General session 3: acquired immunity

Session 3 of the Toxicologic Pathology and the Immune System Symposium, presented as part of the 30th Annual Symposium of the Society of Toxicologic Pathology in 2011, focused on the biological advances in control of selected cellular and secretory components of acquired immunity. Acquired immunity goes beyond innate immunity to provide controlled recognition and memory for specific antigenic challenges. Predominately involving activation of T and B lymphocytes, the resulting cellular- and secretory-mediated activity provides immediate and long-term host defenses to antigenic challenge. This session highlighted the biological advances in function and dysfunction of acquired immunity through regulatory T cells, the pathophysiology of effector cells and secretory molecules in immunosuppression, allergic inflammatory disease, and dysregulation that leads to loss of tolerance and autoimmune disease. A brief overview of major concepts in acquired immunity and summaries of the above themes are covered herein, and discussions of these themes are covered in greater detail in this issue of Toxicologic Pathology.