Macrophages overcome mycoplasma infections of cells in vitro

Abstract

Mycoplasmal infections still cause severe problems in cell cultures, particularly permanent lines, and although rapid detection is possible^1,2 the only methods proposed for the elimination of the mycoplasma are either laborious or unsatisfactory. Treatment with antibiotics often leads to the development of resistance³ and we have found it more successful to passage contaminated cells in nude (thymusless) mice⁴ although the cells cannot always be recovered. But when the resulting subcutanous tumours can be collected, the cells are both free of mycoplasma and accompanied by a large number of macrophages. Because nude mice have no T cell-dependent immune response, it seemed possible that the macrophages could be responsible for the elimination of the mycoplasma. The experiments reported here support this hypothesis, and have led to a rapid and reproducible technique for eliminating mycoplasma in vitro by a brief co-cultivation of contaminated cells with mouse macrophages, in the presence of antibiotics.