Identification and characterization of a new gene family induced during macrophage activation.

In this report, we describe the primary structure and regulation of two novel IFN-gamma-inducible genes expressed during the process of macrophage activation. We used the RAW 264.7 cell line to prepare a cDNA library, from which inducible genes were selected by differential hybridization. Two cDNA clones, mag-1 and mag-2 (for macrophage-activation gene-1 and -2), were induced by IFN-gamma treatment in both RAW 264.7 cells and thioglycolate-elicited peritoneal macrophages, but not in the noncytolytic cell line, WEHI-3. A comparison of the nucleotide and deduced amino acid sequences of clones mag-1 and mag-2 with sequences in available data bases revealed no homologs. However, comparison of mag-1 and mag-2 sequences with each other revealed that these genes are homologous, with conserved residues concentrated at the amino terminus. Kinetic analyses revealed similar temporal patterns of induction of mRNA expression for these genes after IFN-gamma treatment. In addition, the genes showed distinct response patterns to the macrophage-activating stimuli IFN-gamma and LPS used either alone or in combination. Analysis of a panel of cell types of various lineages demonstrated that expression of these genes was associated with cellular activation in multiple cell types. As a result of the sequence similarities between these genes, we propose that they define a new family of IFN-gamma-regulated genes in macrophages.     

Biochemical basis of type IB (E1beta ) mutations in maple syrup urine disease. A prevalent allele in patients from the Druze kindred in Israel.

Maple syrup urine disease (MSUD) is a metabolic disorder associated with often-fatal ketoacidosis, neurological derangement, and mental retardation. In this study, we identify and characterize two novel type IB MSUD mutations in Israeli patients, which affect the E1beta subunit in the decarboxylase (E1) component of the branched-chain alpha-ketoacid dehydrogenase complex. The recombinant mutant E1 carrying the prevalent S289L-beta (TCG --> TTG) mutation in the Druze kindred exists as a stable inactive alphabeta heterodimer. Based on the human E1 structure, the S289L-beta mutation disrupts the interactions between Ser-289-beta and Glu-290-beta', and between Arg-309-beta and Glu-290-beta', which are essential for native alpha(2)beta(2) heterotetrameric assembly. The R133P-beta (CGG --> CCG) mutation, on the other hand, is inefficiently expressed in Escherichia coli as heterotetramers in a temperature-dependent manner. The R133P-beta mutant E1 exhibits significant residual activity but is markedly less stable than the wild-type, as measured by thermal inactivation and free energy change of denaturation. The R133P-beta substitution abrogates the coordination of Arg-133-beta to Ala-95-beta, Glu-96-beta, and Ile-97-beta, which is important for strand-strand interactions and K(+) ion binding in the beta subunit. These findings provide new insights into folding and assembly of human E1 and will facilitate DNA-based diagnosis for MSUD in the Israeli population.     

Differential processing of human and rat E1 α precursors of the branched-chain α-keto acid dehydrogenase complex caused by an N-terminal proline in the rat sequence

The N-terminal sequences of the E1 α, E1β and E2 subunits of the human branched-chain α-keto acid dehydrogenase complex have been determined by microsequencing. The N-termini of human E1β and E2 subunits (Val and Gly, respectively) are indentical to those of the corresponding rat and bovine subunits. However, the N-terminus of the human E1 α subunit (Ser) is identical to bovine, but differs from the rat E1 α (Phe0 subunit. Comparison of the N-terminal sequences of human and rat E1 α subunits shows that the serine residue at the + 1 position in the human sequence is replaced by a proline residue in the rat sequence. The presence of the proline residue apparently causes a 5′-shift by one residue in the cleavage site by the mitochondrial processing peptidase in the rat sequence, when compared to the human sequence. The results provide evidence that the mitochondrial processing peptidase cannot cleave an X-pro bond, similar to trypsin, chymotrypsinand microsomal signal peptidases.     

The turnover of hamster fibroblast lysosomal beta-D-glucuronidase.

The half-life of hamster fibroblast beta-D-glucuronidase (EC 3.2.1.31) was estimated to be 4-5 days by measuring the decay with time of the radioactivity in beta-D-glucuronidase isolated from cells grown in the presence of 14C-labelled amino acids. A new affinity-chromatographic procedure for the purification of beta-D-glucuronidase is described.     

Digital data collection in paleoanthropology

Understanding patterns of human evolution across space and time requires synthesizing data collected by independent research teams, and this effort is part of a larger trend to develop cyber infrastructure and e‐science initiatives. 1 At present, paleoanthropology cannot easily answer basic questions about the total number of fossils and artifacts that have been discovered, or exactly how those items were collected. In this paper, we examine the methodological challenges to data integration, with the hope that mitigating the technical obstacles will further promote data sharing. At a minimum, data integration efforts must document what data exist and how the data were collected (discovery), after which we can begin standardizing data collection practices with the aim of achieving combined analyses (synthesis). This paper outlines a digital data collection system for paleoanthropology. We review the relevant data management principles for a general audience and supplement this with technical details drawn from over 15 years of paleontological and archeological field experience in Africa and Europe. The system outlined here emphasizes free open‐source software (FOSS) solutions that work on multiple computer platforms; it builds on recent advances in open‐source geospatial software and mobile computing.     

Exploration of the structure-activity relationship of the diaryl anilide class of ligands for translocator protein-potential novel positron emitting tomography imaging agents

A series of novel ligands based on the diaryl anilide (DAA) class of translocator protein (TSPO) ligands was synthesised and evaluated as potential positron emitting tomography (PET) ligands for imaging TPSO in vivo. Fluorine-18 labelling of the molecules was achieved using direct radiolabelling or synthon based labelling approaches. Several of the ligands prepared have promising profiles as potential TSPO PET imaging ligands and will be evaluated further as potential clinical imaging agents.     

NK cell-derived IFN-gamma differentially regulates innate resistance and neutrophil response in T cell-deficient hosts infected with Mycobacterium tuberculosis

Although it is known that IFN-gamma-secreting T cells are critical for control of Mycobacterium tuberculosis infection, the contribution of IFN-gamma produced by NK cells to host resistance to the pathogen is less well understood. By using T cell-deficient RAG(-/-) mice, we showed that M. tuberculosis stimulates NK cell-dependent IFN-gamma production in naive splenic cultures and in lungs of infected animals. More importantly, common cytokine receptor gamma-chain(-/-)RAG(-/-) animals deficient in NK cells, p40(-/-)RAG(-/-), or anti-IFN-gamma mAb-treated RAG(-/-) mice displayed significantly increased susceptibility to M. tuberculosis infection compared with untreated NK-sufficient RAG(-/-) controls. Studies comparing IL-12 p40- and p35-deficient RAG(-/-) mice indicated that IL-12 plays a more critical role in the induction of IFN-gamma-mediated antimycobacterial effector functions than IL-23 or other p40-containing IL-12 family members. The increased susceptibility of IL-12-deficient or anti-IFN-gamma mAb-treated RAG(-/-) mice was associated not only with elevated bacterial loads, but also with the development of granulocyte-enriched foci in lungs. This tissue response correlated with increased expression of the granulocyte chemotactic chemokines KC and MIP-2 in NK as well as other leukocyte populations. Interestingly, depletion of granulocytes further increased bacterial burdens and exacerbated pulmonary pathology in these animals, revealing a compensatory function for neutrophils in the absence of IFN-gamma. The above observations indicate that NK cell-derived IFN-gamma differentially regulates T-independent resistance and granulocyte function in M. tuberculosis infection and suggest that this response could serve as an important barrier in AIDS patients or other individuals with compromised CD4+ T cell function.