Λεξικό .. Conjunctiva-associated lymphoid tissue, (CALT),

Conjunctiva-associated lymphoid tissue, (CALT),

The conjunctiva contains organized lymphoid tissue that consists of intraepithelial lymphocytes, subepithelial lymphoid follicles and adjacent lymphatics and blood vessels. This conjunctiva-associated lymphoid tissue (CALT) is assumed to play a key role in the protection of the ocular surface by initiating and regulating immune responses [1]. The existence of lymphoid cells at the ocular surface and appendage has been known for many years, but for a long time they were believed erroneously to be inflammatory cells. More recent research has shown that in addition to the known presence of lymphoid cells in the lacrimal gland, they also form MALT in the conjunctiva as conjunctiva-associated lymphoid tissue (CALT) and in the lacrimal drainage system as lacrimal drainage-associated lymphoid tissue (LDALT). Together this constitutes an eye-associated lymphoid tissue (EALT), which is a new component of the mucosal immune system of the body. When the topographical distribution of CALT is projected onto the ocular surface, it overlies the cornea during eye closure and is hence in a suitable position to assist the corneal immune protection during blinking and overnight. It can detect corneal antigens and prime respective effector cells, or distribute protective factors as secretory IgA [2].

References

1. Steven P, Gebert A. Conjunctiva-associated lymphoid tissue - current knowledge, animal models and experimental prospects. Ophthalmic Res. 2009;42(1):2-8. Epub 2009 May 28

2. Knop E, Knop N. The role of eye-associated lymphoid tissue in corneal immune protection. J Anat. 2005 Mar;206(3):271-85