FOXP3+ regulatory T cells in the human immune system. Nat Rev Immunol. 2010;10:490-500. [PMID: 20559327 DOI: 10.1038/nri2785]

Multimodal immune cell phenotyping in GI biopsies reveals microbiome-related T cell modulations in human GvHD

Acute graft-versus-host disease (aGvHD) is a significant complication after allogeneic hematopoietic stem cell transplantation (aHSCT), but major factors determining disease severity are not well defined yet. By combining multiplexed tissue imaging and single-cell RNA sequencing on gastrointestinal biopsies from aHSCT-treated individuals with fecal microbiome analysis, we link high microbiome diversity and the abundance of short-chain fatty acid-producing bacteria to the sustenance of suppressive regulatory T cells (Tregs). Furthermore, aGvHD severity strongly associates with the clonal expansion of mainly CD8 T cells, which we find distributed over anatomically distant regions of the gut, persistent over time, and inversely correlated with the presence of suppressive Tregs. Overall, our study highlights the pathophysiological importance of expanded CD8 T cell clones in the progression of aGvHD toward more severe clinical manifestations and strongly supports the further development of microbiome interventions as GvHD treatment via repopulation of the gut Treg niche to suppress inflammation.

Cathepsin W restrains peripheral regulatory T cells for mucosal immune quiescence

Peripheral regulatory T (pT_reg) cells are a key T cell lineage for mucosal immune tolerance and anti-inflammatory responses, and interleukin-2 receptor (IL-2R) signaling is critical for T_reg cell generation, expansion, and maintenance. The expression of IL-2R on pT_reg cells is tightly regulated to ensure proper induction and function of pT_reg cells without a clear molecular mechanism. We here demonstrate that Cathepsin W (CTSW), a cysteine proteinase highly induced in pT_reg cells under transforming growth factor-β stimulation is essential for the restraint of pT_reg cell differentiation in an intrinsic manner. Loss of CTSW results in elevated pT_reg cell generation, protecting the animals from intestinal inflammation. Mechanistically, CTSW inhibits IL-2R signaling in pT_reg cells by cytosolic interaction with and process of CD25, repressing signal transducer and activator of transcription 5 activation to restrain pT_reg cell generation and maintenance. Hence, our data indicate that CTSW acts as a gatekeeper to calibrate pT_reg cell differentiation and function for mucosal immune quiescence.

Immediate major dynamic changes in the T- and NK-cell subset composition after cardiac transplantation

Early kinetics of lymphocyte subsets involved in tolerance and rejection following heart transplantation (HTx) are barely defined. Here, we aimed to delineate the early alloimmune response immediately after HTx. Therefore, blood samples from 23 heart-transplanted patients were collected before (pre-), immediately (T0), 24 hours (T24), and 3 weeks (3 wks) after HTx. Immunophenotyping was performed using flow cytometry. A significant increase was detected for terminally differentiated (TEMRA) CD4+ or CD8+ T cells and CD56dim CD16+ NK cells immediately after HTx linked to a decrease in naïve CD8+ and CM CD4+ T as well as CD56bright CD16- NK cells, returning to baseline levels at T24. More detailed analyses revealed increased CD69+ CD25- and diminished CD69- CD25- CD4+ or CD8+ T-cell proportions at T0 associated with decreasing S1PR1 expression. Passenger T and NK cells were found at low frequencies only in several patients at T0 and did not correlate with lymphocyte alterations. Collectively, these results suggest an immediate, transient shift toward memory T and NK cells following HTx. Opposite migratory properties of naïve versus memory T and NK cells occurring in the early phase after HTx could underlie these observations and may impinge on the development of allo-specific immune responses.

Pyroptosis: A road to next-generation cancer immunotherapy

The goal of cancer immunotherapy is to clear tumor cells by activating antitumor immunity, especially by mobilizing tumor-reactive CD8+T cells. Pyroptosis, programmed lytic cell death mediated by gasdermin (GSDM), results in the release of cellular antigens, damage-associated molecular patterns (DAMPs) and cytokines. Therefore, pyroptotic tumor cell-derived tumor antigens and DAMPs not only reverse immunosuppression of the tumor microenvironment (TME) but also enhance tumor antigen presentation by dendritic cells, leading to robust antitumor immunity. Exploring nanoparticles and other approaches to spatiotemporally control tumor pyroptosis by regulating gasdermin expression and activation is promising for next-generation immunotherapy.

Modulation of cytokine release from peripheral blood mononuclear cells from multiple sclerosis patients by coenzyme A and soraphen A

By applying the acetyl-CoA-carboxylase inhibitors soraphen A (SorA) and coenzyme A (CoA) ex vivo, we aimed to reduce proinflammatory cytokine release by PBMCs and increase anti-inflammatory cytokine levels, thereby demonstrating a possible application of those pathways in future multiple sclerosis (MS) therapy. In a prospective exploratory monocentric study, we analysed cytokine production by PBMCs treated with SorA (10 or 50 nM) and CoA (600 μM). Thirty-one MS patients were compared to 18 healthy age-matched controls. We demonstrated the immunomodulatory potential of SorA and CoA in targeting the immune function of MS patients, with an overall reduction of cytokines except of IL-2, IL-6 and IL-10.

An oral cancer vaccine using Bifidobacterium vector augments combination of anti-PD-1 and anti-CTLA-4 antibodies in mouse renal cell carcinoma model

Recently, immune checkpoint inhibitor (ICI) based combination therapies, including anti-PD-1 antibody, nivolumab with anti-CTLA-4 antibody, and ipilimumab have become the primary treatment option for metastatic or unresectable renal cell carcinoma (RCC). However, despite the combination of two ICIs, 60-70% of patients are still resistant to first-line cancer immunotherapy. In the present study, undertook combination immunotherapy for RCC using an oral cancer vaccine (Bifidobacterium longum displaying WT1 tumor associated antigen (B. longum 420)) with anti-PD-1 and anti-CTLA-4 antibodies in a mouse syngeneic model of RCC to explore possible synergistic effects. We found that B. longum 420 significantly improved the survival of mice bearing RCC tumors treated by anti-PD-1 and anti-CTLA-4 antibodies compared to the mice treated by the antibodies alone. This result suggests that B. longum 420 oral cancer vaccine as an adjunct to ICIs could provide a novel treatment option for RCC patients. Our microbiome analysis revealed that the proportion of Lactobacilli was significantly increased by B. longum 420. Although the detailed mechanism of action is unknown, it is possible that microbiome alteration by B. longum 420 enhances the efficacy of the ICIs.

Gut microbiota-derived lipid metabolites facilitate regulatory T cell differentiation

Commensal bacteria-derived metabolites are critical in regulating the host immune system. Although the impact of gut microbiota-derived hydrophilic metabolites, such as short-chain fatty acids, on immune cell functions and development has been well documented, the immunomodulatory effects of gut microbiota-derived lipids are still of interest. Here, we report that lipid extracts from the feces of specific-pathogen-free (SPF), but not germ-free (GF), mice showed regulatory T (Treg)-cell-inducing activity. We conducted RP-HPLC-based fractionation and liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based lipidome profiling and identified two bioactive lipids, 9,10-dihydroxy-12Z-octadecenoic acid (9,10-DiHOME) and all-trans retinoic acid (atRA), with Treg-inducing activity in vitro. The luminal abundance of 9,10-DiHOME in the large intestine was significantly decreased by dextran sulfate sodium (DSS)-induced colitis, indicating that 9,10-DiHOME may be a potential biomarker of colitis. These observations implied that commensal bacteria-derived lipophilic metabolites might contribute to Treg development in the large intestine.

Peripheral CD4+CD25hiCD127low regulatory T cells are increased in patients with gastrointestinal cancer

BACKGROUND

Regulatory T cells (Tregs) play an important role in regulation of immune response and immunologic tolerance in cancer. Gastrointestinal cancer is still a leading cause of cancer-related death in the world. This study aimed to detect Tregs in patients with gastrointestinal cancer.

METHODS

In this study, 45 gastric cancer patients, 50 colorectal cancer patients and 50 healthy controls were enrolled. Flow cytometry was used to detect CD4⁺CD25^hiCD127^low Tregs, CD4⁺CD25^hi, and CD4⁺ cells in peripheral blood. Cytokine interleukin-10 (IL-10) and transforming growth factor-β1 (TGF-β1) in peripheral blood and in the supernatant of Tregs cultures were measured by enzyme linked immunosorbent assay.

RESULTS

Compared with healthy controls, the levels of CD4⁺CD25^hiCD127^low Tregs and CD4⁺CD25^hi cells increased significantly in patients with gastrointestinal cancer. Patients with gastrointestinal cancer also showed a significantly increased levels of IL-10 and TGF-β1 in both peripheral blood and CD4⁺CD25^hiCD127^low Tregs culture medium.

CONCLUSION

The present study firstly demonstrated that gastrointestinal patients have a compromised immune status where the CD4⁺CD25^hiCD127^low Tregs, as well as levels of IL-10 and TGF-β1 are elevated. The data offered new information for understanding the immunological features of gastrointestinal patients, as well as provided new insights into approaches to develop new immunotherapies for patients with gastrointestinal cancer.

The Effect of Lung Resection for NSCLC on Circulating Immune Cells: A Pilot Study

This pilot study sought to evaluate the circulating levels of immune cells, particularly regulatory T-cell (Treg) subsets, before and after lung resection for non-small cell lung cancer. Twenty-five patients consented and had specimens collected. Initially, peripheral blood of 21 patients was collected for circulating immune cell studies. Two of these patients were excluded due to technical issues, leaving 19 patients for the analyses of circulating immune cells. Standard gating and high-dimensional unsupervised clustering flow cytometry analyses were performed. The blood, tumors and lymph nodes were analyzed via single-cell RNA and TCR sequencing for Treg analyses in a total of five patients (including four additional patients from the initial 21 patients). Standard gating flow cytometry revealed a transient increase in neutrophils immediately following surgery, with a variable neutrophil-lymphocyte ratio and a stable CD4-CD8 ratio. Unexpectedly, the total Treg and Treg subsets did not change with surgery with standard gating in short- or long-term follow-up. Similarly, unsupervised clustering of Tregs revealed a dominant cluster that was stable perioperatively and long-term. Two small FoxP3hi clusters slightly increased following surgery. In the longer-term follow-up, these small FoxP3hi Treg clusters were not identified, indicating that they were likely a response to surgery. Single-cell sequencing demonstrated six CD4+FoxP3+ clusters among the blood, tumors and lymph nodes. These clusters had a variable expression of FoxP3, and several were mainly, or only, present in tumor and lymph node tissue. As such, serial monitoring of circulating Tregs may be informative, but not completely reflective of the Tregs present in the tumor microenvironment.

New Flow Cytometric Methods for Monitoring STAT5 Signaling Reveal Responses to SARS-CoV-2 Antigen-Specific Stimulation in FOXP3+ Regulatory T Cells also in Patients with Advanced Chronic Lymphocytic Leukemia

Increased frequency of CD4⁺CD25⁺ regulatory T-cells (Treg) has been associated with disease progression in chronic lymphocytic leukemia (CLL). Flow cytometric methods, which allow for the simultaneous analysis of their specific transcription factor Foxp3 and activated STAT proteins, together with proliferation can help to elucidate the signaling mechanisms driving Treg expansion and suppression of FOXP3- conventional CD4⁺T-cells (Tcon). Herein, we first report a novel approach in which STAT5 phosphorylation (pSTAT5) and proliferation (BrdU-FITC incorporation) could be analyzed specifically in FOXP3+ and FOXP3- responding cells after CD3/CD28 stimulation. The addition of magnetically purified CD4⁺CD25⁺ T-cells from healthy donors to cocultured autologous CD4⁺CD25^- T-cells resulted in suppression of Tcon cell cycle progression accompanied by a decrease in pSTAT5. Next, a method using imaging flow cytometry is presented for the detection of cytokine-dependent pSTAT5 nuclear translocation in FOXP3-expressing cells. Finally, we discuss our experimental data obtained by combining Treg pSTAT5 analysis and antigen-specific stimulation with SARS-CoV-2 antigens. Applying these methods on samples from patients revealed Treg responses to antigen-specific stimulation and significantly higher basal pSTAT5 in CLL patients treated with immunochemotherapy. Thus, we speculate that through the use of this pharmacodynamic tool, the efficacy of immunosuppressive drugs and their possible off-target effects can be assessed.

Role of regulatory T cells in spinal cord injury

Spinal cord injury is an intricate process involving a series of multi-temporal and multi-component pathological events, among which inflammatory response is the core. Thus, it is crucial to find a way to prevent the damaging effects of the inflammatory response. The research has found that Treg cells can suppress the activation, proliferation, and effector functions of many parenchymal cells by multiple mechanisms. This review discusses how Treg cells regulate the inflammatory cells to promote spinal cord recovery. These parenchymal cells include macrophages/microglia, oligodendrocytes, astrocytes, and others. In addition, we discuss the adverse role of Treg cells, the status of treatment, and the prospects of cell-based therapies after spinal cord injury. In conclusion, this review provides an overview of the regulatory role of Treg cells in spinal cord injury. We hope to offer new insights into the treatment of spinal cord injury.

Automated clustering reveals CD4+ T cell subset imbalances in rheumatoid arthritis

Background

Despite the report of an imbalance between CD4+ T helper (Th) cell subsets in rheumatoid arthritis (RA), patient stratification for precision medicine has been hindered by the discovery of ever more Th cell subsets, as well as contradictory association results.

Objectives

To capture previously reported Th imbalance in RA with deep immunophenotyping techniques; to compare hypothesis-free unsupervised automated clustering with hypothesis-driven conventional biaxial gating and explore if Th cell heterogeneity accounts for conflicting association results.

Methods

Unstimulated and stimulated peripheral blood mononuclear cells from 10 patients with RA and 10 controls were immunophenotyped with a 37-marker panel by mass cytometry (chemokine receptors, intra-cellular cytokines, intra-nuclear transcription factors). First, conventional biaxial gating and standard definitions of Th cell subsets were applied to compare subset frequencies between cases and controls. Second, unsupervised clustering was performed with FlowSOM and analysed using mixed-effects modelling of Associations of Single Cells (MASC).

Results

Conventional analytical techniques fail to identify classical Th subset imbalance, while unsupervised automated clustering, by allowing for unusual marker combinations, identified an imbalance between pro- and anti-inflammatory subsets. For example, a pro-inflammatory Th1-like (IL-2+ T-bet+) subset and an unconventional but pro-inflammatory IL-17+ T-bet+ subset were significantly enriched in RA (odds ratio=5.7, p=2.2 x 10-3; odds ratio=9.7, p=1.5x10-3, respectively). In contrast, a FoxP3+ IL-2+ HLA-DR+ Treg-like subset was reduced in RA (odds ratio=0.1, p=7.7x10-7).

Conclusion

Taking an unbiased approach to large dataset analysis using automated clustering algorithms captures non-canonical CD4+ T cell subset imbalances in RA blood.

Intestinal Behcet's Disease: A Review of the Immune Mechanism and Present and Potential Biological Agents

Behcet's disease (BD) is a chronic and recurrent systemic vasculitis involving almost all organs and tissues. Intestinal BD is defined as BD with predominant gastrointestinal involvement, presenting severe complications such as massive gastrointestinal hemorrhage, perforation, and obstruction in some cases. To some extent, intestinal BD is classified as a member of inflammatory bowel disease (IBD), as it has a lot in common with classical IBD including Crohn's disease (CD) and ulcerative colitis (UC). Certainly, the underlying pathogenesis is not the same and dysregulation of immune function is believed to be one of the main pathogeneses in intestinal BD, although the etiology has not been clear up to now. Biological agents are an emerging category of pharmaceuticals for various diseases, including inflammatory diseases and cancers, in recent decades. Based on the deep understanding of the immune mechanism of intestinal BD, biological agents targeting potential pathogenic cells, cytokines and pathways are optimized options. Recently, the adoption of biological agents such as anti-tumor necrosis factor agents has allowed for the effective treatment of patients with refractory intestinal BD who show poor response to conventional medications and are faced with the risk of surgical treatment. In this review, we have tried to summarize the immune mechanism and present potential biological agents of intestinal BD.

CD69 on Tumor-Infiltrating Cells Correlates With Neuroblastoma Suppression by Simultaneous PD-1 and PD-L1 Blockade

INTRODUCTION

Tumor-infiltrating cells play an important role in tumor immunology, and tumor-infiltrating lymphocytes (TILs) are critical in antitumor reaction related to immune checkpoint inhibition targeting programmed cell death protein 1 (PD-1) and programmed cell death ligand 1 (PD-L1).

METHODS

In nude mice, which are immune deficient because they lack T cells, and inbred A/J mice, which are syngeneic to neuroblastoma cells (Neuro-2a) and have normal T cell function, we investigated the importance of T lymphocytes in immune checkpoint inhibition in mouse neuroblastoma and analyzed the immune cells in the tumor microenvironment. Then, we subcutaneously injected mouse Neuro-2ainto nude mice and A/J mice, administered anti-PD-1 and anti-PD-L1 antibodies by intraperitoneal injection, and evaluated tumor growth. At 16 d after Neuro-2a cells injection, mice were euthanized, tumors and spleens were harvested, and immune cells were analyzed by flow cytometry.

RESULTS

The antibodies suppressed tumor growth in A/J but not in nude mice. The co-administration of antibodies did not affect regulatory T cells (culster of differentiation [CD]4⁺CD25⁺FoxP3⁺ cells) or activated CD4⁺ lymphocytes (expressing CD69). No changes in activated CD8⁺ lymphocytes (expressing CD69) were observed in spleen tissue. However, increased infiltration of activated CD8⁺ TILs was seen in tumors weighing less than 300 mg, and the amount of activated CD8⁺ TILs was negatively correlated with tumor weight.

CONCLUSIONS

Our study confirms that lymphocytes are essential for the antitumor immune reaction induced by blocking PD-1/PD-L1 and raises the possibility that promoting the infiltration of activated CD8⁺ TIL into tumors may be an effective treatment for neuroblastoma.

Stereocomplexed microparticles loaded with Salvia cadmica Boiss. extracts for enhancement of immune response towards Helicobacter pylori

Controlled delivery of therapeutic substance gives numerous advantages (prevents degradation, improves uptake, sustains concentration, lowers side effects). To encapsulate Salvia cadmica extracts (root or aerial part), enriched with polyphenols with immunomodulatory activity, in stereocomplexed microparticles (sc-PLA), for using them to enhance the immune response towards gastric pathogen Helicobacter pylori. Microparticles were made of biodegradable poly(lactic acid) (PLA) and poly(D-lactic acid) (PDLA). Their stereocomplexation was used to form microspheres and enhance the stability of the obtained particles in acidic/basic pH. The release of Salvia cadmica extracts was done in different pH (5.5, 7.4 and 8.0). The obtained polymers are safe in vitro and in vivo (guinea pig model). The sc-PLA microparticles release of S. cadmica extracts in pH 5.5, 7.4, and 8.0. S. cadmica extracts enhanced the phagocytic activity of guinea pig bone marrow-derived macrophages, which was diminished by H. pylori, and neutralized H. pylori driven enhanced production of tumor necrosis factor (TNF)-α and interleukin (IL)-10. The sc-PLA encapsulated S. cadmica extracts can be recommended for further in vivo study in guinea pigs infected with H. pylori to confirm their ability to improve an immune response towards this pathogen.

Immune cellular patterns of distribution affect outcomes of patients with non-small cell lung cancer

Studying the cellular geographic distribution in non-small cell lung cancer is essential to understand the roles of cell populations in this type of tumor. In this study, we characterize the spatial cellular distribution of immune cell populations using 23 makers placed in five multiplex immunofluorescence panels and their associations with clinicopathologic variables and outcomes. Our results demonstrate two cellular distribution patterns-an unmixed pattern mostly related to immunoprotective cells and a mixed pattern mostly related to immunosuppressive cells. Distance analysis shows that T-cells expressing immune checkpoints are closer to malignant cells than other cells. Combining the cellular distribution patterns with cellular distances, we can identify four groups related to inflamed and not-inflamed tumors. Cellular distribution patterns and distance are associated with survival in univariate and multivariable analyses. Spatial distribution is a tool to better understand the tumor microenvironment, predict outcomes, and may can help select therapeutic interventions.

The Regulation and Double-Edged Roles of the Deubiquitinase OTUD5

OTUD5 (OTU Deubiquitinase 5) is a functional cysteine protease with deubiquitinase activity and is a member of the ovarian tumor protease (OTU) family. OTUD5 is involved in the deubiquitination of many key proteins in various cellular signaling pathways and plays an important role in maintaining normal human development and physiological functions. Its dysfunction can affect physiological processes, such as immunity and DNA damage repair, and it can even lead to tumors, inflammatory diseases and genetic disorders. Therefore, the regulation of OTUD5 activity and expression has become a hot topic of research. A comprehensive understanding of the regulatory mechanisms of OTUD5 and its use as a therapeutic target for diseases is of great value. Herein, we review the physiological processes and molecular mechanisms of OTUD5 regulation, outline the specific regulatory processes of OTUD5 activity and expression, and link OTUD5 to diseases from the perspective of studies on signaling pathways, molecular interactions, DNA damage repair and immune regulation, thus providing a theoretical basis for future studies.

The immunomodulatory mechanisms for acupuncture practice

The system physiology approaches that emerge in western countries in recent years echo the holistic view of ancient Traditional Chinese Medicine (TCM) practices that deal with the root, rather than only the symptoms of diseases. Particularly, TCM practices, including acupuncture, emphasize the mobilization of self-healing mechanisms to bring back body homeostasis. Acupuncture has been practiced for over two thousand years to modulate body physiology via stimulation at specific body regions (acupoints). With the development of various research on acupuncture therapy, its regulatory effect on the immune system has been gradually recognized, especially on immunological diseases, including infectious and allergic diseases. In this study, we reviewed the immunomodulatory mechanism of acupuncture and systematically integrates existing research to respectively elucidate the modulatory mechanisms of acupuncture on the innate immune system, adaptive immune system, and well-known neuroanatomical mechanisms, including intact somatosensory-autonomic reflex pathway. With the advances made in recent systems physiology studies, we now have a great opportunity to gain insight into how acupuncture modulates immunity, and subsequently improves its efficacy.

Treg cells require Izumo1R to regulate γδT cell-driven inflammation in the skin

Izumo1R is a pseudo-folate receptor with an essential role in mediating tight oocyte/spermatozoa contacts during fertilization. Intriguingly, it is also expressed in CD4+ T lymphocytes, in particular Treg cells under the control of Foxp3. To understand Izumo1R function in Treg cells, we analyzed mice with Treg-specific Izumo1r deficiency (Iz1rTrKO). Treg differentiation and homeostasis were largely normal, with no overt autoimmunity and only marginal increases in PD1+ and CD44hi Treg phenotypes. pTreg differentiation was also unaffected. Iz1rTrKO mice proved uniquely susceptible to imiquimod-induced, γδT cell-dependent, skin disease, contrasting with normal responses to several inflammatory or tumor challenges, including other models of skin inflammation. Analysis of Iz1rTrKO skin revealed a subclinical inflammation that presaged IMQ-induced changes, with an imbalance of Rorγ+ γδT cells. Immunostaining of normal mouse skin revealed the expression of Izumo1, the ligand for Izumo1R, electively in dermal γδT cells. We propose that Izumo1R on Tregs enables tight contacts with γδT cells, thereby controlling a particular path of skin inflammation.

Unleashing the potential of combining FGFR inhibitor and immune checkpoint blockade for FGF/FGFR signaling in tumor microenvironment

BACKGROUND

Fibroblast growth factors (FGFs) and their receptors (FGFRs) play a crucial role in cell fate and angiogenesis, with dysregulation of the signaling axis driving tumorigenesis. Therefore, many studies have targeted FGF/FGFR signaling for cancer therapy and several FGFR inhibitors have promising results in different tumors but treatment efficiency may still be improved. The clinical use of immune checkpoint blockade (ICB) has resulted in sustained remission for patients. MAIN: Although there is limited data linking FGFR inhibitors and immunotherapy, preclinical research suggest that FGF/FGFR signaling is involved in regulating the tumor microenvironment (TME) including immune cells, vasculogenesis, and epithelial-mesenchymal transition (EMT). This raises the possibility that ICB in combination with FGFR-tyrosine kinase inhibitors (FGFR-TKIs) may be feasible for treatment option for patients with dysregulated FGF/FGFR signaling.

CONCLUSION

Here, we review the role of FGF/FGFR signaling in TME regulation and the potential mechanisms of FGFR-TKI in combination with ICB. In addition, we review clinical data surrounding ICB alone or in combination with FGFR-TKI for the treatment of FGFR-dysregulated tumors, highlighting that FGFR inhibitors may sensitize the response to ICB by impacting various stages of the "cancer-immune cycle".

Impaired response of memory Treg to high density lipoproteins is associated with intermediate/high cardiovascular disease risk in persons with HIV

Cardiovascular disease (CVD) is a leading cause of enhanced morbidity and mortality in persons with HIV (PWH) in the era of highly active antiretroviral therapy (AART). However, the underlying mechanisms are not fully understood. Regulatory T cells (Treg), notably the highly suppressive memory subset, have been shown to limit CVD. Importantly, memory Treg cell numbers remain low in many treated PWH. High density lipoproteins (HDL) also protect from CVD, and we previously found that Treg-HDL interactions reduce oxidative stress in these cells. Here, we evaluated Treg-HDL interactions in PWH and whether they were operative in those higher CVD risk. To do that, we recruited a cohort of PWH with intermediate/high CVD risk (median ASCVD risk score of 13.2%, n=15) or low/borderline risk (median ASCVD risk score of 3.6%, n=14), as well as a group of statins treated PWH with intermediate/high CVD risk (median ASCVD risk score of 12.7%, n=14). We evaluated Treg frequency, phenotype and response to HDL. PWH with Int/High CVD risk had a significantly lower number of memory Treg, but memory Treg were more activated and displayed an inflammatory phenotype, versus those with Low/BL CVD risk. In untreated patients, Treg absolute numbers were negatively correlated with ASCVD score. Although HDL decreased oxidative stress in memory Treg in all subjects, memory Treg from PWH with Int/High CVD risk were significantly less responsive to HDL than those from PWH with Low/BL CVD risk. The level of oxidative stress in memory Treg positively correlated with ASCVD scores. In contrast, plasma HDL from PWH, regardless of CVD risk, retained their anti-oxidative properties, suggesting that the defect in memory Treg response to HDL is intrinsic. Statin treatment partially ameliorated the memory Treg defect. In conclusion, the defective HDL-Treg interactions may contribute to the inflammation-induced increased CVD risk observed in many AART-treated PWH.

Clostridium butyricum Prevents Dysbiosis and the Rise in Blood Pressure in Spontaneously Hypertensive Rats

Hypertension is accompanied by dysbiosis and a decrease in the relative abundance of short-chain fatty acid (SCFA)-producing bacteria. However, there is no report to examine the role of C. butyricum in blood pressure regulation. We hypothesized that a decrease in the relative abundance of SCFA-producing bacteria in the gut was the cause of spontaneously hypertensive rats (SHR)-induced hypertension. C. butyricum and captopril were used to treat adult SHR for six weeks. C. butyricum modulated SHR-induced dysbiosis and significantly reduced systolic blood pressure (SBP) in SHR (p < 0.01). A 16S rRNA analysis determined changes in the relative abundance of the mainly SCFA-producing bacteria Akkermansia muciniphila, Lactobacillus amylovorus, and Agthobacter rectalis, which increased significantly. Total SCFAs, and particularly butyrate concentrations, in the SHR cecum and plasma were reduced (p < 0.05), while C. butyricum prevented this effect. Likewise, we supplemented SHR with butyrate for six weeks. We analyzed the flora composition, cecum SCFA concentration, and inflammatory response. The results showed that butyrate prevented SHR-induced hypertension and inflammation, and the decline of cecum SCFA concentrations (p < 0.05). This research revealed that increasing cecum butyrate concentrations by probiotics, or direct butyrate supplementation, prevented the adverse effects of SHR on intestinal flora, vascular, and blood pressure.

Chemokine receptors on human regulatory T cells during cutaneous leishmaniasis

The aim of this work was to define the population of regulatory T cells (Tregs) which are circulating in the blood of Leishmania infected individuals clinically displaying a lesion (active disease-AD) and sub-clinical (SC) ones. We have individually collected blood samples, processed the PBMC and stained with fluorochrome-conjugated antibodies against CD3, CD4, Foxp3, CD25, CTLA-4, Ki-67, CCR4, CCR5, and CCR7. Cells were analyzed by flow cytometry. Our results suggest that CD25 and CTLA-4 are upregulated in Tregs of AD patients when compared to SC and uninfected (UN) controls. Moreover, Tregs proliferate upon infection based on Ki-67 nuclear antigen staining. Finally, we have observed that these Tregs of SC and AD patients upregulate CCR4, but not CCR5 and CCR7. There is an increase in the number of circulating Tregs in the blood of Leishmania infected individuals. These cells are potentially more suppressive based on the increased upregulation of CD25 and CTLA-4 during clinical infection (AD) when compared to SC infection. Tregs of both SC and AD cohorts are proliferating and express CCR4, which potentially guide them to the skin, but do not upregulate CCR5 and CCR7.

Number of FoxP3+ regulatory T-cells are associated with recurrence in vulvar squamous cell carcinoma

OBJECTIVE

Surgical management is essential in early-stage vulvar squamous cell carcinoma (SCC), but these surgical procedures often cause significant morbidity. Immunotherapy may be a new treatment option in these patients. FoxP3+ Tregs suppress anti-tumor immune responses. High intratumoral FoxP3+ Treg infiltration has been reported to be associated with poor prognosis in most solid tumors. However, there are also conflicting results. We evaluated FoxP3+ lymphocyte infiltration in vulvar SCC and aimed to determine its relationship with prognosis and clinicopathological parameters.

METHODS

Cases diagnosed with vulvar SCC in our department were retrospectively reviewed. The paraffin block that best reflects the morphology was selected, and immunohistochemical studies were performed in accordance with the manufacturer's instructions. FoxP3+ lymphocyte counts were made in tumoral stroma and within tumoral cell islands separately in hot-spot areas.

RESULTS

We found a positive correlation between high FoxP3+ lymphocyte count and good prognostic parameters. There was less recurrence in the group with high FoxP3+ lymphocyte counts in tumoral cell islands. Overall survival was not statistically different between these groups. Less lymphovascular invasion was observed in the group with high lymphocyte count in the tumoral stroma.

CONCLUSION

In vulvar SCC, FoxP3+ Treg infiltration into the tumor stroma and into tumoral cell islands is associated with good prognostic features. In these tumors, stage appeared as the only independent prognostic parameter. Studies to be conducted in larger series may reveal whether Tregs can be targeted in cancer treatment.

FOXP3+ regulatory T cells use heparanase to access IL-2 bound to ECM in inflamed tissues

FOXP3+ regulatory T cells (Treg) depend on exogenous IL-2 for their survival and function, but circulating levels of IL-2 are low, making it unclear how Treg access this critical resource in vivo. Here, we show that Treg use heparanase (HPSE) to access IL-2 sequestered by heparan sulfate (HS) within the extracellular matrix (ECM) of inflamed central nervous system tissue. HPSE expression distinguishes human and murine Treg from conventional T cells and is regulated by the availability of IL-2. HPSE-/- Treg have impaired stability and function in vivo, including the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis. Conversely, endowing Treg with HPSE enhances their ability to access HS-sequestered IL-2 and their tolerogenic function in vivo. Together, these data identify novel roles for HPSE and the ECM in immune tolerance, providing new avenues for improving Treg-based therapy of autoimmunity.

A bibliometric analysis of primary immune thrombocytopenia from 2011 to 2021

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia. This bibliometric analysis was applied to identify the characteristics of global scientific output, the hotspots, and frontiers of ITP over the past 10 years. We retrieved publications from 2011 to 2021 from the Web of Science Core Collection (WoSCC). Bibliometrix package, VOSviewer, and Citespace were used to analyse and visualize the trend, distribution, and hotspots of research on ITP. Altogether, there were 2084 papers, written by 9080 authors from 410 organizations in 70 countries/regions, published in 456 journals with 37 160 co-cited references. In the last decades, the most productive journal was British Journal of Haematology, China was the most productive country. and the most cited journal was Blood. Shandong University was the most productive institution in the field of ITP. NEUNERT C, 2011, BLOOD, CHENG G, 2011, LANCET, and PATEL VL, 2012, BLOOD were the top three most cited documents. "Thrombopoietin receptor agonist", "regulatory T cell" and "sialic acid" were three hotspots of the last decade. And "immature platelet fraction", "Th17", and "fostamatinib" would be research frontiers in the feature. The present study provided a novel insight for future research directions and scientific decision-making.

Pre-eclampsia

Pre-eclampsia is a life-threatening disease of pregnancy unique to humans and a leading cause of maternal and neonatal morbidity and mortality. Women who survive pre-eclampsia have reduced life expectancy, with increased risks of stroke, cardiovascular disease and diabetes, while babies from a pre-eclamptic pregnancy have increased risks of preterm birth, perinatal death and neurodevelopmental disability and cardiovascular and metabolic disease later in life. Pre-eclampsia is a complex multisystem disease, diagnosed by sudden-onset hypertension (>20 weeks of gestation) and at least one other associated complication, including proteinuria, maternal organ dysfunction or uteroplacental dysfunction. Pre-eclampsia is found only when a placenta is or was recently present and is classified as preterm (delivery <37 weeks of gestation), term (delivery ≥37 weeks of gestation) and postpartum pre-eclampsia. The maternal syndrome of pre-eclampsia is driven by a dysfunctional placenta, which releases factors into maternal blood causing systemic inflammation and widespread maternal endothelial dysfunction. Available treatments target maternal hypertension and seizures, but the only 'cure' for pre-eclampsia is delivery of the dysfunctional placenta and baby, often prematurely. Despite decades of research, the aetiology of pre-eclampsia, particularly of term and postpartum pre-eclampsia, remains poorly defined. Significant advances have been made in the prediction and prevention of preterm pre-eclampsia, which is predicted in early pregnancy through combined screening and is prevented with daily low-dose aspirin, starting before 16 weeks of gestation. By contrast, the prediction of term and postpartum pre-eclampsia is limited and there are no preventive treatments. Future research must investigate the pathogenesis of pre-eclampsia, in particular of term and postpartum pre-eclampsia, and evaluate new prognostic tests and treatments in adequately powered clinical trials.

Selective depletion of regulatory T cells enhances the immunogenicity of a recombinant-based vaccine against Sporothrix spp

Introduction

Regulatory T cells (Tregs) have been shown to limit the protective immune response against pathogenic species of the fungus Sporothrix spp, the causal agent of sporotrichosis. However, the specific function of Tregs during vaccination against these fungi is known.

Methods

We evaluated the effect of Tregs depletion on the immunogenicity of an experimental recombinant anti-Sporothrix vaccine, using the DEREG mice. In this model, only Foxp3(+) Tregs express eGFP and diphtheria toxin (DT) receptors, and transient Tregs depletion is achieved by DT administration.

Results

Tregs depletion enhanced the frequency of specific IFNγ+ T cells (Th1 lymphocytes) and cytokine production after either the first or second vaccine dose. However, depletion of Tregs during the second dose caused greater stimulation of specific Th1 lymphocytes than depletion during the first dose. Similarly, the highest production of IgG, IgG1, and IgG2a anti rSsEno antibody was detected after Tregs depletion during boost immunization compared to the other immunized groups. Importantly, vaccine immunogenicity improvement after Tregs depletion also had an impact on the more efficient reduction of fungal load in the skin and liver after the challenge with S. brasiliensis in an experimental infection model. Interestingly, the reduction in fungal load was greatest in the Tregs depleted group during boosting.

Discussion

Our results illustrate that Tregs restrict vaccine-induced immune response and their transient depletion could enhance anti-Sporothrix vaccine immunogenicity. Further studies are required to elucidate whether Tregs depletion may be a way to improve the efficacy of vaccination against Sporothrix spp.

Sodium perturbs mitochondrial respiration and induces dysfunctional Tregs

FOXP3⁺ regulatory T cells (Tregs) are central for peripheral tolerance, and their deregulation is associated with autoimmunity. Dysfunctional autoimmune Tregs display pro-inflammatory features and altered mitochondrial metabolism, but contributing factors remain elusive. High salt (HS) has been identified to alter immune function and to promote autoimmunity. By investigating longitudinal transcriptional changes of human Tregs, we identified that HS induces metabolic reprogramming, recapitulating features of autoimmune Tregs. Mechanistically, extracellular HS raises intracellular Na⁺, perturbing mitochondrial respiration by interfering with the electron transport chain (ETC). Metabolic disturbance by a temporary HS encounter or complex III blockade rapidly induces a pro-inflammatory signature and FOXP3 downregulation, leading to long-term dysfunction in vitro and in vivo. The HS-induced effect could be reversed by inhibition of mitochondrial Na⁺/Ca²⁺ exchanger (NCLX). Our results indicate that salt could contribute to metabolic reprogramming and that short-term HS encounter perturb metabolic fitness and long-term function of human Tregs with important implications for autoimmunity.

Computational design of candidate multi-epitope vaccine against SARS-CoV-2 targeting structural (S and N) and non-structural (NSP3 and NSP12) proteins

The COVID-19 pandemic caused by SARS-CoV-2 virus has created a global damage and has exposed the vulnerable side of scientific research towards novel diseases. The intensity of the pandemic is huge, with mortality rates of more than 6 million people worldwide in a span of 2 years. Considering the gravity of the situation, scientists all across the world are continuously attempting to create successful therapeutic solutions to combat the virus. Various vaccination strategies are being devised to ensure effective immunization against SARS-CoV-2 infection. SARS-CoV-2 spreads very rapidly, and the infection rate is remarkably high than other respiratory tract viruses. The viral entry and recognition of the host cell is facilitated by S protein of the virus. N protein along with NSP3 is majorly responsible for viral genome assembly and NSP12 performs polymerase activity for RNA synthesis. In this study, we have designed a multi-epitope, chimeric vaccine considering the two structural (S and N protein) and two non-structural proteins (NSP3 and NSP12) of SARS-CoV-2 virus. The aim is to induce immune response by generating antibodies against these proteins to target the viral entry and viral replication in the host cell. In this study, computational tools were used, and the reliability of the vaccine was verified using molecular docking, molecular dynamics simulation and immune simulation studies in silico. These studies demonstrate that the vaccine designed shows steady interaction with Toll like receptors with good stability and will be effective in inducing a strong and specific immune response in the body.Communicated by Ramaswamy H. Sarma.

Human FOXP3 and tumour microenvironment

The tumour microenvironment (TME) is a complex system composed of cancer cells, stromal cells and immune cells. Regulatory T cells (Tregs) in the TME impede immune surveillance of tumours and suppress antitumor immune responses. Transcription factor forkhead box protein 3 (FOXP3) is the main marker of Tregs, which dominates the function of Tregs. FOXP3 was originally thought to be a Tregs-specific expression molecule, and recent studies have found that FOXP3 is expressed in a variety of tumours with inconsistent functional roles. This review summarizes the recent progress of infiltrating Treg-FOXP3 and tumour-FOXP3 in TME, discusses the communication mechanism between FOXP3⁺ cells and effector T cells in TME, the relationship between FOXP3 and clinical prognosis, and the potential of FOXP3-targeted therapy.

EVs vs. EVs: MSCs and Tregs as a source of invisible possibilities

Extracellular vesicles (EVs) are produced by various cells and exist in most biological fluids. They play an important role in cell-cell signaling, immune response, and tumor metastasis, and also have theranostic potential. They deliver many functional biomolecules, including DNA, microRNAs (miRNA), messenger RNA (mRNA), long non-coding RNA (lncRNA), lipids, and proteins, thus affecting different physiological processes in target cells. Decreased immunogenicity compared to liposomes or viral vectors and the ability to cross through physiological barriers such as the blood-brain barrier make them an attractive and innovative option as diagnostic biomarkers and therapeutic carriers. Here, we highlighted two types of cells that can produce functional EVs, namely, mesenchymal stem/stromal cells (MSCs) and regulatory T cells (Tregs), discussing MSC/Treg-derived EV-based therapies for some specific diseases including acute respiratory distress syndrome (ARDS), autoimmune diseases, and cancer.

Tumour microenvironment and heterotypic interactions in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is a disease with a survival rate of 9%; this is due to its chemoresistance and the large tumour stroma that occupies most of the tumour mass. It is composed of a large number of cells of the immune system, such as Treg cells, tumour-associated macrophages (TAMs), myeloid suppressor cells (MDCs) and tumour-associated neutrophiles (TANs) that generate an immunosuppressive environment by the release of inflammatory cytokines. Moreover, cancer-associated fibroblast (CAFs) provide a protective coverage that would difficult the access of chemotherapy to the tumour. According to this, new therapies that could remodel this heterogeneous tumour microenvironment, such as adoptive T cell therapies (ACT), immune checkpoint inhibitors (ICI), and CD40 agonists, should be developed for targeting PDA. This review organizes the different cell populations found in the tumour stroma involved in tumour progression in addition to the different therapies that are being studied to counteract the tumour.

CD4 T-Cell Subsets and the Pathophysiology of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an umbrella term for the chronic immune-mediated idiopathic inflammation of the gastrointestinal tract, manifesting as Crohn's disease (CD) or ulcerative colitis (UC). IBD is characterized by exacerbated innate and adaptive immunity in the gut in association with microbiota dysbiosis and the disruption of the intestinal barrier, resulting in increased bacterial exposure. In response to signals from microorganisms and damaged tissue, innate immune cells produce inflammatory cytokines and factors that stimulate T and B cells of the adaptive immune system, and a prominent characteristic of IBD patients is the accumulation of inflammatory T-cells and their proinflammatory-associated cytokines in intestinal tissue. Upon antigen recognition and activation, CD4 T-cells differentiate towards a range of distinct phenotypes: T helper(h)1, Th2, Th9, Th17, Th22, T follicular helper (Tfh), and several types of T-regulatory cells (Treg). T-cells are generated according to and adapt to microenvironmental conditions and participate in a complex network of interactions among other immune cells that modulate the further progression of IBD. This review examines the role of the CD4 T-cells most relevant to IBD, highlighting how these cells adapt to the environment and interact with other cell populations to promote or inhibit the development of IBD.

Mechanisms driving the immunoregulatory function of cancer cells

Tumours display an astonishing variation in the spatial distribution, composition and activation state of immune cells, which impacts their progression and response to immunotherapy. Shedding light on the mechanisms that govern the diversity and function of immune cells in the tumour microenvironment will pave the way for the development of more tailored immunomodulatory strategies for the benefit of patients with cancer. Cancer cells, by virtue of their paracrine and juxtacrine communication mechanisms, are key contributors to intertumour heterogeneity in immune contextures. In this Review, we discuss how cancer cell-intrinsic features, including (epi)genetic aberrations, signalling pathway deregulation and altered metabolism, play a key role in orchestrating the composition and functional state of the immune landscape, and influence the therapeutic benefit of immunomodulatory strategies. Moreover, we highlight how targeting cancer cell-intrinsic parameters or their downstream immunoregulatory pathways is a viable strategy to manipulate the tumour immune milieu in favour of antitumour immunity.

Stress-Related Immune Response and Selenium Status in Autoimmune Thyroid Disease Patients

Autoimmune thyroid disease (AITD), including Graves' disease (GD) or Hashimoto's thyroiditis (HT), occurs due to genetic susceptibility and environmental factors, among which the role of stressful events remains controversial. This study investigated the relationship between the number and impact of stressful life events in AITD patients with selenium status, and the Th1/Th2/Th17 immune response. The study population included three groups: HT (n = 47), GD (n = 13), and a control group (n = 49). Thyroid function parameters, autoantibody levels, and the plasma levels of cytokines, selenium, selenoprotein P (SeP), and glutathione peroxidase 3 (GPx) activity were measured. Participants filled out the Life Experiences Survey. No significant differences in the number of stressful life events were found among the patients with HT, GD, and the controls. A higher (median (interquartile range)) negative stress level (8 (4-12)) than a positive stress level (3 (1-9)) was found in the HT group. The HT group showed a correlation between SeP and the positive stress level: r_s = -0.296, p = 0.048, and the GD group between GPx and the negative stress level (r_s = -0.702, p = 0.011). Significant positive correlations between thyroid peroxidase antibody level and the total number of major life events (p = 0.023), the number of major life events in the last 7-12 months, and the number of major life events with no impact and a negative stress level were found. We suggest that the measurements of Th2-related cytokines and selenoproteins could be used as biomarkers for the development of AITD in cases where stress is considered a component cause of the pathogenic mechanism of the disease.

Identification and classification of distinct surface markers of T regulatory cells

Background

Regulatory T (Treg) cells have emerged as key players in the maintenance of immune homeostasis. Although significant progress has been made in recent years to define the Treg surface markers involved with or identifying their suppressive function, there remains much to be elucidated, and many questions persist. This study determined the expression of surface markers on human peripheral Treg cells and conventional T (Tconv) cells in a steady state and after activation to gain insight into their mechanism of action and more precisely characterize this regulatory population in humans.

Methods

To screen Treg and Tconv cells, peripheral blood mononuclear cells (PBMCs) were isolated from volunteers, stained with a commercially available lyophilized antibody array comprising 371 surface antigens, and analyzed by flow cytometry. To compare Treg cells with activated Tconv cells, PBMCs were stimulated with PMA and further stained similar to freshly isolated cells.

Results

Treg and Tconv cells were positive for 135 and 168 of the 371 antigens, respectively. Based on the frequency distribution, all of the most highly expressed markers identified were shared by both Treg and Tconv cells and participate in T cell activation, act as costimulatory and signaling molecules, or exhibit adhesion and migratory functions. Additionally, we identified several differences in marker expression between Treg and Tconv cells, with most found in the expression of co-stimulatory (ICOS, GITR, 4-1BB) and co-inhibitory (TIGIT, CTLA-4) molecules, as well as chemokine receptors (CXCR4, CXCR5, CCR4, CCR5, CCR7, CCR8, and CXCR7). Furthermore, post-activation expression of surface molecules identified molecules capable of discriminating Treg cells from activated Tconv cells (GITR, 4-1BB, TIGIT, CD120b, and CD39); however, almost all of these markers were also expressed in a small fraction of activated Tconv cells.

Conclusions

These results offer insight into the biology of Tregs and contribute to their accurate identification and characterization in variety of immunological diseases as well as physiological processes.

Protein Ubiquitination Assay

Ubiquitin, a 76-amino acid protein which could covalently bind to a target protein, is catalyzed by an enzymatic cascade comprising of ATP-dependent ubiquitin-activating enzyme E1, ubiquitin-conjugating enzyme E2, and ubiquitin-protein ligase E3. Histidine (His) pull-down and immunoprecipitation (IP) assays are frequently adopted to detect FOXP3 ubiquitination, which is one of the most important posttranslational modifications and may induce signal transduction or 26S proteasome-dependent degradation of FOXP3 in various immune milieus.

Non-invasive diagnosis of endometriosis: Immunologic and genetic markers

Endometriosis, a benign gynecologic and chronic inflammatory disease, is defined by the presence of endometrial tissue outside the uterus characterized mainly by pelvic pain and infertility. Because endometriosis affects approximately 10% of females, it represents a significant socioeconomic burden worldwide having tremendous impact on daily quality of life. Accurate and prompt diagnosis is crucial for the management of this debilitating disorder. Unfortunately, diagnosis is typically delayed to lack of specific symptoms and readily accessible biomarkers. Although histopathologic examination remains the current gold standard, this approach is highly invasive and not applicable for early screening. Recent work has focused on the identification of reliable biomarkers including immunologic, ie, immune cells, antibodies and cytokines, as well as genetic and biochemical markers, ie, microRNAs, lncRNAs, circulating and mitochondrial nucleic acids, along with some hormones, glycoproteins and signaling molecules. Confirmatory research studies are, however, needed to more fully establish these markers in the diagnosis, progression and staging of these endometrial lesions.

Regulatory T Cells Overexpressing Peli1 Show Better Efficacy in Repairing Ovarian Endocrine Function in Autoimmune Premature Ovarian Insufficiency

Regulatory T (Treg) cell dysfunction is involved in the pathogenesis of autoimmune premature ovarian insufficiency (POI). Adoptive transfer of Treg cells has been shown to be effective in the treatment of autoimmune POI in mice. However, the therapeutic effect of Treg cell therapy is limited because the phenotype and function of Treg cells is not properly maintained when they are reinfused in an inflammatory environment. Therefore, enhancing the function of Treg cells using genetic engineering is of great significance for improving the efficacy of Treg cells in the treatment of immune diseases. In this study, we investigated the role of the E3 ubiquitinated ligase Pellino 1 (Peli1) in the proliferation and immunosuppressive function of Treg cells and the therapeutic effect of Treg cells overexpressing Peli1 on autoimmune POI. The results showed that the overexpression of Peli1 promoted cell proliferation and enhanced the immunosuppressive function of Treg cells in vitro. After the adoptive transfer of Treg cells overexpressing Peli1 in autoimmune POI mice, the apoptosis rate of ovarian granulosa cells declined. The levels of the inflammatory inhibitors interleukin 10 and transforming growth factor-β as well as the ovarian hormone estradiol were elevated. The number of primordial, primary, secondary, and mature follicles was restored to a certain extent compared with those in control subjects. These results revealed that the adoptive transfer of Treg cells overexpressing Peli1 promoted its efficacy against zona pellucida protein 3 peptide-induced POI, which provides new insights into the treatment of autoimmune POI.

Extracorporeal photopheresis as an immunomodulatory treatment modality for chronic GvHD and the importance of emerging biomarkers

Haematopoietic stem cell transplantation (HSCT) is the treatment of choice for malignant haematological diseases. Despite continuous improvements in pre- and post-transplantation procedures, the applicability of allo-HSCT is limited by life-threatening complications such as graft-versus-host disease (GvHD), engraftment failure, and opportunistic infections. Extracorporeal photopheresis (ECP) is used to treat steroid resistant GvHD with significant success. However, the molecular mechanisms driving its immunomodulatory action, whilst preserving immune function, require further understanding. As ECP is safe to administer with few significant adverse effects, it has the potential for earlier use in the post-HSCT treatment of GvHD. Thus, further understanding the immunomodulatory mechanisms of ECP action may justify more timely use in clinical practice, as well as identify biomarkers for using ECP as first line or pre-emptive GvHD therapy. This review aims to discuss technical aspects and response to ECP, review ECP as an immunomodulatory treatment modality for chronic GvHD including the effect on regulatory T cells and circulating vs. tissue-resident immune cells and consider the importance of emerging biomarkers for ECP response.

Genetic differences between smokers and never-smokers with lung cancer

Smoking is a major risk factor for lung cancer, therefore lung cancer epidemiological trends reflect the past trends of cigarette smoking to a great extent. The geographic patterns in mortality closely follow those in incidence. Although lung cancer is strongly associated with cigarette smoking, only about 15% of smokers get lung cancer, and also some never-smokers develop this malignancy. Although less frequent, lung cancer in never smokers is the seventh leading cause of cancer deaths in both sexes worldwide. Lung cancer in smokers and never-smokers differs in many aspects: in histological types, environmental factors representing a risk, and in genes associated with this disease. In this review, we will focus on the genetic differences between lung cancer in smokers versus never-smokers: gene expression, germ-line polymorphisms, gene mutations, as well as ethnic and gender differences. Finally, treatment options for smokers and never-smokers will be briefly reviewed.

Potential predictors of immunotherapy in small cell lung cancer

Lung cancer is one of the leading causes of cancer-related deaths worldwide, with small cell lung cancer (SCLC) having the worst prognosis. SCLC is diagnosed late in the disease's progression, limiting treatment options. The most common treatment for SCLC is chemotherapy. As the disease progresses, immunotherapy, most commonly checkpoint inhibitor medication, becomes more important. Efforts should be made in the development of immunotherapy to map specific biomarkers, which play a role in properly assigning a type of immunotherapy to the right cohort of patients, where the benefits outweigh any risks or adverse effects. The objective of this review was to provide a thorough assessment of current knowledge about the nature of the tumor process and treatment options for small cell lung cancer, with a focus on predictive biomarkers. According to the information obtained, the greatest potential, which has already been directly demonstrated in some studies, has characteristics such as tumor microenvironment composition, tumor mutation burden, and molecular subtyping of SCLC. Several other aspects appear to be promising, but more research, particularly prospective studies on a larger number of probands, is required. However, it is clear that this field of study will continue to expand, as developing a reliable method to predict immunotherapy response is a very appealing goal of current medicine and research in the field of targeted cancer therapy.

Cellular and molecular insights into incomplete immune recovery in HIV/AIDS patients

Highly active antiretroviral therapy (ART) can effectively inhibit virus replication and restore immune function in most people living with human immunodeficiency virus (HIV). However, an important proportion of patients fail to achieve a satisfactory increase in CD4⁺ T cell counts. This state is called incomplete immune reconstitution or immunological nonresponse (INR). Patients with INR have an increased risk of clinical progression and higher rates of mortality. Despite widespread attention to INR, the precise mechanisms remain unclear. In this review, we will discuss the alterations in the quantity and quality of CD4⁺ T as well as multiple immunocytes, changes in soluble molecules and cytokines, and their relationship with INR, aimed to provide cellular and molecular insights into incomplete immune reconstitution.

Research progress of therapeutic effects and drug resistance of immunotherapy based on PD-1/PD-L1 blockade

The binding of programmed death-1 (PD-1) on the surface of T cells and PD-1 ligand 1 (PD-L1) on tumor cells can prevent the immune-killing effect of T cells on tumor cells and promote the immune escape of tumor cells. Therefore, immune checkpoint blockade targeting PD-1/PD-L1 is a reliable tumor therapy with remarkable efficacy. However, the main challenges of this therapy are low response rate and acquired resistance, so that the outcomes of this therapy are usually unsatisfactory. This review begins with the description of biological structure of the PD-1/PD-L1 immune checkpoint and its role in a variety of cells. Subsequently, the therapeutic effects of immune checkpoint blockers (PD-1 / PD-L1 inhibitors) in various tumors were introduced and analyzed, and the reasons affecting the function of PD-1/PD-L1 were systematically analyzed. Then, we focused on analyzing, sorting out and introducing the possible underlying mechanisms of primary and acquired resistance to PD-1/PD-L1 blockade including abnormal expression of PD-1/PD-L1 and some factors, immune-related pathways, tumor immune microenvironment, and T cell dysfunction and others. Finally, promising therapeutic strategies to sensitize the resistant patients with PD-1/PD-L1 blockade treatment were described. This review is aimed at providing guidance for the treatment of various tumors, and highlighting the drug resistance mechanisms to offer directions for future tumor treatment and improvement of patient prognosis.

Regulatory T-Cell Phenotyping Using CyTOF

Regulatory T cells are an important component of the immune system that plays a key role in maintaining homeostasis. Identification of distinct regulatory T cell subsets is essential to understand their function. Mass cytometry or CyTOF is a technology that enables the simultaneous measurement of up to 50 markers in single cells by using antibodies tagged with heavy metals, which are then detected with time-of-flight mass spectrometry. This chapter describes a mass cytometry approach for phenotypic characterization of regulatory T cells and determination of their master transcription factor Foxp3.

Pediatric neuropsychiatric disorders with motor and nonmotor phenomena

The concept of pediatric autoimmune neuropsychiatric disorders associated with group A beta-hemolytic streptococcus (PANDAS) has become seminal since first introduced more than two decades ago. At the time of this writing, most neurologists, pediatricians, psychiatrists, and general pediatricians will probably have heard of this association or treated an affected child with PANDAS. The concept of an acute-onset, and typically self-limited, postinfectious autoimmune neuropsychiatric disorder resembling PANDAS manifesting vocal and motor tics and obsessive-compulsive disorder has broadened to other putative microbes and related endogenous and exogenous disease triggers. These disorders with common features of hypometabolism in the medial temporal lobe and hippocampus in brain 18fluorodeoxyglucose positron emission tomography fused to magnetic resonance imaging (FDG PET-MRI), form a spectrum: with the neuropsychiatric disorder Tourette syndrome and PANDAS with its well-defined etiopathogenesis at one end, and pediatric abrupt-onset neuropsychiatric syndrome (PANS), alone or associated with specific bacterial and viral pathogens, at the other end. The designation of PANS in the absence of a specific trigger, as an exclusionary diagnosis, reflects the current problem in nosology.

A scoping review of regulatory T cell dynamics in convalescent COVID-19 patients - indications for their potential involvement in the development of Long COVID?

Background

Recovery from coronavirus disease 2019 (COVID-19) can be impaired by the persistence of symptoms or new-onset health complications, commonly referred to as Long COVID. In a subset of patients, Long COVID is associated with immune system perturbations of unknown etiology, which could be related to compromised immunoregulatory mechanisms.

Objective

The objective of this scoping review was to summarize the existing literature regarding the frequency and functionality of Tregs in convalescent COVID-19 patients and to explore indications for their potential involvement in the development of Long COVID.

Design

A systematic search of studies investigating Tregs during COVID-19 convalescence was conducted on MEDLINE (via Pubmed) and Web of Science.

Results

The literature search yielded 17 relevant studies, of which three included a distinct cohort of patients with Long COVID. The reviewed studies suggest that the Treg population of COVID-19 patients can reconstitute quantitatively and functionally during recovery. However, the comparison between recovered and seronegative controls revealed that an infection-induced dysregulation of the Treg compartment can be sustained for at least several months. The small number of studies investigating Tregs in Long COVID allowed no firm conclusions to be drawn about their involvement in the syndrome's etiology. Yet, even almost one year post-infection Long COVID patients exhibit significantly altered proportions of Tregs within the CD4+ T cell population.

Conclusions

Persistent alterations in cell frequency in Long COVID patients indicate that Treg dysregulation might be linked to immune system-associated sequelae. Future studies should aim to address the association of Treg adaptations with different symptom clusters and blood parameters beyond the sole quantification of cell frequencies while adhering to consensualized phenotyping strategies.