Primary Research On Latency Of Herpes Simplex Virus Type 1 In The Iris, Ciliary Body And Retina Of Normal Human

Background and Aims Herpes simplex virus type 1 has been the primary cause of ocular diseases. The former research had discovered HSV-1 mainly latency in some ganglia such as trigeminal ganglion and cervix sympathetic ganglion. After that, HSV-1 had been demonstrated in iris, ciliary body and super cervical ganglion of mice, cornea, amygdala, hippocampus and brain stem of human. Recently there were some evidence to imply HSV-1 DNA latency in human ciliary ganglion and pterygium. Cornea has been proved to be another ocular latency site of HSV-1.As trigeminal ganglion innervates cornea, iris and ciliary body, it is not clear by now whether iris and ciliary body exist HSV-1 latency just as cornea. Although HSV-1 could cause acute retinal necrosis syndrome (ARN), there were deficiency in evidence of latent HSV-1 in retina. The purpose of our studies was to explore whether HSV-1 latency in iris ,ciliary body and retina through cell co-culture, immunohistochemical staining and PCR amplification . Materials and Methods After penetrating cornea transplantion, 20 samples of normal healthy donors'fresh eyeballs were collected, 1/3 parts of each eyeball was removed for immunohistochemical staining to exclude from acute infection of HSV-1.Residual iris, ciliary body and retina were taken out from the negetive staining samples. Among them, 1/3 parts of each tissue was centrifugated for co-culture with Vero cells and then blindly transfered to the third generation separately for detecting active HSV-1, while DNA was extracted from the other 2/3 parts respectively to amplify by polymerase chain reaction for detecting sequence of HSV-1 DNA and latency associated transcript(LAT). Results 1. All the 20 samples were negative for immunohistochemical staining and had no HSV-1 infection. 2. It was negative for co-culture of Vero cells with upper fluid of iris, ciliary body and retina which were blindly transfered to the third generation. No Cytopathological effects were observed, while the positive contrast group had CPE including such as ballooning degeneration, karyopyknosis ,multinucleated giant cell even cell necrosis. 3. In the 20 samples, four samples of ciliary body were positive for HSV-1 DNA sequence and three samples of retina positive for HSV-1 DNA, whereas the other results were negative for HSV-1 DNA. All samples of iris, ciliary body and retina were negative for HSV-1 LAT. Conclusion HSV-1 DNA existed in normal human ciliary body and retina,which implied that there probably was HSV-1's latency in ciliary body and retina and maybe have relation with the cause of cyclitis and acute necrosis syndrom of HSV-1 in adults.It will lead a novel way for further research on recurrent mechanism of HSV-1 in normal human ciliary body and retina.