The class II (Ia) MHC molecules are cell surface proteins that regulate the activation of T cells. B lymphocyte expression of class II molecules has been shown to be influenced by a number of external stimuli. It has been previously demonstrated that treatment of these cells with @entity58 leads to an increase in class II gene transcription at 18 h as well as to an increase in steady state class II mRNA. It has also been previously demonstrated that @entity558 treatment of splenic B cells from athymic @entity19 results in a decrease in steady state mRNA encoding the @entity56389 class II protein. This decrease persists for at least 18 h. Nuclear run-on transcription assays now demonstrate that although steady state mRNA levels for @entity56389 are decreased by @entity558 treatment of athymic @entity19 lymphocytes, @entity558 does not decrease @entity56389 gene transcription, but rather modestly activates transcription of this class II gene. @entity558 and @entity58 have been demonstrated to be synergistic stimuli for a number of genes. Costimulation of splenic lymphocytes from athymic @entity19 with @entity58 plus @entity558 leads to activation of transcription, but the increase in transcription is no more than that seen with @entity58 stimulation alone. However, in costimulated lymphocytes, steady state @entity56389 -encoding mRNA levels are intermediate between the increased levels seen with @entity58 stimulation and the decreased levels seen with @entity558 stimulation. Therefore, @entity558 and @entity58 act nonsynergistically in class II gene transcription and the effects of @entity558 in decreasing steady state mRNA are most likely posttranscriptional. An @entity58 -inducible and an @entity558 -inducible @entity19776 have been previously identified in splenic lymphocytes from athymic @entity19 . Both nuclear binding proteins form complexes with the same DNA fragments from a control region of the @entity56389 gene. These nucleoprotein complexes comigrate under nondenaturing conditions and display identical patterns of binding with a panel of oligonucleotide competitors. Oligonucleotides representing protein binding sites of the @entity58 and @entity558 -induced DNA-binding proteins cross-compete for protein binding. Therefore, the binding proteins induced by @entity558 and @entity58 are likely related, and may function at different efficiencies as activators of @entity56389 gene transcription.

Role of lipopolysaccharide and @entity58 in control of transcription of the class II XXXX gene.

@entity558 :: ('MESH:C536528', 'Disease') :: ['LPS'] @entity19 :: ('10090', 'Species') :: ['mice', 'mouse'] @entity56389 :: ('14960(Tax:10090)', 'Gene') :: ['A alpha'] @entity58 :: ('16189(Tax:10090)', 'Gene') :: ['IL-4'] @entity19776 :: ('26386(Tax:10090)', 'Gene') :: ['DNA-binding protein']
@entity56389 :: (14960(Tax:10090),Gene) :: ['A alpha']
