CD4 and Huntington disease: In order to verify whether CD28-induced IL-22 expression was also effective in HD and clarify the molecular basis of this activity, we performed a kinetic analysis of IL-22 gene expression by stimulating human CD4+ T cells from HD with an agonistic anti-CD28 Ab (CD28.2) binding the same epitope recognized by B7 molecules (40) or anti-CD3 (UCHT1) or anti-CD3 plus anti-CD28 Abs.