ABSTRACT
Toll like receptor ( TLRs) is a highly conserved transmembrane protein expressed in epithelial cells and immune cells,which is a kind of important receptor to identify the damage associated molecular patterns (DAMPs). TLRs and DAMP produced by tumor cells after chemotherapy combine to produce the corresponding biological effects via MyD88 dependent and independent path-ways. At present,the research application of TLRs identifying DAMP clinically is mainly focused on promoting the release of the DAMP and enhancing the expression of TLRs to strengthen the immune effect of chemotherapy drugs.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate effect of oxidized low-density lipoprotein (ox-LDL) on memory CD8T cell subpopulation differentiation in mice with autoimmune diabetes.</p><p><b>METHODS</b>Cultured splenic CD8T cells from pre-diabetic NOD mice isolated with magnetic beads were treated with 30 µg/mL ox-LDL and 10 U/mL interleukin-2 (IL-2) for 24 h and the control cells were treated with IL-2 only. Flow cytometry was used to determine the percentage of splenic CD8IFN-γT cells, expressions of CD8, CD44 and CD62L on the T cells, and the activation of T cell factor-1 (TCF-1) and STAT-3. The CD127memory T cells were purified and transplanted into the pre-diabetic NOD mice via the tail vein, and the blood glucose was recorded weekly and survival time of the mice was monitored.</p><p><b>RESULTS</b>Treatment with ox-LDL significantly reduced islet β cell-specific cytotoxic CD8T cells as compared with the control group [(0.7∓0.03)% vs (2.7∓0.14)%, P<0.01]. The percentage of effector memory CD8T cells (Tem) in the total memory CD8T cells was reduced [(10.3∓0.71)% vs (30.3∓1.36)%, P<0.01] and that of stem cell-like memory T cells was significantly increased [(72.3∓3.8)% vs (55.1∓2.61)%, P<0.05] following ox-LDL treatment, which also resulted in significantly decreased activation of TCF-1 [(14.5∓0.82)% vs (34.2∓1.23)%, P<0.01] and pSTAT-3 [(3.3∓0.12)% vs (22.1∓1.1)%, P<0.01]. Transplantation of ox-LDL-treated memory T cells in pre-diabetic NOD mice obviously inhibited the increase of blood glucose and prolonged the survival time of the mice (P<0.05).</p><p><b>CONCLUSION</b>Ox-LDL decreases the activation of transcriptional factors TCF-1 and phosphorylation of STAT-3, inhibits the formation of effector memory CD8T cells with long-term cytotoxicity, but promote the generation of stem cell-like memory CD8T cells, which result in suppression of islet β cell-specific effector cytotoxic CD8T cell differentiation to lessen autoimmune injury to the islet β cells.</p>