Abstract |
Accumulating evidence suggests that intestinal epithelial cells (IECs) constitutively express the immunoregulatory cytokine interleukin (IL)-18. IECs also serve as the host cell for the intracellular parasitic protozoan Cryptosporidium parvum. In the present study, C. parvum infection of a human enterocyte cell-line HCT-8 resulted in increased expression of IL-18 mRNA as measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR). IL-18 protein was detected in control uninfected cells and following infection there was increased expression as measured by enzyme-linked immunosorbent assay (ELISA). Gene expression revealed the presence of the IL-18 receptor subunits not only in cell-lines but also in freshly isolated IECs, suggesting that IL-18-mediated signalling events may contribute to epithelial host defence during infection. Recombinant IL-18 inhibited intracellular development of the parasite in HCT-8 and HT-29 cells. Increased expression of bactericidal antibiotic peptides LL-37 and alpha-defensin 2 by IL-18 in HCT-8 and HT-29 cells may represent one mode of action by which this pluripotent cytokine aids in limiting the development of intracellular pathogens such as C. parvum in the gastrointestinal tract.
|
Authors | V McDonald, R C G Pollok, W Dhaliwal, S Naik, M J G Farthing, M Bajaj-Elliott |
Journal | Clinical and experimental immunology
(Clin Exp Immunol)
Vol. 145
Issue 3
Pg. 555-62
(Sep 2006)
ISSN: 0009-9104 [Print] England |
PMID | 16907926
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Anti-Bacterial Agents
- Antimicrobial Cationic Peptides
- IL18R1 protein, human
- Interleukin-18
- Interleukin-18 Receptor alpha Subunit
- RNA, Messenger
- Receptors, Interleukin
- Receptors, Interleukin-18
- Recombinant Proteins
- alpha-Defensins
- Cathelicidins
|
Topics |
- Animals
- Anti-Bacterial Agents
(metabolism)
- Antimicrobial Cationic Peptides
(metabolism)
- Case-Control Studies
- Cell Line
- Cryptosporidiosis
(immunology, metabolism)
- Cryptosporidium parvum
(drug effects, physiology)
- Enterocytes
(immunology, microbiology)
- HT29 Cells
- Humans
- Interleukin-18
(genetics, physiology)
- Interleukin-18 Receptor alpha Subunit
- RNA, Messenger
(analysis)
- Receptors, Interleukin
(metabolism)
- Receptors, Interleukin-18
- Recombinant Proteins
(pharmacology)
- alpha-Defensins
(metabolism)
- Cathelicidins
|