Merceditas S Villanueva

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Listeria monocytogenes is an intracellular pathogen that enters the cytoplasm of infected cells by secreting listeriolysin (LLO), a protein that destroys the phagosomal membrane. In infected mice, LLO is a major Ag detected by protective, MHC class I-restricted CTLs. Although the role of LLO in pathogenesis and host immunity is well established, its rate of(More)
A new member of a family of site-specific retrotransposons is described in the New World trypanosome Trypanosoma cruzi. This element, CZAR (cruzi-associated retrotransposon), resembles two previously described retrotransposons found in the African trypanosome T. brucei gambiense and the mosquito trypanosomatid Crithidia fasciculata in specifically inserting(More)
Listeria monocytogenes is an intracellular pathogen that secretes proteins into host cell cytosol. One such protein, the murein hydrolase p60, is processed by the host cell into the nonamer peptide p60 217-225 and presented to cytotoxic T lymphocytes by the H-2Kd MHC class I molecule. Using strains of L. monocytogenes that secrete different amounts of p60,(More)
Incubation of the simian virus 40 (SV40) large tumor antigen (T) from either transformed or lytically infected cells with adenosine [8-3H]-, [alpha-32P]-, or [alpha-[35S]thio]-triphosphate in the presence of Mg2+ resulted in its labeling as defined by the appearance of an intact, appropriately immunoreactive band in NaDodSO4/polyacrylamide gels.(More)
Listeria monocytogenes (L. monocytogenes) secretes proteins associated with its virulence into the cytosol of infected cells. These secreted proteins are degraded by host cell proteasomes and processed into peptides that are bound by MHC class I molecules in the endoplasmic reticulum. We have found that the MHC class I antigen-processing pathway is very(More)
Listeria monocytogenes is a facultative intracellular bacterium that causes severe disease in neonates and immunocompromised adults. Although entry, multiplication, and locomotion of Listeria in the cytosol of infected cells are well described, the impact of such infection on the host cell is unknown. In this report, we investigate the effect of L.(More)
The spliced leader RNA(SL RNA)-encoding genes of the salivarian New World trypanosome, Trypanosoma rangeli, are organized within the 5S rRNA tandem repeats. Each repeat contains genes encoding an SL RNA and a 5S rRNA in the same orientation of transcription. This SL-5S organization is also present in the African trypanosome, Trypanosoma vivax. A similar(More)
Listeria monocytogenes is a pathogenic intracellular bacterium that secretes proteins into the cytosol of host cells. A major secreted protein, p60, is processed by the host cell into the nonamer peptides p60 217-225 and p60 449-457, which are presented to CTL by H-2Kd MHC class I molecules. Herein, we use two membrane permeable peptide aldehyde protease(More)
American (Chagas' disease) and African (sleeping sickness) trypanosomiasis are diseases that are endemic in parts of Latin American and Africa, respectively. Physicians in developed countries may occasionally see cases because of extensive travel and immigration from endemic countries. In addition, in American trypanosomiasis, transmission via contaminated(More)
In the era of antiretroviral therapy, people living with HIV/AIDS live longer and are subject to co-morbidities that affect the general population, such as chronic kidney disease. An increasing number of people living with HIV/AIDS with end-stage renal disease are candidates for renal transplantation. Prior experience demonstrated that HIV-positive renal(More)