抄録
In the present study, we have found that unusual lymphocytes which phenotypically express Mac-1 (CD11b) exist in a large proportion (-20%) in murine lung. Further study revealed that these cells were T lymphocytes which expressed low intensity of CD3 and αβ T cell receptor. In addition, they express neither CD4 nor CD8, while conventional thymus-derived T lymphocytes usully have either of these molecules.
Mac-1+ lymphocytes accumulated in the lung and the expression of MHC class II and ICAM-1 on their surface was augmented after intravenous infection with Mycobacterium bovis BCG. Taken together, this population of lymphocytes might play some important role in the host defense against mycobacterial infection, although it remains to be elucidated whether they are double negative αβ T cells or the other population.
