Dysfunction of Immune System and Induction of Autoantibodies to Liver Antigens by Neonatal Thymectomy in Mice

Myozaki Mitsuru

Wang Mei Qi

Yoshida Yasuhiro

Liu Jia Nuo

Kuroda Etsushi

Yamashita Uki

Hiroshima Journal of Medical Sciences

[PISSN] 0018-2052

[EISSN] 2433-7668

[NCID] AA00664312

We examined the development of autoantibodies to liver proteins and hepatitis in BALB/c mice thymectomized 2 days after birth and attempted to characterize the immune function of these mice. Autoantibodies to crude liver proteins detected by ELISA were found in 21(84%) of 25 mice thymectomized 2 days after birth. In these mice, sera of 11 animals showed reactivity with both liver specific proteins (LSP) and the second fraction of crude liver proteins; sera of 3 mice showed reactivity with only the second fraction but no sera showed reactivity with only LSP. By Western-immunoblotting, sera of BALB/c mice which showed high autoantibody level to liver proteins detected a strong band around 150kD in the second fraction of crude liver proteins. Still more, hepatic inflammation; mononuclear cell infiltration in the portal area, was induced in mice with apparently high autoantibody level to crude liver proteins. These results in BALB/c mice corresponded with our previous reports which employed C3H/HeN mice.　　

Next, we examined immune functions of mice thymectomized 2 days after birth. In thymectomized mice, the proportion of Thy-1, L3T4 and Lyt-2 positive cells (T cells) decreased and the proportion of B220 positive cells (B cells) increased. The proliferative response of lymph node lymphocytes cultured with mitomycin C-treated syngeneic spleen cells was lower, and the total IgG level in the sera was higher when compared with control normal mice. Anti-nuclear antibody (ANA) also appeared in the sera of thymectomized mice 2 days after birth.　　

All these results suggest that the dysfunction of T cell and polyclonal activation of B cell were induced in neonatally thymectomized mice and resulted in the production of ANA and autoantibodies to liver proteins.

Neonatal thymectomy

Immune dysfunction

Autoantibody to liver

医学 [ 490 ]

英語

Hiroshima University Medical Press

[ISSN] 0018-2052

[NCID] AA00664312