Project/Area Number |
12670256
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Bacteriology (including Mycology)
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Research Institution | Okayama University |
Principal Investigator |
YOKOTA Kenji Okayama University Graduate School of Dentistry and Medicine, Department of Bacteriology, Lecturer, 大学院・歯学総合研究科, 講師 (00243460)
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Co-Investigator(Kenkyū-buntansha) |
OGUMA Keiji Okayama University Graduate School of Dentistry and Medicine, Department of Bacteriology, Professor, 大学院・歯学総合研究科, 教授 (00002262)
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Project Period (FY) |
2000 – 2002
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Project Status |
Completed (Fiscal Year 2002)
|
Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2001: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
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Keywords | Helicobacter phlori / Heat shock protein / Mucosa-associated lympho tissue (MALT) / T helper 1 and 2 (Th-1 and -2) / DNA microarray / Mucosal immunit / Heat shock protein / ヘリコバクターピロリ / HSP60 / IgGサブクラス / Th-1 and Th-2 / CD40L |
Research Abstract |
We have previously reported that heat shock protein 60kDa (HSP60) is an important antigen in the pathogenesis of mucosa-associated lymphoid tissue (MALT) lymphoma. To investigate association with host immunity and HSP60, DC40 ligand (CD40L) and cytokine production in peripheral blood mononuclear cells (PBMCs) from the patients were analyzed following stimulation with HSP60. PBMCs obtained from patients with gastritis and MALT lymphoma, and those from healthy volunteer were stimulated with recombinant-HSP60 or H. pylori cell fysate in the presence of cytokines (IL-4) and GM-CSF). The mRNA expression was also analyzed by a cDNA microarray containing 1100 genes. The expression of CD40L on the CD4 positive cells was increased in the PBMCs from patients with MALT lymphoma stimulated by cytokines and/or HSP60 antigens. The production of IL-4 in PBMCs cultures was increased in patients with MALT lymphoma ; however, the production of IFN-_γ was at low levels. A cDNA microarray analysis indicat
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ed increased mRNA levels of HLA-DR and integrin. In cases of low-grade MALT lymphoma, adaptive immune responses against HSP60 may be enhanced by host factors, such as antigen presentation and T cell activation, resulting in B cell proliferation, which can be demonstrated during H. pylori infection. To study immunological roles of HSP60 in H. pylori infection, we immunized HSP60 to H. pylori infected mice. Whole HSP60 and two partial regions of helicobacterial hsp60 were expressed as GST-fusion proteins. Three recombinant proteins were designated rHSPw, rHSP2, and rHSP4-5. rHSPw was expressed as whole hsp60 (MeT_1-Met_<545>). rHSP2 (Glu_<101>-Ser_<200>) contained a domainT cell epitope cluster (Lys_<159>-Tnr_<178>). The rHSP4-5 contained a domain existing in both T cell epilope cluster (Asp_<396>-Gly_<4l2>) and its upstream of region (Ser_<356>-Asp_<392>) in common between H. pylori and human hsp60. Recombinant heat-labile enterotoxin (rLT) of E. coli was also employed as adjuvant for nasal immunization. Three different mouse groups (BALB/c, C3H/He, C57BL/6) were injected 10^8 CRJ of live H. pylori (SS -1) at two times a week and kept in a clean isolator for 2 weeks. Those mice were immunized H. pylori lysate or rHSPs (10μg/mouse) with rLT (10μg/mouse) by injecting into nasal mucosa four times in 1 month. Mice were sacrificed at 1 momtn after last immunization, and then histopathology and antibodies were investigated. Mucosal immunization by H. pylori lysate and rHSPs induced severe gastritis in BALB/c and C57BL/6 mice. Inflammation grades in those two groups immunized by rHSP4-5 were highest in aft groups. Mucosal immunization by hsp60 accelerated production of IgG and IgA. These -results indicated that HSP60 was closely associated with H. pylori induced gastric inflammation. Less
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