Objective: 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.
Methods: 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.
Results: 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.
Conclusion: 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.