Aiko Hasegawa

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The selectins (lectin-EGF-complement binding-cell adhesion molecules [LEC-CAMs]) are a family of mammalian receptors implicated in the initial interactions between leukocytes and vascular endothelia, leading to lymphocyte homing, platelet binding, and neutrophil extravasation. The three known selectins, L-selectin (leukocyte adhesion molecule-1 [LECAM-1]),(More)
Zinc is an essential trace element required for enzymatic activity and for maintaining the conformation of many transcription factors; thus, zinc homeostasis is tightly regulated. Although zinc affects several signaling molecules and may act as a neurotransmitter, it remains unknown whether zinc acts as an intracellular second messenger capable of(More)
The present study was undertaken to clarify the mechanisms of cytotoxicity mediated by virus-specific human CD4+ CTLs using the lymphocytes of family members with a Fas gene mutation. CD4+ CTL bulk lines and clones directed against HSV-infected cells were established from lymphocytes of a patient with a homozygous Fas gene mutation and of the patient's(More)
Human telomerase reverse transcriptase (hTERT) is considered a potential target for cancer immunotherapy because it is preferentially expressed in malignant cells. hTERT-derived peptides carrying motifs for HLA-A24 (HLA-A*2402), the most common allele among Japanese and also frequently present in persons of European descent, were examined for their capacity(More)
Zinc (Zn) is an essential nutrient and its deficiency causes immunodeficiency. However, it remains unknown how Zn homeostasis is regulated in mast cells and if Zn transporters are involved in allergic reactions. We show that Znt5/Slc30a5 is required for contact hypersensitivity and mast cell-mediated delayed-type allergic response but not for immediate(More)
Recent studies have shown that zinc ion (Zn) can behave as an intracellular signaling molecule. We previously demonstrated that mast cells stimulated through the high-affinity IgE receptor (FcεRI) rapidly release intracellular Zn from the endoplasmic reticulum (ER), and we named this phenomenon the "Zn wave". However, the molecules responsible for releasing(More)
Mast cells are major players in allergic responses. IgE-dependent activation through FcεR leads to degranulation and cytokine production, both of which require Gab2. To clarify how the signals diverge at Gab2, we established Gab2 knock-in mice that express Gab2 mutated at either the PI3K or SH2 domain-containing protein tyrosine phosphatase-2 (SHP2) binding(More)
The lipid A portion of bacterial lipopolysaccharide (LPS) plays a central role in the production of endotoxic mediators. Different responses between human and murine macrophages to lipid A-like structures have been indicated. We investigated a series of structurally related monosaccharide lipid A analogues for their potency to activate human macrophage U937(More)
Amyloid-beta protein (A beta) is known to induce microglial activation with concomitant release of cytokines. Gangliosides have documented neuritogenic and neurotrophic properties. We determined the effects of A beta on the release of interleukin-1beta (IL-1beta) from the human monocytic cell line, THP-1 cells. A beta 1-42 significantly induced the release(More)
Monoclonal antibody AM-3 (MAb AM-3) raised against a sialomucin from human colorectal carcinoma has previously been shown to define a carbohydrate epitope, which is detectable by immunocytochemistry on all investigated colonic carcinomas and is expressed in correlation with the grade of dysplasia in colonic adenomas (Hanski et al., J. Clin. Pathol., 43:(More)