Linfopoyesis B aumentada en los ratones CTSLnkt/nkt

BADANO MN; CAMICIA G; COSTA H; D LORENZO; I PIAZZON; I NEPOMNASCHY

Mar del Plata

Congreso; LIV Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica y LVII Reunión Científica Anual de la Sociedad Argentina de Inmunología; 2009

Cathepsin-L deficient mice (CTSLnkt/nkt) show increases inB lymphocytes number and in the extracellular matrix (ECM) componentsin lymph nodes (LN). In this study we investigated the mechanismsinvolved in the variation of LN B cells numbers in CTSLnkt/nktmice.Neither LN nor spleen showed alterations in B cell basal apoptosis(propidium iodide) and proliferative (5´-bromo-2´-deoxyuridine)levels in CTSLnkt/nkt mice. When studied the adhesion molecules that enable the entry oflymphocytes into the LN, we observed an increase in the percentage of CD19+ cellsexpressing high levels of LFA-I and CD44 in the CTSLnkt/nktmice.To investigate the B-cell production by the bone marrow (which showslow levels of ECM glycoproteins) we performed colony-forming unitpre-B (CFU pre-B) assays in a methylcellulose and IL-7supplemented medium (7 days of culture). The numbers of B cellcolonies from CTSLnkt/nkt mice were higher than the number of wildtype colonies. These results suggest that the elevated numbers of B220+cells in the LN of CTSLnkt/nkt mice, is in part, aconsequence of an increased B lymphopoyesis.We hypothesized that Cathepsin-L -probably acting on the ECMcomposition- play a role in the regulation of B cell production andtheir distribution in the peripheral lymphoid organs. p { margin-bottom: 0.25cm; direction: ltr; color: rgb(0, 0, 0); line-height: 120%; }p.western { font-family: "Times New Roman", serif; font-size: 12pt; }p.cjk { font-family: "Times New Roman", serif; font-size: 12pt; }p.ctl { font-family: "Times New Roman", serif; font-size: 12pt; }