Absence of Peyer's patches and abnormal lymphoid architecture in chronic proliferative dermatitis (cpdm/cpdm) mice

The chronic proliferative dermatitis (cpdm) mutation causes inflammation in multiple organs, most prominently in the skin. Examination of the immune s ystem revealed severe abnormalities in the architecture of lymphoid tissues . Peyer's patches were absent. In contrast, the spleen, lymph nodes, and na sal-associated lymphoid tissues were present, The spleen had normal numbers of T and B cells, but the spleen, lymph nodes, and nasal-associated lympho id tissues had poorly defined follicles and lacked germinal centers and fol licular dendritic cells, The marginal zone in the spleen was absent, The to tal concentration of serum IgG, IgA, and IgE in cpdm/cpdm mice was signific antly decreased, whereas serum IgM was normal. Fecal IgA was low to undetec table in mutant mice, and the concentration of fecal IgM was increased. The titer of DNP-specific Abs following immunization with DNP-keyhole limpet h emocyanin was significantly decreased for all IgG subclasses. In contrast, T cell function appeared normal as assessed by evaluation of the contact hy persensitivity response in cpdm/cpdm mice. The cpdm mutation causes a compl ex phenotype that is characterized by multiorgan inflammation and the defec tive development of lymphoid tissues. The cpdm/cpdm mouse may be a useful m odel to study the factors that control the development of lymphoid tissues, in particular the Peyer's patches, and the mechanisms that control the hum oral immune response.