Further studies on a hybrid cell-surface antigen associated with human chromosome 11 using a monoclonal antibody

A monoclonal antibody has been obtained that recognizes an antigen encoded by human chromosome 11. We present evidence that this monoclonal antibody recognizes the same or a similar antigenic activity as that previously called a 1 . Genetic information necessary for a 1 expression and recognition by the monoclonal antibody both map to 11p13 → 11pter. Mutants that have lost a 1 are no longer recognized by the monoclonal antibody. The macroglycolipid fraction of human erythrocyte membranes which contains the a 1 antigenic activity is able to convert antigen-negative Chinese hamster ovary cells into cells which are killed by the monoclonal antibody plus complement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45556/1/11188_2005_Article_BF01543049.pd

The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics

Immunochemical characterization of surface antigens of TerC, a teratocarcinoma-derived cell line.

Rabbit and mouse antisera prepared against teratocarcinoma cells precipitate both glycoproteins and glycolipids from detergent extracts of radiolabeled cells. Extracts of immunoprecipitates with chloroform/methanol, 2:1 (vol/vol) have been resolved on thin-layer gels into multiple peaks. There are more species seen in extracts of teratocarcinoma cells than in extracts of the crossreacting cultured cell line, cl 1d. The teratocarcinoma antigens may be extracted out of chloroform/methanol into buffered saline. Incubation in these secondary extracts converts unreactive cells (lymphocytes to cells reactive with antisera against teratocarcinoma. Furthermore, the coated cells absorb at least 80% of the activity of antisera against teratocarcinoma targets

Structure of tyrosine aminotransferase from Leishmania infantum

5 p.-4 fig.-1 tab.The trypanosomatid parasite Leishmania infantum is the causative agent of visceral leishmaniasis (VL), which is usually fatal unless treated. VL has an incidence of 0.5 million cases every year and is an important opportunistic co-infection in HIV/AIDS. Tyrosine aminotransferase (TAT) has an important role in the metabolism of trypanosomatids, catalyzing the first step in the degradation pathway of aromatic amino acids, which are ultimately converted into their corresponding l-2-oxoacids. Unlike the enzyme in Trypanosoma cruzi and mammals, L. infantum TAT (LiTAT) is not able to transaminate ketoglutarate. Here, the structure of LiTAT at 2.35 A ° resolution is reported, and it is confirmed that the presence of two Leishmania-specific residues (Gln55 and Asn58) explains, at least in part, this specific reactivity. The difference in substrate specificity between leishmanial and mammalian TAT and the importance of this enzyme in parasite metabolism suggest that it may be a useful target in the development of new drugs against leishmaniasis.This research was funded under Federal Contract No. HHSN272201200025C from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services. The project was also funded by grant AGL 2010-21806-C02-01 from the Spanish Ministry of Economy and Competitiveness and by contract No. 050204100014 from Fundación Ramón Areces. MAM thanks the National Research Council for grant 2012EST JAE Predoc.Peer reviewe