Effects of neonatal thymectomy on Propionibacterium acnes and lipopolysaccharide induced liver injury in mice

Abstract

A study was made on the various effects of neonatal thymectomy (NTx) on hepatic injury induced by intravenous infusion of lipopolysaccharide (LPS) one week after administration of heat-killed Propionibacterium acnes in A/J mice. Spleen cells of non-thymectomized or NTx donor mice with hepatitis were transferred to normal or NTx recipient mice to determine whether passive transfer of hepatitis would be possible.
No difference could be observed in the mortality rate within 24 hours after LPS injection, serum GPT level and histological changes in the liver during the acute stage between the two groups. However, in the chronic stage, mononuclear cell infiltration in the portal area was more severe in NTx mice than in normal mice and the levels of autoantibody to liver-specific membrane lipoprotein (LSP) and serum GPT were higher in the former than the latter. Passive transfer of hepatitis was possible only when spleen cells of NTx donor mice with hepatitis were transferred to NTx recipient mice.
These results suggest that spleen cells are more weakly sensitized to LSP in non-thymectomized donor mice with hepatitis and that passive transfer of hepatitis by sensitized spleen cells is suppressed in normal recipient mice. More severe hepatitis in the chronic stage in NTx mice is considered to be attributable to defective suppressor function induced by NTx.