B7-2/CD28 costimulatory pathway in children with atopic dermatitis and its connection with immunoglobulin E, intracellular interleukin-4 and interferon-gamma production by T cells during a 1-month follow-up

The best defined costimulators for activation of T lymphocytes are B7-1 and B7-2 on antigen presenting cells (APC) that bind to CD28 on T cells. Several studies showed that CD28 is critical for type 2 T helper cells (Th2) inflammation and depends mainly on the interaction of CD28 with B7-2. Some authors suggested a role for B7-2 B cells in immunoglobulin E (IgE) synthesis. We decided to study B7-2/CD28 interaction in atopic dermatitis (AD) and correlations with total and specific IgE, intracellular interleukin 4-(IL-4) and interferon-gamma (IFN-gamma) production during a 1-month follow-up. We studied 24 AD children with allergy to cow's milk. Lymphocyte subsets (B7-2 on B cells, CD28(+) on T cells, IL-4 and IFN-gamma producing T helper cells), total and specific IgE, and IgG4 at days 1 and 30 were also studied. Scoring of atopic dermatitis (SCORAD) significantly decreased. CD28(+)/CD3(+)/CD57 correlated with B7-2 B cells at days 1 and 30, with IL-4 and IFN-gamma producing T helper cells at day 1 and with SCORAD at day 30. B7-2 B cells negatively correlated with IgE at day 30. Percentage of B7-2 B cells negatively correlated with total and specific IgE at day 30. Our results support the importance of CD28/B7 costimulation in AD children and the relation of CD28 with Th1 and Th2 cytokines. However, our results do not confirm the hypothesis about the preferential role of B7-2 in Th2 activation and IgE synthesis. It could raise a question about B7-2 blockade efficacy in AD children. Further investigations on B7 family members and their functions could help to distinguish target for more clinically efficient B7/CD28 blockage in AD. None declared.