillus Calmette-Guérin mycobacteria.

Live, but not dead Bacillus Calmette-Guérin (BCG) is partially protective against infection by Mycobacterium tuberculosis, which causes a disease with high mortality in immune compromised individuals. We have shown that uptake of BCG induces maturation of immature dendritic cells (DCs) regardless of the viability of the bacteria. Importantly, when T cells are cocultured with live BCG-infected DCs, the proportion of CD45RA(-) perforin(+) CD8+ T cells is markedly expanded markedly; however, little expansion is seen when T cells are cocultured with DCs harboring heat-killed BCG. The direct contact of T cells with live BCG-infected DCs was required for the expansion of perforin(+) CD8+ T cells. These CD8+ T cells demonstrated a high level of killing activity against BCG-infected macrophages. There was little contribution of cytokines, including IFN-gamma, TNF-alpha, and IL-12, to the expansion of CD8+ T cells by live BCG-infected DCs. We found that the interaction between BCG-infected DCs and CD8+ T cells through CD40/CD40L was crucial for the expansion and maturation of CD8+ T cells, the process of which was CD4-independent. In contrast, blocking the CD58/CD2 but not the CD40/CD40L interaction reduced production of IFN-gamma without affecting the maturation of CD8+ T cells. This indicates that the production of IFN-gamma and perforin by CD8+ T cells is mediated by distinct signals delivered from BCG-infected DCs. Thus, BCG-specific CD8+ CTL memory cells may be maintained for a long period of time in BCG-vaccinated hosts, and these cells could mature rapidly into effectors through the potent antigen-presenting function of DCs upon mycobacterial infection.

CD4-Positive T-Lymphocytes↗

PubMed2002

Characteristic of HIV-1 in V3 loop region based on seroreactivity and amino acid sequences in Thailand.

The third variable (V3) domain of the envelop (env) protein has been used for determining genetic subtype and phenotypic characteristics of human immunodeficiency virus type 1 (HIV-1) isolates. Based on the seroreactivity of the HIV-1 subtype by V3 peptide binding enzyme immunoassay (EIA) of 351 samples obtained in 1998 from HIV-1 infected individuals and AIDS patients, we found that 283 (80.6%) were subtype E, 20 (5.7%) were subtype B, 28 (8.0%) were cross-reactive between both types and 20 (5.7%) were non-typeable. The degree of seroreactivity of HIV-1 subtype E decreased significantly when the amino acid at the crown of the V3 loop was substituted from a GPGQ motif to GPGR motif. Interestingly, AIDS patients who had V3 sequences of subtype E as GPGR motif had a stronger immunoreactivity to GPGQ motif peptides than to GPGR motif peptides, in contradiction for their proviral sequences. The results suggested that mutations in the V3 loop may lead to a changed immunoreactivity that makes HIV-1 mutants unrecognizable or allow escape from the primary immune response by means of neutralizing sensitivity. In connection with vaccine development, it should be pointed out that the combination of V3 sequencing and peptide EIA could provide a novel approach to obtain a primarily infected virus sequence as a target for a preventive AIDS vaccine.

Acquired Immunodeficiency Syndrome↗