More MS news articles for June 2002

Transendothelial migratory pathways of Vdelta1(+)TCRgammadelta(+) and Vdelta2(+)TCRgammadelta(+) T lymphocytes from healthy donors and multiple sclerosis patients: involvement of phosphatidylinositol 3 kinase and calcium calmodulin-dependent kinase II

J Immunol 2002 Jun 15;168(12):6071-7
Poggi A, Zocchi MR, Carosio R, Ferrero E, Angelini DF, Galgani S, Caramia MD, Bernardi G, Borsellino G, Battistini L.
Laboratory of Immunology, National Institute for Cancer Research, Genoa, Italy.

We have previously reported that the Vdelta2(+)TCRgammadelta(+) T lymphocyte subset, expressing the NK receptor protein 1a (NKRP1a; CD161), is expanded in patients with relapsing-remitting multiple sclerosis and uses this molecule to migrate through endothelium.

In this work, we show that Vdelta1(+) and Vdelta2(+) gammadelta T lymphocytes use distinct signal transduction pathways to accomplish this function.

Indeed, we have found that Vdelta1(+) cells lack NKRP1a and selectively express the platelet endothelial cell adhesion molecule 1 (PECAM1; CD31), which drives transendothelial migration of this cell subset, at variance with Vdelta2(+) T cells, which are PECAM1 negative and use NKRP1a for transmigration.

Interestingly, when Vdelta2(+) T cells were pretreated with two specific inhibitors of the calcium calmodulin-dependent kinase II KN62 and KN93, but not with the inactive compound KN92, the number of migrating cells and the rate of transmigration were significantly decreased.

In turn, the phosphatidylinositol 3 kinase blockers wortmannin and LY294002 exerted a dose-dependent inhibition of Vdelta1(+) cell migration.

Finally, NKRP1a and PECAM1 engagement led to activation of different signal transduction pathways: indeed, oligomerization of NKRP1a on Vdelta2(+) T cells activates calcium calmodulin-dependent kinase II, while occupancy of PECAM1 on Vdelta1(+) cells triggers the phosphatidylinositol 3 kinase-dependent Akt/protein kinase Balpha activation.

These findings suggest that subsets of gammadelta T lymphocytes may migrate to the site of lesion in multiple sclerosis using two different signaling pathways to extravasate.