01707nas a2200277   4500000000100000008004100001260001600042653001200058653002000070653002100090653001500111100001200126700001500138700001300153700001200166700001500178700001000193700001000203700001200213700001400225700001400239700001100253245007200264520107900336022001401415       2012                            d  c2012 Dec 1810aleprosy10aImmune response10aHuman monocytes.10aGalectin-31 aChung A1 aSieling PA1 aSchenk M1 aTeles R1 aKrutzik SR1 aHsu D1 aLiu F1 aSarno E1 aStenger S1 aModlin RL1 aLee DJ00aGalectin-3 regulates the innate immune response of human monocytes.3 aGalectin-3 is a β-galactoside binding lectin widely expressed on epithelial and hematopoietic cells and its expression is frequently associated with a poor prognosis in cancer. Since it has not been well-studied in human infectious disease, we examined galectin-3 expression in mycobacterial infection by studying leprosy, an intracellular infection caused by Mycobacterium leprae. Galectin-3 was highly expressed on macrophages in lesions of patients with the clinically progressive lepromatous form of leprosy; in contrast, galectin-3 was almost undetectable in self-limited tuberculoid lesions. We investigated the potential function of galectin-3 in cell-mediated immunity using peripheral blood monocytes. Galectin-3 enhanced monocyte IL-10 production to a TLR2/1 ligand, while IL-12p40 secretion was unaffected. Furthermore, galectin-3 diminished monocyte to DC differentiation and T cell antigen presentation. These data demonstrate an association of galectin-3 with unfavorable host response in leprosy and a potential mechanism for impaired host defense in humans.  a1537-6613