Presentation of CMV immediate-early antigen to cytolytic T lymphocytes is selectively prevented by viral genes expressed in the early phase

The regulation of antigen processing and presentation to MHC class I-restricted cytolytic T lymphocytes was studied in cells infected with murine cytomegalovirus. Recognition by cytolytic T lymphocytes of the phosphoprotein pp89, the immunodominant viral antigen expressed in the immediate-early phase of infection, was selectively prevented during the subsequent expression of viral early genes. The surface expression of MHC class I glycoproteins and their capacity to present externally added pp89-derived antigenic peptides were not affected. Because recognition of several other antigens occurred during the early phase, a general failure in processing and presentation was excluded. Since neither rate of synthesis, amount, stability, nor nuclear transport of pp89 was modified, the failure in recognition indicates a selective interference with pp89 antigen processing and presentation

Reproductive performance of native and imported dairy cows in the Tadla region (Morocco)

Parmi les performances de reproduction des vaches laitières dans la région du Tadla (Maroc) sur une période de 4 années, l’âge à la première insémination artificielle (IA) a été de 573,4 ± 35,6 jours et à l’âge au premier vêlage de 853,8 ± 103,5 jours, l’intervalle vêlage-1ère IA de 75,5 ± 35,6 jours. Celui-ci a été plus court chez les femelles importées que chez les natives. La race Montbéliarde a été inséminée plus tôt que la race Prim’Holstein. Le taux de réussite en 1ère IA a été de 53,2% avec de larges variations inter-annuelles et inter-élevages. Les Prim’holstein ont été mieux fécondées que les autres races. 18,2% des vaches ont nécessité 3 IA ou plus et l’indice coïtal a été de 1,8 ±1,3. La campagne, l’élevage et la race ont affecté significativement le taux de femelles ayant nécessité 3 IA ou plus. La race Prim’holstein française a manifesté un taux inférieur à celui de la race Prim’holstein canadienne. L’intervalle vêlage - insémination fécondante a été de 119,2 ± 83,8 jours. Ce paramètre a varié très significativement selon l’année, l’élevage, la race et le numéro de lactation. La race Montbéliarde a présenté undélai moyen de fécondation plus court que la race Prim’Holstein Canadienne

Evaluation of transduction efficiency in macrophage colony-stimulating factor differentiated human macrophages using HIV-1 based lentiviral vectors

<p>Abstract</p> <p>Background</p> <p>Monocyte-derived macrophages contribute to atherosclerotic plaque formation. Therefore, manipulating macrophage function could have significant therapeutic value. The objective of this study was to determine transduction efficiency of two HIV-based lentiviral vector configurations as delivery systems for the transduction of primary human blood monocyte-derived macrophages.</p> <p>Results</p> <p>Human blood monocytes were transduced using two VSV-G pseudotyped HIV-1 based lentiviral vectors containing EGFP expression driven by either native HIV-LTR (VRX494) or EF1α promoters (VRX1090). Lentiviral vectors were added to cultured macrophages at different times and multiplicities of infection (MOI). Transduction efficiency was assessed using fluorescence microscopy and flow cytometry. Macrophages transduced between 2 and 120 hours after culturing showed the highest transduction efficiency at 2-hours transduction time. Subsequently, cells were transduced 2 hours after culturing at various vector concentrations (MOIs of 5, 10, 25 and 50) to determine the amount of lentiviral vector particles required to maximally transduce human monocyte-derived macrophages. On day 7, all transduced cultures showed EGFP-positive cells by microscopy. Flow cytometric analysis showed with all MOIs a peak shift corresponding to the presence of EGFP-positive cells. For VRX494, transduction efficiency was maximal at an MOI of 25 to 50 and ranged between 58 and 67%. For VRX1090, transduction efficiency was maximal at an MOI of 10 and ranged between 80 and 90%. Thus, transductions performed with VRX1090 showed a higher number of EGFP-positive cells than VRX494.</p> <p>Conclusions</p> <p>This report shows that VSV-G pseudotyped HIV-based lentiviral vectors can efficiently transduce human blood monocyte-derived macrophages early during differentiation using low particle numbers that do not interfere with differentiation of monocytes into macrophages.</p

UNE PRODUCTION ACCRUE DE FACTEURS DE CROISSANCE ET UN HAUT NIVEAU D'AMPLIFICATION DU GENE C-MYC DIFFERENCIE LES CLONES TUMORIGENES DES CLONES NON TUMORIGENES DE LA LIGNEE DE CANCER DU SEIN SW613-S

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