Related Experiment Video
Updated: Oct 1, 2026
A Choroid Plexus Epithelial Cell-based Model of the Human Blood-Cerebrospinal Fluid Barrier to Study Bacterial Infection from the Basolateral Side
Published on: May 6, 2016
Supernatants of HIV-infected immune cells affect the barrier function of human HT-29/B6 intestinal epithelial cells
Heinz Schmitz1, Katharina Rokos, Peter Florian
1Department of Gastroenterology, Infectious Diseases and Rheumatology, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, 12200 Berlin, Germany.
Objectives:
Characterization of the diarrhoea-inducing effect of altered cytokine production in HIV infection.
Methods:
Monocyte-derived macrophages (MDM) were infected with macrophagetropic (SF162) and lymphocytotropic (IIIB) HIV-1 strains and cocultured with autologous peripheral blood mononuclear cells (PBMC). After 24 h the supernatants were collected and tested for their immunoreactive levels of cytokines by enzyme-linked immunosorbent assay. The effects of the supernatants and the respective recombinant human cytokines on barrier function of HT-29/B6 cells were determined.
Results:
Infection of MDM with HIV-1 SF162 or IIIB led to increased production of tumour necrosis factor-alpha (TNFalpha), interleukin-1-beta, interferon-alpha and interferon-gamma after cell-cell contact with PBMC. Supernatants of infected cells decreased transepithelial resistance (R(t)), with higher effects on R(t) in HIV IIIB infection, which was due to higher cytokine concentrations. The effect was not due to cytotoxicity (negative LDH assay) or epithelial monolayer disruption [zonula occludens protein-1 (ZO-1) immunofluorescence staining]. The effect of HIV-1 IIIB coculture supernatants could be mimicked by the respective recombinant human cytokines. TNFalpha is an effector cytokine, because inhibition of TNFalpha by its soluble receptor decreased the effect of the supernatants on transepithelial resistance. Conductance scanning indicated the cytokine-induced barrier defect to be due to both, induction of epithelial apoptoses and tight junction alterations.
Conclusions:
Cell-cell interaction of HIV-infected macrophages with PBMC leads to a release of cytokines sufficient to alter intestinal epithelial barrier function. The main effect was mediated by TNFalpha inducing a leak-flux which may contribute to the diarrhoea by HIV per se (HIV-enteropathy).
Insights
HIV infection alters cytokine production, damaging the intestinal barrier and causing diarrhea. Tumor necrosis factor-alpha (TNFalpha) is a key mediator, leading to epithelial cell apoptosis and tight junction changes, contributing to HIV-enteropathy.
Area of Science:
- Immunology
- Gastroenterology
- Virology
Background:
- HIV infection is associated with gastrointestinal complications, including diarrhea.
- Altered cytokine profiles are implicated in HIV pathogenesis.
- The precise mechanisms by which HIV affects intestinal barrier function require further elucidation.
Purpose of the Study:
- To characterize the diarrhea-inducing effects of altered cytokine production in HIV infection.
- To investigate the role of cytokines released by HIV-infected cells on intestinal epithelial barrier function.
- To identify specific cytokines responsible for disrupting the intestinal barrier.
Main Methods:
- Monocyte-derived macrophages (MDM) were infected with HIV-1 strains (SF162, IIIB) and co-cultured with peripheral blood mononuclear cells (PBMC).
- Supernatants were analyzed for cytokine levels using ELISA.
- The impact of supernatants and recombinant cytokines on HT-29/B6 intestinal cell barrier function (transepithelial resistance, apoptosis, tight junctions) was assessed.
Main Results:
- HIV-1 infection of MDM induced increased production of TNFalpha, IL-1beta, IFNalpha, and IFNgamma.
- Supernatants from infected cells reduced transepithelial resistance, with a greater effect from the IIIB strain.
- TNFalpha was identified as a key effector cytokine, mediating barrier defects through epithelial apoptosis and tight junction alterations.
Conclusions:
- Cell-cell interaction in HIV infection triggers cytokine release that impairs intestinal epithelial barrier function.
- TNFalpha plays a significant role in mediating this barrier defect, leading to a "leak-flux" phenomenon.
- This cytokine-mediated disruption likely contributes to diarrhea in HIV infection (HIV-enteropathy).
More Related Videos
08:11Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.
Published on: September 1, 2015
11:14Ex Vivo Infection of Human Lymphoid Tissue and Female Genital Mucosa with Human Immunodeficiency Virus 1 and Histoculture
Published on: October 12, 2018