[Killer cell immunoglobulin-like receptors and their ligands]

The Natural killer [NK] cells are a subset of lymphocytes comprising around 10% of total lymphocytes in peripheral blood. Due to their role in the innate response, NK cells provide a 'first line of defense' against infectious agents and cancer and are also thought to play a role in autoimmunity. The killer cell immunoglobulin-like receptors [KIR] are regulatory surface molecules, found on NK cells and on a subset of T lymphocytes. The genes for KIR are present on chromosome 19 in the leukocyte receptor complex and show a major difference for both the type and number of KIR genes present among different ethnic groups. They have been divided into two groups of 2D or 3D, depending on the number of external immunoglobulin domains. The presence of a long cytoplasmic tail with two immune tyrosine-based inhibitory motifs [ITIM] allows the transduction of inhibitory signals and characterizes the inhibitory KIRs [2DL and 3DL], whereas the presence of short cytoplasmic tails corresponds to the activating KIR receptors [2DS and 3DS]. These polymorphic receptors interact with specific motifs on human leukocyte antigen [HLA] class I molecules, modulate NK cytolytic activity. Some KIRs are known to interact with HLA-C molecules of target cells, HLA-Bw4 molecules and HLA-A3/11. For some KIRs the corresponding ligands are still unknown

study of soluble adhesion molecules [SICAM-1, SVCAM-1, SELAM-1] in serum and membrane form of adhesion molecules [VCAM-1, ICAM-1] on the monocytes in diabetic subjects type 1

The adhesion molecules are involved in adhesion of leukocytes to endothelial cells and other immune cells. Not only adhesion molecules have membrane form, but they also have soluble form. In this paper, we attempted to investigate the concentration of soluble adhesion molecules in the type 1 diabetic patients [n = 40] and healthy subjects [n = 10]. The results indicated that there was an increase in the concentration of soluble adhesion molecules: sICAM-1, sVCAM-1 and sELAM-1, in the sera of diabetic patients rather than the healthy ones [p = 0/00]. Increased concentration of sVCAM-1 with the insulin injection dose [p = 0.01] and sICAM-1 with duration of disease [p = 0.05] indicated significant reversel linear correlation in the patients groups. Also, sELAM-1 with sVCAM-1 and sICAM-1 showed significant direct linear correlation in the same group [p = 0.01]. Adhesion molecules were determined by the sandwich ELISA principle. One of the most important factors in the development of atherosclerosis is the adhesion of monocytes to endothelial cells. Therefore, in this study, the percentage of expression of membrane form of VCAM-1, not ICAM-1, was increased on 10000 monocytes of diabetic patients type-1 [n=20] in comparison with normal subjects [n = 20, p = 0.05]. The expression tensive of membrane form of cams on the surface of monocytes was performed by flowcytometry technique. We concluded that the increase in sICAM-1, sVCAM-1 specially sELAM-1 and also mVCAM-1 indicated endothelial activation, stimulatability of leukocyte cells and increased interaction to endothelial cells. Although, scientists are not aware about the role of elevated CAMs concentration, it can be suggested that the increasing level of sICAM-1, sVCAM-1, sELAM-1 and mVCAM may reflect cellular expression, function of CAMs in autoimmune disease and also provide a potential therapeutic target for human IDDM