Plasminogen activator derived from tonsillar lymphocytes of rabbits with arthus tonsillitis

As an experimental model of human tonsillitis, Arthus tonsillitis of the rabbit was produced. In a previous paper, we demonstrated that an increased fibrinolytic activity in the circulating blood and increased proteolytic activity of the local tissue with Arthus tonsillitis were observed. In the present study, the mechanism of the increased proteolytic activity at the local site (tonsil with Arthus-type tonsillitis) was examined using cell cultures of lymphocytes originating from the tonsil with Arthus-type inflammation. That is, lymphocytes isolated from tonsil tissue of the rabbit were cultured in a culture medium for the short term. After culture, the used medium was collected and the presence of plasminogen activator in the culture medium and lymphocytes was investigated. It was clarified that plasminogen activator did exist in the culture medium of lymphocytes originating from the tonsil of rabbits with Arthus tonsillitis. Furthermore, addition of T cell growth factor to the culture medium of lymphocytes derived from non-treated tonsil induced the development of plasminogen activator in that culture medium. However, addition of B cell growth factor did not lead to the development of plasminogen activator activity in the culture medium. These results suggest that plasminogen activator originating from lymphocytes of the tonsil may play an important role in the increased proteolytic activity observed at the local site of Arthus tonsillitis.