Figure 1.

(A) Enumeration of circulating peptide-specific effectors from the peripheral blood of NPH54 (HLA class I haplotype: HLA-A2.01, HLA-A68; HLA-B52, HLA-B38). The sequences of peptides ES12 and ES13 are congruent with the peptide motifs of HLA-B52 and HLA-A2.01, respectively. The frequency of ES12-specific effectors during active tuberculosis (1:23,000) is slightly less than the frequency of effectors specific for the HLA-A2-restricted epitope in influenza virus M1 58–66 (1:14,000). Activated effectors specific for ES13, an HLA-A2-restricted epitope, are also evident, but at a lower frequency (1:50,000). Freshly isolated PBMCs (500,000) were seeded in duplicate wells and peptide added to a final concentration of 2 μM in a 12-hr ex vivo ELISPOT assay for IFN-γ. (B) ES12-specific IFN-γ secreting T cells are CD8⁺. Enumeration of IFN-γ SFCs in a 12-hr ELISPOT assay for IFN-γ with cell line 3–20 from donor NPH54 was performed and is shown. After depletion of CD4⁺ or CD8⁺ cells, 20,000 cells were added to each of a pair of duplicate wells and peptide ES12 was added to a final concentration of 2 μM: the mean number of SFCs is shown. No SFCs were observed in the absence of peptide. CD8⁺ cell depletion completely abrogates the response. Similar results were obtained with cell line 3–9. (C) ES13-specific IFN-γ release by an STCL raised against ES13 with PBMCs from donor WB; a healthy contact with HLA haplotype HLA-A2, HLA-A1; HLA-B7, HLA-B8. After magnetic depletion of CD4⁺ or CD8⁺ cells, 20,000 cells were added to each of a pair of duplicate wells in a 12-hr ELISPOT assay and peptide added at 2 μM to the supernatant. The mean number of IFN-γ SFCs for each pair of wells is shown.