0 4 Jak3 Jak3 NNP 5 7 is be VBZ 8 18 associated associate VBN 19 23 with with IN 24 28 CD40 CD40 NNP 29 32 and and CC 33 35 is be VBZ 36 44 critical critical JJ 45 48 for for IN 49 53 CD40 cd40 NN 54 63 induction induction NN 64 66 of of IN 67 71 gene gene NN 72 82 expression expression NN 83 85 in in IN 86 87 B B NNP 88 93 cells cell NNS 93 94 . . . 96 100 CD40 CD40 NNP 101 103 is be VBZ 104 105 a a DT 106 114 receptor receptor NN 115 119 that that WDT 120 122 is be VBZ 123 131 critical critical JJ 132 135 for for IN 136 139 the the DT 140 148 survival survival NN 148 149 , , , 150 156 growth growth NN 156 157 , , , 158 173 differentiation differentiation NN 173 174 , , , 175 178 and and CC 179 186 isotype isotype NN 187 196 switching switching NN 197 199 of of IN 200 201 B B NNP 202 213 lymphocytes lymphocyte NNS 213 214 . . . 215 223 Although although IN 224 228 CD40 CD40 NNP 229 234 lacks lack VBZ 235 244 intrinsic intrinsic JJ 245 253 tyrosine tyrosine NN 254 260 kinase kinase NNP 261 269 activity activity NN 269 270 , , , 271 274 its its PRP$ 275 283 ligation ligation NN 284 291 induces induce VBZ 292 299 protein protein NN 300 308 tyrosine tyrosine NN 309 324 phosphorylation phosphorylation NN 324 325 , , , 326 331 which which WDT 332 334 is be VBZ 335 344 necessary necessary JJ 345 348 for for IN 349 356 several several JJ 357 370 CD40-mediated cd40-mediated JJ 371 377 events event NNS 377 378 . . . 379 381 We we PRP 382 386 show show VBP 387 391 that that IN 392 402 engagement engagement NN 403 405 of of IN 406 410 CD40 CD40 NNP 411 418 induces induce VBZ 419 427 tyrosine tyrosine NN 428 443 phosphorylation phosphorylation NN 444 447 and and CC 448 458 activation activation NN 459 461 of of IN 462 466 Jak3 jak3 NN 467 469 as as RB 470 474 well well RB 475 477 as as IN 478 480 of of IN 481 486 STAT3 STAT3 NNP 486 487 . . . 488 492 Jak3 Jak3 NNP 493 495 is be VBZ 496 510 constitutively constitutively RB 511 521 associated associate VBN 522 526 with with IN 527 531 CD40 CD40 NNP 531 532 , , , 533 536 and and CC 537 541 this this DT 542 553 interaction interaction NN 554 562 requires require VBZ 563 564 a a DT 565 577 proline-rich proline-rich JJ 578 586 sequence sequence NN 587 589 in in IN 590 593 the the DT 594 611 membrane-proximal membrane-proximal JJ 612 618 region region NN 619 621 of of IN 622 626 CD40 CD40 NNP 626 627 . . . 628 636 Deletion deletion NN 637 639 of of IN 640 644 this this DT 645 653 sequence sequence NN 654 663 abolishes abolish VBZ 664 667 the the DT 668 676 capacity capacity NN 677 679 of of IN 680 684 CD40 CD40 NNP 685 687 to to TO 688 694 induce induce VB 695 705 expression expression NN 706 708 of of IN 709 713 CD23 CD23 NNP 713 714 , , , 715 721 ICAM-1 ICAM-1 NNP 721 722 , , , 723 726 and and CC 727 744 lymphotoxin-alpha lymphotoxin-alpha NN 745 750 genes gene NNS 751 753 in in IN 754 755 B B NNP 756 761 cells cell NNS 761 762 . . . 763 768 These these DT 769 776 results result NNS 777 785 indicate indicate VBP 786 790 that that IN 791 800 signaling signaling NN 801 808 through through IN 809 813 Jak3 Jak3 NNP 814 816 is be VBZ 817 826 activated activate VBN 827 829 by by IN 830 834 CD40 CD40 NNP 835 838 and and CC 839 844 plays play VBZ 845 847 an an DT 848 857 important important JJ 858 862 role role NN 863 865 in in IN 866 879 CD40-mediated cd40-mediated JJ 880 889 functions function NNS 889 890 . . .