Role of interleukin-2 in superantigen-induced T-cell anergy

T-cell anergy is a state of immunological tolerance characterized by unresponsiveness to antigenic stimulation. Previous studies have shown that anergy is induced in T cells following stimulation in the absence of adequate costimulatory signals. These cells fail to respond to stimulation via the T-cell receptor (TCR), and fail to produce normal levels of interleukin-2 (IL-2). We present results here which show that low concentrations of the superantigen staphylococcal enterotoxin A (SEA) in the absence of antigen-presenting cells induced both proliferation and anergy in the A.E7 T-cell clone. Furthermore, under these conditions, the A.E7 clone remained responsive to exogenous IL-2. Fluorescence-activated cellular cytometry analysis revealed unaltered expression of the TCR/CD3 complex in the anergized clone; however, both CD4 and CD25 expression increased after 24 hr of stimulation by SEA under these conditions. Interestingly, a low level of IL-2 production was measured during the induction of anergy. Most strikingly, stimulation of the A.E7 clone by SEA in combination with exogenous IL-2 resulted in a more pronounced state of anergy. These results suggest that the induction of anergy is a process that is essentially independent of the production of IL-2

ADHD-like symptoms and attachment in internationally adopted children.

Internationally adopted children seem to be more likely to show ADHD-like symptoms than non-adopted children. The aims of this study were to explore the existence of ADHD-like symptoms and/or diagnosis in a sample of internationally adopted children depending on their country of origin and to describe the links that may exist between the display of these symptoms and observed narrative-based attachment patterns. A Catalan sample of 58 adopted children aged 7-8 (24 from Eastern Europe, 23 from China, and 11 from Ethiopia) was assessed with the Behavioral Assessment System for Children to identify ADHD-like symptoms, and the Friends and Family Interview to identify children's' attachment patterns. Results indicated that children adopted from Eastern Europe showed a trend toward more hyperactivity and significantly more attention problems than girls adopted from China. Children with a secure attachment showed significantly less attention problems and a trend toward less hyperactivity. More studies focusing on the etiology and treatment of these symptoms in adopted children are needed