RESUMO
Two populations of dendritic cells (DCs) are found in mammals, one derived from hematopoietic precursors (conventional/cDC), and another derived from mesenchymal precursors, the follicular DC (FDC); the latter is specialized for antigen presentation to B cells, and has only been definitively demonstrated in mammals. Both cDC and FDC are necessary for induction of germinal centers (GC) and GC-dependent class switch recombination (CSR) and somatic hypermutation (SHM). We demonstrate that in Xenopus, an amphibian in which immunoglobulin CSR and SHM occur without GC formation, a single type of DC has properties of both cDC and FDC, including high expression of MHC class II for the former and display of native antigen at the cell surface for the latter. Our data confirm that the advent of FDC functionality preceded emergence of bona fide FDC, which was in turn crucial for the development of GC formation and efficient affinity maturation in mammals.
Assuntos
Apresentação de Antígeno , Linfócitos B/imunologia , Células Dendríticas/imunologia , Xenopus laevis/imunologia , Animais , Células Dendríticas/classificação , Células Dendríticas Foliculares/classificação , Células Dendríticas Foliculares/imunologia , Centro Germinativo/citologia , Centro Germinativo/imunologia , Switching de Imunoglobulina , Mamíferos/genética , Mamíferos/imunologia , Hipermutação Somática de Imunoglobulina , Especificidade da Espécie , Baço/citologia , Baço/imunologia , Linfócitos T/imunologia , Xenopus laevis/genéticaRESUMO
All patients with Hodgkin's disease should at minimum, undergo staging evaluation. The staging system that has developed in an effort to distinguish patients with different prognose in an anatomic staging system that generally corelates with the tumor burden. In this article the authors describe the early lymph nodes involvement,with a study of patients whose disease has spread to the spleen. Special interest has focused in the study of the early lesions for the complete understanding of the concept of the classical Hodgkin lymphoma
Assuntos
Humanos , Células Dendríticas Foliculares/classificação , Doença de Hodgkin , Linfócitos , Linfonodos/fisiopatologiaRESUMO
All patients with Hodgkins disease should at minimum, undergo staging evaluation. The staging system that has developed in an effort to distinguish patients with different prognose in an anatomic staging system that generally corelates with the tumor burden. In this article the authors describe the early lymph nodes involvement,with a study of patients whose disease has spread to the spleen. Special interest has focused in the study of the early lesions for the complete understanding of the concept of the classical Hodgkin lymphoma