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Stuart M Brown

Publications and source records attributed to Stuart M Brown.

4 recordsLinked to original sources
PubMed2002

Infectivity-associated changes in the transcriptional repertoire of the malaria parasite sporozoite stage.

Injection of Plasmodium salivary gland sporozoites into the vertebrate host by Anopheles mosquitoes initiates malaria infection. Sporozoites develop within oocysts in the mosquito midgut and then enter and mature in the salivary glands. Although morphologically similar, oocyst sporozoites and salivary gland sporozoites differ strikingly in their infectivity to the mammalian host, ability to elicit protective immune responses, and cell motility. Here, we show that differential gene expression coincides with these dramatic phenotypic differences. Using suppression subtractive cDNA hybridization we identified highly up-regulated mRNAs transcribed from 30 distinct genes in salivary gland sporozoites. Of those genes, 29 are not significantly expressed in the parasite's blood stages. The most frequently recovered transcript encodes a protein kinase. Developmental up-regulation of specific mRNAs in the infectious transmission stage of Plasmodium indicates that their translation products may have unique roles in hepatocyte infection and/or development of liver stages.

Animals↗
PubMed2002

Rare, structurally homologous self-peptides promote thymocyte positive selection.

Although it is clear that positive selection of T cells involves recognition of specific self-peptide/MHC complexes, the nature of these self-ligands and their relationship to the cognate antigen are controversial. Here we used two complementary strategies to identify naturally occurring self-peptides able to induce positive selection of T cells bearing a specific T cell receptor, OT-I. Both the bioassay- and bioinformatics-based strategies identified the same self-peptides, derived from F-actin capping protein and beta-catenin. These peptides displayed charge conservation at two key TCR contact residues. The biological activity of 43 other self-peptides and of complex peptide libraries directly correlated to the extent of conservation at TCR contact residues. These results demonstrate that selecting self-peptides are rare and can be identified by homology-based search strategies.

Actin Depolymerizing Factors↗