Type 2-like polarization and elevated CXCL4 secretion of monocyte derived macrophages upon internalization of plasma-derived exosomes from head and neck cancer patients.

BACKGROUND: Exosomes are closely associated with different aspects of tumor-progression in patients with head and neck squamous cell carcinoma (HNSCC), such as angiogenesis or immune regulation. As extracellular vesicles they are involved in the intercellular communication by transferring their cargo such as proteins and nucleic acids from one cell to another. However, the influence of tumor related plasma-derived exosomes on the polarization and characteristics of monocyte derived macrophages is not fully understood. METHODS: Exosomes were isolated from plasma samples of healthy donors (HD) and HNSCC patients and further evaluated with regard to morphology, size and protein composition via transmission electron microscopy, nanoparticle tracking, western blot analysis and cytokine assays. Differentiation and characteristics of monocyte derived macrophages upon exosome internalization were analyzed using flow cytometry and fluorescence microscopy. Macrophage cytokine secretion patterns were analyzed by human cytokine antibody arrays and ELISA measurements. RESULTS: Our data revealed elevated overall plasma levels of CTLA-4, PD-L1, and TIM-3 as well as elevated exosome-associated CTLA-4, PD-L2, TIM-3, and LAG-3 levels in HNSCC patients compared to HD. Furthermore, we observed a significant type 2-like polarization and elevated CXCL4 secretion of monocyte derived macrophages upon internalization of plasma-derived exosomes from HNSCC patients, which could be visualized by fluorescence microcopy of membrane stained exosomes. CONCLUSIONS: The study provides new insights regarding exosome driven pro-tumorigenic immune regulation in the circulation of patients with head and neck cancer and could help to better understand the individual immunologic situation.

Partial recovery of peripheral blood monocyte subsets in head and neck squamous cell carcinoma patients upon radio(chemo)therapy is associated with decreased plasma CXCL11.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) represents a common and heterogeneous malignancy of the oral cavity, pharynx and larynx. Surgery and radio(chemo)therapy are the standard treatment options and also have great influence on the composition of the tumor microenvironment and immune cell functions. However, the impact of radio(chemo)therapy on the distribution and characteristics of circulating monocyte subsets in HNSCC are not fully understood. METHODS: Expression patterns of adhesion molecules and chemokine receptors CD11a (integrin-α L; LFA-1), CD11b (integrin-α M; Mac-1), CD11c (integrin-α X), CX3CR1 (CX3CL1 receptor) and checkpoint molecule PD-L1 (programmed cell death ligand-1) were investigated upon radio(chemo)therapeutic treatment using flow cytometry. Furthermore, comprehensive analysis of plasma cytokines was performed before and after treatment using ELISA measurements. RESULTS: Our data reveal a partial recovery of circulating monocytes in HNSCC patients upon radio(chemo)therapeutic treatment, with differential effects of the individual therapy regimen. PD-L1 expression on non-classical monocytes significantly correlates with the individual plasma levels of chemokine CXCL11 (C-X-C motif chemokine 11). CONCLUSIONS: Further comprehensive investigations on larger patient cohorts are required to elucidate the meaningfulness of peripheral blood monocyte subsets and chemokine CXCL11 as potential bioliquid indicators in HNSCC with regard to therapy response and the individual immunological situation.

A systematic review of the association between modifiable lifestyle factors and circulating anti-Müllerian hormone.

BACKGROUND: Levels of anti-Müllerian hormone (AMH) are known to be associated with lifestyle determinants such as smoking and oral contraception (OC) use. When measuring AMH in clinical practice, it is essential to know which factors may influence circulating levels or ovarian reserve in general. OBJECTIVE AND RATIONALE: To date, there is no systematic review or summarizing consensus of the nature and magnitude of the relation between AMH and modifiable lifestyle factors. The purpose of this review was to systematically assess the evidence on association of lifestyle behaviors with circulating AMH levels. SEARCH METHODS: We performed a pre-registered systematic review of publications in Embase and PubMed on the lifestyle factors BMI, smoking, OC use, alcohol consumption, caffeine consumption, physical activity, and waist-hip ratio (WHR) in relation to circulating AMH levels up to 1 November 2023. The search strategy included terms such as 'Anti-Mullerian hormone', 'lifestyle', and 'women'. Studies were considered eligible if the association between at least one of the lifestyle factors of interest and AMH was assessed in adult women. The quality of included studies was assessed using the Study Quality Assessment Tools of the National Heart, Lung, and Blood Institute. The results were presented as ranges of the most frequently used association measure for studies that found a significant association in the same direction. OUTCOMES: A total of 15 072 records were identified, of which 65 studies were eligible for inclusion, and 66.2% of the studies used a cross-sectional design. The majority of studies investigating BMI, smoking, OC use, and physical activity reported significant inverse associations with AMH levels. For WHR, alcohol, and caffeine use, the majority of studies did not find an association with AMH. For all determinants, the effect measures of the reported associations were heterogeneous. The mean difference in AMH levels per unit increase in BMI ranged from -0.015 to -0.2 ng/ml in studies that found a significant inverse association. The mean difference in AMH levels for current smokers versus non-smokers ranged from -0.4 to -1.1 ng/ml, and -4% to -44%, respectively. For current OC use, results included a range in relative mean differences in AMH levels of -17% to -31.1%, in addition to a decrease of 11 age-standardized percentiles, and an average decrease of 1.97 ng/ml after 9 weeks of OC use. Exercise interventions led to a decrease in AMH levels of 2.8 pmol/l to 13.2 pmol/l after 12 weeks in women with polycystic ovary syndrome or a sedentary lifestyle. WIDER IMPLICATIONS: Lifestyle factors are associated with differences in AMH levels and thus should be taken into account when interpreting individual AMH measurements. Furthermore, AMH levels can be influenced by the alteration of lifestyle behaviors. While this can be a helpful tool for clinical and lifestyle counseling, the nature of the relation between the observed differences in AMH and the true ovarian reserve remains to be assessed. REGISTRATION NUMBER: PROSPERO registration ID: CRD42022322575.

Improved levels of checkpoint molecule PD-L1 on peripheral blood monocyte subsets in obstructive sleep apnea syndrome patients upon hypoglossal nerve stimulation.

Oxidative stress in patients suffering from obstructive sleep apnea syndrome (OSAS) is associated with a low-grade systemic inflammation, immune disturbance, and increased invasion of monocytes into the endothelium. Besides continuous positive airway pressure (PAP), hypoglossal nerve stimulation (HNS) has become a promising treatment option for patients with OSAS. We aimed to analyse the influence of HNS therapy on the cellular characteristics relevant for adhesion and immune regulation of circulating CD14/CD16 monocyte subsets. Whole blood flow cytometric measurements were performed to analyse the expression levels of different adhesion molecules and checkpoint molecule PD-L1 (programmed death-ligand 1) in connection with pro-inflammatory plasma cytokine IL-8 and the clinical values of BMI (body mass index), AHI (apnea-hypopnea index), ODI (oxygen desaturation index), and ESS (Epworth sleepiness scale) upon HNS treatment. Hypoglossal nerve stimulation treatment significantly improved the expression of adhesion molecule CD162 (P-selectin receptor) on non-classical monocytes and significantly downregulated the expression of PD-L1 on all three monocyte subsets. We conclude that the holistic improvement of different parameters such as the oxygenation of the peripheral blood, a reduced systemic inflammation, and the individual sleeping situation upon HNS respiratory support, leads to an improved immunologic situation.