0 5 C/EBP C/EBP NNP 6 14 proteins protein NNS 15 23 activate activate VBP 24 37 transcription transcription NN 38 42 from from IN 43 46 the the DT 47 52 human human JJ 53 69 immunodeficiency immunodeficiency NN 70 75 virus virus NN 76 80 type type NN 81 82 1 1 CD 83 87 long long JJ 88 96 terminal terminal JJ 97 103 repeat repeat NN 104 106 in in IN 107 128 macrophages/monocytes macrophages/monocyte NNS 128 129 . . . 131 136 Three three CD 137 144 binding bind VBG 145 150 sites site NNS 151 154 for for IN 155 160 C/EBP C/EBP NNP 161 169 proteins protein NNS 170 173 are be VBP 174 179 found find VBN 180 182 in in IN 183 186 the the DT 187 192 human human JJ 193 209 immunodeficiency immunodeficiency NN 210 215 virus virus NN 216 220 type type NN 221 222 1 1 CD 223 224 ( ( ( 224 229 HIV-1 HIV-1 NNP 229 230 ) ) ) 231 235 long long JJ 236 244 terminal terminal JJ 245 251 repeat repeat NN 252 253 ( ( ( 253 256 LTR LTR NNP 256 257 ) ) ) 258 259 ( ( ( 259 263 V.M. V.M. NNP 264 270 Tesmer Tesmer NNP 270 271 , , , 272 286 A.Rajadhyaksha A.Rajadhyaksha NNP 286 287 , , , 288 295 J.Babin J.Babin NNP 295 296 , , , 297 300 and and CC 301 307 M.Bina M.Bina NNP 307 308 , , , 309 327 Proc.Natl.Acad.Sci Proc.Natl.Acad.Sci NNP 327 328 . . . 329 332 USA USA NNP 333 345 90:7298-7302 90:7298-7302 CD 345 346 , , , 347 351 1993 1993 CD 351 352 ) ) ) 352 353 . . . 354 356 We we PRP 357 361 have have VBP 362 372 determined determine VBN 373 376 the the DT 377 387 functional functional JJ 388 392 role role NN 393 395 of of IN 396 401 C/EBP C/EBP NNP 402 410 proteins protein NNS 411 414 and and CC 415 420 C/EBP C/EBP NNP 421 426 sites site NNS 427 429 in in IN 430 440 regulating regulate VBG 441 454 transcription transcription NN 455 459 from from IN 460 463 the the DT 464 468 HIV- hiv- NN 469 470 1 1 CD 471 474 LTR ltr NN 475 477 in in IN 478 499 monocytes/macrophages monocytes/macrophage NNS 499 500 . . . 501 511 Inhibition Inhibition NNP 512 514 of of IN 515 525 endogenous endogenous JJ 526 531 C/EBP C/EBP NNP 532 540 proteins protein NNS 540 541 , , , 542 547 using use VBG 548 554 either either CC 555 557 an an DT 558 564 excess excess NN 565 567 of of IN 568 573 C/EBP C/EBP NNP 574 581 binding binding NN 582 587 sites site NNS 588 590 or or CC 591 592 a a DT 593 599 trans- trans- JJ 600 608 dominant dominant JJ 609 617 negative negative JJ 618 627 inhibitor inhibitor NN 627 628 , , , 629 641 demonstrated demonstrate VBD 642 646 that that IN 647 652 C/EBP C/EBP NNP 653 661 proteins protein NNS 662 665 are be VBP 666 674 required require VBN 675 678 for for IN 679 684 basal basal JJ 685 688 and and CC 689 698 activated activate VBN 699 705 levels level NNS 706 708 of of IN 709 714 HIV-1 HIV-1 NNP 715 718 LTR LTR NNP 719 732 transcription transcription NN 733 735 in in IN 736 739 the the DT 740 752 promonocytic promonocytic JJ 753 757 cell cell NN 758 762 line line NN 763 767 U937 u937 NN 767 768 . . . 769 777 Northern Northern NNP 778 779 ( ( ( 779 782 RNA RNA NNP 782 783 ) ) ) 784 789 blots blot NNS 790 793 and and CC 794 801 binding binding NN 802 808 assays assay NNS 809 815 showed show VBD 816 820 that that IN 821 827 NF-IL6 NF-IL6 NNP 828 830 is be VBZ 831 834 the the DT 835 839 only only RB 840 845 known know VBN 846 851 C/EBP C/EBP NNP 852 858 family family NN 859 865 member member NN 866 871 which which WDT 872 874 is be VBZ 875 884 increased increase VBN 885 889 when when WRB 890 894 U937 u937 NN 895 900 cells cell NNS 901 904 are be VBP 905 914 activated activate VBN 914 915 . . . 916 926 Mutational mutational JJ 927 935 analyses analysis NNS 936 938 of of IN 939 942 the the DT 943 948 HIV-1 HIV-1 NNP 949 952 LTR LTR NNP 953 959 showed show VBD 960 964 that that IN 965 968 one one CD 969 974 C/EBP C/EBP NNP 975 979 site site NN 980 982 is be VBZ 983 991 required require VBN 992 995 for for IN 996 1002 normal normal JJ 1003 1006 LTR ltr NN 1007 1020 transcription transcription NN 1021 1025 both both CC 1026 1032 before before IN 1033 1036 and and CC 1037 1042 after after IN 1043 1051 cellular cellular JJ 1052 1062 activation activation NN 1063 1066 and and CC 1067 1071 that that IN 1072 1075 the the DT 1076 1079 two two CD 1080 1081 3 3 CD 1081 1082 ’ ' SYM 1083 1088 C/EBP C/EBP NNP 1089 1094 sites site NNS 1095 1098 are be VBP 1099 1111 functionally functionally RB 1112 1122 equivalent equivalent JJ 1122 1123 . . . 1124 1131 However however RB 1131 1132 , , , 1133 1146 transcription transcription NN 1147 1151 from from IN 1152 1160 crippled crippled JJ 1161 1166 HIV-1 HIV-1 NNP 1167 1171 LTRs LTR NNPS 1172 1179 lacking lack VBG 1180 1185 C/EBP C/EBP NNP 1186 1191 sites site NNS 1192 1195 can can MD 1196 1201 still still RB 1202 1204 be be VB 1205 1212 induced induce VBN 1213 1222 following follow VBG 1223 1233 activation activation NN 1234 1236 of of IN 1237 1241 U937 u937 NN 1242 1247 cells cell NNS 1247 1248 . . . 1249 1256 Several several JJ 1257 1263 models model NNS 1264 1267 are be VBP 1268 1277 suggested suggest VBN 1278 1281 for for IN 1282 1285 how how WRB 1286 1294 elevated elevated JJ 1295 1301 NF-IL6 nf-il6 NN 1302 1305 may may MD 1306 1317 participate participate VB 1318 1320 in in IN 1321 1323 an an DT 1324 1339 autostimulatory autostimulatory JJ 1340 1344 loop loop NN 1345 1354 involving involve VBG 1355 1358 HIV HIV NNP 1359 1368 infection infection NN 1368 1369 , , , 1370 1380 macrophage macrophage NN 1381 1391 activation activation NN 1391 1392 , , , 1393 1401 cytokine cytokine NN 1402 1412 expression expression NN 1412 1413 , , , 1414 1417 and and CC 1418 1421 HIV HIV NNP 1422 1433 replication replication NN 1433 1434 . . .