γδ T Lymphocytes Count Is Normal and Expandable in Peripheral Blood of Patients with Follicular Lymphoma, Whereas It Is Decreased in Tumor Lymph Nodes Compared with Inflammatory Lymph Nodes

Abstract γδ T lymphocytes are attractive effector cells for immunotherapy. In vitro, they can be expanded and kill efficiently a variety of tumor cells. The frequency and distribution of γδ T lymphocytes were compared in tumor lymph nodes of 51 patients with follicular lymphoma lymph nodes (FL-LNs) and 28 patients with inflammatory lymph nodes (I-LNs). γδ and CD8 T lymphocytes were less abundant in FL-LNs than in I-LNs (p ≤ 10−7). These lymphocytes were localized in the perifollicular zone outside of the tumor follicles. Perifollicular γδ T lymphocytes expressed CCR7, in contrast to peripheral blood γδ T lymphocytes and both perifollicular and peripheral blood γδ T lymphocytes expressed CXCR4. The very low number of perifollicular γδ T lymphocytes in FL-LNs could be explained in part by migratory problems because of absence of CCL19 expression in FL-LNs compared with I-LNs. Conversely, CCL21 and CXCL12 were similarly expressed in both FL-LNs and I-LNs. CCL19 and CCL21 were expressed in high endothelial venules and lymphatic vessels, whereas CXCL12 was expressed by stromal cells surrounding high endothelial venules and lymphatic vessels. Peripheral γδ T lymphocytes from 34 patients with FL, expanded with Phosphostim and IL-2 in vitro, had the same expansion capacity as those from healthy individuals. Thus, γδ T lymphocytes can be an attractive source for adoptive immunotherapy in patients with FL, providing they may home in tumor LNs.