Activation of CD81+ skin ILC2s by cold-sensing TRPM8+ neuron-derived signals maintains cutaneous thermal homeostasis

Piezo1 channels restrain ILC2s and regulate the development of airway hyperreactivity

Mechanosensitive ion channels sense force and pressure in immune cells to drive the inflammatory response in highly mechanical organs. Here, we report that Piezo1 channels repress group 2 innate lymphoid cell (ILC2)-driven type 2 inflammation in the lungs. Piezo1 is induced on lung ILC2s upon activation, as genetic ablation of Piezo1 in ILC2s increases their function and exacerbates the development of airway hyperreactivity (AHR). Conversely, Piezo1 agonist Yoda1 reduces ILC2-driven lung inflammation. Mechanistically, Yoda1 inhibits ILC2 cytokine secretion and proliferation in a KLF2-dependent manner, as we found that Piezo1 engagement reduces ILC2 oxidative metabolism. Consequently, in vivo Yoda1 treatment reduces the development of AHR in experimental models of ILC2-driven allergic asthma. Human-circulating ILC2s express and induce Piezo1 upon activation, as Yoda1 treatment of humanized mice reduces human ILC2-driven AHR. Our studies define Piezo1 as a critical regulator of ILC2s, and we propose the potential of Piezo1 activation as a novel therapeutic approach for the treatment of ILC2-driven allergic asthma.

Analysis of influencing factors of serum SCCA elevation in 309 CAP patients with normal CEA,NSE and CYFRA21-1

Introduction

Squamous cell carcinoma antigen (SCCA) is one of the auxiliary diagnostic indicators of lung squamous cell carcinoma, and an increase in serum SCCA can predict the occurrence of lung squamous cell carcinoma. However, whether SCCA is also elevated in pneumonia patients without malignancy is still not clear. Therefore, we studied influencing factors of elevated serum SCCA in patients with community-acquired pneumonia.

Methods

We retrospectively enrolled 309 patients who were admitted to the Respiratory department with normal serum Carcinoembryonic antigen (CEA), Neuron specific enolase (NSE), and Cytokeratin 19 fragment (CYFRA21-1) level and were diagnosed with community-acquired pneumonia (CAP). The patients' serum SCCA level, body temperature, age, sex, white blood cell (WBC) count, hypersensitive C-reactive protein (Hs-CRP) level, and serum amyloid A (SAA) were recorded. Logistic regression models were used to analyze the risk factors of SCCA elevation. The dose-response relationship between temperature and risk of SCCA increase was analyzed using Restricted cubic splines (RCS).

Results

Of the 309 patients, 143(46.3%) showed elevated SCCA levels. The logistic regression analysis revealed a significant influence of age and body temperature on elevated SCCA (P<0.05) levels. For every one-year increase in age, the probability of elevated SCCA decreased by 3% [OR=0.97,95%CI:0.95,0.99].For every 1°C increase in body temperature, the risk of elevated SCCA increased by 2.75 times [OR=3.75,95%CI:2.55,5.49].The patients were sorted into quartiles based on body temperature. Compared with patients in the Q1 of body temperature group, patients in the Q3 group were at 7.92 times higher risk [OR=7.92, 95%CI:3.27,19.16].and the risk of elevated SCCA was increased by 22.85 times in the Q4 group [OR=23.85,95%CI:8.38,67.89] after adjusting for age, gender, Hs-CRP, SAA, and WBC. RCS analysis showed there was a linear relationship between temperature index and risk of elevated SCCA.

Conclusion

In summary, for CAP patients with normal CEA,NSE and CYFRA21-1 level, age and body temperature are influencing factors of SCCA elevation. Higher body temperature has a strong association with the occurrence of SCCA elevation.

New genetic and epigenetic insights into the chemokine system: the latest discoveries aiding progression toward precision medicine

Over the past thirty years, the importance of chemokines and their seven-transmembrane G protein-coupled receptors (GPCRs) has been increasingly recognized. Chemokine interactions with receptors trigger signaling pathway activity to form a network fundamental to diverse immune processes, including host homeostasis and responses to disease. Genetic and nongenetic regulation of both the expression and structure of chemokines and receptors conveys chemokine functional heterogeneity. Imbalances and defects in the system contribute to the pathogenesis of a variety of diseases, including cancer, immune and inflammatory diseases, and metabolic and neurological disorders, which render the system a focus of studies aiming to discover therapies and important biomarkers. The integrated view of chemokine biology underpinning divergence and plasticity has provided insights into immune dysfunction in disease states, including, among others, coronavirus disease 2019 (COVID-19). In this review, by reporting the latest advances in chemokine biology and results from analyses of a plethora of sequencing-based datasets, we outline recent advances in the understanding of the genetic variations and nongenetic heterogeneity of chemokines and receptors and provide an updated view of their contribution to the pathophysiological network, focusing on chemokine-mediated inflammation and cancer. Clarification of the molecular basis of dynamic chemokine-receptor interactions will help advance the understanding of chemokine biology to achieve precision medicine application in the clinic.

Type 2 neuroimmune circuits in the shaping of physiology

Type 2 immune responses drive a broad range of biological processes including defense from large parasites, immunity to allergens, and non-immunity-related functions, such as metabolism and tissue homeostasis. The symptoms provoked by type 2 immunity, such as vomiting, coughing or itching, encompass nervous system triggering. Here, we review recent findings that place type 2 neuroimmune circuits at the center stage of immunity at barrier surfaces. We emphasize the homeostatic functions of these circuitries and how deregulation may drive pathology and impact disease outcomes, including in the context of cancer. We discuss a paradigm wherein type 2 neuroimmune circuits are central regulators of organismal physiology.

ILC2s in skin disorders

The activation of group 2 innate lymphoid cells (ILC2s) is controlled by various tissue-derived factors, including cytokines, whereas T cells respond to foreign antigens. This review discusses the tissue-specific properties of ILC2s in skin and their involvement in human skin diseases. In a steady state, cutaneous ILC2s contribute to tissue homeostasis. In the keratinocytes of patients with atopic dermatitis (AD), the inflammatory cytokine interleukin-33 (IL-33) is overexpressed. ILC2s are stimulated by IL-33-stimulated basophils through IL-4 to produce type 2 cytokines, such as IL-5 and IL-13. According to several studies, ILC2 expression is upregulated in human AD skin lesions, and it is involved in AD pathogenesis. Dupilumab, an antibody against IL-4 receptor α, lowered the number and percentage of ILC2s in the peripheral blood of patients with AD. Cutaneous ILC2s are divided into two subgroups: circulating and skin-resident ILC2s. However, ILC2s are homogeneous cell populations that are highly diverse and plastic, and there is no consensus on the classification that should be used. The variations in the definition for cutaneous ILC2s in different studies make comparisons among studies difficult, and in particular, the weak expression of the IL-33 receptor ST2 in cutaneous ILC2s and its lack of markers have posed a great challenge to researchers. Therefore, further comprehensive analytical studies are warranted.

Innate lymphoid cells: More than just immune cells

Since their discovery, innate lymphoid cells (ILCs) have been described as the innate counterpart of the T cells. Indeed, ILCs and T cells share many features including their common progenitors, transcriptional regulation, and effector cytokine secretion. Several studies have shown complementary and redundant roles for ILCs and T cells, leaving open questions regarding why these cells would have been evolutionarily conserved. It has become apparent in the last decade that ILCs, and rare immune cells more generally, that reside in non-lymphoid tissue have non-canonical functions for immune cells that contribute to tissue homeostasis and function. Viewed through this lens, ILCs would not be just the innate counterpart of T cells, but instead act as a link between sensory cells that monitor any changes in the environment that are not necessarily pathogenic and instruct effector cells that act to maintain body homeostasis. As these non-canonical functions of immune cells are operating in absence of pathogenic signals, it opens great avenues of research for immunologists that they now need to identify the physiological cues that regulate these cells and how the process confers a finer level of control and a greater flexibility that enables the organism to adapt to changing environmental conditions. In the review, we highlight how ILCs participate in the physiologic function of the tissue in which they reside and how physiological cues, in particular neural inputs control their homeostatic activity.