Transplantation Immunity Study Of Human Amniotic Epithelial Cells Transplantation On Treating The Spinal Cord Injury

Objective: The treatment of spinal cord injury have been medical research hot spot.Afterspinal cord injury,Neural repair ability is very limited, and the death of neurons are notinstead of neurons by around or neural regeneration ability very weak. How to realize thenerve regeneration and repair after spinal cord injury is always a difficulty and a focus ofthe field. Severe disability bring great pain to patients after spinal cord injury. In recentyears, the progress of the stem cell research brings hope of nerve function reconstruction topatients.With the progress of the study, all kinds of stem cells appear in succession and thestudy have achieved certain results, at the same time, there are some limitations of cellstransplantation in treatment of spinal cord injury.For example, there are a series ofcomplications to immune rejection after cell transplantation, the content of stem cells andcell proliferation ability decreased significantly with the aging, the ethical problems, and soon.This study aims to through the study of transplantation immune condition of humanamniotic epithelial cells（HAECs） compared with marrow mesenchymal stem cells（BMSCs）to reveal the advantage in transplant immune of human amniotic epithelial cellstransplantation in treatment of traumatic spinal cord injury （SCI）.Methods:1, culture human amniotic epithelial cells and bone marrow mesenchymal cellsin the medium culture at37℃and5%CO₂incubator.2, Choose21SD rats （250³00g,7weeks） at random and establish animal model ofspinal cord transaction under microscope with spinal cord half cross sectional, implantedHAECs, BMSCs, PBS （whose cell density adjusted in advance） to the cross sectional areaof rats immediately, so there are three groups: HAECs transplantation group, BMSCstransplantation group and PBS group as a control.3, Take Basso Beattie Bresnahan movement function score （BBB score） after cellstransplantation every3days, evaluate the condition of hind limbs motor function recoverylast2months. According to the BBB score to observe the trends of change of BBB scores. 4, Select two rats randomly from each group when one week and three months aftercell transplantation, take damage section of spinal cord injury in surgery and fixed in4%paraformaldehyde fixed liquid and embed with paraffin after24h; then mark CD3⁺Tcellsusing immune histochemical methods and observe T lymphocytes under a microscope.Select the most CD3⁺Tcells slice randomly, select five slice and count positive cellunder under high power field of vision （×400）.5,1week,1month,2months,3months after cell transplantation, extract venousblood and separate serum.Detecte OD value of IL-2and IL-10in rats serum with ELISAmethod and observe the changes.Results:1, two kinds of cells have similar growth cycle and regularity. Amniotic epithelialcells were round or oval, nuclear, cytoplasmic rich in fat drops.2, BBB-score of three groups rats shows quickly risen and into plateau in three weeksafter transplantation, resume is more obvious in three weeks after cell transplantationgroup and amniotic epithelial cells is better than that of bone marrow mesenchymal cellsgroup （P <0.05）.3, CD3immunohistochemical display,there were CD3+cells infiltration with eachsection in the early days,3months after transplantation, CD3+lymphocytes of amnioticepithelial cells group significantly less than the bone marrow mesenchymal cells （P <0.05）.4, the levels of IL–2of HAECs rats serum significantly lower than that of theBMSCs group, but the levels of IL-10on the high side.Conclusion: HAECs have similar growth rule and proliferation compared with rat BMSCs,at the same time, remain strong proliferation activity after five generations; The treatmentof cell transplantation to spinal cord injury is obvious, and the immunogenicity of HAECsis weaker compared with rat BMSCs; Human amniotic epithelial cells used in thetreatment of spinal cord injury has significant advantages as a special "stem cells".