The surface epithelium of recurrent infected palatine tonsils is rich in γδ T cells

Abstract

SUMMARYUsing a large panel of MoAbs in quantitative morphometric analysis of immunohistochemically stained tissue sections, we compared the frequency and distribution of immune cells in palatine tonsils from patients with recurrent tonsillitis (RT) and patients with idiopathic tonsillar hypertrophy (ITH). We found that differences between the two patient groups in leucocyte populations were limited to the surface epithelium, whereas the cellular composition of interfollicular and follicular areas was similar. Most intraepithelial lymphocytes were CD8 þ T cells in both groups. However, the number of intraepithelial T cells was significantly higher in RT compared with ITH. This was due to a selective increase in the number of intraepithelial CD8 þ gd T cells utilizing Vd1 and Vg9. In both patient groups the majority of the intraepithelial gd T cells expressed Vd1 and Vg9. Subepithelially, gd T cells utilizing Vg9 dominated over cells utilizing Vg8, while equal proportions expressed Vd1 and Vd2. These results suggest that cells utilizing the otherwise rare combination Vd1/Vg9 in their T cell receptors (TCR) may constitute a major gd T cell population in palatine tonsils and are probably reactive to antigens specific to the tonsillar milieu. Furthermore, they indicate that preferentially this gd T cell subpopulation is involved in immune reactions within the surface epithelium in RT. We speculate that gd T cells are involved in clearing infectious bacteria at the tonsillar surface and in limiting inflammatory responses in the tonsils. Both local expansion and infiltration of blood cells probably contribute to the high numbers of gd T cells in RT patients.

Questionable Relevance of γδ T Lymphocytes in Renal Cell Carcinoma

“…Finally, sections were counterstained with Hematoxylin 7211 (Richard-Allan Scientific). Positive controls for CD3 and ␥␦ TCR staining consisted of human tonsillar tissue resected for chronic tonsillitis (12). Irrelevant isotypematched Abs were used to control for nonspecific staining.…”

“…We initially optimized our immunohistochemistry (IHC) protocol using the Immu510 Ab because this Ab is a published pan-␥␦ TCR-recognizing Ab that can be used for IHC study of freshfrozen human tissues (12,18). To confirm that Immu510 was capable of accurately identifying ␥␦ T cells, we compared it to a second mAb, TCR-␥␦-1 (19), in flow cytometry experiments.…”

The immune status in situ of recurrent tonsillitis and idiopathic tonsillar hypertrophy

“…Previous studies observed that ITH occurs with follicular hyperplasia (9,12) and RT with a higher number of follicules (9,13). We didn´t measure the follicular area by histological investigation and we didn´t observe any signifi cant changes in follicular number between patients with RT and ITH.…”

The Immune Response in Adenoids and Tonsils

“…Approximately 50% of the intraepithelial lymphocytes are immunoglobulin-producing B-cells, whilst T-lymphocytes are relatively sparse [7]. Low numbers of a specific T-cell population – the γδ T-cells – can be observed in the cryptepithelium [8]; van Kempen: unpubl. obs.].…”