Autoimmune hepatitis induction can occur in the liver

Area of Science:

• Immunology
• Hepatology
• Autoimmune Diseases

Background:

• T cell priming in the liver is established.
• The site of immune activation in autoimmune hepatitis (AIH) remains debated: liver versus spleen.

Purpose of the Study:

• To investigate the role of the spleen in the induction and severity of experimental murine AIH (emAIH).

Main Methods:

• Mice underwent splenectomy followed by induction of emAIH using an adenovirus expressing formiminotransferase cyclodeaminase (Ad-FTCD).
• Evaluated emAIH development, intrahepatic immune cell populations (B cells, T cells, regulatory T cells [Tregs]), and pathological scores.

Main Results:

• Post-splenectomy, mice exhibited a higher incidence and severity of emAIH compared to controls.
• Splenectomized mice showed increased intrahepatic B cells and a reduced proportion of Tregs within a diminished T cell infiltrate.
• Pathological scores were more severe in splenectomized animals, indicating a protective role for the spleen.

Conclusions:

• The spleen is unlikely to be the primary site for AIH induction.
• The spleen appears to exert a protective effect against AIH development and severity.
• These findings offer critical insights into the etiology of AIH.