The beta2-microglobulin (beta2m)-deficient mutant mice lack alphabeta TCR CD8alphabeta T cells. We found markedly impaired granuloma formation in Listeria monocytogenes-infected beta2m-/- mice. Abundant CD8alphaalpha T cells were identified in loosely structured infiltrative liver lesions. Microfluorescence analysis disclosed that these CD8alphaalpha T cells expressed mostly the gammadelta TCR. CD8alphaalpha T cells were also found in the spleen of Listeria-infected beta2m-/- mice. These data provide first evidence for CD8alphaalpha T cells in listerial lesions of beta2m-/- mice.