Ex vivo culture of human colorectal tissue for the evaluation of candidate microbicides

Patricia S. Fletcher, Julie Elliott, Jean Charles Grivel, Leonid Margolis, Peter Anton, Ian McGowan, Robin J. Shattock

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107 Citations (Scopus)

Abstract

OBJECTIVES: Establishment of an in vitro model to evaluate rectal safety and the efficacy of microbicide candidates. DESIGN: An investigation and characterization of human colorectal explant culture for screening candidate microbicides to prevent rectal transmission of HIV-1 infection. METHODS: Human colorectal explants were cultured at the liquid-air interface on gelfoam rafts. Phenotypic characterization of HIV-1 target cells was performed by fluorescence-activated cell sorter analysis. HIV-1 infection was determined by the measurement of p24 antigen release, viral RNA, and proviral DNA accumulation. RESULTS: Colorectal explant CD4 T cells expressed higher CCR5 and CXCR4 levels compared with blood. Minor differences between the rectal and sigmoid colon were observed with a trend for slightly higher CCR5 and HLA-DR expression in cells from the sigmoid colon. Favourable culture conditions were established for colorectal tissue. Although tissue structure degenerated with time, CD4: CD8 cell ratios remained constant, and tissue supported productive HIV-1 infection. The ability of candidate microbicides to inhibit R5 HIV-1 infection was evaluated. Polyanion candidates, PRO2000 and dextrin sulphate, provided 99% protection at 1 μg/ml and 1 mg/ml, respectively, equivalent to 1/5000 and 1/40 of the vaginal formulations. The nucleotide reverse transcriptase inhibitor (NRTI) 9-[2-(phosphonomethoxy)propyl]adenine (PMPA) provided protection at concentrations 1000-fold lower (10 μg/ml) than the proposed vaginal formulation (1%). Furthermore, non-NRTI UC-781 and TMC-120 provided greater than 99% inhibition at 3.3 or 0.33 μg/ml, respectively. No products demonstrated toxicity to rectal mucosa at inhibitory concentrations. CONCLUSION: Colorectal explant culture was shown to be a useful tool for the preclinical evaluation of potential microbicides. The data suggest that rectally applied microbicides might provide protection from HIV-1 transmission.

Original languageEnglish
Pages (from-to)1237-1245
Number of pages9
JournalAIDS
Volume20
Issue number9
DOIs
Publication statusPublished - 1 Jun 2006

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Keywords

  • Anal intercourse
  • Explants
  • Gut-associated lymphoid tissue
  • HIV prevention
  • Rectal mucosa
  • Sexual transmission
  • Topical microbicides

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology
  • Infectious Diseases

Cite this

Fletcher, P. S., Elliott, J., Grivel, J. C., Margolis, L., Anton, P., McGowan, I., & Shattock, R. J. (2006). Ex vivo culture of human colorectal tissue for the evaluation of candidate microbicides. AIDS, 20(9), 1237-1245. https://doi.org/10.1097/01.aids.0000232230.96134.80