A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

The decline of tree diversity on newly isolated tropical islands: A test of a null hypothesis and some implications

Summary Six islands, each less than a hectare in area, were isolated in about 1913 from the mainland of central Panamá by the rising waters of Gatun Lake. By 1980, the diversity of trees on all but one of these islands was far lower than on mainland plots of comparable size. A restricted subset of tree species has spread on these islands, notablyProtium panamense, Scheelea zonensis, Oenocarpus panamanus andSwartzia simplex. We constructed a null model to predict how chance would change tree diversity and the similarity of tree species compositions of different islands, assuming that each mature tree has equal chances of dying and/or reproducing, regardless of its species. This model cannot account for the diminished diversity of the changes in vegetation on these islands: some factors must be favoring a particular set of tree species.Two factors, exposure to wind and absence of mammals, seem needed to bring about the vegetation changes observed on these small islands. Their vegetation shows many signs of wind damage and of adaptation to resist wind, reflecting its exposure to dry season winds and storm winds sweeping across the lake from the west. Their most common tree species appear to have spread because mammals rarely visit these small and isolated islands. Seed of these common species are normally much eaten by mammals and do not need burial by mammals to escape insect attack.A thorough grasp of plant—animal interactions is needed to understand the events that have taken place on these islands. Identifying those keystone animals essential for maintaining plant diversity is a necessary element of reserve design and forest management in the tropics.The US government has the right to retain a non-exclusive, royalty-free license in and to any copyright covering this paper.     

Plasminogen activator and collagenase production by cultured capillary endothelial cells

Cultured bovine capillary endothelial (BCE) cells produce low levels of collagenolytic activity and significant amounts of the serine protease plasminogen activator (PA). When grown in the presence of nanomolar quantities of the tumor promoter 12-O-tetradecanoyl phorbol-13-acetate (TPA), BCE cells produced 5-15 times more collagenolytic activity and 2-10 times more PA than untreated cells. The enhanced production of these enzymes was dependent on the dose of TPA used, with maximal response at 10(-7) to 10(-8) M. Phorbol didecanoate (PDD), an analog of TPA which is an active tumor promoter, also increased protease production. 4-O-methyl-TPA and 4α-PDD, two analogs of TPA which are inactive as tumor promoters, had no effect on protease production. Increased PA and collagenase activities were detected within 7.5 and 19 h, respectively, after the addition of TPA. The TPA-stimulated BCE cells synthesized a urokinase-type PA and a typical vertebrate collagenase. BCE cells were compared with bovine aortic endothelial (BAE) cells and bovine embryonic skin (BES) fibroblasts with respect to their production of protease in response to TPA. Under normal growth conditions, low levels of collagenolyic activity were detected in the culture fluids from BCE, BAE, and BES cells. BCE cells produced 5-13 times the basal levels of collagenolytic activity in response to TPA, whereas BAE cells and BES fibroblasts showed a minimal response to TPA. Both BCE and BAE cells exhibited relatively high basal levels of PA, the production of which was stimulated approximately threefold by the addition of TPA. The observation that BCE cells and not BAE cells produced high levels of both PA and collagenase activities in response to TPA demonstrates a significant difference between these two types of endothelial cells and suggests that the enhanced detectable activities are a property unique to bovine capillary and microvessel and endothelial cells.     

Separation of dissociated thyroid follicular and parfollicular cells: association of serotonin binding protein with parafollicular cells

Parafollicular cells (PC) of the sheep thyroid gland are neural crest derivatives that synthesize and release the biogenic amine serotonin (5-HT) as well as the hormone calcitonin. The thyroid also contains a highly specific serotonin-binding protein (SBP). Separation of dissociated thyroid cells was done to study the cellular localization of SBP and to develop a means of isolating PC for study. Various methods were used to obtain an enriched and purified population of PC. Minced thyroid glands were enzymatically dissociated and the cells were layered on a Ficoll linear density gradient. Fractions obtained from the gradient were examined for cell number, viability, 5-HT concentration, SBP activity, and morphology by electron microscopy. One of the fractions was found to be enriched in PC. High levels of 5-HT and SBP were also found in this fraction, whereas these levels were low where the majority of cells were found. This PC-rich fraction, however, contained numerous follicular cells (FC); therefore, additional approaches to cell separation were used. FC can be stimulated in vitro with thyroid stimulating hormone (TSH) to become intensely phagocytic. When stimulated cells were incubated in the presence of silica microspheres, the FC engulfed the microspheres, which were toxic to them. PC did not become phagocytic and were unharmed by the microspheres. Suspended cells, after incubation with microspheres, were centrifuged on a discontinuous gradient, and a PC-rich fraction was obtained. Silica, however, interfered with analysis of SBP. Another method to take advantage of the phagocytic potential of FC was therefore used. TSH-stimulated cell suspensions were passed through a column of sepharose to which thyroglobulin had been coupled. Stimulated FC apparently adhered to the beads and were retained by the columns. Fractions eluting from the columns were greatly enriched with PC. These fractions contained high levels of 5-HT and SBP, and considerably reduced FC contamination was found by quantitative electron microscopy. It is concluded that SBP is localized to PC in the sheep thyroid. The idea that these cells resemble serotonergic neurons in their mechanisms of 5-HT storage is supported.     

Bemerkungen zur Evolution von., Sprachen bei Säugetieren1 Zur Variabilität innerartlicher Kommunikation bei Caniden

Remarks on the evolution of “languages” of mammals. The variability of the intraspecific communication of canids The canid species mainly considered in this study, the golden jackal (Canis aureus), the cojote (Canis latrans), and especially the wolf (Canis lupus) have an extremely variable species-specific intraspecific communication. Communities, but also differences between the species become evident; the wolf with its distinct social behavior has the greatest differentiation. These results make also clear, that forms of communication in mammals develop in evolutionary processes and events. A safe statement on the beginning of the forms of communication in canids cannot be given so far. This is also true for humans. The ideas of Lenneberg (1967) of the parallel and disjunct origin of the forms of communication in mammals has a high probability for higher systematic units, but on lower systematic level a gradual change can be observed. The forms of communication in mammals are highly differentiated structures, where specific pecularities of the brain are of a special importance. The observations on the variability of intraspecific communication of canids, representing nonhuman mammals, suggest to define “language” in a very general form. In this way, similarities, analogies, and differences between the species of mammals, inclusive man, can be seen more clearly. In only this way the material can be gained to answer the question, if the language of man has in principle exceptional position biologically. It is important for the valuation of forms of intraspecific communication, the “languages”, of mammals not to choose human theory of life and human thinking as a basis, but to start with the biological pecularities of the species. Also canids, as higher mammals, have the ability to abstract, a form of thinking. In their special, species-specific way also non-human mammals arrange their area of experience and thinking. They form for themselves a species-specific “theory of live”. This will of course be different from the human one, according to the systematic position and the biological environment of the species. It is generally accepted that man has special abilities of thinking, he possesses an extraordinary developed brain, compared to all other mammals. This must effect his communication, his language, and result in differences to other mammal species. Gipper (1977) pointed out especially these differences, but they should not be interpreted as differences in principle. Canids use different gestures and sounds for communication within the species; dialog relations can be observed. Different connections of gestures and sounds have different contents of information. It is remarkable that canids do not use their total abilities in using the means of communication in the same way. This is very striking in the change from the wolf, as the only ancestor, to the domestic dog. It is evident that the brain has a greater importance in developing intraspecific communication, than do the peculuarities of organs causing the understanding. A dependanc of intraspecific communication from the environment can be observed either in differences of wird species of canids as well as in the domestication. In the domestic dog, but also in other domestic animals, there is an increase in vocalisations. But the content of information of sounds and gestures decreases in domestication, expressions of arousal become more important. A remarkable plasticity of intraspecific communication becomes evident by domestication. The transformations can be evaluated in the sense of Kosswig (1963, 1965) as first stages of a regressive evolution. Experiments of cross-breeding canid species show exemplarily that forms of communication within these mammal species have a highly polygene regulation, and that processes of learning have an influence. Also from this point of view, no basic differences between nonhuman mammals and humans can be assured, especially when taking into account the facts and thoughts described by Lenneberg. The findings in the canids give useful hints for a better understanding of the human language and its relations to the forms of communication in other mammals. Altogether one can conclude that genetic variability, numerous recombinations, the synorganisation of the processes caused in this way, and natural selection plays definite role in the evolution of “languages”.     

Palatability and feeding preferences of Uresiphita maorialis (Lepidoptera: Crambidae) for three Sophora species

In a three-hour bioassay, we tested the palatability and feeding preferences of Uresiphita maorialis (kōwhai moth) for Sophora tetraptera, Sophora microphylla and Sophora prostrata. Palatability tests showed no differences among the Sophora species. Feeding preferences, on the other hand, showed that S. tetraptera and S. microphylla leaves are preferred over S. prostrata leaves. Our results support our field observations in Wellington city parks and gardens showing that S. tetraptera and S. microphylla plants frequently have higher densities of larvae than S. prostrata.     

Molecular diversity of arbuscular mycorrhizal fungi and patterns of host association over time and space in a tropical forest

We have used molecular techniques to investigate the diversity and distribution of the arbuscular mycorrhizal (AM) fungi colonizing tree seedling roots in the tropical forest on Barro Colorado Island (BCI), Republic of Panama. In the first year, we sampled newly emergent seedlings of the understory treelet Faramea occidentalis and the canopy emergent Tetragastris panamensis, from mixed seedling carpets at each of two sites. The following year we sampled surviving seedlings from these cohorts. The roots of 48 plants were analysed using AM fungal-specific primers to amplify and clone partial small subunit (SSU) ribosomal RNA gene sequences. Over 1300 clones were screened for random fragment length polymorphism (RFLP) variation and 7% of these were sequenced. Compared with AM fungal communities sampled from temperate habitats using the same method, the overall diversity was high, with a total of 30 AM fungal types identified. Seventeen of these types have not been recorded previously, with the remainder being similar to types reported from temperate habitats. The tropical mycorrhizal population showed significant spatial heterogeneity and nonrandom associations with the different hosts. Moreover there was a strong shift in the mycorrhizal communities over time. AM fungal types that were dominant in the newly germinated seedlings were almost entirely replaced by previously rare types in the surviving seedlings the following year. The high diversity and huge variation detected across time points, sites and hosts, implies that the AM fungal types are ecologically distinct and thus may have the potential to influence recruitment and host composition in tropical forests.     

Successful immunotherapy with matrix metalloproteinase-derived peptides in adjuvant arthritis depends on the timing of peptide administration

We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development of such therapies.