CD8+ alpha beta+ T cells that lack surface CD5 antigen expression are a major lymphotactin (XCL1) source in peripheral blood lymphocytes.

To better characterize the cellular source of lymphotactin (XCL1), we compared XCL1 expression in different lymphocyte subsets by real-time PCR. XCL1 was constitutively expressed in both PBMC and CD4(+) cells, but its expression was almost 2 log higher in CD8(+) cells. In vitro activation was associated with a substantial increase in XCL1 expression in both PBMC and CD8(+) cells, but not in CD4(+) lymphocytes.

Expression and functional activity of CXCR-4 and CCR-5 chemokine receptors in human thymocytes.

In this paper we addressed the expression of the HIV co-receptors CXCR-4 and CCR-5 in human thymocytes by phenotypic, molecular and functional approaches. Cytofluorimetric analysis disclosed that CXCR-4 was constitutively expressed by freshly isolated thymocytes (~10 000 molecules/cell in about 30% of thymocytes); the receptor was endowed with functional activity, as it mediated polarization, migration and intracellular Ca2+ increase in response to its ligand, SDF-1. On the contrary, CCR-5 expression in freshly isolated thymocytes was significantly lower (<4000 molecules/cell in less than 5% of the cells), and no functional response to CCR-5 agonists could be documented.

Expression from cell type-specific enhancer-modified retroviral vectors after transduction: influence of marker gene stability.

The enhanced green fluorescent protein (EGFP) is increasingly used as a reporter gene in viral vectors for a number of applications. To establish a system to study the activity of cis-acting cellular regulatory sequences, we deleted the viral enhancer in EGFP-carrying retroviral vectors and replaced it with cell type-specific elements. In this study, we use this system to demonstrate the activity of the human CD2 lymphoid-specific and the Tie2 endothelial cell type-specific enhancers in cell lines and in primary cells transduced by retroviral vectors.

[Sarcoidosis gastropathy: diagnosis and contribution of echo-endoscopy].

We report a case of gastric sarcoidosis in a 36-year old woman. The clinical and endoscopic ultrasonography findings initially suggested linitis plastica. Subsequently the discovery of unexpected gastric and then, bronchial granulomas after bronchoscopy and bilateral ocular fixation on gallium scanning, led to the diagnosis of sarcoidosis.