Microanatomy and Function of the Spleen

This publication provides the first comprehensive review of human splenic microanatomy in correlation with up-to-date information on the immunological function of different splenic compartments. The authors provide an inter-species comparison of splenic microstructure in humans and rats to highlight the species-specific peculiarities of human spleens revealed by immunohistology. The finer structure of human B- and T-cell compartments and their surroundings is defined in detail based on the nomenclature established in rodent immunology. The authors review the typical microscopical features of an antibody response in the spleen of rodents. All information on vascular structures, lymphocytes, special macrophage and fibroblast populations is finally integrated into a hypothesis of lymphocyte recirculation through the human spleen.

---

5 Function of Splenic Compartments . . . . . . . . . . . . . . . 45 5. 1 Splenic White Pulp Compartments during Primary T Cell-Dependent Antibody Responses against Protein Antigens . . . . . . . . . . . . . . . . . . . . . . . . . 46 5. 1. 1 Priming of CD4+ Helper T Cells by Dendritic Cells in the PALS . . . . . . . . . . . . . . . . . . . . 46 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 5. 1. 1. 1 5. 1. 2 Interaction of Primed CD4+ T Cells with Antigen-Specific B Cells in the PALS and Formation of Extrafollicular Foci . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 5. 1. 2. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 5. 1. 3 Formation of Germinal Centres . . . . . . . . . . . . . . . . . . . 50 5. 1. 3. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 5. 1. 4 Localisation of Memory B Cells in the Marginal Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 5. 1. 4. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 5. 2 Function of the Marginal Zone during Primary Antibody Responses against T Cell-Independent Type 2 Antigens . . . . . . . . 57 5. 2. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Function of the Red Pulp . . . . . . . . . . . . . . . . . . . . . . . . . 59 5. 3 5. 3. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 5. 4 Role of the Spleen in CD8+ Cytotoxic T Cell Responses . . . . . . . . . . . . . . . 61 5. 4. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 The Spleen, Natural Killer Cells 5. 5 and Gamma/Delta T Cells . . . . . . . . . . . . . . .. . . . . . . . . 62 5. 5. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 6 Recirculation of Lymphocytes Through the Spleen . . 65 6. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 7 The Role of Cytokines and Chemokines in the Development of Splenic Compartments . . . . . . 69 7. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 8 Unsolved Problems of Human Splenic Structure and Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 VI 8. 1 Arterial Blood Supply to the Splenic Follicles and to the Perifollicular Zone. . . . . . . . . . . . . . . . . 73 . . . . 8. 1. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 8.