Isolated cells from LL skin lesions were evaluated
by flow cytometry to identify their phenotype and placed in culture. Flow cytometry revealed that after 24 h of culture, 41.74 ± 0.17% of the isolated cells were CD163+ (n = 6). Analysis of other cell markers revealed that these same cells also expressed CD209 (56.22 ± 0.66%, n = 4), HLA-DR (81.42 ± 0.94%, n = 5), and IDO (40.01 ± 2.50%, n = 3) (Fig. 2A). As observed by confocal microscopy, almost all cells were CD68+ (data not shown), confirming a macrophage phenotype. In addition, most of the cells were CD163+ while some coexpressed with IDO after 6 days of culture (Fig. 2B). Increased levels of CD163 in the sera of LL patients were observed in comparison with what was ascertained in the sera of healthy controls (HC) (6017.0 ± 593.9 in LL versus 1435.0 ± 129.6 in HC, p < 0.001) and BT (6017.0 ± 593.9 in LL versus 2150.0 ± 112.1 in NVP-AUY922 mw BT, p < 0.001) (Fig. Interestingly, the higher levels of sCD163 correlated with our recent report of higher IDO activity in LL patient sera MLN0128 . IL-10 levels in sera were also examined (Fig. 3B). The data confirmed previous reports showing higher levels of IL-10 in LL sera in comparison with BT and HC sera (36.08 ± 11.80 in LL versus 3.88 ± 1.27 in
HC, p < 0.01; 36.08 ± 11.80 in LL versus 9.48 ± 4.93 in BT, p < 0.01). We evaluated the ability of pathogenic mycobacteria such as ML and M. bovis BCG to induce CD163 and compared them to another pathogenic species Eschericia coli. ML (5: 1)-induced high CD163 expression in human monocytic culture (ML = 5.07 ± 2.32 versus the nonstimulated (n.s.) = 0.69 ± 0.38, p < 0.05), in contrast to BCG and E. coli, which did not (data not shown). Both dead and live ML were able to induce increased expressions of CD163, IDO, and CD209 in human monocytes (Fig. 4A and B), which were Adenosine accompanied by an uptick in TNF (46.91 ± 10.44 in nonstimulated versus 206.8 ± 21.78
in ML-stimulated, p < 0.01), TGF-β (71.3 ± 12.9 in nonstimulated versus 1093 ± 386.5 in ML-stimulated, p < 0.01), and IL-10 (154.4 ± 71.34 in nonstimulated versus 571.5 ± 199.5 in ML-stimulated, p < 0.05) in ML (MOI 10:1)-stimulated cultures (Fig. 4B). As explained in our previous report, IDO expression observed by increased ML MOI was met by an increase in IDO activity and a decrease in nitrate levels in cell supernatants . We attempted to clarify whether ML interference in IL-10 production positively regulates CD163. It was verified that the blockade of IL-10 reduced ML-induced CD163 expression (7.60 ± 1.93 in ML versus 1.53 ± 0.60 in ML + neutralizing IL-10, p < 0.05) (Fig. 4D), suggesting that ML-induced IL-10 is capable of upregulating CD163 expression in human monocytes. It was also shown that in ML-stimulated cultures, the IL-10 blockade reduced IDO activity, evaluated via the Kyn/Trp ratio (Fig. 4E).