Introduction

Abstract

The avian immune system involves complex interactions between cells, antigens, cytokines, and the microenvironments in which they exist. Recent research has focused on understanding how these interactions occur as well as how the changes in the interactions alter immune function. This knowledge will aid in the improvement of the overall immune response. A special symposium was convened at the 1992 Poultry Science Association meeting to highlight the most recent data on “The Cellular and Fluid Microenvironment of Immune Tissues.”Bruce Glick began the symposium with a discussion of the “Bursal Secretory Dendritic Cells.” The microenvironment of the bursa of Fabricius plays a significant role in the development of antibody diversity. A special cell, the bursal secretory dendritic cell, has been identified in the bursa. The B cell development in the bursal-dependent stage occurs through expansion of immunoglobulin rearranged cells and gene conversion. These two processes contribute to antibody diversity. Expression …