Morphological changes in lymph nodes and expression of VCAM1 and cytokines at the late stages of SIV-induced disease in rhesus monkeys.
Four patterns of structural alterations were found in lymph nodes (LNs) from rhesus monkeys 17 to 34 months after infection with simian immunodeficiency virus (SIV-mac251). SIV p27gag antigen and viral particles were localized either between the processes of follicular dendritic cells (FDCs) or in the cytoplasm of macrophages. In hyperplastic follicles, enlarged germinal centres contained numerous Ki67+ proliferating centroblasts which were rather rare in light zones occupied by the CD23+ FDC network. Involuted follicles contained a small number of Ki67+ centroblasts and the CD23 labelling was limited to a very small apical zone. A correlation was found between the morphological characteristics of the follicles (hyperplasia-involution) and the level of expression of the vascular cell adhesion molecule 1 (VCAM1) on FDCs. A gradient in VCAM1 intensity with no expression in the subcapsular-intermediary sinuses, low membrane labelling in the mantle and strong expression in the FDC network was observed. IL1 alpha+ and IL6+ (interleukin) cells (lymphocytes and macrophages) were detected in the mantle, the interfollicular area and the medulla of LNs. Expression of the tumour necrosis factor alpha and ultrastructural markers of interferon alpha production were found in a few FDC and macrophages. Our findings indicate a close relationship between the morphofunctional properties of FDC and the LN structure in SIV infection.
D000818:Animals; D000956:Antigens, Viral / Q000096:biosynthesis; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis*; D015683:Gene Products, gag / Q000378:metabolism; D008198:Lymph Nodes / Q000276:immunology / Q000648:ultrastructure*; D008253:Macaca mulatta; D017455:Receptors, IgE / Q000096:biosynthesis; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology / Q000473:pathology*; D015302:Simian Immunodeficiency Virus / Q000648:ultrastructure; D019010:Vascular Cell Adhesion Molecule-1 / Q000096:biosynthesis*
D000956:Antigens, Viral; D016207:Cytokines; C066594:Gag protein p27, Simian immunodeficiency virus; D015683:Gene Products, gag; D017455:Receptors, IgE; D019010:Vascular Cell Adhesion Molecule-1