rAAV2/Retro serving as delivery system for retina photoreceptor cells and application of rAAV2/Retro in preparation of medicine for treating retina diseases

Abstract

The invention belongs to the technical field of bioengineering and biomedicine, and relates to rAAV2 / Retro serving as a delivery system for retina photoreceptor cells and application of the rAAV2 / Retro in preparation of drugs for treating retinal diseases. The method comprises the following steps: constructing an expression system carrying an exogenous target gene or shRNA (short hairpin Ribonucleic Acid) by taking rAAV2 / Retro as a carrier; taking the rAAV2 / Retro as a delivery system to effectively infect retina photoreceptor cells and specifically express the target gene or knock out the endogenous gene. According to the invention, a unique reverse backtracking infection mode of rAAV2 / Retro is utilized to specifically act on photoreceptor cells, so that non-specificity of a traditional adeno-associated virus delivery system is avoided; the medicine for treating the retinal diseases adopts safe and comprehensive intravitreal injection, the infection range is larger than that of traditional adeno-associated viruses, and a better treatment effect is achieved. Therefore, the gene medicine for treating the retinal diseases, which is prepared by utilizing the rAAV2 / Retro virus carrier disclosed by the invention, has the advantages of strong specificity, high safety and good treatment effect.

Description

technical field [0001] The invention belongs to the technical fields of bioengineering and biomedicine, and specifically relates to a novel rAAV2 / Retro as a delivery system for retinal photoreceptor cells and its application in the preparation of drugs for treating retinal diseases. [0002] technical background [0003] The retina consists of a variety of cells, of which the outer nuclear layer is mainly composed of photoreceptor cells (such as figure 1 ). Photoreceptor cells are a type of special nerve cells in the retina that have the function of transforming light signals, and are the basis for normal vision. In retinal diseases, photoreceptor cell lesions and abnormal gene expression are common, which seriously affect visual function impairment. In addition, retinal diseases (such as retinoschisis, congenital achromatopsia, age-related macular degeneration, diabetic retinopathy, glaucoma and lesions caused by ocular trauma) caused by gene mutations or abnormal gene expr...

AI Technical Summary

Problems solved by technology

At present, there are two main methods of drug delivery to the photoreceptor cells of the outer nuclear layer: ① Intravitreal injection ( figure 2 A), the injection needle of this method only needs to pass through the outer sclera and the pars plana of the ciliary body to enter the vitreous cavity, thus not causing retinal detachment, less damage to retinal cells, and lighter inflammatory reactions; but its disadvantage is that common viruses are very Difficult to reach the outer core

② Subretinal injection: This method needs to cross the vitreous and pass through the retina again, such as figure 2 As shown in B, the subretinal space is a potential cavity that exists when the retinal neuroepithelium and pigment epithelium separate, and the spread of the virus is very limited; at the same time, subretinal injection will cause partial separation of the retina, which may cause glial cells Hyperplasia, retinal detachment, photoreceptor degeneration, and visual impairment

[0007] (2) The scope of infection is limited

Since the existing adeno-associated virus drugs cannot reach the outer nuclear layer through intravitreal injection, they can only be injected into the subretinal space. The subretinal space is a potential cavity, and local subretinal injection cannot make the virus fully Infects the entire retina ( figure 2 B), leading to a limited range of infection

[0008] (3) Poor specific targeting of broad-spectrum strong promoters

The infection of AAV2, AAV5, AAV7 and AAV8 adeno-associated virus is not specific to the type of neurons, and will infect all types of neurons and glial cells at the site of virus injection, and the infection of non-target cells by the virus will reduce the target photoreceptor cells infection efficiency and create potential disturbances and risks

[0009] (4) Poor expression of photoreceptor cell-specific promoters

The expression system carrying NR2E3 and IRBP photoreceptor cell-specific promoters only expresses the target protein in photoreceptor cells, but the expression intensity is far inferior to that of broad-spectrum strong promoters

Images