TABLE 1.
B. bigemina RAP-1 CT-1-specific Th cell clones respond to RAP-1 CT-1 from four strains
| Antigen (Source) | Mean cpm incorporated by RAP-1-specific Th cell clonesa
|
|||
|---|---|---|---|---|
| CT-1-specific Th clones
|
aa 144–187-specific Th clone (2216.1H4) | |||
| 2216.1G8 | 2216.2B2 | 2234.1E3 | ||
| Medium | 1,126 | 4,283 | 4,056 | 4,972 |
| Native parasite antigen | ||||
| B. bigemina (Mexico) | 6,959 (6.2) | 16,087 (3.8) | ND | 10,080 (2.0) |
| B. bigemina (Texcoco) | 3,531 (3.1) | 5,706 (1.3) | 24,455 (6.0) | 11,013 (2.2) |
| Recombinant proteins | ||||
| MBP | 1,929 (0.8) | 4,419 (1.0) | 6,633 (1.6) | 3,737 (0.8) |
| RAP-1α1 (Mexico) | 16,235 (14.4) | 29,793 (7.0) | 54,413 (13.4) | 18,068 (3.6) |
| CT-1 (Mexico) | 8,299 (7.4) | 14,094 (3.3) | ND | 3,869 (0.8) |
| CT-1 (Texcoco) | 7,569 (6.7) | 17,158 (4.0) | 42,359 (10.4) | 302 (0.1) |
| CT-1 (Uruguay) | 14,081 (12.5) | 17,366 (4.1) | 47,788 (11.8) | 4,401 (0.9) |
| CT-1 (Argentina S2P) | 11,463 (10.2) | 21,777 (5.1) | 47,221 (11.6) | 4,653 (0.9) |
a
T cells (3 × 104) were cultured in duplicate wells for 3 days with antigen and 105 APC. Results are presented for 5 μg of native B. bigemina CM antigen per ml and 25 μg of recombinant protein per ml. All clones except 2234.1E3 were assayed with IL-2 (2 U per ml) in the culture medium. Numbers in parentheses represent stimulation indices, calculated as mean cpm of T cells + antigen/mean cpm of T cells + medium. ND, not determined.