Current Understanding of the Role of Dendritic Cells and Their Co-Stimulatory Molecules in Generating Efficient T Cell Responses in Lepromatous Leprosy

Leprosy is a chronic infectious disease caused by Mycobacterium leprae that needs continued vigilance, particularly for detection and treatment of hidden and undiagnosed cases. Cell-mediated immunity in leprosy has been identified as a key mechanism for the understanding of this disease. The dendritic cell (DC) is the most potent professional antigenpresenting cell and recently has been the focus of much interest as the main initiator of naive T-cell responses to several antigens. For rational use of DCs in adjuvant therapy of lepromatous leprosy, the patterns of synthesis and secretion of cytokines by DCs during some mycobacterial infections must be better understood. Therefore, the aim of this review is to illustrate some of the cellular events involved in the immune recognition of the antigens during leprosy and the role of antigen- presenting cell (DC) and their co-stimulatory molecules, such as DC-SIGN, CD-40, B7-1 and B7-2, in generating efficient T-cell responses.