Antigenic changes during intracellular differentiation of Leishmania mexicana in cultured macrophages.

Antigenic changes during the intracellular transformation of Leishmania mexicana subsp. amazonensis from promastigotes to amastigotes in macrophages of J774G8 line were noted mostly among protein bands of 24 to 68 kilodaltons in apparent molecular weight. In this region, six were identified as common antigens of both stages, six to seven were identified as promastigote specific, and three to five were identified as amastigote specific. At the higher-molecular-weight region (greater than 68 kilodalton) were two bands, one being predominant in amastigotes and the other in promastigotes. There may be a transformation-specific band (apparent molecular weight = 20 kilodaltons). The transition of these stage-specific antigens varies considerably with different protein species and may play important roles in intracellular leishmanial differentiation.