Regulatory B cells producing IL-10 are increased in human tumor draining lymph nodes.

The contribution of different immune cell subsets, especially T cells, in anti-tumor immune response is well established. In contrast to T cells, the anti-tumor contribution of B cells has been scarcely investigated. B-cells are often overlooked, even though they are important players in a fully integrated immune response and constitute a substantial fraction of tumor draining lymph nodes (TDLNs) known also as Sentinel Nodes. In this project, samples including TDLNs, non-TDLNs (nTDLNs) and metastatic lymph nodes from 21 patients with oral squamous cell carcinoma were analyzed by flow cytometry. TDLNs were characterized by a significantly higher proportion of B cells compared with nTDLNs (P = .0127). TDLNs-associated B cells contained high percentages of naïve B cells, in contrary to nTDLNs which contained significantly higher percentages of memory B cells. Patients having metastases in TDLNs showed a significantly higher presence of immunosuppressive B regulatory cells compared with metastasis-free patients (P = .0008). Elevated levels of regulatory B cells in TDLNs were associated with the advancement of the disease. B cells in TDLNs were characterized by significantly higher expression of an immunosuppressive cytokine-IL-10 compared with nTDLNs (P = .0077). Our data indicate that B cells in human TDLNs differ from B cells in nTDLNs and exhibit more naïve and immunosuppressive phenotypes. We identified a high accumulation of regulatory B cells within TDLNs which may be a potential obstacle in achieving response to novel cancer immunotherapies (ICIs) in head and neck cancer.

High-dose pollen intralymphatic immunotherapy: Two RDBPC trials question the benefit of dose increase.

BACKGROUND: The same dosing schedule, 1000 SQ-U times three, with one-month intervals, have been evaluated in most trials of intralymphatic immunotherapy (ILIT) for the treatment of allergic rhinitis (AR). The present studies evaluated if a dose escalation in ILIT can enhance the clinical and immunological effects, without compromising safety. METHODS: Two randomized double-blind placebo-controlled trials of ILIT for grass pollen-induced AR were performed. The first included 29 patients that had recently ended 3 years of SCIT and the second contained 39 not previously vaccinated patients. An up-dosage of 1000-3000-10,000 (5000 + 5000 with 30 minutes apart) SQ-U with 1 month in between was evaluated. RESULTS: Doses up to 10,000 SQ-U were safe after recent SCIT. The combined symptom-medication scores (CSMS) were reduced by 31% and the grass-specific IgG4 levels in blood were doubled. In ILIT de novo, the two first patients that received active treatment developed serious adverse reactions at 5000 SQ-U. A modified up-dosing schedule; 1000-3000-3000 SQ-U appeared to be safe but failed to improve the CSMS. Flow cytometry analyses showed increased activation of lymph node-derived dendritic but not T cells. Quality of life and nasal provocation response did not improve in any study. CONCLUSION: Intralymphatic immunotherapy in high doses after SCIT appears to further reduce grass pollen-induced seasonal symptoms and may be considered as an add-on treatment for patients that do not reach full symptom control after SCIT. Up-dosing schedules de novo with three monthly injections that exceeds 3000 SQ-U should be avoided.

Dividing neutrophils in subsets reveals a significant role for activated neutrophils in the development of airway hyperreactivity.

BACKGROUND: Previous research has emphasized the importance of eosinophils in allergic asthma, while paying less attention to neutrophils. The known functionality of neutrophils in the inflammatory process has recently changed and knowledge about subsets of neutrophils, as characterized by their expression of CD16 and CD62L, has surfaced. Their specific roles in asthma are still unknown. OBJECTIVE: To study the functional differences between subsets of neutrophils by characterizing the impact of individual subsets on airway smooth muscle reactivity. METHODS: The direct effect of neutrophils on airway hyperresponsiveness was assessed by co-culturing different subsets of neutrophils (produced by LPS in vitro stimulation) with human isolated small airways or murine tracheae with subsequent evaluation of smooth muscle reactivity to bradykinin in myographs. Supernatants and tissue were saved for ELISA and immunohistochemistry. RESULTS: The CD16high CD62Ldim neutrophils were found to enhance the response to bradykinin in both human isolated small airways and murine tracheae. No such effects were obtained for the other subsets. The response is due to an upregulation of bradykinin receptor 2 through release of TNFα from the neutrophil. CONCLUSIONS AND CLINICAL RELEVANCE: The present study introduces a new concept regarding the role of neutrophils and defines a novel direct link between a specific activated neutrophil subset and airway smooth muscle, establishing neutrophils as important players in the development of asthmatic airway hyperactivity.

Rapid nodal staging of head and neck cancer surgical specimens with flow cytometric analysis.

BACKGROUND: Detection of metastatic spread of head and neck cancer to cervical lymph nodes is essential for optimal design of therapy. Undetected metastases lead to mortality, which can be prevented by better detection methods. METHODS: We analysed 41 lymph nodes from 19 patients with oral squamous cell carcinoma (OSCC). Each lymph node was divided in two, one half processed for histopathology and the other half dissociated into single-cell suspension, stained for the carcinoma cell markers cytokeratin 5/8 (CK5/8), epithelial cell adhesion molecule (EpCAM) and epithelial mucin (MUC-1), and analysed with flow cytometry. Flow cytometry data were compared with histopathology performed on serial sections and immunohistochemistry. Six cervical lymph nodes from cancer-free patients were used to establish baseline levels in flow cytometry. RESULTS: Flow cytometry analysis (fluorescence-activated cell sorting; FACS) detected all six metastases confirmed by histopathology as well as the histologically negative nodes. Importantly, among nine sentinel lymph nodes, FACS analysis detected <1% malignant cells in four cases, not found in histopathology. Results from flow cytometry analysis can be obtained within 3 h of the time of biopsy. CONCLUSIONS: We show that flow cytometric analysis of nodal tissue is sensitive and reliable in identifying metastases of OSCC. Flow cytometry is inexpensive and fast, providing a possibility of perioperative diagnostics and immediate treatment planning.

Upregulated expression of Notch1/4 - JAG-1/DLL-1 detected in allergic rhinitis.

BACKGROUND: Allergic rhinitis (AR) is a chronic disease with high prevalence. There are currently many treatments available. However, despite an often good therapeutic response, many patients still report impairment in quality of life (QoL) during the pollen season. A skewed T helper (Th)2 polarization is a well-acknowledged pathologic feature of AR. In animal models, local notch signaling in peripheral tissue seems crucial for Th2 cell differentiation and the development of AR. However, the involvement of Notch signaling in Th2 cell differentiation and the development of AR in humans remains unknown. Hence, the present study investigated the human expression of Notch receptors on CD4+ T-cells in nasal mucosa and blood. Correspondingly Notch ligand expression was assessed on nasal epithelial cells and neutrophils. METHODOLOGY: Nasal brush and blood samples from 18 patients with pollen-induced AR and 22 healthy controls were collected outside the pollen season. Notch 1-4 and Jagged-1,2 and Delta-like ligand 1,3-4 was analyzed using flow cytometry. RESULTS: The fraction of CD4+Notch1+ and CD4+Notch4+ T-cells was higher in AR patients than in healthy control patients. Further, the expression levels of the Notch ligands JAG-1 and DLL-1 were increased in nasal epithelial cells from AR patients compared to healthy control patients. In addition, AR patients displayed higher expression of JAG-1 on neutrophils both in the nasal mucosa and in peripheral blood. CONCLUSION: The present study is the first to demonstrate increased activity in the Notch1/4 - JAG-1/DLL-1 pathways among allergic individuals. Further propagating the importance of Notch signalling in AR and blocking JAG-1 and DLL-1-induced Notch signalling by nasal epithelial cells and Neutrophils are potential targets to reduce allergic airway inflammation.

Sentinel node-assisted neck dissection in advanced oral squamous cell carcinoma-A new protocol for staging and treatment.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is used to improve the staging of and guide treatment in patients with early-stage T1-T2 N0 oral squamous cell carcinoma (OSCC). The role of sentinel nodes (SNs) and the use of SN-technique in advanced OSCC (T3-T4 and/or N+) remain to be evaluated. This study investigates the nodal drainage and the rate of positive SNs (SNs+) in all stages of OSCC. MATERIALS AND METHODS: In total, 85 patients with T1-T4 OSCC diagnosed 2019-2021 were included. We used a prolonged interval between peritumoral injection of radionuclide and SPECT-CT to include all SNs. RESULTS: Patients with advanced OSCC presented a higher proportion of contralateral lymphatic drainage and a higher rate of SN+ compared to patients with early-stage disease. T3-T4 and N+ tumors presented a tendency for a higher rate of contralateral lymphatic drainage compared to T1-T2 and N0 tumors (p = 0.1). The prevalence of positive nodes (SNs+) was higher among patients with advanced disease, T3-T4 versus T1-T2 (p = 0.0398). CONCLUSION: SN-assisted ND enables identification and removal of all SNs + and has the potential for more accurate staging and could possibly give prognostic advantages regarding regional recurrence for all OSCC patients, especially among those with advanced disease. The precise localization of the SNs + also suggests that a more individualized ND approach might be possible in the future even for patients with advanced OSCC.

Pulmonary exposure to single-walled carbon nanotubes does not affect the early immune response against Toxoplasma gondii.

BACKGROUND: Single-walled carbon nanotubes (SWCNT) trigger pronounced inflammation and fibrosis in the lungs of mice following administration via pharyngeal aspiration or inhalation. Human exposure to SWCNT in an occupational setting may occur in conjunction with infections and this could yield enhanced or suppressed responses to the offending agent. Here, we studied whether the sequential exposure to SWCNT via pharyngeal aspiration and infection of mice with the ubiquitous intracellular parasite Toxoplasma gondii would impact on the immune response of the host against the parasite. METHODS: C57BL/6 mice were pre-exposed by pharyngeal administration of SWCNT (80 + 80 µg/mouse) for two consecutive days followed by intravenous injection with either 1x103 or 1x104 green fluorescence protein and luciferase-expressing T. gondii tachyzoites. The dissemination of T. gondii was monitored by in vivo bioluminescence imaging in real time for 7 days and by plaque formation. The inflammatory response was analysed in bronchoalveolar lavage (BAL) fluid, and by assessment of morphological changes and immune responses in lung and spleen. RESULTS: There were no differences in parasite distribution between mice only inoculated with T. gondii or those mice pre-exposed for 2 days to SWCNT before parasite inoculum. Lung and spleen histology and inflammation markers in BAL fluid reflected the effects of SWCNT exposure and T. gondii injection, respectively. We also noted that CD11c positive dendritic cells but not F4/80 positive macrophages retained SWCNT in the lungs 9 days after pharyngeal aspiration. However, co-localization of T. gondii with CD11c or F4/80 positive cells could not be observed in lungs or spleen. Pre-exposure to SWCNT did not affect the splenocyte response to T. gondii. CONCLUSIONS: Taken together, our data indicate that pre-exposure to SWCNT does not enhance or suppress the early immune response to T. gondii in mice.

Tumour-draining lymph nodes in head and neck cancer are characterized by accumulation of CTLA-4 and PD-1 expressing Treg cells.

INTRODUCTION: High Tregs infiltration within the tumour microenvironment (TME) of various cancers shows a positive correlation with poor prognosis. Despite the fact that tumour draining lymph nodes (TDLNs) are recognized as key organs playing a crucial role in response to immunotherapy and modulating anti-cancer immunity, the distribution of Tregs and their role in TDLNs remain uncertain thus far. The purpose of this project is to investigate the density of Tregs in TDLNs and non-TDLNs and their expression of immune checkpoint molecules - PD-1 and CTLA-4. METHODS: Samples including TDLNs, non-TDLNs and metastatic lymph nodes (LNs) from 23 patients with oral squamous cell carcinoma (OSCC) were analyzed by multicolour flow cytometry with a focus on Tregs population and expression of CTLA-4 and PD-1. RESULTS: TDLNs and metastatic LNs were characterized by a significantly higher infiltration of Tregs defined as CD4+FoxP3+CD25highCD127low cells and significantly higher expression of CTLA-4 and PD-1 on Tregs compared with non-TDLNs. Tregs in TDLNs and metastatic LNs co-expressed CTLA-4 and PD-1 abundantly. High expression of these immune check-point molecules correlated with positive N-stage but not with T-stage. CONCLUSION: TDLNs and metastatic LNs are characterized by a high accumulation of Tregs expressing high levels of CTLA-4 and PD-1. High infiltration of Tregs can be a potential driver of an immunosuppressive milieu in TDLNs that can, in turn, favour cancer progression. High accumulation of Tregs expressing CTLA-4 and PD-1 in TDLNs is associated with lymph node involvement, but not with the size of the primary tumour.

Single-cell analysis pinpoints distinct populations of cytotoxic CD4+ T cells and an IL-10+CD109+ TH2 cell population in nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by a chronic inflammatory process often associated with comorbid asthma. In this study, we analyzed the transcriptomes of single T helper (TH) cells from nasal polyps of patients with CRSwNP and validated these findings using multiparameter flow cytometry. Polyp tissue contained suppressive T regulatory (Treg) cells, TH2 cells, type 2 innate lymphoid cells, and three transcriptionally distinct subsets of cytotoxic CD4+ T cells (CD4+ CTL). GATA3 expression was a feature of polyp Treg cells, whereas TH2 cells highly expressed TCN1, CD200R, and HPGDS and were enriched for genes involved in lipid metabolism. Only a portion of polyp TH2 cells expressed the prostaglandin D2 receptor CRTH2, whereas a subpopulation of CD109+CRTH2- TH2 cells expressed mRNA for common inhibitor receptors including LAG3 and TIM3 and produced IL-10. Together, we resolved the complexity of TH cells in patients with CRSwNP, identifying several distinct clusters of CD4+ CTL and a population of CD109+CRTH2- TH2 cells with putative regulatory potential.

Extensive qPCR analysis reveals altered gene expression in middle ear mucosa from cholesteatoma patients.

The middle ear is a small and hard to reach compartment, limiting the amount of tissue that can be extracted and the possibilities for studying the molecular mechanisms behind diseases like cholesteatoma. In this paper 14 reference gene candidates were evaluated in the middle ear mucosa of cholesteatoma patients and two different control tissues. ACTB and GAPDH were shown to be the optimal genes for the normalisation of target gene expression when investigating middle ear mucosa in multiplex qPCR analysis. Validation of reference genes using c-MYC expression confirmed the suitability of ACTB and GAPDH as reference genes and showed an upregulation of c-MYC in middle ear mucosa during cholesteatoma. The occurrence of participants of the innate immunity, TLR2 and TLR4, were analysed in order to compare healthy middle ear mucosa to cholesteatoma. Analysis of TLR2 and TLR4 showed variable results depending on control tissue used, highlighting the importance of selecting relevant control tissue when investigating causes for disease. It is our belief that a consensus regarding reference genes and control tissue will contribute to the comparability and reproducibility of studies within the field.

Activation of T helper cells in sentinel node predicts poor prognosis in oral squamous cell carcinoma.

Recurrence in oral squamous cell carcinoma (OSCC) significantly reduces overall survival. Improved understanding of the host's immune status in head and neck cancer may facilitate identification of patients at higher risk of recurrence and improve patients' selection for ongoing clinical trials assessing the effectiveness of immune checkpoint inhibitors (CPI). We aimed to investigate Sentinel Node-derived T-cells and their impact on survival. We enrolled prospectively 28 OSCC patients treated at Karolinska University Hospital, Stockholm, Sweden with primary tumour excision and elective neck dissection. On top of the standard treatment, the enrolled patients underwent sentinel node procedure. T cells derived from Sentinel nodes, non-sentinel nodes, primary tumour and PBMC were analyzed in flow cytometry. Patients who developed recurrence proved to have significantly lower level of CD4+ CD69+ in their sentinel node (31.38 ± 6.019% vs. 43.44 ± 15.33%, p = 0.0103) and significantly higher level of CD8+ CD HLA-DR+ (38.95 ± 9.479% vs. 24.58 ± 11.36%, p = 0.0116) compared to disease-free individuals. Survival analysis of studied population revealed that patients with low proportion of CD4+ CD69+ had significantly decreased disease-free survival (DFS) of 19.7 months (95% CI 12.6-26.9) compared with 42.6 months (95% CI 40.1-45.1) in those with high CD4+ CD69+ proportion in their Sentinel Nodes (log-rank test, p = 0.033). Our findings demonstrate that characterization of T-cell activation in Sentinel Node serves as a complementary prognostic marker. Flow cytometry of Sentinel Node may be useful in both patients' surveillance and selection for ongoing CPI clinical trials in head and neck cancer.

Activation of Activin receptor-like kinases curbs mucosal inflammation and proliferation in chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a widespread disease causing obstruction of the nasal cavity. Its cause remains unclear. The transforming growth-factor beta (TGF-ß) superfamily and their receptors, termed Activin receptor-like kinases (ALKs), have recently been suggested to play a role in local airway inflammation, but have so far not been evaluated in human nasal epithelial cells (HNECs) from CRSwNP patients. We demonstrated that ALK1-7 were expressed in the nasal polyp epithelium, and the expression of ALK1-6 was markedly elevated in polyps compared to nasal mucosa from healthy controls. Stimulation with the ALK ligand TGF-ß1 decreased Ki67 expression in HNECs from CRSwNP patients, not evident in controls. Likewise, TGF-ß1, Activin A and Activin B, all ALK ligands, decreased IL-8 release and Activin A and Activin B reduced ICAM1 expression on HNECs from CRSwNP patients, not seen in controls. Pre-stimulation with TGF-ß1, Activin A, BMP4 and Activin B attenuated a TNF-α-induced ICAM1 upregulation on HNECs of CRSwNP. No effect was evident in controls. In conclusion, an increased expression of ALK1-6 was found on polyp epithelial cells and ligand stimulation appeared to reduce proliferation and local inflammation in polyps.

LEAP-2, LL-37 and RNase7 in tonsillar tissue: downregulated expression in seasonal allergic rhinitis.

In the upper airway, the production of antimicrobial peptides (AMPs) protects against bacteria, viruses and fungi. Previous investigations have revealed downregulated expression of AMPs in different manifestations of allergic disease. In this study, we examined the expression of LL-37, Ribonuclease7 (RNase7) and Liver-expressed antimicrobial peptide 2 (LEAP-2) in tonsillar tissue and studied a possible relation to seasonal allergic rhinitis (SAR). Tonsils, obtained from patients with SAR and nonallergic controls, were examined for the occurrence of LL-37, RNase7 and LEAP-2 with real-time RT-PCR and immunohistochemistry. Tonsillar mononuclear cells were cultured in presence or absence of LEAP-2 or LL-37 and analyzed for cytokine levels using ELISA. mRNA and protein for LL-37, RNase 7 and LEAP-2 were found in all tonsils. Immunohistochemistry revealed prominent staining for LL-37 and RNase7 in the tonsillar epithelium, whereas a moderate staining was seen with LEAP-2. Real-time RT-PCR showed a downregulation of RNase7 and LEAP-2 in the allergic as compared to the nonallergic group. Mononuclear cells cultured in presence of LEAP-2 or LL-37 demonstrated reduced levels of IL-10. The present study demonstrates the presence and function of LEAP-2, LL-37 and RNase7 in tonsils. Moreover, a downregulation of LEAP-2 and RNase7 is seen in SAR patients, indicating that allergic individuals may be more susceptible to respiratory tract infections due to an impaired antimicrobial defense.

Toll-like receptor (TLR) 7 decreases and TLR9 increases the airway responses in mice with established allergic inflammation.

Toll-like receptor (TLR) 7 and TLR9 recognise microbial products of viral descent. Since viruses are a common trigger of asthma exacerbations these TLRs have emerged as interesting therapeutic targets. Even though their effects on allergic inflammation have been evaluated in several models their effects on established allergic airway inflammation remains to be described. Therefore, mice with an on-going ovalbumin (OVA)-induced allergic airway inflammation were given R848 or CpG (TLR7 and TLR9 agonists, respectively) intranasally during four consecutive days. At day five, the R848 treatment had reduced OVA-induced airway hyperresponsiveness (measured as the increased resistance to methacholine), counteracted the accompanying influx of eosinophils and macrophages, and decreased the OVA-enhanced release of interleukin (IL)-5 and leukotriene (LT) B4 in bronchoalveolar lavage fluid. CpG, which by itself caused airway hyperresponsiveness, did not influence the OVA-induced airway hyperresponsiveness, and release of IL-5 and LTB4, but decreased the OVA-induced influx of cells in bronchoalveolar lavage fluid, and increased the amount of pro-inflammatory mediators like IL-12, CXCL1 and CXCL9. To conclude, TLR7 dampens the allergic airway reactivity and local inflammation, whereas TLR9 that causes airway hyperresponsiveness and increased cellular response per se, do generally not interfere with the effects induced by allergic inflammation.

Early timing of low-dose dexamethasone decreases inflammation in a murine model of eosinophilic airway disease.

CONCLUSION: A very low dose of dexamethasone (DEX) was as equally as sufficient as a pharmacological dose to decrease eosinophil inflammation in airways and bone marrow. The timing of DEX treatment in relation to allergen challenge was strongly decisive for the outcome of the inflammatory response. OBJECTIVES: We aimed to study compartmental allergic airway inflammatory responses to classic pharmacological and also extremely low physiological DEX dosage, given at different time points close to allergen challenge in a murine model. MATERIALS AND METHODS: Ovalbumin-sensitized BALB/c-mice were exposed to intra-nasal ovalbumin. DEX was given i.p. as 1 microg/kg low-dose or 500 microg/kg pharmacological single-dose 2 h before, immediately before or 7 h after each of three challenges. Inflammatory cells were evaluated in bronchoalveolar lavage (BAL), lungs, nasal mucosa, and bone marrow. RESULTS: Groups treated with low-dose DEX decreased eosinophilia in BAL to the same extent as the pharmacological dose, but only when administered before challenge. The most prominent decrease of eosinophils in BAL was seen in mice treated with the low dose 2 h before challenge. A similar response pattern as in BAL eosinophilia was detected in lung histopathology. DEX treatments had no obvious effects on inflammation in nasal mucosa.