AIDS is characterized by a progressive decrease of CD4 ؉ helper T lymphocytes. Destruction of these cells may involve programmed cell death, apoptosis. It has previously been reported that apoptosis can be induced even in noninfected cells by HIV-1 gp120 and anti-gp120 antibodies. HIV-1 gp120 binds to T cells via CD4 and the chemokine coreceptor CXCR4 (fusin͞LESTR). Therefore, we investigated whether CD4 and CXCR4 mediate gp120-induced apoptosis. We used human peripheral blood lymphocytes, malignant T cells, and CD4͞CXCR4 transfectants, and found cell death induced by both cell surface receptors, CD4 and CXCR4. The induced cell death was rapid, independent of known caspases, and lacking oligonucleosomal DNA fragmentation. In addition, the death signals were not propagated via p56 lck and G i ␣. However, the cells showed chromatin condensation, morphological shrinkage, membrane inversion, and reduced mitochondrial transmembrane potential indicative of apoptosis. Significantly, apoptosis was exclusively observed in CD4 ؉ but not in CD8 ؉ T cells, and apoptosis triggered via CXCR4 was inhibited by stromal cell-derived factor-1, the natural CXCR4 ligand. Thus, this mechanism of apoptosis might contribute to T cell depletion in AIDS and might have major implications for therapeutic intervention.

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Background: Bipolar disorders (BD) belong to the most severe mental disorders, characterized by an early onset and recurrent, severe episodes or a chronic course with poor psychosocial functioning in a proportion of patients. Many patients with BD experience substantial symptomatology months or even years before full BD manifestation. Adequate diagnosis and treatment is often delayed, which is associated with a worse outcome. This study aims to prospectively evaluate and improve early recognition and intervention strategies for persons at-risk for BD. Methods: Early-BipoLife is a prospective-longitudinal cohort study of 1419 participants (aged 15-35 years) with at least five waves of assessment over a period of at least 2 years (baseline, 6, 12, 18 and 24 months). A research consortium of ten university and teaching hospitals across Germany conducts this study. The following risk groups (RGs) were recruited: RG I: help-seeking youth and young adults consulting early recognition centres/facilities presenting ≥ 1 of the proposed risk factors for BD, RG II: in-/outpatients with unipolar depressive syndrome, and RG III: in-/outpatients with attention-deficit/hyperactivity disorder (ADHD). The reference cohort was selected from the German representative IMAGEN cohort. Over the study period, the natural course of risk and resilience factors, early symptoms of BD and changes of symptom severity (including conversion to manifest BD) are observed. Psychometric properties of recently developed, structured instruments on potential risk factors for conversion to BD and subsyndromal symptomatology (Bipolar Prodrome Symptom Scale, Bipolar at-risk criteria, EPIbipolar) and biomarkers that potentially improve prediction are investigated. Moreover, actual treatment recommendations are monitored in the participating specialized services and compared to recently postulated clinical categorization and treatment guidance in the field of early BD.