Yoshitane Dohi

Induction of Eczematous Skin Reaction in Experimentally Induced Hyperplastic Skin of Balb/C Mice by Monoclonal Anti-DNP IgE Antibody: Possible Implications for Skin Lesion Formation in Atopic Dermatitis

Biphasic skin reaction with peak response at 1 and 24 h with prominent mast cell degranulation was induced by intravenous application of a monoclonal anti-DNP IgE antibody and subsequent skin test. This reaction was hapten-specific and mast-cell-dependent because no reaction was observed when oxasolone was used as an elicitation antigen or skin test was elicited in genetically mast-cell-deficient mice (W/Wvv). A partial spongiotic reaction and mononuclear cell infiltration into the epidermis were observed in mice with hyperplastic epidermis induced by topical retinoic acid. Cotransfer of DNFB-sensitized lymph node cells with anti-DNP IgE antibodies failed to enhance the skin test reaction in unsensitized mice. These results suggest that, to some degree, IgE antibody may play some role in the development of eczematous skin lesions in the rodent system without the involvement of cellular hypersensitivity.

Cell-mediated immunity to virus causing haemorrhagic fever with renal syndrome: generation of cytotoxic T lymphocytes.

Cytotoxic T lymphocytes (CTLs) were generated when spleen cells from mice infected with viruses causing haemorrhagic fever with renal syndrome were stimulated in vitro with syngeneic cells infected with viruses. These cytotoxic effector cells, with Lyt2+ L3T4- markers on their surface, demonstrated H-2 restriction. CTLs induced by Hantaan virus (76-118 strain) or Seoul virus (B-1 strain) showed cross-reactivity with infected target cells. Hantaan virus infection induced a higher CTLs response than Seoul virus infection, although the antibody responses to these two viruses and the replication of the two virus strains in athymic nude mice were not significantly different. Viral antigen detected with a monoclonal antibody reacting with nucleocapsid antigen was observed mainly in the cytoplasm of macrophages infected with Hantaan virus, but in the nucleus of cells infected with Seoul virus. The major viral antigens recognized by CTLs are discussed on the basis of these findings.

Infiltration of peroxidase-producing eosinophils into the lamina propria of patients with ulcerative colitis

Abstract: Little information is available to explain the pathogenesis of ulcerative colitis (UC). In this study, we focused on eosinophils in the lamina propria of the mucosa of patients with UC in the active phase. Biopsy specimens were taken from 17 patients with UC in the active phase, 17 in the inactive phase, and 20 control patients, and submitted for histochemical staining for peroxidase and chloroacetate esterase for microscopic examination. Both peroxidase-producing and chloroacetate esterase-producing cells in the lamina propria increased markedly in the active phase (8.3 ± 3.1/0.01 mm2 and 6.6 ± 2.7/0.01 mm2, respectively), compared with values in the inactive phase (0.8 ± 0.6/0.01 mm2 and 1.3 ± 0.6/0.01 mm2) or in the controls (1.3 ± 0.8/0.01 mm2 and 1.3 ± 0.4/0.01 mm2). Triple staining for peroxidase, chloroacetate esterase, and nonspecific esterase in the specimens revealed that the peroxidase-producing cells constituted a different population from that of neutrophils, macrophages/monocytes, or basophils. A monoclonal antibody specific for eosinophil peroxidase stained almost all infiltrated peroxidase-producing cells. These results indicated that eosinophils with strong peroxidase activity had infiltrated the lamina propria in UC, suggesting an allergic background and the involvement of released peroxidase in the mucosal damage characteristic of UC.

Eradication of metastatic tumour cells from lymph nodes by local administration of anti-CD3 antibody

The possibility of in vivo removal of metastatic tumour cells from lymph nodes by local intradermal administration of an anti-CD3 monoclonal antibody (mAb) was examined. Murine tumour cells in the lymph nodes were completely eradicated by intradermal injections of the mAb. This treatment was effective for removal of Lewis lung cancer cells from lymph nodes, but not for removal of subcutaneous tumours of this cell line. This treatment induced in vivo cytotoxicity in the regional lymph nodes against the syngeneic tumour cells. The following in vitro studies suggested that the cytotoxicity was probably mediated mainly by CD4+ T cells, with slight participation of CD8+ T cells. Normal lymph node and spleen cells showed cytotoxicity after in vitro incubation with the mAb for 2 days. Cell sorting with a fluoresceinactivated cell sorter showed that CD4+ T cells developed during the incubation to lyse syngeneic tumor cells directly by themselves, macrophages not being involved in this tumour cell lysis. The lytic activity was detected in the cellular fractions, but not in the culture supernatants of these T cells. Furthermore, it was completely blocked by specific antiserum for tumour necrosis factor-α (TNFα). An immunoprecipitation study revealed that these T cells expressed TNFα molecules of 26 kDa, but not of 17 kDa, suggesting that tumour cell lysis was caused by membraneintegrated TNFα molecules. These results strongly suggest that local administration of anti-CD3 antibody is a very effective and appropriate procedure for eradication of metastatic tumour cells from regional lymph nodes.

Use of the hemagglutinating virus of Japan (HVJ)-liposome method for analysis of infiltrating lymphocytes induced by hepatitis B virus gene expression in liver tissue.

We previously developed a method for introducing foreign genes into liver tissue using liposomes with incorporated hemagglutinating virus of Japan (HVJ, Sendai virus), and found that liver cells transfected with the E. coli beta-galactosidase gene or the gene for hepatitis B virus (HBV) surface protein (HBsAg) expressed these proteins in vivo. Here, we analyzed cellular reactions leading to hepatitis in the liver by expressing the genes of HBV in vivo. Lymphocytes were eluted directly from liver transfected with the HBsAg genes and shown to be cytotoxic only to cells expressing HBsAg in vitro. These lymphocytes were identified as cytotoxic T lymphocytes with the CD4- CD8+ phenotype. Transfer of these lymphocytes to transgenic mice with the whole HBV genome led to elevation of the serum glutamic-pyruvic transaminase (SGPT) level, indicating the induction of hepatitis due to the cytotoxic T lymphocytes in vivo. Similarly, direct transfer of the gene for the HBV secretory core protein (HBeAg) induced expression of HBeAg in hepatocytes and the appearance of antibody against HBeAg in the serum. However, using this system, we found that the lymphocytes infiltrating the transfected liver showed no cytotoxicity specific for HBeAg. These results indicate that expression of HBsAg, one of the components of virions, in animal liver induced hepatitis efficiently through generation of specific cytotoxic T lymphocytes (CTL) without any expression of the other viral components. This in vivo experimental system should be useful for evaluating how expression of a given gene induces cellular reactions and intrinsic functions in the living body.