Comparative studies on the adhesiveness of granulocytes of guinea pig and man

Summary The high affinity of granulocytes of guinea pig and man to glass surfaces is modified by serum. Native serum contains both an adherence-promoting activity, which is related to complement, and components which reduce the adhesiveness of granulocytes. These components are stable at 56°C for 30 min and are tightly bound to the glass surface. -Lipoproteins are candidates for this adherence reducing ability of serum. Adherence promotion by native serum is mediated by coating the glass surface with C3b/C3bi. Human granulocytes from the peripheral blood adhered to glass surfaces coated by native human or guinea pig serum with C3b/C3bi to almost the same extent as in the presence of native serum, but on guinea pig granulocytes elicited in the peritoneal cavity, a cell surface metalloproteinase degraded the C3b/C3bi, thus reducing the adhesiveness of these cells. This proteinase was inhibited by MgEDTA, DTT, and 1,10-phenanthroline, whereby the high adhesiveness of granulocytes was restored to C3b/C3bi-coated glass.Abbreviations BA benzamidine hydrochloride - BTS Bacillus thuringiensis subtoxicus - DTT dithiothreitol - EAC -amino-caproic acid - gp guinea pig - LDL low density lipoproteins - SEM scanning electron microscopy     

Investigations on cellular defense reactions with Galleria mellonella against Bacillus thuringiensis

In contrast to a great number of foreign particles (bacteria and inorganic materials), cells of some strains of Bacillus thuringiensis are not phagocytosed in the first hours after injection into the hemocoel of Galleria mellonella. This phenomenon is not caused by the production of β-exotoxin or exoenzymes, because heat-killed cells are not phagocytosed and the phagocytosis of latex particles is not prevented by the presence of living B. thuringiensis. The phagocytosis of heat-killed B. thuringiensis subtoxicus can be encouraged by treatment of the cells and by simultaneous injection of latex particles. A factor stimulating the phagocytosis is discussed. It is induced by the injection of phagocytosable latex particles into the hemocoel but not by injection of living or killed B. thuringiensis subtoxicus.     

Biochemical characteristics of Eiseniapore, a pore-forming protein in the coelomic fluid of earthworms.

The cytolytic protein Eiseniapore (38 kDa) from coelomic fluid of the earthworm Eisenia fetida functionally requires sphingomyelin as revealed by using mammalian erythrocytes and phospholipid vesicles. The effects of ions, glycoproteins and phospholipids were investigated for the two-step Eiseniapore action mode, binding and pore formation in different assays. Eiseniapore lysis is activated by thiol groups but inhibited by metal ions. Eiseniapore binding to target membranes is inhibited by Eiseniapore-regulating factor, vitronectin, heparin and lysophosphatidylcholine. Ca2+ and Mg2+ were found to be not necessary for membrane binding or lytic activity. Sphingomyelin was essential for Eiseniapore-induced leakage of liposomes. We describe a cytolytic protein/toxin in Eiseniapore which differs from the established classification; it can be activated by thiol groups and is inhibited by sphingomyelin. Electron microscopy of erythrocyte membranes confirmed ring-shaped structures (pores) with a central channel with outer (10 nm) and inner (3 nm) diameters as shown previously [Lange, S., Nüssler, F., Kauschke, E., Lutsch, G., Cooper, E.L. & Herrmann, A. (1997) J. Biol. Chem. 272, 20 884-20 892] using artificial membranes. Functional evidence of pore formation by Eiseniapore was revealed as protection of lysis by carbohydrates occurred at an effective diameter above 3 nm. From these results, we suggest a plausible explanation for the mechanism by which components of the earthworm's immune system destroy non-self components.     

Beiträge zur kenntnis fossiler trauermücken aus Sächsischem Bernstein. teil II. Drei neue sciariden aus tertiär-Harzen des bitterfelder braunkohlereviers (insecta,diptera, sciaridae)

Examination of 278 pieces of fossil resins from the lower Miocene Saxonian amber (opencast mining Goitsche/Bitterfeld/Germany) yielded to a total of 60 Sciarids in 29 pieces of amber. They belong to 9 species from 3 genera. The speciesEpidapus Primarius, Trichosia (Palaeotrichosia) voelsgeni andTrichosia (Palaeotrichosia) kedingi are new. The other species are known also from Baltic amber.     

Immunological activation of phagocytic cells in Galleria mellonella

A phagocytosis-stimulating activity against the normally nonphagocytosable cells of Bacillus thuringiensis subtoxicus develops in the hemolymph of larvae of Galleria mellonella at different periods after injection with readily phagocytosable latex beads. The phagocytosis-stimulating factor can be transferred into new animals with the cell-free hemolymph of treated larvae. It is not detectable in the hemolymph of normal larva but is present in the supernatant of homogenates of the skin. The fractionation of activated hemolymph on Sephadex shows that the active substance has a low molecular weight. It appears to have a biological effect in cellular defense reactions as in the case of lymphokine in vertebrates.     

Phagocytosis-stimulating mediators in insects

The ability of insect blood cells to ingest all kinds of synthetic particles and also a wide range of microorganisms in a very short time after injection has up to now been regarded as a phagocytic function without any humoral mediators. In a phagocytosis model with latex beads and nonhagocytosable cells of Bacillus thuringiensis subtoxicus, we are able to demonstrate the existence of lymphokine-like factors, which intervene in cellular defence reactions of insect. The following results were obtained: 1. Immediately after injection of latex beads, normally non-phagocytosable cells of Bacillus thuringiensis subtoxicus are phagocytosed. 2. Cell-free haemolymph of larvae of Galleria mellonella previously injected with latex beads, stimulates in new larvae phagocytosis of Bacillus thuringiensis subtoxicus after transfusion. 3. The fractionation of homogenates of latex-treated larvae on Sephadex G 50 shows two fractions which stimulate phagocytosis. We suppose that the appearance of these phagocytosis-stimulating factors is the result of a successful recognition of foreign material.     

Cytotoxic activity in the coelomic fluid of the annelidEisenia foetida Sav

The annelid Eisenia foetida not only causes hemolysis of red blood cells of several vertebrate species, but also has a toxic effect on a variety of cell types, such as chicken fibroblasts, guinea-pig polymorphonuclear leukocytes and insect hemocytes. However, it has no influence on the vitality of the coelomocytes of Lumbricus terrestris and other lumbricides, nor on the hemocytes of the snail Helix pomatia, the mussels Anodonta cygnea and Unio tumidus, free cells of the turbellarian Euplanaria sp. or whole Rhabditis oxycerca (nematode) and the protozoons Paramaecium caudatum and an amoeba of the Proteus-type. By electrofocussing the hemolytic activity of pooled coelomic fluid was separated into 7 hemolytic bands. Three of them are cytotoxic. The cytotoxic effect is a result of the destruction of the cell membrane, as shown by measuring the release of lactate dehydrogenase (LDH). The bacteriostatic and bacteriocidal action of the coelomic fluid of E. foetida against a broad spectrum of gram positive and gram negative bacteria was tested. An antibacterial activity could be observed only against Proteus vulgaris and Bacillus megaterium. It was noted that the so-called Eisenia foetida-factor acts on an antigenic structure at the cell surface when anti-sheep-E-antibody was used under competitive conditions. The binding between the Eisenia foetida-factor and this membrane structure is relatively strong as it cannot be removed by subsequent treatment with anti-sheep-E-antibody or 2 M KCl.