Biomedical subjects
N Okabe
Publications and source records attributed to N Okabe.
Role of epidermal Langerhans cells in resistance to herpes simplex virus infection.
To investigate the role of epidermal Langerhans cells (LC) in resistance to herpes simplex virus (HSV) infection, nonadherent spleen cells taken from BALB/c mice immunized with HSV were cultured with syngeneic epidermal cells (EC) and ultraviolet light-inactivated HSV antigen. After five days of culture, T cell-dependent proliferative response was determined by 3H-thymidine incorporation. Treatment of EC with anti-Iad monoclonal antibody plus complement before cultivation prevented this proliferation, which suggested that LC induced stimulation of immune T cells. When these stimulated spleen cells were transferred to intracutaneously infected nude mice, the virus titer in the skin was reduced markedly and the formation of zosteriform skin lesions was completely inhibited. On the other hand, transfer of unstimulated cells, which were cultured with HSV antigen only or with HSV antigen and EC treated with anti-Iad monoclonal antibody plus complement, resulted in delayed viral clearance and development of the lesions. These results indicate that LC are of importance as accessory cells in the control of cutaneous HSV infection. Furthermore, Lyt 1+ T cells in the stimulated population were shown to have greater protective activity than Lyt 2+ T cells.
Immunological studies on Crohn's disease. VI. Increased chemiluminescent response of peripheral blood monocytes.
Oxidative metabolic activity can be measured by a luminol-dependent chemiluminescence (CL) assay. To investigate the phagocytic activity of blood cells, CL responses were assessed in 26 patients with Crohn's disease (CD) and 26 healthy controls, using heparinized peripheral blood. Significantly (p less than 0.005) increased CL responses of whole blood cells were found in 26 patients with CD. However, CL activity was not directly related to disease activity nor to other clinical parameters. The CL responses did not correlate with the number of white blood cells, neutrophils nor monocytes. In consideration of the increased CL, there is the possibility that functional abnormalities in some components of blood cells leads to elevations in CL responses of whole blood cells. To obtain support for this proposal, blood cells were separated into neutrophils and monocytes, and CL of neutrophils or monocytes were studied, using the same number of each type of cells as that of the controls. The oxidative metabolism of monocytes from CD patients was significantly (p less than 0.005) higher than that of controls, while the phagocytic activity of neutrophils was similar to that in the controls. These data suggest that elevations in CL activity of whole blood cells were not due to alterations of the neutrophils but rather to abnormalities in the monocytes. Further attention directed to the significance of monocyte function in the pathogenesis of CD is warranted.
Immunological studies on Crohn's disease. IV. Decreased ADCC activity.
Antibody dependent cell-mediated cytotoxicity (ADCC) activity was studied in 16 Japanese patients with Crohn's disease (CD) and 16 healthy controls. ADCC activity was assessed by measuring 51Cr release from antibody coated human B-cell line. Significantly (p less than 0.002) depressed ADCC activity was found in patients with CD, although ADCC activity was not directly related to the disease activity. To determine causative factors related to reductions in ADCC activity, circulating immune complex (CIC) was also assayed by C1q-binding method. CIC levels in patients with CD were similar to those in the control group, thereby suggesting that this impaired ADCC activity was not due to blocking of the FC-receptor on K cells by CIC. However, serum zinc concentrations did correlate to the ADCC activity. Hence, an assumption can be made that a decreased ADCC activity may be caused by malnutrition, mainly zinc deficiency, a phenomena linked to CD. The significance of serum zinc in considerations of immunological abnormalities was given attention.
Immunological studies on Crohn's disease. V. Enumeration of circulating lymphocytes subsets using monoclonal antibodies.
We found normal levels of suppressor cell activity and reduced natural killer (NK) and antibody dependent cell-mediated cytotoxicity (ADCC) activities in patients with Crohn's disease (CD). To further characterize these activities, studies were carried out using monoclonal antibodies. There were no changes in the proportion of OKT4+ (helper/inducer T cells), OKT8+ or Leu 2+ (suppressor/cytotoxic T cells) and Leu 7+ (large granular lymphocytes: LGL, NK + K cells), thereby suggesting that suppressor cell activity in CD is likely to be normal both in function and in number, and that depressed NK and ADCC activities are not due to a reduction in the number of NK or K cells but rather to functional defects. Using a double staining method, we noted a low percentage of both Leu 2 and Leu 7 positive cells in CD.
Separation of cross-linked products of rat tail tendon collagen from monomeric components by gel chromatography in the presence of Tris dodecyl sulfate at 4 degrees C.
Rat tail tendon collagen can be solubilized by a neutral aqueous solution containing 2% Tris dodecyl sulfate at 4 degrees C without being unfolded to its constituent polypeptides. The solvent at this temperature is particularly suited for gel chromatographic separation of native collagen. Thus Sepharose CL-2B gel chromatography was found to separate the monomeric collagen molecule from the products of intermolecular cross-linking. The procedure can be effectively used to follow progress of intermolecular cross-linking with aging. The monomeric collagen can be subsequently applied to polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate to evaluate the mode of intramolecular cross-linking.
The binding of a thyroid hormone metabolite, 3-monoiodo-L-thyronine, to bovine serum albumin as measured by circular dichroism.
The interaction between a thyroid hormone metabolite, 3-monoiodo-L-thyronine (3-T1) and bovine serum albumin (BSA) was investigated by using the CD method. An enhanced CD band was observed at the absorption wavelength region of 3-T1 around 293 nm suggesting the binding of 3-T1 to the BSA molecule. The ellipticity at 293 nm was measured at various molar ratios of 3-T1 to BSA, and the apparent binding constant and the maximum number of binding sites could be estimated as Kapp = 8.85 +/- 1.07 X 10(4) M-1 and n = 23.8 +/- 0.9 respectively. The CD of a mixture of BSA, 3-T1 and thyroxine (T4) was also studied at various pH's. The pH profile of the two characteristic CD bands at 293 nm and 320 nm, attributed to bound 3-T1 and T4, suggested that the optimum binding condition of 3-T1 was attained at alkaline pH of around 9, while that of T4 was attained over a wide pH range between 5-10. A significant role of the ionized 4'-hydroxyl group of 3-T1 in the binding reaction with BSA is also suggested.
[A case of islet cell tumor].
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Immunological studies on Crohn's disease. II. Lack of evidence for humoral and cellular dysfunctions.
In 16 patients with Crohn's disease, we attempted to determine possible alterations in humoral and/or cellular immunologic dysfunctions. We examined the antinuclear, antithyroglobulin and antimicrosomal autoantibodies, circulating immunoglobulin levels and complement components. To clarify the significance of cellular immunity in Crohn's disease, mitogenic lymphocyte transformation and concanavalin A-induced suppressor cell activities were studied. Evidence for humoral and cellular immunological abnormalities was not obtained. The correlation between these immunological parameters and disease activity was also nil. These results suggest that Crohn's disease may not be an immunodysfunctional disorder such as systemic lupus erythematosus, but rather a multifactorial disease. The immunological abnormalities reported in the literature may represent phenomena related to states of malnutrition, since the patients we studied were clinically not in a severe stage of the disease.
Immunological studies on Crohn's disease. III. Defective natural killer activity.
Natural killer (NK) activity was studied in 23 patients with Crohn's disease (CD) and 23 healthy controls, as assessed by lymphocyte cytotoxicity against K562 target cells. Severely impaired NK activity was found in patients with CD (p less than 0.001). The relationship between NK activity and disease activity was also analyzed. NK activity was not directly related to the disease activity, although NK function was lower in the patients with an active form of the disease.
[Detection of anti-human parvovirus IgM and IgG in erythema infectiosum].
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Detection of antibodies to human parvovirus in erythema infectiosum (fifth disease).
Two Japanese outbreaks of erythema infectiosum were investigated for evidence of human parvovirus infection by a solid phase antibody capture radioimmunoassay based on a monoclonal antibody to human parvovirus. Specific IgM and high concentrations of specific IgG were detected in 37 sera from 27 children with erythema infectiosum. No anti human parvovirus IgM was detected in a remaining case of erythema infectiosum, in five patients with Kawasaki disease, or in the 17 control children. Seven of the controls were also anti human parvovirus IgG negative, and the 10 who were seropositive had lower concentrations of anti human parvovirus IgG than the patients with erythema infectiosum. These data indicate that human parvovirus is a cause of erythema infectiosum.
Effects of antithyroid drugs on Con A-induced suppressor cell activity.
It is well established that Concanavalin A (Con A)-induced human peripheral blood lymphocytes exert suppressive effects on mitogen-induced proliferation of responder cells. Using peripheral blood lymphocytes from healthy individuals, effects of antithyroid drugs on Con A-induced suppressor function were studied. We found an enhancement of Con A-stimulated suppressor activity by MMI and PTU in all these subjects. In the light of these data, an enhancement in suppressor activity by antithyroid drugs may contribute, in part, to a remission of Graves' disease.
[Induction of differentiation of human myelomonocytic cell lines by chemical inducers: analysis of surface antigens with monoclonal antibodies].
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Immunological studies in Crohn's disease. I. Association with HLA systems in the Japanese.
We attempted to clarify the association between HLA and Crohn's disease. HLA-A, -B, -C and -DR locus antigens in 62 Japanese patients with Crohn's disease were analyzed and the results were compared with findings of 231 healthy Japanese. In the patients with Crohn's disease there was a strong association with HLA-DR4 and -DR5 (chi2 = 14 . 013, RR = 4 . 77 and chi2 = 9 . 345, RR = 5 . 04) and a weak association with HLA-Bw46 and -Bw51 (chi2 = 7 . 077, RR = 2 . 63, and chi2 = 5 . 401, RR = 2 . 52). There was a close association between HLA-DR5 in those with the ileocaecal type, and the -Bw51 and small intestine type. Therefore susceptibility to Crohn's disease may relate to specific allotypes on the human major histocompatibility complex. The correlation was weaker than the other diseases such as ankylosing spondylitis and Coeliac disease.
Myeloid differentiation antigen defined by a monoclonal antibody IF10.
A monoclonal antibody of IgM class that defines the antigen present on human peripheral blood granulocytes was produced and characterized. This monoclonal antibody (IF10) was made from a single fusion between P3-X63-Ag8-U1 (P3U1) myeloma cells and splenocytes from a BALB/c mouse immunized against human cultured monocytoid cell line THP-1 cells. IF10-defined antigen(s) was expressed on the cells of granulocyte lineage such as peripheral blood granulocytes and metamyelocytes, myelocytes, promyelocytes, and a part of myeloblasts in the normal bone marrow, whereas it was not detected on resting and activated T lymphocytes, B lymphocytes, adherent monocytes, and thymocytes. The IF10-defined antigen was also expressed on cultured monocytoid cell lines as well as myeloid and myeloid/erythroid (K-562) cell lines. T lymphoblastoid cell lines, particularly those representing the T cells at an early thymocyte level, and a part of null cell lines were also reactive to IF10. Therefore, IF10 may be a unique monoclonal antibody that defines an antigen(s) which is expressed on almost whole stages of granulocytes and early stages of macrophages and T-cell lineages, and possibly during very early stages of erythroid lineage.
The pathology of the involved tendons in patients with familial arthropathy and congenital camptodactyly.
In 2 sisters with congenital camptodactyly and joint effusions, abnormalities in tendons were restricted to the portion within synovial sheaths. This implied a disease of the tenosynovium, rather than one of the tendon itself. In areas of chronic involvement, some tendons were replaced by fibrous tissue. Significant portions of the tendons in fingers with camptodactyly were replaced by hard scars. Congenital camptodactyly is probably the result of an intrauterine tenosynovitis, rather than an isolated congenital anomaly.
Characterization of the human peripheral blood effector cells mediating antibody-dependent cell-mediated cytotoxicity against respiratory syncytial virus.
Peripheral blood lymphocytes were separated into several subpopulations and evaluated for their ability to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) against respiratory syncytial virus (RSV)-infected HeLa cells. Using erythrocyte rosetting methods, nylon wool filtration, and cytolysis with OKT-3 monoclonal antibody, two lymphocyte subpopulations were shown to mediate RSV-ADCC; non-T, non-B, and IgG-Fc receptor-bearing lymphocytes and E-rosetting cells with IgGFc receptors (T gamma cells). Removal of phagocytic cells did not alter ADCC activity. Monoclonal antibody to human NK and K cells, HNK-1, recognized these two lymphocyte effector subpopulations.