Coronin 1 is dispensable for leukocyte recruitment and liver injury in concanavalin A-induced hepatitis

• Naïve T cells are dispensable for liver damage during acute ConA-induced hepatitis.
• Leukocyte adhesion to liver sinusoids occurs in the absence of coronin 1 expression.
• Coronin 1 expression in T cells is required for full activation upon ConA treatment.

Coronin 1, a member of the evolutionary conserved coronin protein family, is highly expressed in all leukocytes. In mice and human, genetic inactivation of coronin 1 results in immuno-deficiencies that are linked to a strong reduction of naïve T cell numbers in peripheral organs, while memory/effector T cells, B cells, monocytes and neutrophils are less or not at all affected. Whether or not coronin 1 is important for leukocyte functions such as migration and phagocytosis has been a matter of debate. The current work addresses coronin 1-dependent leukocyte function by analyzing the response of coronin 1-deficient mice in a model of concanavalin A (Con A)-induced liver injury. Histological evaluation and determination of serum liver enzyme levels showed that coronin 1-deficient mice develop signs of acute hepatitis similar to Con A-treated wild type mice despite a reduced activation of T cells in the absence of coronin 1. Furthermore, analysis by intravital microscopy following Con A stimulation revealed that Gr-1+ neutrophils and CD4+ T cell adhesion in the post-sinusoidal venules increased in wild type as well as in coronin 1-deficient mice. These results suggest that coronin 1, while important for naïve T cell survival, is dispensable for other leukocyte function under inflammatory conditions in vivo.