The Mechanism Of ILT3、ILT4 In The Cellular Immune Deficiency Of Leprosy

Objection:Leprosy is a chronic infectious disease caused by Mycobacterium Leprae (hereinafter called M. leprae). Now studies have shown that, only a few part of people had suffered from such risks under the condition that in the same contact with the infectious leprosy patients, this is because that the leprosy patients have some different degrees of cellular immunodeficiency, and the precise mechanism of cellular immunodeficiency is still unknown. Therefore, the leprosy is an ideal model for studying the interaction between the host innate immune function and pathogen.At present, there are many studies indicate that ILTs is involved in both innate and adaptive immunities, and it also plays the negative and positive regulatory roles in the immune response.Some studies even showed that ILT3 and ILT4 with high or forced expression can induce DC resistance, which result in the body’s immune tolerance. We suppose, therefore, that if ILT3 and ILT4 of the surface of CD14+ monocyte in peripheral blood of leprosy patients are high expression or not; if there is a relationship between such high expression and leprosy occurrence, development and evolution?The reports about the relationship between leprosy and ILTs are rare at present both at home and abroad. To explore the issues above, the study through the detection of double positive expression percentage of ILT3 and ILT4 of the surface of CD14+ monocyte in peripheral blood of leprosy, and the seroculture tests of peripheral blood mononuclear cells of healthy volunteers with multibacillary (MB) leprosy, paucibacillary (PB) leprosy and normal controls respectively are performed, so as to reveal the relationship between ILT3, ILT4 and leprosy, which provides theoretical basis for prevention and treatment of leprosy, and provides new ideas for development and research of leprosy vaccine.Method:Samples were collected from Department of Dermatology and Laboratory, the Second Affiliated Hospital of Kunming Medical University, in which,4 cases of TT group out of leprosy patients,11 cases of BT group,3 cases of BB group,12 cases of BL group,10 cases of LL group, and 40 cases of normal controls group.Flow cytometry was used to test double positive percentage of ILT3 and ILT4 of the surface of CD14+ monocyte in peripheral blood of the 6 groups above.In addition, the seroculture tests of peripheral blood mononuclear cells of healthy volunteers with 14 cases of multibacillary (MB) leprosy,6 cases of paucibacillary (PB) leprosy and 20 cases of normal controls respectively were performed, and also flow cytometry was used to determine double positive percentage of ILT3 and ILT4 of the surface of CD14+ monocyte in peripheral blood. And then, SPSS 19.0 software package was used for the statistical data analysis.Result:1.Double positive expression of ILT3 and ILT4 of CD14+ monocyte in peripheral blood of 5 groups out of leprosy patients was higher than the normal controls group. The double positive expression percentage levels of ILT3 and ILT4 were as follows:Normal controls group<TT group<BT group<BB group<BL group<LL group.2.The levels of expression percentage of ILT3 and ILT4 of the surface of CD14+ monocyte of different groups, after seroculture tests, were as follows:[Blood serum of multibacillary (MB) leprosy + CD14+ monocyte of healthy volunteers]> [Blood serum of paucibacillary (PB) leprosy + CD14+ monocyte of healthy volunteers]>[Blood serum of healthy volunteers + CD14+ monocyte of healthy volunteers].Conclusion:1. It is definite that double positive expression rate of ILT3 and ILT4 of the surface of CD14+ monocyte in peripheral blood of leprosy patients is quite higher than that of the normal.2. It is definite that the expression level of ILT3 and ILT4 of CD14+ monocyte in peripheral blood of 5 groups out of leprosy patients is:TT group<BT group<BB group<BL group<LL group.3. Seroculture tests are performed respectively to prove the soluble factors in serum of leprosy patients has an up-regulation effect on the expression of ILT3 and ILT4 of CD14+ monocyte in peripheral blood. The expression percentage rate of ILT3 and ILT4, after seroculture tests, is as follows:[Blood serum of multibacillary (MB) leprosy + CD14+ monocyte of healthy volunteers]> [Blood serum of paucibacillary (PB) leprosy + CD14+ monocyte of healthy volunteers]> [Blood serum of healthy volunteers + CD14+ monocyte of healthy volunteers].It can be proved that the soluble factors in serum of leprosy patients do have the up-regulatory function on the expression of ILT3 and ILT4 of CD14+ monocyte.4. It is definite that the expression percentage rate of ILT3 and ILT4 of CD14+ monocyte surface is:MB group> PB group, and thus explains that the higher the expression levels of ILT3 and ILT4 (i.e. the contents of M. leprae) are, the lower the autoimmune level is.