Does mapping of the lingual immune system reveal the presence of both regulatory and effector CD4+ T cells?
The sublingual route is pertinent to induce antigen-specific tolerance, due to (i) limited numbers of pro-inflammatory cells, rather located in submucosal tissues, (ii) co-localization of APCs and resident CD4(+) T cells with regulatory functions. Since the oral immune system can also elicit pro-inflammatory effector responses, the cytokine milieu in which allergens are presented by sublingual APCs needs to be controlled during immunotherapy (e.g. with adjuvants) in order to favour tolerance over inflammation.
The use of contrast while taking radiographs for the localisation of long line position improves the likelihood that an observer can see a long line tip and reduces inter-observer variability. Even using contrast, precise localisation of a long line tip can be difficult.