Hierarchical phosphorylation of apical membrane antigen 1 is required for efficient red blood cell invasion by malaria parasites.

Central to the pathogenesis of malaria is the proliferation of Plasmodium falciparum parasites within human erythrocytes. Parasites invade erythrocytes via a coordinated sequence of receptor-ligand interactions between the parasite and host cell. One key ligand, Apical Membrane Antigen 1 (AMA1), is a leading blood-stage vaccine and previous work indicates that phosphorylation of its cytoplasmic domain (CPD) is important to its function during invasion.

The cell surface proteome of Entamoeba histolytica.

Surface molecules are of major importance for host-parasite interactions. During Entamoeba histolytica infections, these interactions are predicted to be of prime importance for tissue invasion, induction of colitis and liver abscess formation. To date, however, little is known about the molecules involved in these processes, with only about 20 proteins or protein families found exposed on the E.

Overexpression of specific cysteine peptidases confers pathogenicity to a nonpathogenic Entamoeba histolytica clone.

Cysteine peptidases (CPs) of Entamoeba histolytica are considered to be important pathogenicity factors. Previous studies have found that under standard axenic culture conditions, only four (ehcp-a1, ehcp-a2, ehcp-a5, and ehcp-a7) out of 35 papain-like ehcp genes present in the E. histolytica genome are expressed at high levels.

Temporal expression and localization patterns of variant surface antigens in clinical Plasmodium falciparum isolates during erythrocyte schizogony.

Avoidance of antibody-mediated immune recognition allows parasites to establish chronic infections and enhances opportunities for transmission. The human malaria parasite Plasmodium falciparum possesses a number of multi-copy gene families, including var, rif, stevor and pfmc-2tm, which encode variant antigens believed to be expressed on the surfaces of infected erythrocytes. However, most studies of these antigens are based on in vitro analyses of culture-adapted isolates, most commonly the laboratory strain 3D7, and thus may not be representative of the unique challenges encountered by P.

Differences in the transcriptome signatures of two genetically related Entamoeba histolytica cell lines derived from the same isolate with different pathogenic properties.

Background: The availability of two genetically very similar cell lines (A and B) derived from the laboratory isolate Entamoeba histolytica HM-1:IMSS, which differ in their virulence properties, provides a powerful tool for identifying pathogenicity factors of the causative agent of human amoebiasis. Cell line A is incapable inducing liver abscesses in gerbils, whereas interaction with cell line B leads to considerable abscess formation. Phenotypic characterization of both cell lines revealed that trophozoites from the pathogenic cell line B have a larger cell size, an increased growth rate in vitro, an increased cysteine peptidase activity and higher resistance to nitric oxide stress.

Comparison of two genetically related Entamoeba histolytica cell lines derived from the same isolate with different pathogenic properties.

Entamoeba histolytica is known for its extraordinary capacity to destroy human tissues, leading to invasive diseases such as ulcerative colitis or extra-intestinal abscesses. In order to identify the virulence factors of this parasite phenotypes and proteomes of two recently identified genetically related cell lines (A and B), derived from the laboratory E. histolytica isolate HM-1:IMSS, were compared.

Major cysteine peptidases of Entamoeba histolytica are required for aggregation and digestion of erythrocytes but are dispensable for phagocytosis and cytopathogenicity.

Cysteine peptidases of Entamoeba histolytica (EhCPs) are considered to be important pathogenicity factors. It has been described that under standard axenic culture conditions, only three (ehcp-a1, ehcp-a2 and ehcp-a5) out of approximately 50 cysteine peptidase genes present in the E. histolytica genome are substantially expressed, thus representing the set of major EhCPs.

The Entamoeba histolytica genome: primary structure and expression of proteolytic enzymes.

Background: A number of studies have shown that peptidases and in particular cysteine peptidases constitute major pathogenicity factors in Entamoeba histolytica. Recent studies have suggested that a considerable number of genes coding for proteolytic enzymes are present within the E. histolytica genome and questions remain about the mode of expression of the various molecules.

Frequency of chromosomal aneuploidies and deletions of the RB and TP53 genes in MALT lymphomas harboring the t(14;18)(q32;q21).

The t(14;18)(q32;q21) involving the MALT1/MLT and IGH genes has been identified recently as a recurrent abnormality in mucosa-associated lymphoid tissue (MALT) lymphomas. The frequency of secondary chromosomal aberrations in MALT lymphomas harboring the t(14;18) is largely unknown. We therefore analyzed six t(14;18)-positive MALT lymphomas (five parotid, one conjunctiva) by interphase fluorescence in situ hybridization for aneuploidies of chromosomes 3, 7, 12, 18, and X, gains or disruption of the CMYC/8q24 and BCL6/3q27 genes, as well as deletions of the retinoblastoma and TP53 tumor suppressor genes.