Thymic and Postthymic Regulation of Naïve CD4(+) T-Cell Lineage Fates in Humans and Mice Models

Isoprinosine as a foot-and-mouth disease vaccine adjuvant elicits robust host defense against viral infection through immunomodulation

Background

Commercial foot-and-mouth disease (FMD) vaccines have limitations, such as local side effects, periodic vaccinations, and weak host defenses. To overcome these limitations, we developed a novel FMD vaccine by combining an inactivated FMD viral antigen with the small molecule isoprinosine, which served as an adjuvant (immunomodulator).

Method

We evaluated the innate and adaptive immune responses elicited by the novel FMD vaccine involved both in vitro and in vivo using mice and pigs.

Results

We demonstrated isoprinosine-mediated early, mid-term, and long-term immunity through in vitro and in vivo studies and complete host defense against FMD virus (FMDV) infection through challenge experiments in mice and pigs. We also elucidated that isoprinosine induces innate and adaptive (cellular and humoral) immunity via promoting the expression of immunoregulatory gene such as pattern recognition receptors [PRRs; retinoic acid-inducible gene (RIG)-I and toll like receptor (TLR)9], transcription factors [T-box transcription factor (TBX)21, eomesodermin (EOMES), and nuclear factor kappa B (NF-kB)], cytokines [interleukin (IL)-12p40, IL-23p19, IL-23R, and IL-17A)], and immune cell core receptors [cluster of differentiation (CD)80, CD86, CD28, CD19, CD21, and CD81] in pigs.

Conclusion

These findings present an attractive strategy for constructing novel FMD vaccines and other difficult-to-control livestock virus vaccine formulations based on isoprinosine induced immunomodulatory functions.

Development of Self-Assembled Protein Nanocage Spatially Functionalized with HA Stalk as a Broadly Cross-Reactive Influenza Vaccine Platform

There remains a need for the development of a universal influenza vaccine, as current seasonal influenza vaccines exhibit limited protection against mismatched, mutated, or pandemic influenza viruses. A desirable approach to developing an effective universal influenza vaccine is the incorporation of highly conserved antigens in a multivalent scaffold that enhances their immunogenicity. Here, we develop a broadly cross-reactive influenza vaccine by functionalizing self-assembled protein nanocages (SAPNs) with multiple copies of the hemagglutinin stalk on the outer surface and matrix protein 2 ectodomain on the inner surface. SAPNs were generated by engineering short coiled coils, and the design was simulated by MD GROMACS. Due to the short sequences, off-target immune responses against empty SAPN scaffolds were not seen in immunized mice. Vaccination with the multivalent SAPNs induces high levels of broadly cross-reactive antibodies of only external antigens, demonstrating tight spatial control over the designed antigen placement. This work demonstrates the use of SAPNs as a potential influenza vaccine.

The roles of T cells in psoriasis

Psoriasis is a recurring inflammatory skin condition characterized by scaly, red patches on the skin. It affects approximately 3% of the US population and is associated with histological changes such as epidermal hyperplasia, increased blood vessel proliferation, and infiltration of leukocytes into the skin's dermis. T cells, which are classified into various subtypes, have been found to play significant roles in immune-mediated diseases, particularly psoriasis. This paper provides a review of the different T lymphocyte subtypes and their functions in psoriasis, as well as an overview of targeted therapies for treating psoriasis.

ITK signaling regulates a switch between T helper 17 and T regulatory cell lineages via a calcium-mediated pathway

The balance of pro-inflammatory T helper type 17 (Th17) and anti-inflammatory T regulatory (Treg) cells is crucial in maintaining immune homeostasis in health and disease conditions. Differentiation of naïve CD4+ T cells into Th17/Treg cells is dependent upon T cell receptor (TCR) activation and cytokine signaling, which includes the kinase ITK. Signals from ITK can regulate the differentiation of Th17 and Treg cell fate choice, however, the mechanism remains to be fully understood. We report here that in the absence of ITK activity, instead of developing into Th17 cells under Th17 conditions, naïve CD4+ T cells switch to cells expressing the Treg marker Foxp3 (Forkhead box P3). These switched Foxp3+ Treg like cells retain suppressive function and resemble differentiated induced Tregs in their transcriptomic profile, although their chromatin accessibility profiles are intermediate between Th17 and induced Tregs cells. Generation of the switched Foxp3+ Treg like cells was associated with reduced expression of molecules involved in mitochondrial oxidative phosphorylation and glycolysis, with reduced activation of the mTOR signaling pathway, and reduced expression of BATF. This ITK dependent switch between Th17 and Treg cells was reversed by increasing intracellular calcium. These findings suggest potential strategies for fine tune the TCR signal strength via ITK to regulate the balance of Th17/Treg cells.

Assessment of the Relationship Between Inflammation and Glomerular Filtration Rate

Background

Chronic kidney disease (CKD) is a global health problem. As it progresses to end stages, renal replacement therapy is required but ultimately, the best treatment is transplantation. Decreased renal function has been associated with an inflammatory state associated to primary CKD and in kidney transplant recipients (KTRs).

Objective

To establish how the serum concentrations of some cytokines, such as interleukin (IL)-2, IL-8, IL-22, IL-17α, interferon-gamma, IL-4, and transforming growth factor-β, correlate with various CKD stages.

Methods

One hundred and forty-one KTRs between the ages of 18 and 75 years were included in the study. We also included 112 live kidney donors, 37 CKD PG_CKD+3, and 76 GP_healthy. Participants were grouped according to their glomerular filtration rate (GFR) and their circulating cytokine levels, previously quantified by ELISA.

Results

By linear regression analysis, we established the relation of each cytokine with the GFR. Transforming growth factor-β correlated positively with the GFR in the study population, except in healthy individuals. A negative correlation of IL-8 and IL-17α and GFR was found in all cases.

Conclusions

Whether these cytokines (IL-8 and IL-17α) could be used as inflammatory biomarkers indicating CKD progression, regardless of the type of population, remains to be prospectively determined.

Positive Effects of Biologics on Osteoporosis in Rheumatoid Arthritis

Osteoporosis is a systemic skeletal disorder that causes vulnerability of bones to fracture owing to reduction in bone density and deterioration of the bone tissue microstructure. The prevalence of osteoporosis is higher in patients with autoimmune inflammatory rheumatic diseases, including rheumatoid arthritis (RA), than in those of the general population. In this autoimmune inflammatory rheumatic disease, in addition to known risk factors for osteoporosis, various factors such as chronic inflammation, autoantibodies, metabolic disorders, drugs, and decreased physical activity contribute to additional risk. In RA, disease-related inflammation plays an important role in local or systemic bone loss, and active treatment for inflammation can help prevent osteoporosis. In addition to conventional synthetic disease-modifying anti-rheumatic drugs that have been traditionally used for treatment of RA, biologic DMARDs and targeted synthetic DMARDs have been widely used. These agents can be employed more selectively and precisely based on disease pathogenesis. It has been reported that these drugs can inhibit bone loss by not only reducing inflammation in RA, but also by inhibiting bone resorption and promoting bone formation. In this review, the pathogenesis and research results of the increase in osteoporosis in RA are reviewed, and the effects of biological agents on osteoporosis are discussed.

Small and mighty - microRNAs pulling the strings

The current issue of Biomedical Journal gives an insight into the influence miRNAs have in myocardial injury, and in hepatocellular carcinoma. Furthermore the association between dysmobility syndrome and vertebral fractures is assessed, the role of doxycycline in schistosomiasis is elucidated, and the effect of stress on the blood-brain barrier is examined. An article proving the accuracy of Taiwan's largest medical record databank is presented, as well as a potential biomarker for Parkinson's. Risk factors for recurrence of papillary thyroid cancer are identified, the outcome of reirradiation in oral squamous cell carcinoma is investigated, and the post-surgery outcomes in cases of infantile hypertrophic pyloric stenosis are reviewed. Finally this issue contains two articles about COVID-19, one describes the potential neurological damage left after the infection, and the second article analysis the outcome of uptake in vaccination against SARS-CoV-2.

Thymic stromal lymphopoietin-stimulated CD4+ T cells induce senescence in advanced breast cancer

Thymic Stromal Lymphopoietin (TSLP) plays a prominent role in inducing type 2 immune response, commonly associated with atopic diseases. TSLP-activated CD4+ T helper 2 cells block early carcinogenesis by inducing terminal differentiation in spontaneous breast and lung cancer models. However, the impact of TSLP induction on advanced cancer with altered cellular phenotypes is unclear. Using an established MMTV-PyMttg breast cancer cell line, we demonstrate that TSLP-stimulated CD4+ T cells possess an antitumor effect in advanced breast cancer. In contrast to early breast cancer suppression, the antitumor immunity mediated by TSLP-stimulated CD4+ T cells in advanced breast cancer is mediated by the induction of a senescent-like phenotype in cancer cells. Inflammatory CD4+ T cells drive breast cancer cells into senescence by releasing interferon-gamma and tumor necrosis factor-alpha, which directly bind to their receptors on cancer cells. Our findings reveal a novel mechanism of TSLP-activated CD4+ T cell immunity against advanced breast cancer, mediated by cellular senescence as a distinct effector mechanism for cancer immunotherapy.

Thymic and Peripheral T-cell Polarization in an Experimental Model of Russell's Viper Venom-induced Acute Kidney Injury

Venom pathology is not restricted to the direct toxic effects of venom. Immunoinflammatory alteration as the etiology of snake venom-induced acute kidney injury (SAKI) is a less trodden path toward the development of alternative therapeutic approach. In the present study, we have associated the crest of renal damage stage to the immunological alteration, as reflected in thymic and peripheral T cell polarization in the murine model of SAKI. Renal injury in mice was confirmed from significant dysuresis and adversely altered biochemical renal markers. Histopathological alterations, as revealed by marked tubular and glomerular damage, reaffirmed kidney injury. SAKI is accompanied by significant inflammatory changes as indicated by neutrophilic leucocytosis, increased neutrophil to lymphocyte ratio and plasma CRP levels. Thymic immunophenotyping revealed significantly increased CD8+ cytotoxic T cell, and CD25+ both single positive population (p = .017-0.010) and CD44-CD25+ double negative population (DN3) (p = .002) accompanied by an insignificantly reduced CD4+ helper T cells (p = .451). Peripheral immunophenotyping revealed similar pattern as indicated by reduced helper T cells (p = .002) associated with significantly elevated cytotoxic T cells (p = .009) and CD25+ subset of both helper (p = .002) and cytotoxic (p = .024) T cells. The IL-10+ subset of both CD25+ and CD25- T cells were also found to be significantly elevated in the SAKI group (p ≤ 0.020) suggesting an immunosuppressive phenotype in SAKI. It can be concluded that T cells responds to venom-induced renal injury particularly through IL-10+ reparative phenotypes which are known for their immunosuppressive and anti-inflammatory activity.

The Natural Janus Kinase Inhibitor Agerarin Downregulates Interleukin-4-Induced PER2 Expression in HaCaT Keratinocytes

The circadian clock system is closely associated with inflammatory responses. Dysregulation of the circadian clock genes in the skin impairs the skin barrier function and affects the pathophysiology of atopic dermatitis. Interleukin 4 (IL-4) is a proinflammatory cytokine derived from T-helper type 2 cells; it plays a critical role in the pathogenesis of atopic dermatitis. Agerarin (6,7-dimethoxy-2,2-dimethyl-2H-chromene) is a natural JAK1/2/3 inhibitor isolated from Ageratum houstonianum that has a protective effect on the epidermal skin barrier. However, it remains unclear whether agerarin affects the circadian clock system. The aim of this study is to investigate the effect of agerarin on IL-4-induced PER2 gene expression in human keratinocytes through reverse transcription (RT)-PCR, quantitative real-time PCR (qPCR), immunoblotting, immunofluorescence microscopic analysis, and real-time bioluminescence analysis. We found that agerarin reduced IL-4-induced PER2 mRNA expression by suppressing the JAK-STAT3 pathway. In addition, real-time bioluminescence analysis in PER2:luc2p promoter-reporter cells revealed that agerarin restored the oscillatory rhythmicity of PER2 promoter activity altered by IL-4. These findings suggest that agerarin may be useful as a cosmeceutical agent against inflammatory skin conditions associated with disrupted circadian rhythms, such as atopic dermatitis.

Vitamin C and its therapeutic potential in the management of COVID19

COVID19 has emerged as one of the worst pandemics in the history of mankind. Several vaccines have been approved by different government agencies worldwide, but data on their efficacy and safety are limited, and distribution remains a massive challenge. As per WHO, personal immunity is vital for protection against COVID19. Earlier, Vitamin C-mediated pathways have been shown to play critical role in boosting immunity attributed to its antioxidant properties. Recently, the involvement of such pathways in protection against COVID19 has been suggested. The controlled doses of Vitamin C administered through intravenous (IV) injections are being studied for determining its role in the prognosis of COVID19. In this article, we have discussed the potential role of Vitamin C in the management in COVID19 patients and presented recent clinical trials data. Additionally, we have elaborated the possibility of administering Vitamin C through inhalers in order to achieve local high concentration and the challenges of such approach.

Innate Immunity: A Balance between Disease and Adaption to Stress

Since first being documented in ancient times, the relation of inflammation with injury and disease has evolved in complexity and causality. Early observations supported a cause (injury) and effect (inflammation) relationship, but the number of pathologies linked to chronic inflammation suggests that inflammation itself acts as a potent promoter of injury and disease. Additionally, results from studies over the last 25 years point to chronic inflammation and innate immune signaling as a critical link between stress (exogenous and endogenous) and adaptation. This brief review looks to highlight the role of the innate immune response in disease pathology, and recent findings indicating the innate immune response to chronic stresses as an influence in driving adaptation.

Systemic Interleukins' Profile in Early and Advanced Colorectal Cancer

Tumor microenvironment (TME) is characterized by mutual interactions of the tumor, stromal and immune cells. Early and advanced colorectal tumors differ in structure and present altered serum cytokine levels. Mutual crosstalk among TME infiltrating cells may shift the balance into immune suppressive or pro-inflammatory, antitumor response this way influencing patients' prognosis. Cancer-related inflammation affects all the body and this way, the systemic level of cytokines could reflect TME processes. Despite numerous studies, it is still not known how systemic cytokines levels change during colorectal cancer (CRC) tumor development. Better understanding tumor microenvironment processes could help in planning therapeutic interventions and more accurate patient prognosis. To contribute to the comprehension of these processes within TME, we reviewed cytokines levels from clinical trials in early and advanced colorectal cancer. Presented data were analyzed in the context of experimental studies and studies analyzing tumor infiltration with immune cells. The review summarizes clinical data of cytokines secreted by tumor microenvironment cells: lymphocytes T helper 1 (Th1), lymphocytes T helper 2 (Th2), lymphocytes T helper 17 (Th17), regulatory T cells (Treg cells), regulatory T cells (Breg cells), M1/M2 macrophages, N1/N2 neutrophils, myeloid-derived suppressor cells (MDSC), dendritic cells (DC), innate lymphoid cells (ILC) natural killer (NK) cells and tumor cells.

Proteomics analysis of tissue small extracellular vesicles reveals protein panels for the reoccurrence prediction of colorectal cancer

Many stage II/III colorectal cancer (CRC) patients might relapse after routine treatment and there is a great need of reliable biomarkers for predicting its reoccurrence risk. Small extracellular vesicles (sEVs) could regulate many pathophysiological processes of diseases, which are promising source for biomarker discovery. In this study, we implemented a MS-based workflow that utilizes data-dependent acquisition (DDA) for discovery and parallel reaction monitoring (PRM) for validation of high relapse risk related biomarkers. We compared the protein profiling of sEVs from CRC tissues and paired adjacent tissues in relapsed group (n = 5) and non-relapsed group (n = 5). 417 and 1140 proteins were differentially expressed between the tumor tissues and adjacent tissues in relapsed group and non-relapsed group, respectively. Bioinformatics analysis showed that immunity of the relapsed patients (Z-score - 0.69) was relatively poorer than the non-relapsed patients (Z-score 2.59), while chronic inflammatory response was activated (Z-score 3.0), which might enhance the reoccurrence risk. Four proteins (HLA-DPA1, S100P, NUP205, PCNA) showed significant expressions in the adjacent tissues of the relapsed group by PRM validation. ROC analysis of HLA-DPA1 (AUC = 0.96) achieved the best classification accuracy in separating the relapsed group and the non-relapsed group. Our data demonstrate that tissue-derived sEVs harbor prognostic proteomic signatures of CRC. SIGNIFICANCE: In this research, our proteomics analysis of tissue sEVs revealed that poor immunity as well as chronic inflammatory of the CRC relapsed patient likely lead to poor prognosis and high risk of reoccurrence. The significant expression levels of four proteins (HLA-DPA1, S100P, NUP205, PCNA) in the adjacent tissues of the relapsed group might be used to predict the risk of relapse in postoperative follow-ups.

A Systems Biology Workflow for Drug and Vaccine Repurposing: Identifying Small-Molecule BCG Mimics to Reduce or Prevent COVID-19 Mortality

PURPOSE

Coronavirus disease 2019 (COVID-19) is expected to continue to cause worldwide fatalities until the World population develops 'herd immunity', or until a vaccine is developed and used as a prevention. Meanwhile, there is an urgent need to identify alternative means of antiviral defense. Bacillus Calmette-Guérin (BCG) vaccine that has been recognized for its off-target beneficial effects on the immune system can be exploited to boast immunity and protect from emerging novel viruses.

METHODS

We developed and employed a systems biology workflow capable of identifying small-molecule antiviral drugs and vaccines that can boast immunity and affect a wide variety of viral disease pathways to protect from the fatal consequences of emerging viruses.

RESULTS

Our analysis demonstrates that BCG vaccine affects the production and maturation of naïve T cells resulting in enhanced, long-lasting trained innate immune responses that can provide protection against novel viruses. We have identified small-molecule BCG mimics, including antiviral drugs such as raltegravir and lopinavir as high confidence hits. Strikingly, our top hits emetine and lopinavir were independently validated by recent experimental findings that these compounds inhibit the growth of SARS-CoV-2 in vitro.

CONCLUSIONS

Our results provide systems biology support for using BCG and small-molecule BCG mimics as putative vaccine and drug candidates against emergent viruses including SARS-CoV-2.

Checkpoint inhibitor blockade and epigenetic reprogrammability in CD8+ T-cell activation and exhaustion

CD8⁺ T-cell exhaustion is a dysfunctional state that is regulated through the expression of inhibitory checkpoint receptor genes including the cytotoxic T-lymphocyte–associated antigen 4, programmed death 1, and DNA methylation of effector genes interferon-γ, perforin, and granzyme B. Different strategies have been used to reverse T-cell exhaustion, which is an adverse event of checkpoint inhibitor blockade. Here, we present the mechanisms by which DNA methyltransferase inhibitors and Simian virus 40 large T antigen through viral mimicry can promote the reversion of exhausted CD8⁺ T cells. We examine how these pharmacological strategies can work together to improve the clinical efficacy of immunotherapies.

Murine DX5+NKT Cells Display Their Cytotoxic and Proapoptotic Potentials against Colitis-Inducing CD4+CD62Lhigh T Cells through Fas Ligand

Introduction

It has been previously shown that immunoregulatory DX5⁺NKT cells are able to prevent colitis induced by CD4⁺CD62L^high T lymphocytes in a SCID mouse model. The aim of this study was to further investigate the underlying mechanism in vitro.

Methods

CD4⁺CD62L^high and DX5⁺NKT cells from the spleen of Balb/c mice were isolated first by MACS, followed by FACS sorting and cocultured for up to 96 h. After polyclonal stimulation with anti-CD3, anti-CD28, and IL-2, proliferation of CD4⁺CD62L^high cells was assessed using a CFSE assay and activity of proapoptotic caspase-3 was determined by intracellular staining and flow cytometry. Extrinsic apoptotic pathway was blocked using an unconjugated antibody against FasL, and activation of caspase-3 was measured.

Results

As previously shown in vivo, DX5⁺NKT cells inhibit proliferation of CD4⁺CD62L^high cells in vitro after 96 h coculture compared to a CD4⁺CD62L^high monoculture (proliferation index: 1.39 ± 0.07 vs. 1.76 ± 0.12; P = 0.0079). The antiproliferative effect of DX5⁺NKT cells was likely due to an induction of apoptosis in CD4⁺CD62L^high cells as evidenced by increased activation of the proapoptotic caspase-3 after 48 h (38 ± 3% vs. 28 ± 3%; P = 0.0451). Furthermore, DX5⁺NKT cells after polyclonal stimulation showed an upregulation of FasL on their cell surface (15 ± 2% vs. 2 ± 1%; P = 0.0286). Finally, FasL was blocked on DX5⁺NKT cells, and therefore, the extrinsic apoptotic pathway abrogated the activation of caspase-3 in CD4⁺CD62L^high cells.

Conclusion

Collectively, these data confirmed that DX5⁺NKT cells inhibit proliferation of colitis-inducing CD4⁺CD62L^high cells by induction of apoptosis. Furthermore, DX5⁺NKT cells likely mediate their cytotoxic and proapoptotic potentials via FasL, confirming recent reports about iNKT cells. Further studies will be necessary to evaluate the therapeutical potential of these immunoregulatory cells in patients with colitis.

The Pivotal Role of Thymus in Atherosclerosis Mediated by Immune and Inflammatory Response

Atherosclerosis is one kind of chronic inflammatory disease, in which multiple types of immune cells or factors are involved. Data from experimental and clinical studies on atherosclerosis have confirmed the key roles of immune cells and inflammation in such process. The thymus as a key organ in T lymphocyte ontogenesis has an important role in optimizing immune system function throughout the life, and dysfunction of thymus has been proved to be associated with severity of atherosclerosis. Based on previous research, we begin with the hypothesis that low density lipoprotein or cholesterol reduces the expression of the thymus transcription factor Foxn1 via low density lipoprotein receptors on the membrane surface and low density lipoprotein receptor related proteins on the cell surface, which cause the thymus function decline or degradation. The imbalance of T cell subgroups and the decrease of naive T cells due to thymus dysfunction cause the increase or decrease in the secretion of various inflammatory factors, which in turn aggravates or inhibits atherosclerosis progression and cardiovascular events. Hence, thymus may be the pivotal role in coronary heart disease mediated by atherosclerosis and cardiovascular events and it can imply a novel treatment strategy for the clinical management of patients with atherosclerosis in addition to different commercial drugs. Modulation of immune system by inducing thymus function may be a therapeutic approach for the prevention of atherosclerosis. Purpose of this review is to summarize and discuss the recent advances about the impact of thymus function on atherosclerosis by the data from animal or human studies and the potential mechanisms.