The role of regulatory T cells and genes involved in their differentiation in pathogenesis of selected inflammatory and neoplastic skin diseases. Part I: Treg properties and functions

Immune-related adverse events in non-small cell lung cancer: Occurrence, mechanisms and therapeutic strategies

The emergence of immune checkpoint inhibitors (ICIs) has heralded a transformative era in the therapeutic landscape of non-small cell lung cancer (NSCLC). While ICIs have demonstrated clinical efficacy in a portion of patients with NSCLC, these treatments concurrently precipitate a spectrum of immune-related adverse events (irAEs), encompassing mild to severe manifestations, collectively posing a risk of significant organ damage. Consequently, there exists an imperative to augment our comprehension of the pathophysiological underpinnings of irAEs and to formulate more efficacious preventive and ameliorative strategies. In this comprehensive review, we delineate the clinical presentation of organ-specific irAEs in patients with NSCLC and provide an in-depth analysis of recent advancements in understanding the mechanisms driving ICI-induced toxicity. Furthermore, we discuss potential strategies and targets for ameliorating these irAEs. Ultimately, this review aims to furnish valuable insights to guide further research endeavours in the context of irAEs in NSCLC patients.

Differentiation, regulation and function of regulatory T cells in non-lymphoid tissues and tumors

Regulatory T cells (Tregs) play a substantial role in inhibiting excessive immune response. A large number of studies have focused on the tissue homeostasis maintenance and remodeling characteristics of Tregs in non-lymphoid tissues, such as the skin, colon, lung, brain, muscle, and adipose tissues. Herein, we overview the kinetics of Treg migration to non-lymphoid tissues and adaptation to the specific tissue microenvironment through the development of tissue-specific chemokine receptors, transcription factors, and phenotypes. Additionally, tumor-infiltrating Tregs (Ti-Tregs) play an important role in tumor generation and immunotherapy resistance. The phenotypes of Ti-Tregs are related to the histological location of the tumor and there is a large overlap between the transcripts of Ti-Tregs and those of tissue-specific Tregs. We recapitulate the molecular underpinnings of tissue-specific Tregs, which might shed new light on Treg-based therapeutic targets and biomarkers for inflammatory diseases and cancer.

Mastocytosis and Skin Cancer: The Current State of Knowledge

Mastocytosis is a heterogeneous group of diseases associated with excessive proliferation and accumulation of mast cells in different organs. Recent studies have demonstrated that patients suffering from mastocytosis face an increased risk of melanoma and non-melanoma skin cancer. The cause of this has not yet been clearly identified. In the literature, the potential influence of several factors has been suggested, including genetic background, the role of cytokines produced by mast cells, iatrogenic and hormonal factors. The article summarizes the current state of knowledge regarding the epidemiology, pathogenesis, diagnosis, and management of skin neoplasia in mastocytosis patients.

Assessment of the Potential Role of Selected Single Nucleotide Polymorphisms (SNPs) of Genes Related to the Functioning of Regulatory T Cells in the Pathogenesis of Psoriasis

Recent studies have indicated a key role of the impaired suppressive capacity of regulatory T cells (Tregs) in psoriasis (PsO) pathogenesis. However, the genetic background of Treg dysfunctions remains unknown. The aim of this study was to evaluate the association of PsO development with selected single nucleotide polymorphisms (SNPs) of genes in which protein products play a significant role in the regulation of differentiation and function of Tregs. There were three study groups in our research and each consisted of different unrelated patients and controls: 192 PsO patients and 5605 healthy volunteers in the microarray genotyping group, 150 PsO patients and 173 controls in the ARMS-PCR method group, and 6 PsO patients and 6 healthy volunteers in the expression analysis group. The DNA microarrays analysis (283 SNPs of 57 genes) and ARMS-PCR method (8 SNPs in 7 genes) were used to determine the frequency of occurrence of SNPs in selected genes. The mRNA expression of selected genes was determined in skin samples. There were statistically significant differences in the allele frequencies of four SNPs in three genes (TNF, IL12RB2, and IL12B) between early-onset PsO patients and controls. The lowest p-value was observed for rs3093662 (TNF), and the G allele carriers had a 2.73 times higher risk of developing early-onset PsO. Moreover, the study revealed significant differences in the frequency of SNPs and their influence on PsO development between early- and late-onset PsO. Based on the ARMS-PCR method, the association between some polymorphisms of four genes (IL4, IL10, TGFB1, and STAT3) and the risk of developing PsO was noticed. Psoriatic lesions were characterized with a lower mRNA expression of FOXP3, CTLA4, and IL2, and a higher expression of TNF and IL1A in comparison with unaffected skin. In conclusion, the genetic background associated with properly functioning Tregs seems to play a significant role in PsO pathogenesis and could have diagnostic value.

Complexity and diversity of FOXP3 isoforms: Novel insights into the regulation of the immune response in metastatic breast cancer

FOXP3 is a key transcription factor in the regulation of immune responses, and recent studies have uncovered the complexity and diversity of FOXP3 isoforms in various cancers, including metastatic breast cancers (mBCs). It has dual role in the tumor microenvironment of mBCs. This review aims to provide novel insights into the complexity and diversity of FOXP3 isoforms in the regulation of the immune response in breast cancer. We discuss the molecular mechanisms underlying the function of FOXP3 isoforms, including their interaction with other proteins, regulation of gene expression, and impact on the immune system. We also highlight the importance of understanding the role of FOXP3 isoforms in breast cancer and the potential for using them as therapeutic targets. This review highlights the crucial role of FOXP3 isoforms in the regulation of the immune response in breast cancer and underscores the need for further research to fully comprehend their complex and diverse functions.

Checkpoint Inhibitor Pneumonitis Induced by Anti-PD-1/PD-L1 Therapy in Non-Small-Cell Lung Cancer: Occurrence and Mechanism

Immune checkpointty inhibitors (ICIs), particularly those targeting programmed death 1 (PD-1) and anti-programmed death ligand 1 (PD-L1), enhance the antitumor effect by restoring the function of the inhibited effector T cells and produce durable responses in a large variety of metastatic and late patients with non-small-cell lung cancer. Although often well tolerated, the activation of the immune system results in side effects known as immune-related adverse events (irAEs), which can affect multiple organ systems, including the lungs. The occurrence of severe pulmonary irAEs, especially checkpoint inhibitor pneumonitis (CIP), is rare but has extremely high mortality and often overlaps with the respiratory symptoms and imaging of primary tumors. The development of CIP may be accompanied by radiation pneumonia and infectious pneumonia, leading to the simultaneous occurrence of a mixture of several types of inflammation in the lungs. However, there is a lack of authoritative diagnosis, grading criteria and clarified mechanisms of CIP. In this article, we review the incidence and median time to onset of CIP in patients with non-small-cell lung cancer treated with PD-1/PD-L1 blockade in clinical studies. We also summarize the clinical features, potential mechanisms, management and predictive biomarkers of CIP caused by PD-1/PD-L1 blockade in non-small-cell lung cancer treatment.

Lymphatic filariasis and visceral leishmaniasis coinfection: A review on their epidemiology, therapeutic, and immune responses

Coinfection is less commonly observed in individuals around the world, yet it is more common than the single infection. Around 800 million people worldwide are infected with helminths as a result of various diseases. Lymphatic filariasis (LF) and visceral leishmaniasis (VL) are chronic, deadly, crippling, and debilitating neglected tropical diseases (NTDs) that are endemic in tropical and subtropical regions of the world. Due to poor hygienic conditions, poverty, and genetic predisposition, those living in endemic areas are more likely to develop both leishmaniasis and filariasis. One of the key challenges in the management of LF/VL coinfection is the development of an effective therapeutic strategy that not only treats the first episode of VL but also prevents LF. However, there is a scarcity of knowledge and data on the relationship between LF and VL coinfection. While reviewing it was apparent that only a few studies relevant to LF/VL coinfections have been reported from southeastern Spain, Sudan, and the Indian subcontinents, highlighting the need for greater research in the most affected areas. We also looked at LF and VL as a single disease and also as a coinfection. Some features of the immune response evolved in mammalian hosts against LF and VL alone or against coinfection are also discussed, including epidemiology, therapeutic regimens, and vaccines. In addition to being potentially useful in clinical research, our findings imply the need for improved diagnostic methodology and therapeutics, which could accelerate the deployment of more specific and effective diagnosis for treatments to lessen the impact of VL/LF coinfections in the population.

A Comparison of Automated Perfusion- and Manual Diffusion-Based Human Regulatory T Cell Expansion and Functionality Using a Soluble Activator Complex

Absence or reduced frequency of human regulatory T cells (Tregs) can limit the control of inflammatory responses, autoimmunity, and the success of transplant engraftment. Clinical studies indicate that use of Tregs as immunotherapeutics would require billions of cells per dose. The Quantum® Cell Expansion System (Quantum system) is a hollow-fiber bioreactor that has previously been used to grow billions of functional T cells in a short timeframe, 8–9 d. Here we evaluated expansion of selected Tregs in the Quantum system using a soluble activator to compare the effects of automated perfusion with manual diffusion-based culture in flasks. Treg CD4⁺CD25⁺ cells from three healthy donors, isolated via column-free immunomagnetic negative/positive selection, were grown under static conditions and subsequently seeded into Quantum system bioreactors and into T225 control flasks in an identical culture volume of PRIME-XV XSFM medium with interleukin-2, for a 9-d expansion using a soluble anti-CD3/CD28/CD2 monoclonal antibody activator complex. Treg harvests from three parallel expansions produced a mean of 3.95 × 10⁸ (range 1.92 × 10⁸ to 5.58 × 10⁸) Tregs in flasks (mean viability 71.3%) versus 7.00 × 10⁹ (range 3.57 × 10⁹ to 13.00 × 10⁹) Tregs in the Quantum system (mean viability 91.8%), demonstrating a mean 17.7-fold increase in Treg yield for the Quantum system over that obtained in flasks. The two culture processes gave rise to cells with a memory Treg CD4⁺CD25⁺FoxP3⁺CD45RO⁺ phenotype of 93.7% for flasks versus 97.7% for the Quantum system. Tregs from the Quantum system demonstrated an 8-fold greater interleukin-10 stimulation index than cells from flask culture following restimulation. Quantum system–expanded Tregs proliferated, maintained their antigenic phenotype, and suppressed effector immune cells after cryopreservation. We conclude that an automated perfusion bioreactor can support the scale-up expansion of functional Tregs more efficiently than diffusion-based flask culture.

IL-23/Th17 Axis: A Potential Therapeutic Target of Psoriasis

Psoriasis is an immune-mediated skin disease that leads to the initiation of abnormal production of inflammatory mediators and keratinocytes hyper-proliferation. Th-1 cell expressing cytokines such as IL-1β and TNF-α have been the important hallmarks in the management of psoriasis. However, investigations carried out in the previous few years underline the involvement of another subset of T helper cells, i.e. Th-17 in psoriasis exacerbation, and hence become the point of focus now. The immunopathogenesis of Th-17 is the result of the IL-23/Th-17 axis. It involves the release of IL-17 and IL-22 in response to the activated NF-kβ dependent activation of IL-23. The function of human Th-17 cells as well as the crucial role of IL-23/Th-17 axis in the exacerbation of psoriasis and treatment have been well explored. Therefore, considering IL-23/Th17 axis as a pertinent therapeutic target in immune driven disorders, extensive investigations are now highlighting the utility of biopharmaceuticals and/or biological agents acting on these targets. Here, we review the IL-23/Th-17 axis based therapeutic targets, different types of active moieties based on their source of availability and most useful USFDA approved Mabs targeting the IL-23/Th17 axis in psoriasis for a better understanding of the future possibilities in this area.

Therapeutic Potentials of Low-Dose Tacrolimus for Aberrant Endometrial Features in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a major anovulatory infertility affecting a great proportion of women of childbearing age and is associated with obesity, insulin resistance and chronic inflammation. Poor endometrial receptivity and recurrent implantation failure are major hurdles to the establishment of pregnancy in women with PCOS. The accumulating body of evidence obtained from experimental and clinical studies suggests a link between inherent adaptive and innate immune irregularities and aberrant endometrial features in PCOS. The use of conventional therapeutic interventions such as lifestyle modification, metformin and ovarian stimulation has achieved limited clinical success in restoring ovulation and endometrial receptivity in women with PCOS. Unlike other immunosuppressive drugs prescribed in the clinical management of autoimmune and inflammatory disorders that may have deleterious effects on fertility and fetal development, preclinical studies in mice and in women without PCOS but with repeated implantation failure revealed potential therapeutic benefits for the use of low-dose tacrolimus in treating female infertility. Improved systemic and ovarian immune functions, endometrial progesterone receptor and coreceptor expressions and uterine vascular adaptation to pregnancy were among features of enhanced progesterone-receptor sensitivity in the low-dose tacrolimus-treated mouse model of the disease. In this review, we have compiled available experimental and clinical data in literature on endometrial progesterone resistance and current therapeutic options, as well as mechanisms of actions and reported outcomes relevant to the potential therapeutic benefits for the use of low-dose tacrolimus in treating PCOS-associated female infertility.

Effects of RORγt overexpression on the murine central nervous system

Objective

T helper 17 (Th17) cells are a subset of CD4⁺ T cells that produce interleukin (IL)‐17A. Recent studies showed that an increase in circulating IL‐17A causes cognitive dysfunction, although it is unknown how increased systemic IL‐17A affects brain function. Using transgenic mice overexpressing RORγt, a transcription factor essential for differentiation of Th17 cells (RORγt Tg mice), we examined changes in the brain caused by chronically increased IL‐17A resulting from excessive activation of Th17 cells.

Results

RORγt Tg mice exhibited elevated Rorc and IL‐17A mRNA expression in the colon, as well as a chronic increase in circulating IL‐17A. We found that the immunoreactivity of Iba1 and density of microglia were lower in the dentate gyrus of RORγt Tg mice compared with wild‐type mice. However, GFAP⁺ astrocytes were unchanged in the hippocampi of RORγt Tg mice. Levels of synaptic proteins were not significantly different between RORγt Tg and wild‐type mouse brains. In addition, novel object location test results indicated no difference in preference between these mice.

Conclusion

Our findings indicate that a continuous increase of IL‐17A in response to RORγt overexpression resulted in decreased microglia activity in the dentate gyrus, but had only a subtle effect on murine hippocampal functions.

Using transgenic mice overexpressing RORγt, a transcription factor essential for differentiation of Th17 cells, we examined changes in the brain caused by chronically increased IL‐17A resulting from excessive activation of Th17 cells. RORγt Tg mice exhibited elevated Rorc and IL‐17A mRNA expression in the colon, as well as a chronic increase in circulating IL‐17A. Our findings indicate that a continuous increase of IL‐17A in response to RORγt overexpression resulted in decreased microglia activity in the dentate gyrus but had a subtle effect on murine hippocampal functions.

Correlation of Blood FoxP3+ Regulatory T Cells and Disease Activity of Atopic Dermatitis

Objectives

To investigate CD4+CD25+FoxP3+ T regulatory cells (Tregs) in the peripheral blood of patients with atopic dermatitis (AD) and its correlation with disease severity.

Methods

Blood samples from 79 AD patients before and after four-week conventional treatment were collected. Cell counts of CD4+CD25+FoxP3+Tregs, CD4+CD25+FoxP3-T effector cells (Teffs), and CD4+IL-10+Tregs were analyzed by flow cytometry. Serum levels of IL-4, IL-10, IL-12, IL-13, IFN-γ, and TGF-β were measured by ELISA.

Results

The pretreatment cell count of CD4+CD25+FoxP3+Tregs positively correlated with disease severity in all patients (P < 0.0001). However, when that correlation was rechecked based on the treatment response, a much stronger correlation of that was found in those patients with remission after treatment, while no correlation of that was found in patients without remission. Both the cell count and proportions of peripheral CD4+CD25+FoxP3+Tregs and CD4+CD25+FoxP3-Teffs reduced significantly after treatment in patients with remission, but remained unchanged in patients without remission. The cell count and proportion of CD4+IL-10+Tregs did not change after treatment in both groups. In patients with remission, serum levels of IL-4 and IL-13 significantly reduced (all P < 0.05); IL-12 and IFN-γ levels increased significantly (all P < 0.05); IL-10 and TGF-β levels remained unchanged after treatment. None of those cytokine levels changed in patients without remission.

Conclusions

CD4+CD25+FoxP3+Tregs is associated with AD development and severity in some patients but not in others. AD maybe divided into CD4+CD25+FoxP3+Treg-associated subtype, which CD4+CD25+FoxP3+Treg is parallel to the activity of AD, and nonassociated subtype, which CD4+CD25+FoxP3+Treg is not related. This subgroup difference may contribute partly to the nonidentical markers that have been found in AD and should be studied further.

Analysis of circulating soluble programmed death 1 (PD-1), neuropilin 1 (NRP-1) and human leukocyte antigen-G (HLA-G) in psoriatic patients

Introduction

Circulating soluble programmed death 1 (PD-1), neuropilin 1 (NRP-1) and human leukocyte antigen-G (HLA-G) take part in modulating immune tolerance causing disturbances in the molecular mechanisms responsible for maintenance of balance between effector and regulatory components of the immune system. Since their cell-surface expression levels were found to be changed in lesional and/or non-lesional skin of psoriatic patients, analysis of soluble PD-1, NRP-1 and HLA-G concentrations sheds more light on their role in detecting unbalanced immune tolerance in psoriasis.

Aim

To assess soluble PD-1, NRP-1 and HLA-G concentrations in psoriasis.

Material and methods

The study included 57 psoriatic patients and 29 controls. Duration of psoriasis was in the range 1 to 55 years; the median was 19 years. The plasma concentrations of soluble HLA-G (sHLA-G), soluble NRP-1 (sNRP-1) and soluble PD-1 (sPD-1) were examined using the ELISA method. Severity of the skin lesions was assessed by means of Psoriasis Area Severity Index (PASI), body surface area (BSA) and Physician Global Assessment (PGA).

Results

Psoriasis Area Severity Index in the studied group was in the range 3 to 43; the median was 12. Body surface area was in the range 2–75%; the median was 15%. The median value of PGA was 3. Soluble NRP concentration was significantly higher in the psoriatic patients (median: 1.59 pg/ml; range: 0.67–2.62 pg/ml) than in the control group (median: 1.35 pg/ml; range: 0.05–2.61 pg/ml) (p = 0.010). Soluble PD-1 and sHLA-G concentrations were not significantly different between the studied and control groups (p = 0.094 and p = 0.482, respectively).

Conclusions

Increased concentrations of sNRP-1 and unchanged values of sHLA-G and sPD-1 concentrations may be indicative of impaired immune tolerance mechanisms in psoriasis.

Differential effects of anaphylatoxin C5a on antigen presenting cells, roles for C5aR1 and C5aR2

The anaphylatoxin C5a is well-known for its role as chemoattractant and contributes to immune cell recruitment into inflamed tissue and local inflammation. C5a has recently been implicated in modulation of antigen presenting cell function, such as macrophages and dendritic cells, which are pivotal for T cell activation and final T cell effector function. The published data on the effect of C5a on APC function and subsequent adaptive immune responses are in part conflicting, as both pro and anti-inflammatory effects have been described. In this review the opposing effects of C5a on APC function in mice and human are summarized and discussed in relation to origin of the involved APC subset, being either of the monocyte-derived lineage or dendritic cell lineage. In addition, the current knowledge on the expression of C5aR1 and C5aR2 on the different APC subsets is summarized. Based on the combined data, we propose that the differential effects of C5a on APC function may be attributed to absence or presence of co-expression of C5aR2 and C5aR1 on the specific APC.

Inhibitory Receptors and Pathways of Lymphocytes: The Role of PD-1 in Treg Development and Their Involvement in Autoimmunity Onset and Cancer Progression

Regulatory T (Treg) cells represent a subpopulation of suppressor CD4⁺ T cells critically involved in the establishment of peripheral tolerance through the inhibition of effector T (Teff) cells and the suppression of the immune-mediated tissue destruction toward self-antigens. Treg generation, their suppressive properties and also Treg-Teff cell interactions could be modulated at least in part by programmed cell death-1 (PD-1) expression on their surface and through binding between PD-1 and programmed cell death ligand-1 (PD-L1). Defects involving PD-1 and Tregs can lead to the development of pathological conditions, including autoimmune disorders or promote cancer progression by favoring tumor evasion from the host immune response. At the same time, PD-1 and Tregs could represent attractive targets for treatment, as demonstrated by the therapeutic blockade of PD-L1 applied for the management of different cancer conditions in humans. In the present Review, we focus specifically the role of PD-1/PD-L1 on Treg development and activity.

Effects of Gui Zhi Ma Huang Ge Ban Tang on the TLR7 Pathway in Influenza Virus Infected Mouse Lungs in a Cold Environment

OBJECTIVE

We wished to investigate the effects of the traditional Chinese medicine Gui Zhi Ma Huang Ge Ban Tang on controlling influenza A virus (IAV) infection and improving inflammation in mouse lungs.

METHOD

Mice were maintained in normal and cold environments and infected with IAV by intranasal application, respectively. Real-time quantitative polymerase chain reaction was used to measure mRNA expression of TLR7, myeloid differentiation primary response 88 (MyD88), and nuclear factor-kappa B (NF-κB)p65 in the TLR7 signaling pathway and virus replication in lungs. Western blotting was used to measure expression levels of TLR7, MyD88, and NF-κB p65 proteins. Flow cytometry was used to detect the proportion of T-helper (Th)1/Th2 and Th17/T-regulatory (Treg) cells.

RESULTS

Application of Gui Zhi Ma Huang Ge Ban Tang in influenza-infected mice in a cold environment showed (i) downregulation of TLR7, MyD88, and NF-κBp65; (ii) inhibition of transcriptional activities of promoters coding for TLR7, MyD88, and NF-κBp65; (iii) reduction in the proportion of Th1/Th2 and Th17/Treg cells.

CONCLUSIONS

Gui Zhi Ma Huang Ge Ban Tang had a good therapeutic effect on mice infected with IAV, especially in the cold environment. It could reduce lung inflammation in mice significantly and elicit an anti-influenza effect by downregulating expression of the key factors in TLR7 signaling pathway.