Genetic characterization of an α-specific gene responsible for sexual agglutinability in Saccharomyces cerevisiae: mapping and gene dose effect

Summary A recessive ag1 mutation leads to specific defect in sexual agglutinability specifically in cells of the yeast Saccharomyces cerevisiae. The cryptopleurine resistance gene cry^R 1, closely linked to the mating type locus, was used to select / strains which emerged from / strains by mitotic nonreciprocal recombination, to genetically analyse ag1, since ag1 is expressed only in mating type. The ag1 gene was found to be linked to the centromere tightly, to met3 at 4.4 cM, and to ilv3 at 12 cM on chromosome X. Sexual agglutinability of cells was shown to be dependent on the dose of the AG1 gene, using / isogenic strains carrying AG1/AG1, AG1/ag1 or ag1/ag1. The sst2-1 mutation did not suppress the ag1 mutation. Based on these results, function of the AG1 gene is discussed.Abbreviations cM centimorgan - FDS first division segregation - NPD nonparental ditype - PD parental ditype - SDS second division segregation - TT tetratype     

Comparative evaluation of integrin α- and β-chain expression in colorectal carcinoma cell lines and in their tumours of origin

The integrin family consists of broadly expressed cell surface adhesion receptors, each member of which is composed of a non-covalently linked / heterodimer. Integrin receptors are involved in the interaction with matrix proteins and may contribute to invasion and metastasis of carcinomas. To examine the biological role integrins play in colorectal carcinoma we compared the expression of integrin - and -subunits in situ and in vitro. Eight newly established cell lines derived from immunohistochemically characterized colorectal carcinomas together with two sublines obtained after nude mouse passage and the commonly used colon carcinoma lines HT-29, SW480, SW620, and COLO 205 were investigated by immunocytochemistry and flow cytometry. The carcinomas in situ expressed 1-, 2-, 3-, 6-, v-and 1-subunits in variable amounts while being devoid of 4, 5 and 3. The individual integrin profile of the tumour in tissue was essentially maintained in vitro. However, a neo-expression of the 5 chain was found, together with an induction or increase in 1, 2, 3, v and 1 levels. No decrease in integrin subunit expression was observed. Standard-serum and serum-free medium revealed no striking differences in - and -chain expression in the cell lines HT-29 and COLO 205. In serum-free medium, SW480 showed a slight increase of 1 and 5 and a decrease of 3 and v while SW620 expressed more 1. We conclude that the great variability of adhesion receptor expression of the integrin family in colorectal carcinomas in situ is essentially maintained in vitro, although culture conditions which are only marginally influenced by serum factors unpredictably lead to some increase in expression or even induction of several integrin subunits.This work is dedicated to Prof. Wilhelm Doerr on the occasion of this 80th birthday     

Posttranslational modifications of α-tubulin of Toxoplasma gondii

The posttranslational modifications of -tubulin of Toxoplasma gondii were characterized by antibodies and biochemical analysis of the carboxy-terminal peptide. -Tubulin is acetylated and glutamylated. Side chains with up to three glutamate residues are linked to Glu445 of T. gondii -tubulin. The data suggest that the site of glutamylation on -tubulin is conserved over a broad range of species.     

Distinct Tumor Necrosis Factor-α Responses in Alveolar and Peritoneal Macrophages Are Associated with Local Levels of Endotoxin

Tumor necrosis factor alpha (TNF-) responses of alveolar macrophages (AMs) and peritoneal macrophages (PMs) were studied in rats after intravenous injection of lipopolysaccharide (LPS). High levels of plasma TNF-, increased pulmonary myeloperoxidase activity, and leukopenia occurred within 2 h after LPS injection. Alveolar spaces exhibited a strict compartment property, as manifested by only slightly increased LPS and TNF- levels in alveolar lavage fluid and an unchanged capacity of AMs to produce TNF-. By contrast, the peritoneal cavity had greatly increased local LPS and TNF- levels and a diminished PMs TNF- response to LPS. The amount of LPS in the alveolar spaces was less than 0.2% of the level in peritoneal fluid. These results indicate that activation of resident macrophages is dependent on the amounts of local LPS and, in addition, suggest that resident AMs neither participate in the plasma TNF- response nor contribute to neutrophil sequestration in the lung during the early stages of endotoxemia.     

Nephritogenicity and α-chain composition of NC1 fractions of type IV collagen from bovine renal basement membrane

Nephritogenicity (anti-GBM-nephritis-inducing activity) and -chain composition of globular-domain (NC1) fractions of type IV collagen from bovine renal, pulmonary, and placental basement membranes (BMs) was examined by injecting these fractions with adjuvant into WKY/NCrj rats and by Western blotting using epitope-defined monoclonal antibodies to the six different chains of type IV collagen. A purified nephritogenic fraction from renal BM contained 1–6(IV)NC1, whereas a non-nephritogenic fraction contained only 1–2(IV)NC1. Renal and pulmonary NC1 had strong nephritogenic activity; placental NC1 had weak activity. The renal and pulmonary fractions contained 1–6(IV)NC1, and the placental fraction had a large amount of 1–2(IV)NC1 and a very small amount of 3–6(IV)NC1. Immunohistochemical study of bovine renal BM with the monoclonal antibodies revealed that bovine glomerular BM contained 1–5(IV) chains, but not the 6(IV) chain. The absence of 6(IV) chain in glomerular BM in bovine and in humans indicates that 6(IV) chain is not a target antigen of anti-GBM nephritis. Nephritogenicity is apparently a property of 3–5(IV)NC1.     

Transient expression of myosin heavy chain MHCIα in rabbit muscle during fast-to-slow transition

The expression of an -cardiac-like myosin heavy chain, MHCI, was investigated at both the mRNA and protein levels in rabbit tibialis anterior muscle undergoing fast-to-slow transition by continuous chronic low-frequency stimulation (CLFS). According to sequence analyses of the PCR product, the MHCI isoform was found to be identical to the -cardiac MHC expressed in rabbit atrium. In muscles at different degrees of transformation, the upregulation of MHCI mRNA preceded that of the MHCI mRNA. At more advanced stages of the transformation, MHCI mRNA decayed while MHCI mRNA persisted at high levels. The expression of MHCI, therefore, was transitory. Studies at the protein level were based on immunoblotting using a monoclonal antibody (F88 12F8,1), characterized to be specific to MHCI in rabbit muscle. These studies revealed a similar relationship between initial increase and successive decline of the MHCI protein as seen at themRNA level. Immunohistochemistry of 30-day stimulated muscle revealed that up to 65% of the fibres expressed the MHCI isoform in combination with other adult MHC isoforms. The most frequent patterns of coexistence were MHCIIa+MHCI + MHCI (28%), MHCI+MHCI (18%), and MHCIIa + MHCI (11%). According to these combinations, the upregulation of MHCI may be assigned as an intermediate step in the transformation of existing fibres during theMHCIIa MHCI transition. A small fraction of fibres contained, in addition to the MHCI + MHCI and MHCIIa + MHCI combinations, developmental myosin, suggesting that MHCI was also expressed in regenerating fibres originating from satellite cell-derived myotubes.     

Differential Production of Chemokines by Phagocytosing Rat Neutrophils and Macrophages

In this study, rat neutrophils and macrophages produced cytokine-induced neutrophil chemoattractants (CINCs) and rat macrophage inflammatory protein-1 (MIP-l) in different patterns during phagocytosis of heat-killed yeast cells in vitro. The cultured supernatants of the phagocytosing rat neutrophils and macrophages had chemotactic activities toward neutrophils, and the chemotactic potencies were markedly inhibited by anti-CINCs IgGs or/and anti-MIP-l IgG, suggesting that CINCs and MIP-l are major neutrophil chemoattractants produced by the phagocytosing neutrophils and macrophages. Dexamethasone suppressed the production of CINCs and MIP-1 by the phagocytosing cells in a dose-dependent manner. Our results demonstrate significant differences in the production of CINCs and MIP-1 by neutrophils and macrophages during phagocytosis of yeast cells and thus may suggest the different contribution of each chemokine to neutrophil recruitment in the processes of inflammation in rats.     

Bioactive 5-Reduced 16α,17α-Cyclohexanoprogesterone Derivatives Weakly Interact with Proteins of the Soluble Uterine Fraction

We studied competitive activities of 16,17-cyclohexano-5- and 5-dihydroprogesterone in replacing ₃H-progesterone and ₃H-16,17-cyclohexano-6-methylprogesterone from protein complexes. Direct binding of ₃H-5-reduced derivatives with proteins of soluble fractions from rat and rabbit uteri was also assayed. Cd values for 5-reduced derivatives were in the micro- or submicromolar range. The data suggest that biological effects of these analogues are not mediated via soluble uterine receptors.     

Interferon-α activates cytotoxic function but inhibits interleukin-2-mediated proliferation and tumor necrosis factor-α secretion by immature human natural killer cells

Natural killer (NK) cells play an important role in host defense mechanisms against infection and neoplasia. Interferon- (IFN-) has been shown to activate NK cells and to augment their cytotoxic activity, albeit its role in the maturation pathway of NK cells has not been elucidated. The present study examined whether IFN- activates the immature NK subset (Free cells) to become cytotoxic and also ascertained whether IFN- uses the same pathway of activation as that mediated by interleukin-2 (IL-2). Incubation of sorted Free cells overnight with IFN- resulted in augmentation of their cytotoxic function against NK sensitive target cells. The enhanced cytotoxic activity was not accompanied by a new recruitment of NK-target binder cells but by an increase in the frequency of killer cells in the conjugate fraction. Activation of the Free subset by IFN- resulted in upregulation of CD69, CD11b, and CD2 surface expression and stimulated secretion of IFN-. Unlike IL-2, IFN- did not stimulate the Free cells to proliferate or secrete TNF- and activation of cytotoxicity and modulation of surface antigens by IFN- were independent of TNF-. The failure of IFN- to stimulate secretion and proliferation by Free cells appeared to be mediated by negative signals. This was corroborated in experiments demonstrating that when Free cells were cultured with both IFN- and IL-2, a significant inhibition was observed for both the IL-2 dependent secretion of TNF- and proliferation. These results demonstrate that IFN- serves as both an activator and a regulator of NK function. Further, activation of the immature Free NK cells by IL-2 and IFN- proceeds by TNF--dependent and independent pathways, respectively. The findings also support our contention that the mechanism of activation of the cytotoxic machinery of NK cells is not linked to the mechanism of activation of cytokine secretion and/or proliferation.Abbreviations used IFN interferon - IL interleukin - PBL peripheral blood leukocytes - PE phycoerythrin - PE-GAM PE-conjugated Fab2 goat anti-mouse IgG - NK natural killer - NRS normal rabbit serum - TNF tumor necrosis factor - FCS fetal calf serum - FITC fluorescein isothiocyanate - PBS phosphate-buffered saline - MACS magnetic cell sorting - ELISA enzyme-linked immunosorbent assay - BSA bovine serum albumin - PKC protein kinase C - mAb monoclonal antibody - PBMC peripheral blood mononuclear cells - BCLL B-chronic lymphocytic leukemia - E effector - T target     

A comparative study of skeletal and cardiac tropomyosins

Summary The subunit composition, the thiol group content and the biological activities of cardiac tropomyosin (TM) of various animal species were compared. Cardiac TM from small animals such as rabbit, guinea-pig, rat and dog contain 2 SH/mole and were resolved into one band on SDS and acid urea electrophoresis and into two bands on alkaline urea electrophoresis. Chicken cardiac TM likewise gave one band and it contains 4 SH/mole. In contrast pig, sheep and human cardiac TM contain respectively 2.6, 2.4, and 2.4 SH/mole and were resolved into two bands and on the different electrophoresis systems used, with a : ratio respectively of I:4.2, I:4.6, I:4.8. The -TM components from sheep skeletal and pig and sheep cardiac muscles were more positively charged than the rabbit skeletal -TM component, as shown in alkaline urea electrophoresis system. The and combinations of dimers found for skeletal muscle by other authors, were also found for cardiac pig TM.All the TM have the same effect on the Ca²⁺-stimulated ATPase activity of desensitized actomyosin (DAM) and on the Mg²⁺-stimulated ATPase activity of DAM with troponin-complex.This work suggests that the subunits of the TM from skeletal and cardiac muscles are heterogenous in their M.W. and their charges and that in the heart as well as in skeletal muscle a relationship seems to exist between the amount of the component and the speed of contraction of the muscle: a higher amount of this component was found in the bulky hearts which are also those which contract slower.     

A comparative immunohistological study of cerebellar enolases

Summary A comparative immunohistological study of the neurone-specific enolase and enolase, demonstrates the exclusive neuronal localization of enolase and its absence from glial cells. In contrast, enolase is located in astroglial cells. The validity of enolase as a neuronal marker and enolase as an astrocytic marker, is confirmed both by a double labelling technique, using antibodies to and to revealed with fluorescence or peroxidase in the same tissue sections, and by immunoelectronmicroscopy.     

Sublocalization on chromosome 21 of human interferon-alpha receptor gene and the gene for an interferon-gamma response protein

The cellular responses to alpha and beta interferons (IFN- and -) are mediated through the IFN-/ (type I) receptor, while the response to IFN- is mediated through the IFN- (type II) receptor. The receptors for IFN-/ and IFN- are encoded by genes on human chromosomes 21 and 6q, respectively. The presence of chromosome 21q confers both ligand binding and responsiveness to human IFN-/, whereas chromosome 6q confers binding of Hu-IFN-, but not cellular responsiveness on somatic cell hybrids. Chromosome 6q (i.e., the Hu-IFN- receptor gene) and chromosome 21q are both necessary for the cellular response of somatic cell hybrids (from fibroblasts) to Hu-IFN-. It is conceivable that the factor mediating activity through the IFN- receptor is, in fact, the IFN- receptor, or that the two genes are distinct but part of an interferon response region. Here we more precisely localize on human chromosome 21 the genes for the IFN- receptor and for the factor(s) mediating the action of IFN- through the chromosome 6-encoded receptor. Hamster-human somatic cell hybrids containing various fragments of human chromosome 21 were used. The presence of the human IFN-/ receptor was determined by binding³²P-labeled human IFN- to cells, covalently cross-linking the [³²P]IFN--receptor complex, and analyzing it by SDS-polyacrylamide gel electrophoresis. The presence of the IFN- receptor-related factor mediating cellular responsiveness was determined by HLA induction in hybrid cells containing the IFN- receptor (chromosome 6q), a transfected copy of the human HLA-B7 gene, and various portions of chromosome 21. In all hybrids examined, the two genes cosegregate. Specifically, both genes are localized to the region of chromosome 21 containing the markers D21S58, D21S65, and GART and appear to be proximal to D21S58. The implications for IFN action are discussed.     

Differential expression of β1, β3 and β4 integrins in sarcomas of the small,round, blue cell category

Integrins are a large and complex family of membrane spanning heterodimeric cell surface glycoproteins mediating cell/cell and cell/matrix interactions. Small, round, blue cell sarcomas (SRBCS) are a group of poorly differentiated tumours of various and in part uncertain histogenesis displaying similar cytomorphology. Among them are rhabdomyosarcomas (RMS), ganglioneuroblastomas [(G)NB], primitive peripheral neuroectodermal tumours (pPNET) and Ewing's sarcomas (ES). Thirty-two SRBCS were studied immunohistochemically for the distribution of 1, 3 and 4 integrins in situ. We found complex and to some extent differential patterns of 1, 3 and 4 integrin subunit expression in different types of SRBCS: all of the sarcomas studied were consistently 1⁺, 4^–, 2^–. Four of nine RMS were completely negative for all other integrin subunits studied while one RMS was 5⁺ throughout and three RMS were focally 5⁺. Three RMS expressed the 6 and v chains. In contrast to RMS, pPNET and ES, all of which were 1^–, 3^–, (G)NB were 3⁺ and frequently co-expressed 1. The eight pPNET and seven ES studied showed a similarily restricted integrin profile that was limited to the expression of 1 and 5 in nearly all cases. In summary, RMS were 1⁺, 1^–, 3^– and heterogeneously expressed 5 and 6. (G)NB were generally 1⁺, 1⁺, 3⁺, 5^–, 6^–. pPNET and ES were 1⁺, 1^–, 3^–, 5⁺, 6^–. The data illustrate a complex expression pattern of various integrins in SRBCS, a differential expression pattern of some of the integrin subunits among different types of SRBCS and almost identical integrin profiles in pPNET and ES.This paper is dedicated to Prof. Dr. Dres. h.c. Wilhelm Doerr on the occasion of his 80^th birthday     

Nachweis von 6 neuen Steroiden im Plasma von menschlichem Placentablut (Nabelsehnurblut)

Zusammenfassung 16-Hydroxyprogesteron, 17-Hydroxyprogesteron, ⁴-Pregnen-20-ol-3-on, ⁴-Pregnen-17, 20-diol-3-on, Adrenosteron und 11-Hydroxyandrostendion wurden in Extrakten von Plasma des menschlichen Placentablutes (Nabelschnurblut) nachgewiesen.     

Phenotypic characteristics of lewis lung carcinoma cells

We studied adhesive properties and physiological activity in vivo of cells from Lewis lung carcinoma and its metastases. These cells differed in tumorogenic activity and metastatic potential in the syngeneic system. In vivo non-metastasizing cells are characterized by a lower content of surface lectins to tetrasaccharides SiaLe^x [Neu5Ac2-3Gal1-4(Fuc1-3) GlcNAc] and SiaLe^a [Neu5Ac2-3Gal1-3(Fuc1-4)GlcNAc] and trisaccharide HSO₃Le^x [HSO₃2-3Gal1-4(Fuc1-3)GlcNAc] compared to cells forming metastases in the syngeneic system. Metastatic cells with low tumorogenic activity weakly expressed lectins to disaccharide ligands 6-SiaLac [Neu5Ac2-6Gal1-4Glc], 6-HSO₃LacNAc, and A-di [GalNAc 1-3Gal] and trisaccharides H-type 1 [Fuc1-2Gal1-3GlcNAc and Le^x [Fuc1-3(Gal 1-4)GlcNAc] compared to cells that initiated tumor formation in the syngeneic system (similarly to transplanted tumors). We hypothesized that cell receptors to these carbohydrate determinates are involved in the development and growth of primary tumors, while lectins to SiaLe^x, SiaLe^a, and HSO₃Le^x play a role in the progress of tumor process and metastasizing.     

Immunoreactivity of the JK-132 monoclonal antibody directed against basement membrane collagen in normal and diabetic glomeruli

The possible involvement of basement membrane-associated collagen (recognized by the monoclonal antibody JK-132) in the evolution of diabetic nephropathy was studied in kidney specimens from seven patients with noninsulin-dependent diabetes mellitus, and its distribution was compared with those of antibodies against 1 to 4 chains of type IV collagen. JK-132, a monoclonal antibody against basement membrane-associated collagen, reacted immunohistochemically exclusively with the mesangial matrix of the glomerular capillary. In contrast, antibodies to the 1 and 2 chains (IV) reacted strongly with mesangial matrix, and less strongly with the glomerular basement membrane (GBM). Antibodies to the 3 and 4 chains (IV) reacted mainly with GBM. In diabetes, JK-132 reacted most extensively with the expanded mesangial matrix, its staining intensity increasing with progression of the diabetic glomerulosclerosis. Antibodies to the 1 and 2 chains (IV) reacted prominently with the expanded mesangial matrix but less strongly with the GBM. Antibodies to the 3 and 4 chains reacted intensely with the thickened GBM. These results suggest that basement membrane-associated collagen differs from 1 to 4 chains of type IV collagen and that basement membrane-associated collagen is a good marker of mesangial expansion in diabetic nephropathy.     

Antitumor effects of liposomal IL1α and TNFα against the pulmonary metastases of the B16F10 murine melanoma in syngeneic mice

Interleukin 1 alpha (IL1) and tumor necrosis factor alpha (TNF) have been successfully incorporated into specific phosphatidylcholine (PC) and phosphatidylserine (PS) multilamellar vesicle (MLV) liposomes by modifying the concentration of calcium ion and pH of the encapsulation buffer. Under these conditions, some of the cytokines may attach to the exterior surface of the MLV and therefore be readily accessible to target cells for receptor binding and signal transduction. These cytokine-associated liposomes are stable for up to 2 weeks in serum-free buffer, and leakage of cytokines into medium containing 10% fetal bovine serum was about 50% at the end of a 3-day incubation period at 37°C. The biological activities mediated by liposomal IL1 and TNF were specific: the stimulation of thymidine uptake in T-helper D10 lymphocytes and the cytolysis of TNF-sensitive L929 target cells could be blocked by specific neutralizing antibodies in a dose-dependent fashion. When administered intravenously into C57BL/6 mice bearing the syngeneic B16F10 murine melanoma cells, dual entrapment of liposomal IL1 and TNF significantly reduced the number of metastatic tumor nodules in the lungs and prolonged the life span of the animals. Thus, liposomal IL1 and TNF displayed significant in vivo antitumor activity against the IL1- and TNF-resistant B16F10 metastatic murine melanoma.     

Dysregulated Cytokine Production in Human Cystic Fibrosis Bronchial Epithelial Cells

Although pulmonary inflammation is an important pathologic event in cystic fibrosis (CF), the relationship between expression of the CF gene and the inflammatory response is unclear. We studied tumor necrosis factor (TNF) and IL-1 stimulated production of IL-6 and IL-8 by CF, corrected CF, and normal human bronchial epithelial cells in culture. During the first 24 hours of TNF stimulation, CF cells produced significantly more IL-8 than normal or corrected CF cells. In the second 24 hours of TNF stimulation, IL-6 and IL-8 generation ceased in normal and corrected CF cells but accelerated in CF cells, resulting in marked IL-6 and IL-8 accumulation in CF cells. Similar results were found when cells were stimulated with IL-1. Finally, when CF cells were grown at 27°C (a culture condition which results in transport of CF transmembrane conductance regulator, CFTR, to the cell membrane and normalization of chloride conductance) TNF-stimulated production of IL-6 and IL-8 reverted to normal. We conclude that dysregulation of cytokine generation by CF bronchial epithelial cells is directly related to expression of mutant CFTR and these observations provide a potential mechanism for persistence of airway inflammation in CF.     

Chemically modified ribozyme targeting TNF-alpha mRNA regulates TNF-alpha and IL-6 synthesis in synovial fibroblasts of patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is chronic polyarthritis in which a variety of inflammatory cytokines play a role. Since tumor necrosis factor- (TNF-) is one of the most important cytokines in the pathogenesis of RA, we evaluated the feasibility of ribozymes as a therapeutic agent to control the inflammatory process of RA synovium. A hammerhead ribozyme against TNF- was chemically modified to increase nuclease resistance and added to RA fibroblastlike cell cultures without using a delivery system. The cellular uptake of fluorescent-labeled ribozyme into synovial cells was found to last at least 48 hr by confocal laser scanning microscopy. The ribozyme targeting TNF- gene inhibited both the expression of TNF- mRNA and the secretion of TNF- and IL-6. The cytotoxic effect by the ribozyme on synovial cells was negligible when determined by an alamar blue assay. Chemically modified ribozymes designed to suppress the TNF- gene may be potential as a therapeutic agent for rheumatoid arthritis.     

An α-mating-type-specific mutation causing specific defect in sexual agglutinability in the yeast Saccharomyces cerevisiae

We have identified a recessive -mating-type-specific gene agl causing agglutinability defect without significant effects on other sexual activities. a cells carrying agl showed sexual agglutination with cells but cells carrying agl showed sexual agglutination with neither cells nor a cells. cells carrying agl produced pheromone and responded to a pheromone just like wild cells. cells carrying agl showed a little decreased but significant mating ability when tested on solid media or membrane filter. The agl mutant is different from any -specific ste mutants found so far in many sexual activities. The agl gene is recessive, and unlinked to the mating type locus. Biological significance of the mating type agglutinability is discussed based on the results obtained with the mutant.