IMMUNOHISTOCHEMICAL ANALYSIS OF THE DEVELOPMENT OF THE STRUCTURAL ORGANIZATION OF CHICKEN SPLEEN

The distribution of T cells, B cells, macrophages and dendritic cells in the chicken spleen was investigated by immunohistochemical staining of cryosections using monoclonal antibodies (MAb) specific for leukoc yte (sub)populations. The compartmentalisation of B and T cell zones a s peri-ellipsoid (PELS) and periarteriolar lymphoid sheaths (PALS), re spectively, and the characteristic distribution of leukocyte (sub)popu lations in these compartments was evidenced. Special attention was giv en to the development of structural organisation and lymphoid compartm ents at the end of embryogenesis and in the neonatal phase. The ontoge ny of splenic B cells, T cells and mononuclear phagocytes was examined and is discussed in relationship with the development of immunocompet ence. Further, three B cell subpopulations of the spleen, i.e. resting B cells, germinal centre B cells and plasma cells were discriminated based on their expression levels of immunoglobulins, CD57 and Bu-1.