The macrophage inflammatory protein-1β in the supernatants of Mycoplasma gallisepticum-infected chicken leukocytes attracts the migration of chicken heterophils and lymphocytes

Abstract

Chicken monocytes, macrophages, heterophils and thrombocytes were infected with Mycoplasma gallisepticum, and their supernatants were collected and tested for the presence of chemotactic activities. The supernatants from MG-infected monocytes and macrophages were able to attract the migration of both heterophils and lymphocytes. The chemotactic activity in these supernatants could be abolished by antibodies prepared against the 10 amino acid peptides of the macrophage inflammatory protein (MIP)-1β, indicating that the released chemoattractant was a MIP-1β-like compound. The supernatant from MG-infected heterophils was also able to attract the migration of chicken lymphocytes, but its activity could not be neutralized by the antibody to MIP-1β, indicating that the chemoattractant is not related to MIP-1β. The supernatants from both control and MG-infected thrombocytes were able to attract the migration of lymphocytes. These results indicate that there is more than one chemotactic factor that is released by these cells; one of the chemoattractants has been identified as a MIP-1β. These results also show that MIP-1β may play a role in the recruitment and accumulation of heterophils and lymphocytes to the sites of mycoplasma infection.