Identification Of The Determinants For HIV-associated Neurocognitive Impairment In Gp120 Envelope Protein And Its Animal Model

Background: Although the era of combined antiviral therapy has greatly reduced the virus replication in the periphery of HIV patients,the virus replication is still active in the central Nervous System.Some HIV-1 patients will develop HAND(HIV-associated neurocognitive disorder)symptoms.The viral protein of HIV-1 plays an important role in the development of HAND.For example,proteins such as gp120,tat,and VPR can damage neurons in the central nervous system directly or indirectly,causing cognitive impairment.Currently,there is no effective and reliable models for the research on HAND.Aim: Based on the EcoNDK virus,this experiment will construct a virus that carries HIV-1 gp120 protein fragments and can infect mice which will be used as a HAND model,and explore the importance and relevance of each region of gp120 in the process of nerve damage.Method: Reinsert gp120 into the proline-rich region in the gp70 fragment of EcoNDK virus to construct an infectious EcoNDK-gp120 virus.Explore the effect of EcoNDK-gp120 infection on macrophages.Then these resulted viruses were injected into mice to verify the expression of the virus in vivo,and whether it causes neurocognitive impairment through behavioral tests.Results: We inserted the gp120 fragments into EcoNDK,called EcoNDK-gp120,in which the gp120 could be exposure on surface of the infected cells.EcoNDK-C2,V4,and V5 can infect primary macrophages in vitro and cause significant up-regulation of the mRNA levels of pro-inflammatory factors and chemokines.After EcoNDK-C2 infects mice,it can cause cause significant up-regulation of the mRNA levels of pro-inflammatory factors and chemokines.In addition,EcoNDK-C2,V4,and V5 mice have a significantly higher number of errors than EcoNDK mice,and can detect the expression of P24 protein in the brain tissue,and at the same time find the lesions in the brain caused by injection.Subsequently,we use the HIV-associated neurocognition disorder model constructed with EcoNDK-V5 virus to explore the relationship between the load of EcoNDK-V5 virus in mice and the infection time and injection dose,and to complete its kinetic study.On the basis of EcoNDK-V5,we did a primary mechanism study,and it was found that tight junction protein(ZO-2)mRNA level was up-regulated,and EcoNDK-V5 was not enough to cause the neurocognition disorder in mice under the conditions of CCL2 inhibition or knockout.Conclusion: On the basis of the predecessor EcoNDK,the EcoNDK-C2,V4,and V5 viruses constructed containing gp120 fragments of different sizes have the ability to infect mice,and compared with the neurocognitive impairment caused by EcoNDK,the infected EcoNDK-gp120 mice have more serious degrees of neurocognitive impairment.Aggravate.It indicates that the expression of gp120 can induce neurocognitive damage in mice,and it has been verified that EcoNDK-V5 can cause a decrease in the mRNA level of tight junction protein ZO-2 in the blood-brain barrier of mice,and that EcoDNK-V5 requires CCL2 to cause nerve damage.EcoNDK-V5 mouse model can be used as a neuro-AIDS animal model to explore the molecular mechanism of injury and screen anti-HAND drugs.