Mucosa Associated Lymphoid Tissue MALT Nodule

Mucosa-associated lymphoid tissue, including nodules like Peyer’s patches in ileum, tonsils, and appendix, forms diffuse surveillance networks beneath epithelial surfaces rich in antigens, with M cells sampling lumen contents for presentation to lymphocytes in domes, generating IgA responses and memory cells without typical node structure, crucial for tolerating commensals while fighting pathogens.