Factors Governing B Cell Recognition of Autoantigen and Function in Type 1 Diabetes

Islet autoantibodies predict type 1 diabetes (T1D) but can be transient in murine and human T1D and are not thought to be directly pathogenic. Rather, these autoantibodies signal B cell activity as antigen-presenting cells (APCs) that present islet autoantigen to diabetogenic T cells to promote T1D pathogenesis. Disrupting B cell APC function prevents T1D in mouse models and has shown promise in clinical trials. Autoantigen-specific B cells thus hold potential as sophisticated T1D biomarkers and therapeutic targets. B cell receptor (BCR) somatic hypermutation is a mechanism by which B cells increase affinity for islet autoantigen. High-affinity B and T cell responses are selected in protective immune responses, but immune tolerance mechanisms are known to censor highly autoreactive clones in autoimmunity, including T1D. Thus, different selection rules often apply to autoimmune disease settings (as opposed to protective host immunity), where different autoantigen affinity ceilings are tolerated based on variations in host genetics and environment. This review will explore what is currently known regarding B cell signaling, selection, and interaction with T cells to promote T1D pathogenesis.

Stereotype or reality: another look at alcohol and drug use among African American children

The Center for Substance Abuse Prevention's Division of Communications Programs launched its Urban Youth Public Education Campaign in late 1990 to target African American youth in 14 cities with prevention messages about alcohol and other drugs. During the market research phase of the campaign, the Center sought to determine the extent inner city African American children are impacted by alcohol and other drugs and how widespread the use of these substances is among younger children. Is it rampant and universal, as some press accounts have it, or are the images portrayed by the news media, by popular movies, and by other communication outlets fueling harmful stereotypes? The campaign's market research consisted of in-depth reviews of the literature, of personal communications, conference proceedings, grant and contract reports, monographs, newspaper and magazine articles, and of national survey results, and the analysis of findings from focus groups conducted with 143 African American children living in several urban environments. Although information and conclusions gleaned from the market research revealed a longstanding trend of comparatively lower rates of alcohol and drug use by African American youth, also disclosed was a need for an expanded framework to address the problems of substance abuse within the African American community. An expanded framework acknowledges the dimension of substance use and abuse but also addresses three other dimensions--involvement, exposure, and victimization--that unfold as having major significance for this population of youth who live in urban, high-risk environments.