Modulated TGF-beta response in the hamster model in response to immunization with the recombinant L1b protein from Entamoeba histolytica

Vagotomy induces deregulation of the inflammatory response during the development of amoebic liver abscess in hamsters

BACKGROUND

The parasympathetic nervous system modulates the immune response in the abdominal-pelvic gut through the vagus nerve, which releases acetylcholine. This endogenous ligand acts on α7 nicotinic receptors expressed on immune cells.

OBJECTIVE

To study the mechanism of the production and regulation of cytokines in parasympathectomized and control hamsters during the development of amoebic liver abscesses (ALA) caused by Entamoeba histolytica.

METHODOLOGY

Six- to 8-week-old male hamsters with and without vagotomy were used in a model of ALA. The animals were infected with trophozoites (350,000; HM1:IMSS strain) via the intrahepatic route and sacrificed at 6, 12, and 24 h and at 2, 4, and 7 days postinfection. Immune parameters were recorded at each time point using morphometric techniques including immunofluorescence and immunohistochemistry assays. These parameters included signal transducer and activator of transcription 3 (STAT3) levels, pro- and anti-inflammatory cytokine levels, and nuclear factor-κB (NFκB) activation in neutrophils and macrophages.

RESULTS

Compared to the control groups, the vagotomized (VAG) hamsters showed a significant increase in NFκB activation in neutrophils and macrophages, and higher levels of interleukin (IL)-1β, IL-6, interferon-γ, and tumor necrosis factor-α. VAG hamsters showed an increase in the expression of IL-8 and phosphorylated STAT3 during the first 24 h postinfection as well as slightly increased levels of transforming growth factor-β on days 2-7 postinfection. No significant differences were demonstrated in the levels of IL-10.

CONCLUSIONS

These results suggest that the vagus nerve plays an important role in the regulation of inflammation during ALA formation.

Long-term follow-up of solitary intracerebral juvenile xanthogranuloma. Case report and review of the literature

Juvenile xanthogranuloma is a benign, non-Langerhans-cell histiocytic infiltrate that typically presents as a solitary cutaneous lesion in childhood. There are reports of extracutanous involvement, including tumors in the central nervous system. A solitary, intraparenchymal tumor without skin manifestations is a rare event, with only 3 prior cases reported in the literature. Cerebral lesions have been associated with multifocal or systemic forms of the disease, with an occasionally fulminate clinical course. Considering the rarity of this tumor, it is unclear whether patients need adjuvant therapy after excision of a solitary intraparenchymal tumor. Previous reports suggested that complete excision of the lesion was curative; however long-term follow-up was not provided. This report illustrates a case of surgical excision of a solitary juvenile xanthogranuloma in an 8-year-old male with a 3-year follow-up period.