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.     

On the methodology of morphology and levels of morphologic analysis

Unjustified narrowing of the problems of morphology by merging the terms "morphology" and "anatomy" leads to stagnation in morphology. The merging of "classic" and "modern" biology will enrich both morphology and molecular biology and genetics. The latter will be able apply conceptual models of morphology to more primitive structural level of life. The possibility to apply V. A. Dogel' 's ideas on the role of oligomerization and polymerization in science to the analysis of molecular evolution has been demonstrated with the analysis of DNA content in the genomes of Chordata taken as an example. The data on DNA content do not allow both to consider lungfishes as ancestors of all Tetrapoda and develop monophyletic concept of Tetrapoda origin at the same time. The possibility of application of concepts of comparative morphology to analysis of molecular evolution has been considered.     

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.     

Study of the Mg2+-ATPase reaction of myosin using the NMR-31P method. Detection of adenylate kinase activity in a purified myosin subfragment I]

Isolated myosin heads (HMM-S1) were concentrated by ultrafiltration in an "Amicon" cell to a concentration of 120 mg/ml. Incubation of HMM-S1 with ATP in the presence of Mg2+ produced an AMP peak in the spectrum of NMR-31P whose size was increasing linearly with the reaction time. It was demonstrated that after heating of the sample the appearance of AMP in the incubation mixture was due to the presence of a small amount of adenylate kinase (or myokinase) in the purified preparation of HMM-S1.     

Populational chromosomal polymorphism the Asian forest mouse Apodemus peninsulae]

29 individuals of Apodemus peninsulae, an Asian forest mouse from the Suputin State Nature Reserve (Maritime Territory) were studied karyologically. Diploid chromosome sets of the animals studied contained from 48 to 52 chromosomes. The difference in the diploid chromosome numbers is caused by the presence in some individuals of supernumerary metacentric chromosomes (up to 4). The set is always represented by 48 acrocentric chromosomes, gradually decreasing in size. The supernumerary metacentric chromosomes vary in size from medium-sized to the smallest in the set. The character of intrapopulational chromosome polymorphism of continental and island populations of Apodemus peninsulae is discussed. Attempts are made to explain the polymorphism with respect to supernumerary chromosomes as the result of some viral diseases.