0 3 The the DT 4 15 suppression suppression NN 16 18 of of IN 19 20 T t NN 21 25 cell cell NN 26 34 function function NN 35 38 and and CC 39 49 NF(kappa)B nf(kappa)b NN 50 60 expression expression NN 61 63 by by IN 64 70 serine serine NN 71 79 protease protease NN 80 90 inhibitors inhibitor NNS 91 93 is be VBZ 94 101 blocked block VBN 102 104 by by IN 105 121 N-acetylcysteine N-acetylcysteine NNP 121 122 . . . 124 130 Direct direct JJ 131 139 evidence evidence NN 140 144 that that IN 145 161 N-acetylcysteine N-acetylcysteine NNP 162 163 ( ( ( 163 166 NAC NAC NNP 166 167 ) ) ) 168 176 enhances enhance VBZ 177 180 the the DT 181 187 immune immune JJ 188 196 response response NN 197 199 of of IN 200 210 peripheral peripheral JJ 211 216 blood blood NN 217 218 T t NN 219 224 cells cell NNS 225 227 at at IN 228 231 the the DT 232 237 level level NN 238 240 of of IN 241 251 NF(kappa)B NF(kappa)B NNP 252 254 is be VBZ 255 264 presented present VBN 264 265 . . . 266 268 In in IN 269 277 addition addition NN 277 278 , , , 279 282 NAC NAC NNP 283 289 blocks block VBZ 290 293 the the DT 294 305 suppression suppression NN 306 308 of of IN 309 310 T t NN 311 315 cell cell NN 316 327 mitogenesis mitogenesis NN 328 331 and and CC 332 340 cytokine cytokine NN 341 351 production production NN 352 354 by by IN 355 363 protease protease NN 364 374 inhibitors inhibitor NNS 375 379 such such JJ 380 382 as as IN 383 403 N-tosylphenylalanine N-tosylphenylalanine NNP 404 416 chloromethyl chloromethyl NN 417 423 ketone ketone NN 424 425 ( ( ( 425 429 TPCK TPCK NNP 429 430 ) ) ) 430 431 . . . 432 435 The the DT 436 449 proliferative proliferative JJ 450 459 responses response NNS 460 462 of of IN 463 471 purified purify VBN 472 476 CD4+ cd4+ JJ 477 479 or or CC 480 484 CD8+ cd8+ JJ 485 486 T t NN 487 492 cells cell NNS 493 496 are be VBP 497 507 suppressed suppress VBN 508 512 more more RBR 513 521 strongly strongly RB 522 524 by by IN 525 529 TPCK TPCK NNP 530 534 when when WRB 535 544 anti-CD28 anti-cd28 NN 545 551 rather rather RB 552 556 than than IN 557 560 the the DT 561 568 phorbol phorbol NN 569 574 ester ester NN 575 578 PMA PMA NNP 579 581 is be VBZ 582 586 used use VBN 587 589 as as IN 590 593 the the DT 594 603 mitogenic mitogenic JJ 604 615 coactivator coactivator NN 615 616 . . . 617 625 Cytokine Cytokine NNP 626 627 ( ( ( 627 631 IL-2 IL-2 NNP 631 632 , , , 633 637 IL-6 IL-6 NNP 637 638 , , , 639 648 INF-gamma INF-gamma NNP 648 649 ) ) ) 650 660 production production NN 661 663 is be VBZ 664 673 inhibited inhibit VBN 674 680 95-100 95-100 CD 680 681 % % NN 682 684 by by IN 685 699 concentrations concentration NNS 700 702 of of IN 703 707 TPCK tpck NN 708 712 that that WDT 713 720 totally totally RB 721 729 suppress suppress VBP 730 733 the the DT 734 745 mitogenesis mitogenesis NN 746 748 of of IN 749 753 CD4+ cd4+ JJ 754 756 or or CC 757 761 CD8+ cd8+ JJ 762 767 cells cell NNS 767 768 . . . 769 774 Using use VBG 775 790 electrophoretic electrophoretic JJ 791 799 mobility mobility NN 800 805 shift shift NN 806 812 assays assay NNS 812 813 , , , 814 816 we we PRP 817 821 find find VBP 822 826 that that IN 827 831 TPCK tpck NN 832 841 virtually virtually RB 842 851 abolishes abolish VBZ 852 853 ( ( ( 853 855 to to TO 856 860 less less JJR 861 865 than than IN 866 867 1 1 CD 867 868 % % NN 868 869 ) ) ) 870 873 the the DT 874 880 levels level NNS 881 883 of of IN 884 894 NF(kappa)B NF(kappa)B NNP 895 896 ( ( ( 896 899 but but CC 900 903 not not RB 904 909 Oct-1 oct-1 NN 909 910 ) ) ) 911 916 found find VBN 917 919 in in IN 920 927 nuclear nuclear JJ 928 931 and and CC 932 937 whole whole JJ 938 942 cell cell NN 943 951 extracts extract NNS 952 954 of of IN 955 964 activated activate VBN 965 966 T t NN 967 972 cells cell NNS 972 973 . . . 974 984 Strikingly strikingly RB 984 985 , , , 986 989 the the DT 990 1007 immunosuppressive immunosuppressive JJ 1008 1015 effects effect NNS 1016 1018 of of IN 1019 1023 TPCK TPCK NNP 1024 1027 are be VBP 1028 1035 blocked block VBN 1036 1040 when when WRB 1041 1042 T t NN 1043 1048 cells cell NNS 1049 1052 are be VBP 1053 1063 pretreated pretreate VBN 1064 1067 for for IN 1068 1070 15 15 CD 1071 1074 min min NN 1075 1079 with with IN 1080 1081 5 5 CD 1082 1084 mM mM NNP 1085 1088 NAC NAC NNP 1088 1089 . . . 1090 1093 NAC NAC NNP 1094 1097 not not RB 1098 1102 only only RB 1103 1109 blocks block VBZ 1110 1113 the the DT 1114 1120 effect effect NN 1121 1123 of of IN 1124 1128 TPCK TPCK NNP 1129 1132 but but CC 1133 1141 enhances enhance VBZ 1142 1153 mitogenesis mitogenesis NN 1154 1157 and and CC 1158 1166 cytokine cytokine NN 1167 1177 production production NN 1178 1179 ( ( ( 1179 1188 >2.5-fold >2.5-fold JJ 1189 1191 in in IN 1192 1196 some some DT 1197 1202 cases case NNS 1202 1203 ) ) ) 1204 1208 upon upon IN 1209 1219 activation activation NN 1220 1222 of of IN 1223 1235 unsuppressed unsuppressed JJ 1236 1237 T t NN 1238 1243 cells cell NNS 1243 1244 . . . 1245 1248 Our our PRP$ 1249 1253 data datum NNS 1254 1261 support support VBP 1262 1265 the the DT 1266 1272 notion notion NN 1273 1277 that that IN 1278 1288 NF(kappa)B NF(kappa)B NNP 1289 1292 and and CC 1293 1302 I(kappa)B I(kappa)B NNP 1303 1312 proteases protease NNS 1313 1317 play play VBP 1318 1326 obligate obligate JJ 1327 1332 roles role NNS 1333 1335 in in IN 1336 1337 T t NN 1338 1342 cell cell NN 1343 1353 activation activation NN 1354 1357 and and CC 1358 1369 mitogenesis mitogenesis NN 1369 1370 , , , 1371 1376 roles role NNS 1377 1381 that that WDT 1382 1385 are be VBP 1386 1394 enhanced enhance VBN 1395 1408 significantly significantly RB 1409 1411 by by IN 1412 1415 NAC NAC NNP 1415 1416 . . .