Characterization of CD18-Deficient Neutrophil Functions and Some Modulations of Bovine Neutrophils from Cattle with Bovine Leukocyte Adhesion Deficiency

点击翻译按钮获取中文摘要

The above-entitled study was performed and the results were summarized as follows :Clinical and pathobiological findings of the bone marrow (BM) -transplanted heifer with leukocyte adhesion deficiency were evaluated for 1.6 years, from 27 months after BM transplantation until deceased. Serum cytokine levels and their expression of mRNA on neutrophils from a bone marrow (BM) transplanted heifer with leukocyte adhesion deficiency were evaluated. the clinical condition of the affected heifer was relatively stable after BM-transplantation. Persistent hyper Ei - globulinemia and increased serum immunoglobulin G (IgG) concentrations were monitored longitudinally. The concentration of interleukin (IL) -1E? In serum from the affected heifer ranged from 15.8 to 321.7 ng/ml, and maximum concentration occurred at the time which coincided with peak IL-6. Serum Levels of IL-6 ranged from 0.32 to 27.9 ng/ml, and they appeared to be associated with the increment of serum IgG in the affected heifer mR … More NAs for IL-1E?, IL-6, IL-8 and granulocyte and macrophage colony stimulating factor (GM-CSF) were increased in neutrophils from the affected heifer compacted to controls. Persistent hyper Ei-globulinemia of the affected heifer appeared to be associated with enhanced mRNA expression for IL-6 and its serum levels. There findings suggesting that humoral immunity of the affected heifer is activated and the production of neutrophils appears to be enhanced under the incapability of E?2 integrin-mediated functions of phagocytic cells.Killing activity (KA) and antibody-dependent cell cytotoxicity (ADCC) of neutrophils from normal cattle and with bovine leukocyte adhesion deficiency (BLAD) were compared in order to evaluate the cytotoxicity of CD18-deficient bovine neutrophils. The KA of CD18-deficient neutrophils was significantly lowered (P =< 0.01) when compared to normal neutrophils, whereas ADCC activity was increased. Fc receptor for immunoglobulin G (FcyR-IgG) mediated ADCC of neutrophils appeared to be enhanced in BLAD neutrophils.In vivo responsiveness to epinephrine, expression of L-selectin on neutrophils, changes in intracellular calcium ([Ca2+]i), sulfatide-induced superoxide production and tyrosine phosphorylation in neutrophils were evaluated to elucidate the role of L-selectin-associated functions of normal and CD18 deficient bovine neutrophils. The number of neutrophils in peripheral blood was significantly (P < 0.05) increased in 4 normal calves at 5-20 minutes after in vivo administration of epinephrine, however, no significant increase of neutrophils was found in 3 calves with bovine leukocyte adhesion deficiency (BLAD). Expression of L-selectin on neutrophils from 3 calves with BLAD was 61-77 % of that of normal calves. Pretreatment of neutrophils with phorbol myristate acetate (PMA) caused a marked decrease in the expression of L-selectin on neutrophils from both normal- and BLAD-calves. Sulfatide-induced sustained phase of [Ca2+]i concentration in neutrophils from calves with BLAD was significantly (P < 0.05) decreased ; following.Costimulatory effects of complement receptor type 3 (CR3) and Fc receptor for immunoglobulin G (FCR) expressed on bovineneutropfils on superoxide production and signal transduction were evaluated. Superoxide production of normal neutrophils stimulated together with CR3 FCR was much greater than that stimulated with CR3 or FCR alone, and was closely associated with the rise of intracellular calcium ([Ca2+]i) concentration and the amount of tyrosine phosphorylated 100kDa protein. The costimulatory effect of there receptors on superoxide production in CR3-deficient neutrophils was not found. The costimulation of CR3 and FCR on bovine neutrophils leads to enhanced superoxide production and signal transduction, and appears to be ralated to the comsummation of neutrophil activity.DEMPO is useful to detect superoxide of extracellular space including the intraphagosome but not that of intracellular space in opsonized zymosan-stimulated phagocytes. The roles of p38 MARK inhibitor and PKC inhibitor suppressed the superoxide production of neutrophils. Both inhibitors also caused significant attenuation of opsonized zymosan-induced phosphorylation of p47 phox, whereas phagocytosis was found to be inhibited by MAPK inhibitor but not by PKC inhibitor. The results suggest that p38 MARK participates in both signaling pathways of superoxide production and phagocytosis. The formation of F-actin is dependent on PI3-K and independent of PKC, ERK and p38MARK as well as the increase in intracellular calcium, whereas the activation of NADPH oxidase is partly dependent on the activation of PKC and the increase in intracelluar calcium. Less