tokens: The NF-Y complex derived from class II+ mature B-cells bound with high affinity to anion exchangers , and eluted as an intact trimeric complex , whereas , NF-Y derived from class II- plasma B-cells , and from bare lymphocyte syndrome group II cell lines , RJ2.2.5 and RM3 , dissociated into discrete NF-YA and NF-YB : C subunit fractions .