THE TRANSFORMATION OF PNELIMOCOCCAL TYPES I. "IME COI~-ERSlON 01 ~ R FoP.~S or PNEIr~OCOCClIS INTO S FOR~S O1~

In previous communications (1, 2) it was shown that avirulent, non-type-specific R forms of Pneumococcus may be converted into virulent, type-specific, S organisms either "in vivo " by animal passage, or "in vitro " by growth in anti-R serum. Conversion by both methods was invariably accompanied by the acquisition of all the characteristics of the S type, including maximal virulence. In every instance in which the change was effected by these procedures the R forms were converted to the same specific type from which they were originally derived. Since the publication of the foregoing results there has appeared a most significant article by F. Griffith (3), in which he stated that: 1) R forms of Pneumococcus may be converted into S forms of the homologous type by the subcutaneous injection, in white mice, of large amounts of living R organisms. 2) R forms of Pneumococcus may be similarly converted into S forms of the homologous type by the subcutaneous injection, in white mice, of small amounts of living R organisms together with the heat-killed bacteria from large amounts of homologous S cultures. 3) R forms of Pneumococcus may be transformed into S forms of heterologous types by the subcutaneous injection, in white mice, of small amounts of living R organisms together with the heat-killed bacteria from large amounts of heterologous S cultures. The present communication is concerned with the first two of the * In this and succeeding instances 'homologous type ' indicates that specific S type from which the R forms were originally derived. 99 I00 TRANSFORMATION O~ " PNEUMOCOCCAL TYPES. I above findings. The third finding, which involves the question of actual transformation of type, is the subject of the succeeding paper

Ted Powers Two proteins from Escherichia coli, Ffh and FtsY, are

Co-translational protein targeting catalyzed by the Escherichia coli signal recognition particle and its recepto

THE PATHOGENESIS OF EXPERIMENTAL MEMBRANOUS GLOMERULONEPHRITIS INDUCED WITH

We have previously reported on patients with idiopathic membranous glomerulonephritis considered to be mediated by renal tubular epithelial antigen. Immunoglobulins and fllc, as well as the antigen that had antigenic determinants in common with the brush border of proximal tubular epithelia, were found in immune deposits along glomerular capillary walls by a fluorescent antibody technique (1, 2). The ~'nephritogenic " tubular antigen (Tub-Ag) 1 was purified after it had been solubilized from kidney tissue by digestion with a potent proteolytic enzyme, Pronase, and utilizing radiolabeled Tub-Ag, a sensitive radioimmunoassay was developed that enabled us to identify Tub-Ag activity in the serum, as well as in various organs of humans (3). These findings prompted us to purify Tub-Ag of the rat with the same procedure employed to isolate the Tub-Ag of humans, in order to develop a laboratory model of membranous glomerulonephritis mediated by Tub-Ag-antibody complexes. The rats that received a single injection of partially purified Tub-Ag preparation with adjuvant developed a typical membranous glomerulonephriti

RESULTS Inverted Repeats Finder (IRF) Reveals a Preponderance

Warburton et al. chromosome. The program IRF, as well as updated descriptions of the IR structure of future assemblies of the human genome, will be made publicly available at the Inverted Repeat Data Bas

Identification of RANTES Receptors on Human Monocytic Cells: Competition for Binding and

R.ANTES (regulated on activation, normal T expressed and secreted) is a member of the chemotactic cytokine (chemokine) ~/subfamily. High affinity receptors for RANTES have been identified on a human monocytic leukemia cell line THP-1, which responded to RANTES in chemotaxis and calcium mobilization assays. Steady-state binding data analyses revealed approximately 700 binding sites/cell on THP-1 cells with a Kd value of 400 pM, comparable to that expressed on human peripheral blood monocytes. The RANTES binding to monocytic cells was competed for by monocyte chemotactic and activating factor (MCAF) and macrophage inflammatory protein 1 (MIP-1) c~, two other chemokine ~ cytokines. Although MCAF and MIP-loL competed for R.ANTES binding to monocytes with apparent lower affinity (with estimated Kd of 6 and 1.6, nM respectively) both of these cytokines effectively desensitized the calcium mobilization induced by RANTES. The chemotactic response of THP-1 cells to RANTES was also markedly inhibited by preincubation with MCAF or MIP-lcr In contrast, R.ANTES did not desensitize the THP-1 calcium mobilization and chemotaxis in response to MCAF or MIP-lc~. These results, together with our previous observations that RANTES did not compete for MCAF or MIP-lot binding on monocytic cells, indicate the expression of promiscuous receptors on monocytes that recogniz

Recommended Citation

The synthesis of four homologous anthraquinones (AQ I-IV) bearing increasing lengths of polyethylene glycol (PEG) side chains and their binding to AT- and GC-rich DNA hairpins are reported. The molecules were designed such that the cationic charge is at a constant position and the ethylene glycol units chosen to allow significant increases in size with minimal changes in hydrophobicity. The mode and affinity of binding were assessed using circular dichroism (CD), nuclear magnetic resonance (NMR), surface plasmon resonance (SPR), and isothermal titration calorimetry (ITC). The binding affinity decreased as the AQ chain length increased along the series with both AT- and GC-rich DNA. ITC measurements showed that the thermodynamic parameters of AQ I-IV binding to DNA exhibited significant enthalpy-entropy compensation. The enthalpy became more favorable while the entropy became less favorable. The correlationbetween enthalpy and entropy may involve not only the side chains, but also changes in the binding of water and associated counterions and hydrogen bonding. The interactions of AQ I-IV with GC-rich DNA have been studied via molecular dynamics (MD) simulations. The geometry, conformation, interactions, and hydration of the complexes were examined. As the side chain lengthened, binding to DNA reduced the conformationa

BMC Biotechnology BioMed Central Methodology article

genomic DNA regions using Gateway and recombineering system

SKINS*

If viable suspensions of normal homologous lymphoid ceils are inoculated into the skins of tmsensitized guinea pigs (1), hamsters (2), rabbits (3, 4), men (5), or chickens (6, 7), they may provoke slowly developing cutaneous inflammatory reactions. If homologous ceils, lymphoid or otherwise, are injected into the skins of specifically presensitized hosts of these species, somewhat similar reactions, usually referred to as "direct reactions", are elicited (2--4, 8); but their onset is more rapid. Both of these cutaneous reactivities are believed to be manifestations of hypersensitivity to cellular transplantation antigens. The first type of reaction results from an in situ sensitization on the part of the inoculated immunologicaUy competent cells against the alien antigens of their host. The second type of reaction expresses the host's sensitivity to the inoculated foreign ceils. This paper describes quantitative studies designed to define the various cutaneous reactivities incitable in hamsters ' skins by inoculation of various types of cellular inocula under different immunogenetic conditions, and to elucidate their etiology. Materials and Methods The hamsters (Mesocrivetus auratus) used belonged to three different isogenic strains, MHA, CB, and LSH, and their Fx hybrids. MHA's are albino, while CB and LSH animals ar

Identification of RANTES Receptors on Human Monocytic Cells: Competition for Binding and

R.ANTES (regulated on activation, normal T expressed and secreted) is a member of the chemotactic cytokine (chemokine) ~/subfamily. High affinity receptors for RANTES have been identified on a human monocytic leukemia cell line THP-1, which responded to RANTES in chemotaxis and calcium mobilization assays. Steady-state binding data analyses revealed approximately 700 binding sites/cell on THP-1 cells with a Kd value of 400 pM, comparable to that expressed on human peripheral blood monocytes. The RANTES binding to monocytic cells was competed for by monocyte chemotactic and activating factor (MCAF) and macrophage inflammatory protein 1 (MIP-1) c~, two other chemokine ~ cytokines. Although MCAF and MIP-loL competed for R.ANTES binding to monocytes with apparent lower affinity (with estimated Kd of 6 and 1.6, nM respectively) both of these cytokines effectively desensitized the calcium mobilization induced by RANTES. The chemotactic response of THP-1 cells to RANTES was also markedly inhibited by preincubation with MCAF or MIP-lcr In contrast, R.ANTES did not desensitize the THP-1 calcium mobilization and chemotaxis in response to MCAF or MIP-lc~. These results, together with our previous observations that RANTES did not compete for MCAF or MIP-lot binding on monocytic cells, indicate the expression of promiscuous receptors on monocytes that recogniz