Immunohistochemistry and ultrastructure of the Tubal Tonsil in Bactrian Camel

Abstract

The tonsils from 6 adult (5–10 years) healthy Bactrian  camels of both sexes without symptoms of clinical disease were examined by immunohistochemistry, scanning and transmission electron microscopy. The camel tubal tonsil   was covered by pseudostratified columnar ciliated epithelia which were randomly interrupted by the lymphoid follicles.
Follicle associated epithelium demonstrated morphology characteristic of microvillus cells. The inter-follicular and
parafollicular areas contained diffusely localized lymphocytes. The bright germinal centre of the lymphoid follicles
appeared less electron dense than the rest of the follicle, which contained lymphoblasts, follicular dendritic cells, apoptotic cells, plasma cells and tingible body macrophages. High endothelial venules, a few inter-digitating cells with processes of varying length and thickness, macrophages,   and plasma cells were observed among lymphocytes. CD20+ B lymphocytes, CD3+ T lymphocytes and a few CD68+ macrophages were identified in the follicle associated epithelium, lamina propria mucosae, and parafollicular      and inter-follicular areas. The positive follicular dendritic   cells  were only found in germinal centers. These findings suggested that the camel tubal tonsil contains all the elements necessary to function as an effector and inductor immunological organ.