Opposing roles of endothelial and leukocyte-expressed IL-7Rα in the regulation of psoriasis-like skin inflammation

The shared circulating diagnostic biomarkers and molecular mechanisms of systemic lupus erythematosus and inflammatory bowel disease

Background

Systemic lupus erythematosus (SLE) is a multi-organ chronic autoimmune disease. Inflammatory bowel disease (IBD) is a common chronic inflammatory disease of the gastrointestinal tract. Previous studies have shown that SLE and IBD share common pathogenic pathways and genetic susceptibility, but the specific pathogenic mechanisms remain unclear.

Methods

The datasets of SLE and IBD were downloaded from the Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) were identified using the Limma package. Weighted gene coexpression network analysis (WGCNA) was used to determine co-expression modules related to SLE and IBD. Pathway enrichment was performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis for co-driver genes. Using the Least AbsoluteShrinkage and Selection Operator (Lasso) regressionand Support Vector Machine-Recursive Feature Elimination (SVM-RFE), common diagnostic markers for both diseases were further evaluated. Then, we utilizedthe CIBERSORT method to assess the abundance of immune cell infiltration. Finally,we used the single-cell analysis to obtain the location of common diagnostic markers.

Results

71 common driver genes were identified in the SLE and IBD cohorts based on the DEGs and module genes. KEGG and GO enrichment results showed that these genes were closely associated with positive regulation of programmed cell death and inflammatory responses. By using LASSO regression and SVM, five hub genes (KLRF1, GZMK, KLRB1, CD40LG, and IL-7R) were ultimately determined as common diagnostic markers for SLE and IBD. ROC curve analysis also showed good diagnostic performance. The outcomes of immune cell infiltration demonstrated that SLE and IBD shared almost identical immune infiltration patterns. Furthermore, the majority of the hub genes were commonly expressed in NK cells by single-cell analysis.

Conclusion

This study demonstrates that SLE and IBD share common diagnostic markers and pathogenic pathways. In addition, SLE and IBD show similar immune cellinfiltration microenvironments which provides newperspectives for future treatment.

IL-7 Deficiency Exacerbates Atopic Dermatitis in NC/Nga Mice

Interleukin-7 (IL-7) plays a vital role in the homeostasis of CD4⁺ and CD8⁺ T cells. Although IL-7 has been implicated in T helper (Th)1- and Th17-mediated autoinflammatory diseases, its role in Th2-type allergic disorders, such as atopic dermatitis (AD), remains unclear. Thus, to elucidate the effects of IL-7 deficiency on AD development, we generated IL-7-deficient AD-prone mice by backcrossing IL-7 knockout (KO) B6 mice onto the NC/Nga (NC) mouse strain, a model for human AD. As expected, IL-7 KO NC mice displayed defective development of conventional CD4⁺ and CD8⁺ T cells compared with wild type (WT) NC mice. However, IL-7 KO NC mice presented with enhanced AD clinical scores, IgE hyperproduction, and increased epidermal thickness compared with WT NC mice. Moreover, IL-7 deficiency decreased Th1, Th17, and IFN-γ-producing CD8⁺ T cells but increased Th2 cells in the spleen of NC mice, indicating that a reduced Th1/Th2 ratio correlates with severity of AD pathogenesis. Furthermore, significantly more basophils and mast cells infiltrated the skin lesions of IL-7 KO NC mice. Taken together, our findings suggest that IL-7 could be a useful therapeutic target for treating Th2-mediated skin inflammations, such as AD.

Recent Developments in Protein Lactylation in PTSD and CVD: Novel Strategies and Targets

In 1938, Corneille Heymans received the Nobel Prize in physiology for discovering that oxygen sensing in the aortic arch and carotid sinus was mediated by the nervous system. The genetics of this process remained unclear until 1991 when Gregg Semenza while studying erythropoietin, came upon hypoxia-inducible factor 1, for which he obtained the Nobel Prize in 2019. The same year, Yingming Zhao found protein lactylation, a posttranslational modification that can alter the function of hypoxia-inducible factor 1, the master regulator of cellular senescence, a pathology implicated in both post-traumatic stress disorder (PTSD) and cardiovascular disease (CVD). The genetic correlation between PTSD and CVD has been demonstrated by many studies, of which the most recent one utilizes large-scale genetics to estimate the risk factors for these conditions. This study focuses on the role of hypertension and dysfunctional interleukin 7 in PTSD and CVD, the former caused by stress-induced sympathetic arousal and elevated angiotensin II, while the latter links stress to premature endothelial cell senescence and early vascular aging. This review summarizes the recent developments and highlights several novel PTSD and CVD pharmacological targets. They include lactylation of histone and non-histone proteins, along with the related biomolecular actors such as hypoxia-inducible factor 1α, erythropoietin, acid-sensing ion channels, basigin, and Interleukin 7, as well as strategies to delay premature cellular senescence by telomere lengthening and resetting the epigenetic clock.

Modulation of Dietary Fatty Acids in an Open-Label Study Improves Psoriasis and Dampens the Inflammatory Activation Status

Obesity and high abdominal fat mass are risk factors for developing the chronic inflammatory skin disease psoriasis. They are associated with increased incidence, prevalence and severity of the disease. A positive effect of weight loss on psoriasis activity has been shown in several studies. Obesity-related factors such as the dysregulation of glucose and lipid metabolism, the activation of adipose tissue and resultant persistent low-grade inflammation have been discussed as links of obesity and inflammatory diseases. Recently, we demonstrated a critical role of free fatty acids (FFAs) in obesity-mediated exacerbation of psoriatic skin inflammation in both mice and humans. In the present study, we translated these findings into a therapeutic intervention. An open-label study focusing on the dietary reduction of FFAs was conducted in patients with mild-to-moderate plaque psoriasis, and disease severity and serum markers of inflammation were analyzed. Here, we show that such a dietary intervention improves psoriatic disease activity independently of weight loss. Diet-related metabolic changes, such as a reduction in saturated free fatty acids (SFAs), may thus be more important than weight loss itself. Moreover, dietary intervention inhibited the overall pro-inflammatory activation status in patients, as shown by analysis of serum inflammatory parameters using the Olink platform. From our pilot study, we conclude that dietary intervention focusing on SFA reduction has the capacity to reduce disease activity and general inflammatory status in psoriasis patients.

Co-expression IL-15 receptor alpha with IL-15 reduces toxicity via limiting IL-15 systemic exposure during CAR-T immunotherapy

Background

Chimeric antigen receptor (CAR)-T cell therapy is a powerful adoptive immunotherapy against both B-cell malignancies and some types of solid tumors. Interleukin (IL) -15 is an important immune stimulator that may provide ideal long-term persistent CAR-T cells. However, higher base line or peak serum IL-15 levels are also related to severe toxicity, such as cytokine release syndrome (CRS), graft-versus-host disease (GVHD), and neurotoxicity.

Methods

We successfully constructed CD19 specific armored CAR-T cells overexpressing IL-I5 and IL-15 receptor alpha (IL-15Ra). In vitro cell differentiation and viability were monitored by flow cytometry, and an in vivo xenograft mouse models was used to evaluate the anti-tumor efficiency and liver damage of CAR-T cells.

Results

CAR-T cells overexpressing IL-15 alone demonstrated enhanced viability, retarded exhaustion in vitro and superior tumor-inhibitory effects in vivo. However, these tumor-free mice had lower survival rates, with serious liver injuries, as a possible result of toxicity. As expected, CAR-T cells overexpressing IL-15 combined with IL-15Ra had reduced CD132 expression and released fewer cytokines (IFNγ, IL-2 and IL-15) in vitro, as well as had the tendency to improve mouse survival via repressing the growth of tumor cells and keeping livers healthier compared to CAR-IL-15 T cells.

Conclusions

These results indicated the importance of IL-15 in enhancing T cells persistence and IL-15Ra in reducing the adverse effects of IL-15, with superior tumor retardation during CAR-T therapy. This study paves the way for the rapid exploitation of IL-15 in adoptive cell therapy in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03626-x.

Mechanosensitive ACKR4 scavenges CCR7 chemokines to facilitate T cell de-adhesion and passive transport by flow in inflamed afferent lymphatics

T cell migration via afferent lymphatics to draining lymph nodes (dLNs) depends on expression of CCR7 in T cells and CCL21 in the lymphatic vasculature. Once T cells have entered lymphatic capillaries, they slowly migrate into contracting collecting vessels. Here, lymph flow picks up, inducing T cell detachment and rapid transport to the dLNs. We find that the atypical chemokine receptor 4 (ACKR4), which binds and internalizes CCL19 and CCL21, is induced by lymph flow in endothelial cells lining lymphatic collectors, enabling them to scavenge these chemokines. In the absence of ACKR4, migration of T cells to dLNs in TPA-induced inflammation is significantly reduced. While entry into capillaries is not impaired, T cells accumulate in the ACKR4-deficient dermal collecting vessel segments. Overall, our findings identify an ACKR4-mediated mechanism by which lymphatic collectors facilitate the detachment of lymph-borne T cells in inflammation and their transition from crawling to free-flow toward the dLNs.

Anti-Inflammatory Activity of a Medicinal Herb Extract Mixture, HM-V, on an Animal Model of DNCB-Induced Chronic Skin Inflammation

Chronic inflammatory skin diseases, such as atopic dermatitis, are caused by the accumulation of immune cells and the overproduction of chemokines, including CCL17 and CCL22, due to the activation of pro-inflammatory cytokines secreted from keratinocytes. In the present study, the inhibitory activity of HM-V on tumor necrosis factor alpha (TNF-α)/interferon gamma (IFN-γ)-induced pro-inflammatory cytokines was examined in human keratinocytes (HaCaTs) and 2,4-dinitrofluorobenzene (DNCB)-induced chronic skin contact dermatitis animal models. Traditional Asian medicinal herb extracts mixture (HM-V), which have been extensively used in Asian medicine, were utilized. In TNF-α/IFN-γ-induced HaCaTs, HM-V strongly inhibited mRNA and protein expression of CCL17 and CCL22 in a concentration-dependent manner. The expression of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 was also inhibited. Therefore, localized administration of HM-V in the DNCB-induced animal model alleviated immune cell deposition and skin inflammation. The results indicate that HM-V exerts inhibitory effects on keratinocyte production of CCL17 and CCL22. Furthermore, HM-V may be a useful anti-inflammatory agent for the prevention and treatment of inflammatory skin diseases.

Profiling and Characterization of Localized Cytokine Response in Congenital Cleft Affected Lip Tissue

(1) Background: Despite cleft lips and palates belonging to the most common orofacial congenital anomalies, their morphopathogenesis is not yet fully understood. The study aimed to determine the distribution and relation of cytokines interferon-γ (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-2, IL-7, IL-12, and IL-13 in the cleft affected mucosa of the lip. (2) Materials and Methods: Twenty cleft lip (CL) mucosal samples and seven control tissues of oral cavity mucosa were included in the study. Specimen were obtained during reconstruction surgeries and processed by hematoxylin and eosin staining and immunohistochemistry for IFN-γ, TNF-α, IL-2, IL-7, IL-12, and IL-13. (3) Results: The distribution of cytokines was higher overall in the cleft affected epithelium compared to the connective tissue, with TNF-a, IL-2, and IL-12 displaying the highest number of immunopositive cells. With the exception of IL-2, CL specimen showed higher immunoreactivity. IFN-γ displayed only minor immunoreactivity, with no expression in the control epithelium. Correlation analysis was strongest between CL epithelial IL-13 and IFN-γ (z = 0.71, p < 0.0001). (4) Conclusions: The CLP affected epithelium displays high degrees of plasticity in expressing different cytokines, pointing towards the stimulation of a local adaptive immune response based on consistent inflammatory processes.

In Sickness and in Health: The Immunological Roles of the Lymphatic System

The lymphatic system plays crucial roles in immunity far beyond those of simply providing conduits for leukocytes and antigens in lymph fluid. Endothelial cells within this vasculature are distinct and highly specialized to perform roles based upon their location. Afferent lymphatic capillaries have unique intercellular junctions for efficient uptake of fluid and macromolecules, while expressing chemotactic and adhesion molecules that permit selective trafficking of specific immune cell subsets. Moreover, in response to events within peripheral tissue such as inflammation or infection, soluble factors from lymphatic endothelial cells exert “remote control” to modulate leukocyte migration across high endothelial venules from the blood to lymph nodes draining the tissue. These immune hubs are highly organized and perfectly arrayed to survey antigens from peripheral tissue while optimizing encounters between antigen-presenting cells and cognate lymphocytes. Furthermore, subsets of lymphatic endothelial cells exhibit differences in gene expression relating to specific functions and locality within the lymph node, facilitating both innate and acquired immune responses through antigen presentation, lymph node remodeling and regulation of leukocyte entry and exit. This review details the immune cell subsets in afferent and efferent lymph, and explores the mechanisms by which endothelial cells of the lymphatic system regulate such trafficking, for immune surveillance and tolerance during steady-state conditions, and in response to infection, acute and chronic inflammation, and subsequent resolution.

Association of Behçet disease with psoriasis and psoriatic arthritis

Behçet disease (BD) is a debilitating multi-systemic vasculitis with a litany of muco-cutaneous manifestations and potentially lethal complications. Meanwhile, psoriasis (PSO) is a cutaneous and systemic inflammatory disorder marked by hyperplastic epidermis and silvery scales, which may be accompanied by a distinct form of arthropathy called psoriatic arthritis (PsA). While the clinical pictures of these two are quite different, they feature some important similarities, most of which may stem from the autoinflammatory components of BD and PSO. Therefore, the aim of this study was to investigate the prospective link between BD and cutaneous and articular manifestations of psoriasis. BD, PSO, and PsA cohorts were extracted using the National Health Insurance Service of Korea database. Using χ² tests, prevalence of PSO and PsA with respect to BD status was analysed. Relative to non-BD individuals, those with personal history of BD were nearly three times more likely to be diagnosed with PSO. The adjusted odds ratio (aOR) was 2.36 [95% confidence interval (CI), 1.91–2.93, p < 0.001]. Elevated PSO risk was more pronounced in the male BD cohort (aOR = 1.19, 95% CI 1.16–1.23, p < 0.001). In age-group sub-analysis, individuals over 65 years with PSO were one and a half times more likely to be affected with BD, relative to those under 65. The adjusted OR for the older group was 1.51 (95% CI 1.43–1.59, p < 0.001). BD individuals with “healthy” body weight were significantly less likely to be affected by PSO (aOR = 0.59, 95% CI 0.57–0.62, p < 0.001). On the other hand, there was a correlation between BMI and the risk of BD, with the “moderately obese (30–35 kg/m²)” group having an aOR of 1.24 (95% CI 1.12–1.38, p < 0.001). BD patients were also twice more likely to be associated with PsA (aOR = 2.19, 95% CI 1.42–3.38, p < 0.001). However, in contrast to the case of psoriatic disease itself, females were exposed to a greater risk of developing BD compared to the male PsA cohort (aOR = 2.02, 95% CI 1.88–2.16, p < 0.001). As with PSO, older BD patients were exposed to a significantly higher risk of developing PsA (aOR = 3.13, 95% CI 2.90–3.40, p < 0.001). Behçet disease may place an individual at a significantly increased risk of psoriasis, and still greater hazard of being affected with psoriatic arthritis. This added risk was pronounced in the male cohort, and tended to impact senile population, and this phenomenon may be related with the relatively poor prognosis of BD in males and PSO in older patients.