Functional Characteristics of Enhanced Fc Receptor Expression of β2 Integrin-Deficient Bovine Mononuclear Phagocytes

Fc receptor expression, cytoplasmic Ca²⁺ signaling, chemiluminescent (CL) response, and electron spin resonance (ESR) combined with spin trapping of blood mononuclear phagocytes from control heifers and a heifer with leukocyte adhesion deficiency (LAD) were evaluated to elucidate the relationships between complement receptor type 3 (CR3) and Fc receptor expression and their functional responses. The mean fluorescence intensity of fluorescein isothiocyanate (FITC)-conjugated anti-bovine IgG bound to mononuclear phagocytes from the heifer with LAD was 1.8-fold higher than that of control heifers. The mean increments of cytoplasmic Ca²⁺ concentrations of mononuclear phagocytes from the heifer with LAD stimulated with OPZ, Agg-IgG, and PMA were 39.4 (P<0.05), 118, and 71.6% compared with those of control heifers. A 1.27-fold increase in the CL response relative to control heifers was detected when mononuclear phagocytes from the heifer with LAD were stimulated with Agg-IgG. The OPZ-induced CL response of mononuclear phagocytes from the heifer with LAD was significantly (P<0.05) decreased, whereas the PMA-induced CL response was similar to that of control heifers. The ESR spectrum of mononuclear phagocytes from the heifer with LAD was increased when stimulated with Agg-IgG, and was impaired when stimulated by OPZ compared with that of control heifers. The ESR spectrum of mononuclear phagocytes stimulated with PMA was similar in control heifers and the heifer with LAD. Fc receptors on mononuclear phagocytes from the heifer with LAD were enhanced, and their cytoplasmic Ca²⁺ signaling, CL response, and ESR-spin trapping when stimulated with Agg-IgG and OPZ appeared to be associated with enhanced Fc receptors.     

Synthesis of glycosylated human interleukin-1α, neoglyco IL-1α, coupled with N-acetylneuraminic acid

In order to develop glycosylated cytokine, recombinant human IL-1 was chemically modified with N-acetylneuraminic acid (NANA). NANA with C9 spacer, 8-(hydrazinocarbonyl)octyl 5-acetamido-3, 5-dideoxy-D-glycero--D-galacto-2-nonulo-pyranosidonic acid potassium salt (6), was synthesized by glycosylation of C9 spacer, 8-[2-N-(benzyloxycarbonyl)hydrazinocarbonyl]octanol, with methylthio glycoside derivatives of NANA in the presence of molecular sieves 3Å and methyl(methylthio)sulfonium trifrate in propionitrile, followed by separation of and anomers with a column chromatography and deprotection. Compound 6 was coupled to IL-1 by the acyl azide method. The glycosylated IL-1 was purified by anion-exchange chromatography, and NANA coupled to IL-1 was confirmed by oxidation with NalO_4–. Based on the molecular weight average number of carbohydrate molecules introduced per molecule of IL-1 was estimated to be 2.9.     

Fc Receptor-Mediated Phagocytosis,Superoxide Production and Calcium Signaling of β2 Integrin-Deficient Bovine Neutrophils

Fc receptor for immunoglobulin G-mediated phagocytosis, superoxide production and intracellular calcium ([Ca²⁺]ⁱ) signaling of complement receptor type 3 (CR3)-deficient neutrophils from a heifer with leukocyte adhesion deficiency (BLAD) were compared to those of control heifers. The mean phagocytic activity of IgG-coated yeasts and aggregated bovine IgG (Agg-IgG)-induced superoxide production of CR3-deficient neutrophils were 10% and 77.9%, respectively, of those of control neutrophils. The [Ca²⁺]ⁱ signals in CR3-deficient neutrophils stimulated with Agg-IgG or concanavalin A were different with mean peak [Ca²⁺]ⁱ concentrations of 78% and 41.9%, respectively, of those of control neutrophils. These findings suggest that Fc receptor-mediated neutrophil functions are closely dependent on the presence of CR3 (CD11b/CD18) on the neutrophil cell surfaces.     

841. ILEX DIMORPHOPHYLLA

The holly, Ilex dimorphophylla Koidz., an endangered endemic from the Ryukyu Islands, is illustrated and described. The habit of leaf dimorphy, between spiny and spineless leaves, is discussed.     

Strong genetic structure revealed by microsatellite variation in Callicarpa species endemic to the Bonin (Ogasawara) Islands

Journal of Plant Research - Adaptive radiation is the diversification of a founding population into multiple taxa that are differentially adapted to diverse ecological niches. The three Callicarpa...     

Hamster PIWI proteins bind to piRNAs with stage-specific size variations during oocyte maturation

In animal gonads, transposable elements are actively repressed to preserve genome integrity through the PIWI-interacting RNA (piRNA) pathway. In mice, piRNAs are abundantly expressed in male germ cells, and form effector complexes with three distinct PIWIs. The depletion of individual Piwi genes causes male-specific sterility with no discernible phenotype in female mice. Unlike mice, most other mammals have four PIWI genes, some of which are expressed in the ovary. Here, purification of PIWI complexes from oocytes of the golden hamster revealed that the size of the PIWIL1-associated piRNAs changed during oocyte maturation. In contrast, PIWIL3, an ovary-specific PIWI in most mammals, associates with short piRNAs only in metaphase II oocytes, which coincides with intense phosphorylation of the protein. An improved high-quality genome assembly and annotation revealed that PIWIL1- and PIWIL3-associated piRNAs appear to share the 5′-ends of common piRNA precursors and are mostly derived from unannotated sequences with a diminished contribution from TE-derived sequences, most of which correspond to endogenous retroviruses. Our findings show the complex and dynamic nature of biogenesis of piRNAs in hamster oocytes, and together with the new genome sequence generated, serve as the foundation for developing useful models to study the piRNA pathway in mammalian oocytes.     

Geographic patterns of endemism and speciation in amphibians and reptiles of the Ryukyu Archipelago, Japan, with special reference to their paleogeographical implications

This paper analyzes the phylogeographical patterns of amphibian and reptile lineages distributed in the Ryukyu islands south of the Tokara Gap on the basis of relevant distributional data and phylogenetic hypotheses hitherto published. Results indicate the numerical dominance of highly relict lineages in the central Ryukyus, and the occurences of a few more or less relict lineages in the Miyako Group as well. On the other hand, most species and subspecies endemic to the Yaeyama Group or to the Yaeyama and Miyako Groups are considered to be direct consequences of vicariance with adjacent regions. Three major hypotheses regarding the Cenozoic paleogeography of the central and the southern Ryukyus are examined in the light of the present results and a modified hypothesis is proposed accordingly.     

A possible association between basic amino acids of position 13 of DRB1 chains and autoimmune hepatitis

Fifty-one patients with autoimmune hepatitis have been studied for HLA association by conventional serology and also by modified polymerase chain reaction-restriction fragment lenght polymorphism (PCR-RFLP) genotyping.HLA-DR4 was significantly associated with autoimmmune hepatitis (46 of 51 patients, 90.2%). DNA typing of the DRB1 gene for 43 DR4-positive patients by using the PCR-RFLP technique revealed that of 43 patients, 33 had DRB1 ^* 0405 (Dw15), five had DRB1 ^* 0406 (DwKT2), four had DRB1 ^* 0403 (Dw13a), two had DRB1 ^* 0401 (Dw4), two of 43 had DRB1 ^* 0407 (Dw13b) and one had DRB1 ^* 0408 (Dw14b). Thus, there was no significant difference in Dw frequencies between DR4-positive patients and DR4-positive healthy subjects. These findings suggest that the DR4-specific sequence (Val 11 and His 13 at amino acid positions 11 and 13, respectively), but not particular Dw-associated DR4 sequence, in the first domain of the DRB1 chain contributes to susceptibility to autoimmune hepatitis among Japanese. Interestingly, all five of the DR4-negative patients had the DR2 specificity (DRB1 ¹⁵⁰² or 1601). Taken together, these results imply that the basic amino acids at position 13, which is present only on the DR2 and DR4 B1 molecules (Arg on DR2 and His on DR4), are most important for determining the predisposition to autoimmune hepatitis. Address correspondence and offprint requests to: M. Ota.