Establishment of human colorectal tissue model in HIV-1 mucosal infection

Abstract

To establish human colorectal tissue model in HIV-1 mucosal infection and by using pseudotyped virus to simulate the biological process of HIV-1 mucosal infection from HIV-1 entering into mucosa to local infection establishment. Tumor adjacent normal colorectal tissues were obtained with informed consent. After excised the muscularis externa, the mucosa and submucosa were dissected into the same blocks and cultured in 12-well cell culture plates. The cultured tissue structure and morphology were observed from day 0 to day 13 by staining with the hematoxylin eosin (HE), and the tissue activity was detected by 3(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The established tissues explants were infected by a single cycle replicated pseudotyped virus and propagated for 6 - 7 days, then subjected to the detection of p24 production within supernatant to verify the applicability of the model for the studying of HIV-1 mucosal infection. The applicability of the established explants for safety and reactivity evaluation of mucosa topical drugs was conducted by the using of first generation antiseptic Nonoxynol-9 (N-9) as an example. HE staining showed the structure of colorectal tissue was remained well until 5(th) day and still evident until 13(th) day. The tissue activity of cultured mucosa was above 80% at day 4, and still remained over 50% at day 7 as detected by MTT assay. After infected by pseudo virus, the increased level of p24 was detected from supernatant collected on 1(st), 4(th), 8(th) day, which indicated a local infection was created. In addition, the dose changing of N-9 was reflected sensitively by the activity of this model. Ex vivo human colorectal tissue model mimic HIV-1 mucosal infection was established that can be used to replicate the bioprocess of human HIV-1 mucosal infection.