Isolation of viable and functional T-cells from human palatine tonsils

Tonsillectomy and the incidence of various types of cancer

A potential connection between tonsillectomy and the development of various cancer types has repeatedly been reported in the scientific literature, but many studies have contradicted these observations. Thus, we have no clear evidence, neither to firmly support nor to refute the above-mentioned connection. Here, I suggest that the main reason for the lack of clearer evidence is that the investigations have so far mainly used incorrect sample groups. I propose that individual differences in the tonsils' involvement in immune reactions should be taken into account to solve this long-standing puzzle.

Validation of a monoclonal antibody directed against the human sphingosine 1-phosphate receptor type 1

The sphingosine 1-phosphate receptor type 1 (S1PR1) has several important functions, including stabilizing endothelial barrier and maintaining lymphocyte circulation. These functions are critically dependent on the regulation of S1PR1 cell surface expression. Currently available antibodies against human S1PR1 are not able to pick up cell surface expression on living cells by flow cytometry due to intracellular epitopes or unspecific binding. Here we describe the generation of a mouse monoclonal antibody specific for the N-terminal region of human S1PR1. It has an immunoglobulin M (IgM) kappa isotype and detects cell surface expression of recombinant human S1PR1 on overexpressing cells. Due to unspecific intracellular cell staining, it cannot be used for staining of dead cells and tissue slides or in microscopic analyses. It is also not suitable for Western blot analysis and immunoprecipitation. However, the antibody can stain for endogenous S1PR1 on human endothelial cell lines and primary human umbilical vein endothelial cells (HUVEC). Incubation of these cells with various S1PR1 agonists revealed potent S1PR1 internalization, which was not the case with the specific antagonist W146. Surprisingly, human T and B cells isolated from blood and palatine tonsils did not show specific staining, demonstrating significantly lower endogenous S1PR1 surface expression on lymphocytes than on endothelial cells.

Cytokine production in patients with recurrent acute tonsillitis: analysis of tonsil samples and blood

The aim of this study was to examine T cell function in tonsils of patients with recurrent acute tonsillitis (RAT) or peritonsillar abscess (PTA) by analyzing the cytokine production following T cell receptor (TCR) and co-receptor stimulation with a combination of anti-CD3 and anti-CD28 antibodies. The release of IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-10 and IL-17A from isolated, stimulated T cells of 27 palatine tonsils (10 RAT, 7 PTA, 10 tonsils without inflammation) was measured via a bead-based flow cytometric analysis. The results were compared with the cytokine release of isolated peripheral T cells in a subset of the same patients (6 PTA, 4 patients without signs of inflammation in the blood). TCR stimulation increased the concentration of released cytokines in tonsil and blood as well as in different forms of inflammation and tissue with no inflammation. Stimulation increased the pro-inflammatory cytokines TNF-α, IFN-γ, and IL-2 more than the anti-inflammatory cytokines IL-4 and IL-10 in tonsil and blood samples in RAT, PTA, and samples without inflammation. Blood of patients with PTA showed a higher pro-inflammatory cytokine level compared to the samples of patients without inflammation. T cells in tonsils are fully responsive and competent for antigen-induced cytokine production in RAT and PTA. One should be aware that tonsillectomy, if indicated, might remove a functioning immune organ. Tonsillotomy might be an alternative even in adults to maintain immunological function.

Long-term outcomes of tonsillectomy for recurrent tonsillitis in adults

BACKGROUND

There is uncertainty regarding the effectiveness of tonsillectomy for recurrent tonsillitis in the adult population. Several studies have described a reduced number and severity of tonsillitis episodes; however, the impact of tonsillectomy on healthcare burden has yet to be studied. The aim of the present study was to evaluate the long-term outcomes of tonsillectomy in the adult population.

METHODS

A retrospective review of the central database of Clalit Health Services, Tel Aviv, Israel, between 2003 and 2009 was performed. The study included all adult patients (>18 years) who underwent tonsillectomy due to recurrent tonsillitis. Clinical and epidemiological data from 3 years before and after surgery were collected and analyzed.

RESULTS

A total of 3,701 patients were included in the study. Mean age was 37.4 years, and 42.9% were males. Following surgery, there was a significant decrease in the total number of tonsillitis episodes, otolaryngologist clinic visits, consumption of pertinent antibiotics, and respiratory complaints. Moreover, a reduced number of hospitalizations to the otolaryngology department and shorter hospitalization duration were also noted. Although the total number of hospitalizations was unaffected, there was an increase in the number of primary care office visits. Finally, a break-even time analysis revealed an average of 2.7 years following tonsillectomy.

CONCLUSION

Tonsillectomy for recurrent tonsillitis is effective in decreasing the number and severity of tonsillitis episodes and might also have an economic benefit. The impact of tonsillectomy on general health needs to be further evaluated; however, it appears that there is no increase in overall morbidity.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:328-331, 2020.

Human Blood and Tonsil Plasmacytoid Dendritic Cells Display Similar Gene Expression Profiles but Exhibit Differential Type I IFN Responses to Influenza A Virus Infection

Influenza A virus (IAV) infection constitutes an annual health burden across the globe. Plasmacytoid dendritic cells (PDCs) are central in antiviral defense because of their superior capacity to produce type I IFNs in response to viruses. Dendritic cells (DCs) differ depending on their anatomical location. However, only limited host-pathogen data are available from the initial site of infection in humans. In this study, we investigated how human tonsil PDCs, likely exposed to virus because of their location, responded to IAV infection compared with peripheral blood PDCs. In tonsils, unlike in blood, PDCs are the most frequent DC subset. Both tonsil and blood PDCs expressed several genes necessary for pathogen recognition and immune response, generally in a similar pattern. MxA, a protein that renders cells resistant to IAV infection, was detected in both tonsil and blood PDCs. However, despite steady-state MxA expression and contrary to previous reports, at high IAV concentrations (typically cytopathic to other immune cells), both tonsil and blood PDCs supported IAV infection. IAV exposure resulted in PDC maturation by upregulation of CD86 expression and IFN-α secretion. Interestingly, blood PDCs secreted 10-fold more IFN-α in response to IAV compared with tonsil PDCs. Tonsil PDCs also had a dampened cytokine response to purified TLR ligands compared with blood PDCs. Our findings suggest that tonsil PDCs may be less responsive to IAV than blood PDCs, highlighting the importance of studying immune cells at their proposed site of function.

Functional characterization of T-cells from palatine tonsils in patients with chronic tonsillitis

The palatine tonsils, localized in the oropharynx, are easily accessible secondary lymphoid tissue in humans. Inflammation of the palatine tonsils, local and chronic in case of chronic tonsillitis (CT) or acute in the presence of a peritonsillar abscess (PTA), ranks among the most common diseases in otolaryngology. However, the functionality of tonsillar immune cells, notably T-cells, in the context of these immune pathologies is poorly understood. We have examined the functional status of human tonsillar T-cells in CT and compared it to the acute inflammatory setting of a PTA. Patients presenting with CT (n = 10) or unilateral PTA (n = 7) underwent bilateral tonsillectomy and a subgroup of 8 patients underwent additional blood sampling. T-cells were purified via automated magnetic selection and subjected to flow cytometry-based immunophenotyping. In addition, the response to T-cell receptor (TCR) stimulation was assessed at the level of proximal signaling, activation marker expression and proliferation. We observed no difference between the percentage of T helper (CD4(+)) cells from tonsil tissue in CT and PTA, but observed a trend towards a higher percentage of T helper cells in the blood of patients with PTA versus CT, probably reflecting an acute, systemic bacterial infection in the former cohort. Tonsils from CT harbored more PD-1(+) CD4(+) T-cells, pointing to T-cell exhaustion due to chronic infection. This notion was supported by functional studies that showed a tendency to weaker TCR responses of tonsillar T-cells from CT. Intriguingly, tonsillar T-cells recurrently featured a dampened response to T-cell receptor stimulation at the level of receptor proximal signaling steps compared to peripheral T-cells. In sum, our study documents distinct differences in tonsillar T-cell class distribution and function between the various pathological conditions. Our observations are consistent with the concept that tonsillar T-cells react to infections by eliciting specific immunological responses in chronic versus acute settings of inflammation.