passages.id: split_6_test_993_passage
passages.type: progene_text
passages.text: High levels of CAT activity were seen with HIV-LTR - derived reporters that contained kappaB and TAR elements in response to transfected Tat in the absence of either transfected Rel A or exogenous TNF-alpha , and overexpression of IkappaBalpha with Tat inhibited CAT activity by 60 % to 80 % , suggesting that some activation of NF-kappaB by Tat was occurring .