0 12 Constitutive constitutive JJ 13 23 activation activation NN 24 26 of of IN 27 32 NF-kB NF-kB NNP 33 35 in in IN 36 41 human human JJ 42 52 thymocytes thymocyte NNS 52 53 . . . 55 60 NF-kB NF-kB NNP 61 63 is be VBZ 64 65 a a DT 66 76 eukaryotic eukaryotic JJ 77 90 transcription transcription NN 91 101 regulatory regulatory JJ 102 108 factor factor NN 108 109 . . . 110 112 In in IN 113 114 T t NN 115 120 cells cell NNS 121 124 and and CC 125 126 T t NN 127 131 cell cell NN 132 137 lines line NNS 137 138 , , , 139 144 NF-kB NF-kB NNP 145 147 is be VBZ 148 153 bound bind VBN 154 156 to to TO 157 158 a a DT 159 170 cytoplasmic cytoplasmic JJ 171 178 proteic proteic JJ 179 188 inhibitor inhibitor NN 188 189 , , , 190 193 the the DT 194 197 IkB IkB NNP 197 198 . . . 199 208 Treatment Treatment NNP 209 211 of of IN 212 213 T t NN 214 219 cells cell NNS 220 224 with with IN 225 233 mitogens mitogen NNS 234 235 ( ( ( 235 242 phorbol phorbol NN 243 249 esters ester NNS 249 250 ) ) ) 251 253 or or CC 254 263 cytokines cytokine NNS 264 265 ( ( ( 265 268 TNF TNF NNP 269 274 alpha alpha NN 274 275 ) ) ) 276 283 induces induce VBZ 284 289 NF-kB NF-kB NNP 290 297 nuclear nuclear JJ 298 311 translocation translocation NN 312 315 and and CC 316 319 the the DT 320 330 subsequent subsequent JJ 331 341 expression expression NN 342 344 of of IN 345 350 NF-kB NF-kB NNP 351 360 dependent dependent JJ 361 362 T t NN 363 367 cell cell NN 368 373 genes gene NNS 373 374 . . . 375 379 Here here RB 380 382 we we PRP 383 391 examined examine VBD 392 395 the the DT 396 406 activation activation NN 407 409 of of IN 410 415 NF-kB NF-kB NNP 416 418 in in IN 419 424 human human JJ 425 426 T t NN 427 431 cell cell NN 432 438 thymic thymic JJ 439 450 progenitors progenitor NNS 450 451 . . . 452 454 We we PRP 455 461 report report VBP 462 473 differences difference NNS 474 476 in in IN 477 478 ( ( ( 478 484 Ca2+)i Ca2+)i NNP 485 496 requirement requirement NN 497 500 for for IN 501 506 NF-kB NF-kB NNP 507 517 activation activation NN 518 520 in in IN 521 531 thymocytes thymocyte NNS 532 534 as as IN 535 543 compared compare VBN 544 546 to to TO 547 553 mature mature JJ 554 555 T t NN 556 561 cells cell NNS 561 562 . . . 563 574 Furthermore furthermore RB 574 575 , , , 576 579 our our PRP$ 580 587 results result NNS 588 597 indicated indicate VBD 598 602 that that IN 603 613 thymocytes thymocyte NNS 614 618 have have VBP 619 620 a a DT 621 635 constitutively constitutively RB 636 642 active active JJ 643 647 form form NN 648 650 of of IN 651 656 NF-kB NF-kB NNP 656 657 , , , 658 668 suggesting suggest VBG 669 673 that that IN 674 678 they they PRP 679 682 are be VBP 683 692 activated activate VBN 693 695 in in FW 696 700 vivo vivo FW 700 701 . . .