Cervical duct cannulation in sheep for collection of afferent lymph dendritic cells from head tissues

Pseudo-afferent cervical lymph-duct cannulation in a sheep model allows large amounts of lymph cells to be collected under physiological conditions, carrying immune signaling information from the head tissues, including oro-nasal mucosae. Importantly, large quantities of dendritic cells (DCs) of several subtypes are obtained (up to 8 million per overnight collection), as well as many other trafficking leukocytes. The technique includes three steps: removal of all head lymph nodes on one side (2 h), catheterization of cervical lymph ducts after 2 months (2-3 h) and collection/purification of lymph-cell subsets (4 h). The approach is challenging (1 in 3 success rate) but fruitful, and can be used to study DC subsets under immunomodulation, in order to assess lymph-cell subset dynamic changes and antigen transportation from oro-nasal tissues. This protocol is directed to experienced postdoctoral researchers.