Rosetting T cells in Hodgkin lymphoma are activated by immunological synapse components HLA class II and CD58

J Veldman, L Visser, M Huberts-Kregel… - Blood, The Journal …, 2020 - ashpublications.org
J Veldman, L Visser, M Huberts-Kregel, N Muller, B Hepkema, A Van den Berg, A Diepstra
Blood, The Journal of the American Society of Hematology, 2020ashpublications.org
A unique feature of Hodgkin lymphoma (HL) is the presence of CD4+ T cells that surround,
protect, and promote survival of tumor cells. The adhesion molecules involved in this so-
called T-cell rosetting are important components of the immunological synapse (IS).
However, it is unknown whether this synapse is fully assembled and leads to T-cell
activation by enabling interaction between the T-cell receptor (TCR) and human leukocyte
antigen class II (HLA-II). We established a novel rosetting model by coculturing HLA-II …
Abstract
A unique feature of Hodgkin lymphoma (HL) is the presence of CD4+ T cells that surround, protect, and promote survival of tumor cells. The adhesion molecules involved in this so-called T-cell rosetting are important components of the immunological synapse (IS). However, it is unknown whether this synapse is fully assembled and leads to T-cell activation by enabling interaction between the T-cell receptor (TCR) and human leukocyte antigen class II (HLA-II). We established a novel rosetting model by coculturing HLA-II–matched peripheral blood mononuclear cells with HL cell lines and showed IS formation with activation of rosetting T cells. HLA-II downregulation by class II transactivator knockout did not affect the extent of rosetting, but almost completely abrogated T-cell activation. Intriguingly, the level of CD58 expression correlated with the extent of rosette formation, and CD58 knockout or CD2 blockade reduced both rosette formation and T-cell activation. The extension of our findings to primary HL tissue by immunohistochemistry and proximity ligation assays showed interaction of CD2 with CD58 and of TCR-associated CD4 with HLA-II. In conclusion, T-cell rosetting in HL is established by formation of the IS, and activation of rosetting T cells critically depends on the interaction of both TCR-HLA-II and CD2-CD58.
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