Biomedical subjects

Carolina Jancic

Publications and source records attributed to Carolina Jancic.

3 recordsLinked to original sources

PubMed2005

Migration of polymorphonuclear leucocytes is influenced by dendritic cells.

Dendritic cells (DCs) are the most potent antigen-presenting cells and populate many tissues where they may participate in inflammatory reactions. The infiltration of polymorphonuclear leucocytes (PMNLs) into tissues is a prominent feature of inflammation. The mechanisms of PMNL recruitment depend on chemotactic factors and adhesion molecules expressed on endothelial cells. The aim of the present study was to determine whether DCs participate in the early recruitment of PMNLs. Dendritic cells derived from peripheral blood monocytes were used for this study. PMNLs incubated with culture supernatant (CS) from untreated or from tumour necrosis factor-alpha (TNF-alpha)-treated (1 hr, 100 U/ml, 37 degrees ) monocyte-derived DCs (moDCs) had increased surface expression of both CD11b and CD18. Moreover, both untreated and TNF-alpha-treated moDCs induced PMNL chemotaxis. By blocking CXCL8, CXCL5, CXCL7 and Pan GRO (CXCL1, CXCL2, CXCL3), we observed that CXCL8/interleukin-8 might be the chemokine that induced the PMNL chemotactic activity in the CS of untreated and TNF-alpha-treated moDC. Furthermore, we investigated the regulation of CXCL8 production in moDCs by adhesion molecule engagement. Our data demonstrated that CD31, CD18, CD29 and CD49d participated in the adhesion of immature moDCs to endothelium. Moreover, engagement of domains 1-3 of CD31, but not of CD29 or CD18, decreased the production of CXCL8 by immature but not mature moDCs (which display lower CD31 levels than immature moDCs). Overall, these results suggest that DCs not only trigger a specific immune response, but also the innate immune response by recruiting PMNLs. Furthermore, our results also suggest that CXCL8 production by immature DCs might be regulated by signalling through CD31 during their migration through the vascular endothelium.

Animals↗

PubMed2004

Dendritic cell maturation controls adhesion, synapse formation, and the duration of the interactions with naive T lymphocytes.

The initiation of adaptive immune responses requires the direct interaction of dendritic cells (DCs) with naive T lymphocytes. It is well established that the maturation state of DCs has a critical impact on the outcome of the response. We show here that mature DCs form stable conjugates with naive T cells and induce the formation of organized immune synapses. Immature DCs, in contrast, form few stable conjugates with no organized immune synapses. A dynamic analysis revealed that mature DCs can form long-lasting interactions with naive T cells, even in the absence of Ag. Immature DCs, in contrast, established only short intermittent contacts, suggesting that the premature termination of the interaction prevents the formation of organized immune synapses and full T cell activation.

Amino Acid Sequence↗

PubMed2004

[Polymorphonuclear leukocytes decrease the immunostimulatry capacity of human dendritic cells].

The aim of this work was to evaluate the ability of polymorphonuclear leukocytes (PMNL) to modulate the function of dendritic cells (DCs). Human DCs were used to analyze the effect of PMNL on DCs. The allostimulatory proliferation of T cells induced by DCs incubated with PMNL was lower (42 +/- 14%, n:8, p<0.05) compared with untreated DCs. The decreased proliferation correlated with lower IFNgamma production (DCs: 781 +/- 3 pg/ ml; DCs-CS: 343 +/- 178 pg/ml, p<0.05). The same effect was observed in an antigen specific assay. However, the effect was not observed when PMNL where incubated with mature DCs. Indeed, the effect of PMNL was partially reverted with serine proteases inhibitors. Overall, these results suggest that PMNL modulates DCs activity by serine proteases.

Antigens, CD↗