CD1a positive DCs and subtypes from inflamed human dental pulps

Objective: In human dental pulp, dendritic cells (DCs) have been described as a first line of defense; these cells can be identified by the expression of different surface molecules. Our previous studies indicate the presence of DCs expressing CD1a+, CD1a+/CD68+ (iDCs), and CD1a+/CD16+ considered as hyper-responsive cells in healthy human dental pulp (hHDP), but there is not evidence of these presences in HDP with symptomatic irreversible pulpitis (SIP), which is the purpose of the present study.  Method: Were obtained 47 HDP samples from healthy premolars indicated to extraction for orthodontic reasons and 25 with SIP diagnosis.  The samples were homogenized and stained with MAbs CD1a, anti-CD16, anti-CD68 to its identification by flow cytometry.  The obtained data were analyzed using SPSS V.18 for Windows. Result: A significant increase of CD1a+ DCs was evidenced in SIP. It was evidenced the presence of iDCs in SIP, however its presences was higher in hHDP (p<0.05 Mann Whitney test).  CD1a+/CD16+ DCs were 17-fold increase in HDP with SIP diagnosis when these levels were compared with those expressed in healthy tissue (p <0.05 Mann Whitney test), suggesting this phenotype as a population apparently related to inflammatory processes in HDP. Conclusion: Although some authors report CD1a + dendritic cells as Langerhans cells and they are not present in HDP, this ex-vivo model showed CDs with this phenotype at different stages of maturation depending of the pulp inflammatory condition. The increased expression of DCs expressing CD1a+/CD16+ in HDP with symptomatic irreversible pulpitis suggest that they have a substantial contribution to these inflammatory processes.