Table I.
Specificity of T Cell Lines Analyzed
| T cell line | Restriction element | Antigen specificity | ||
|---|---|---|---|---|
| CD8-1 | CD1c | Phospholipid | ||
| CD8-2 | CD1a | Lipid | ||
| DN1 | CD1b | Mycolic acid | ||
| DN.POTT | CD1b | Mycolic acid | ||
| LDN5 | CD1b | Glucose monomycolate |
CD8-1 and CD8-2 have specificity for two different lipid antigens present in M. tuberculosis H37Ra extracts. Both antigens are extracted from M. tuberculosis in chloroform/methanol (2:1), and can be resolved by step gradient silica chromatography into fractions eluting in 60:40 (chloroform/methanol) (CD8-1) and 90:10 (chloroform/methanol) (CD8-2). Preliminary characterization of the CD8-1 antigen shows that it is likely to be a phospholipid (Moody, D.B., W. Muchlecker, and S.A. Porcelli, unpublished observations).