Tolouei et al. : IL-23 and IL-27 Levels in Macrophages Collected … Introduction Chealing lesion which heals spontane- utaneous leishmaniasis (CL) is a self- ously but rarely might develop to a non-healing form of disease refractory to various types of remedies (1). It seems that clinical manifestation of leishmaniasis de- pends upon the type of immune response generated and the species of Leishmania (2, 3). Although tremendous data is available in murine model of leishmaniasis which indi- cate generation of Th1 type of response in healing form of disease and Th2 type of re- sponse for progressive infection (4-7) but immunological surrogate marker(s) of heal- ing and protection in human is yet not well defined (8-11). Studies on various cytokine profile of Th1/Th2 are published with con- troversy results (8-12). Cytokines have fun- damental roles in development and regula- tion of immune responses against various infectious and non-infectious diseases (13- 16). Recently, IL-23 and IL-27 were identi- fied as heterodimeric cytokines which are structurally and functionally related to IL-12 family which promote IFN-γ production and Th1 development (17, 18). IL-12 composed of two subunits: p35 and p40, and IL-23 consisted of the p40 subunit of IL-12 and p19 subunit (19). IL-27 is another hetero- dimeric cytokine composed of a p40-related molecule, and p28 (20). There is evidence that IL-27 promotes Th1 differentiation and IL-23 plays an important role in proliferation of memory-type Th1 cells. IL-23 and IL-27 are involved in the regulation of Th17 re- sponse (21), while IL-23 induces differentia- tion of Th17 cells; IL-27 inhibits Th17 dif- ferentiation and IL-17 production by GATA- 3 expression through the Stat1-dependent pathway (22). As it is well established that successful control of infection against intra- cellular pathogens requires the production of IFN-γ, thus presence of IL-12 family as an Available at: http://ijpa.tums.ac.ir inducer of Th1 phenotype is important (17, 23). In this study the level of IL-23 and IL-27 produced by macrophages derived from peri- pheral blood mononuclear cell culture col- lected from patients with healing or non- healing form of lesion were compared before and after treatment with live Leishmania to explore whether IL-23 or IL-27 plays any role in healing process of cutaneous lesions induced by L. major. Materials and Methods This study was approved by the Ethical Committee on Human Research, Isfahan University of Medical Sciences. The volun- teers were informed about the objective and procedure of the study and those who were willing to participate, donate blood sample and sign an informed consent were recruited. Study groups Two groups of CL patients were selected from the patients referred to the Skin Dis- ease and CL Research Center, Isfahan Uni- versity of Medical Sciences. Ten parasitologically proven CL patients with healing form of lesion with onset less than 6 months and no history of treatment for CL and 10 parasitologically proven CL patients with non-healing form of lesion with duration of lesion more than 1 year and history of at least 2 courses of Glucantime treatment were included in this study. Diag- nosis was based on observation of Leish- mania using Giemsa stained smear and/or growth of promastigotes in NNN culture. Identification of Leishmania causative agent of the lesions was done using PCR method. DNA extraction In order to identify the Leishmania species, PCR method was used. The promastigotes 19