Coreceptor Expression Research Articles

CD4+CD8αlow T cells in rheumatoid arthritis are clonally expanded and dependent on co-stimulation.

CD4+CD8+ T cells are increased in patients with rheumatoid arthritis (RA). They are not only associated with joint erosions in established disease, but are also present in the pre-clinical stages of RA. This study aims to further investigate their expansion in the context of T cell clonality in patients with RA, as well as their responsiveness to T cell targeted treatment. Single-cell-(sc)RNA- and scTCR-sequencing data were used to determine co-receptor expression and T cell receptor sequences to assess clonality of CD4+CD8+ T cells in RA (n=3) patients and healthy controls (n=2). Peripheral CD4+CD8+ T cells and their subpopulations were measured in patients with RA (n=53), PsA (n=52) and healthy donors (n=50) using flow cytometry. In addition, changes in CD4+CD8+ T cell frequency were prospectively followed in RA patients receiving therapy with abatacept for 12 weeks. We observed an increase of CD4+ T cells expressing CD8α in RA patients, both in comparison to PsA patients and to healthy controls. Clonality analysis revealed, that these CD4+CD8αlow T cells are part of large T cell clones, which cluster separately from CD4+CD8- T cell clones in the scRNA-seq gene expression analysis. Treatment with abatacept significantly reduced the frequency of peripheral CD4+CD8αlow T cells, and this was linked to reduction in disease activity. In RA, clonal expansion of CD4+ T cell clones culminates in the emergence of peripheral CD4+CD8αlow T cells, which are associated with disease activity and diminished upon abatacept treatment, and which could contribute to disease pathogenesis.

Start codon variant in LAG3 is associated with decreased LAG-3 expression and increased risk of autoimmune thyroid disease

Autoimmune thyroid disease (AITD) is a common autoimmune disease. In a GWAS meta-analysis of 110,945 cases and 1,084,290 controls, 290 sequence variants at 225 loci are associated with AITD. Of these variants, 115 are previously unreported. Multiomics analysis yields 235 candidate genes outside the MHC-region and the findings highlight the importance of genes involved in T-cell regulation. A rare 5’-UTR variant (rs781745126-T, MAF = 0.13% in Iceland) in LAG3 has the largest effect (OR = 3.42, P = 2.2 × 10−16) and generates a novel start codon for an open reading frame upstream of the canonical protein translation initiation site. rs781745126-T reduces mRNA and surface expression of the inhibitory immune checkpoint LAG-3 co-receptor on activated lymphocyte subsets and halves LAG-3 levels in plasma among heterozygotes. All three homozygous carriers of rs781745126-T have AITD, of whom one also has two other T-cell mediated diseases, that is vitiligo and type 1 diabetes. rs781745126-T associates nominally with vitiligo (OR = 5.1, P = 6.5 × 10−3) but not with type 1 diabetes. Thus, the effect of rs781745126-T is akin to drugs that inhibit LAG-3, which unleash immune responses and can have thyroid dysfunction and vitiligo as adverse events. This illustrates how a multiomics approach can reveal potential drug targets and safety concerns.

Modification in Gene Expression of CCR5 Co-Receptor and Down Regulation of Virion Molecule with Primary Human T- cell in HIV Infection

About 1 2% of population in western European white people are resistant to hiv-1 infection due to modified gene of ccr5 receptor molecule. Modification of ccr5 receptor gene blocks the virion molecule to enter into the host cell. Mutations gene lead to slow progress rate of infection and low expression of cd4 + T cell. The hypothesis of researcher is that the modified allogeneic transplant with modified M303/M303 gene in ccr5 leads to resistant for HIV and AIDS patient. Deletion of gene in ccr5 receptor develops the ability of resistant with HIV-1. Down regulation of ccr5 receptor with macrophages T cell reduce the immune response and lead to slow progressive rate of infection. Different gene-editing methods are involved in ccr5 gene editing such as TALEN, ZFN, and CRISP/Cas. Mutant gene transplant in ccr5 receptor prevent the further exposure of dangerous retrovirus. As comparison of heterogeneous and homogenous .The heterogeneous analogues has more resistance as compare to homogenous genetic order. Chemokine and inflammatory mediator are the less active in heterogeneous. The homozygous mutation in ccr5 gene (ccr5∆32) base pair deletion induces nonfunctional ccr5 receptor and heterogonous mutation has resistant of HIV 1 and slow progressive effect.

Single-cell RNA sequencing reveals an immunomodulatory population of double negative T-cells in the diabetic NOD mouse

Abstract NOD mice are a widely used model of type 1 diabetes, an inflammatory autoimmune condition characterized by autoreactive T-cells that target insulin producing beta cells of the pancreatic islets. While T cell biology in the context of this disease is important it is unclear why autoreactive T-cells develop in this model or what they do within the islets themselves. We have designed a single cell sequencing experiment where enriched T-cells taken from diabetic and non-diabetic NOD mice are sequenced for mRNA expression and TCR sequence concurrently. The resulting sequencing data shows abnormal representation of Double Negative (DN) T-cells in all tissues and conditions (~30%). We have observed that like CD8+ and CD4+ T-cells, this population displays normal maturation phenotypes, but experience reduced exhaustion of effector subsets after infiltration of the pancreatic islets. Looking at clonal subpopulations of T-cells we have discovered a subset of CD8+ T-cells that have high expression of GzmA even after loss of the survival signal marker, IL7r. Through investigation of these aberrant T-cell populations, we have found that the diabetic NOD mouse pancreatic is highly immunosuppresive and expression of T-cell co-receptors may have a significant impact on diabetic onset.

Thymocyte migration and emigration

Hematopoietic precursors (HPCs) entering into the thymus undergo a sequential process leading to the generation of a variety of T cell subsets. This developmental odyssey unfolds in distinct stages within the thymic cortex and medulla, shaping the landscape of T cell receptor (TCR) expression and guiding thymocytes through positive and negative selection. Initially, early thymic progenitors (ETPs) take residence in the thymic cortex, where thymocytes begin to express their TCR and undergo positive selection. Subsequently, thymocytes transition to the thymic medulla, where they undergo negative selection. Both murine and human thymocyte development can be broadly classified into distinct stages based on the expression of CD4 and CD8 coreceptors, resulting in categorizations as double negative (DN), double positive (DP) or single positive (SP) cells. Thymocyte migration to the appropriate thymic microenvironment at the right differentiation stage is pivotal for the development and the proper functioning of T cells, which is critical for adaptive immune responses. The journey of lymphoid progenitor cells into the T cell developmental pathway hinges on an ongoing dialogue between the differentiating cell and the signals emanating from the thymus niche. Herein, we review the contribution of the key factors mentioned above for the localization, migration and emigration of thymocytes.

Enhanced Immunomodulatory Effects of Thymosin-Alpha-1 in Combination with Polyanionic Carbosilane Dendrimers against HCMV Infection.

Resistance and toxicity associated with current treatments for human cytomegalovirus (HCMV) infection highlight the need for alternatives and immunotherapy has emerged as a promising strategy. This study examined the in vitro immunological effects of co-administration of Thymosin-alpha-1 (Tα1) and polyanionic carbosilane dendrimers (PCDs) on peripheral blood mononuclear cells (PBMCs) during HCMV infection. The biocompatibility of PCDs was assessed via MTT and LDH assays. PBMCs were pre-treated with the co-administered compounds and then exposed to HCMV for 48 h. Morphological alterations in PBMCs were observed using optical microscopy and total dendritic cells (tDCs), myeloid dendritic cells (mDCs), and plasmacytoid dendritic cells (pDCs), along with CD4+/CD8+ T cells and regulatory T cells (Treg), and were characterized using multiparametric flow cytometry. The findings revealed that Tα1 + PCDs treatments increased DC activation and maturation. Furthermore, increased co-receptor expression, intracellular IFNγ production in T cells and elevated Treg functionality and reduced senescence were evident with Tα1 + G2-S24P treatment. Conversely, reduced co-receptor expression, intracellular cytokine production in T cells, lower functionality and higher senescence in Treg were observed with Tα1 + G2S16 treatment. In summary, Tα1 + PCDs treatments demonstrate synergistic effects during early HCMV infection, suggesting their use as an alternative therapeutic for preventing virus infection.

A Novel Biallelic LCK Variant Resulting in Profound T-Cell Immune Deficiency and Review of the Literature

Lymphocyte-specific protein tyrosine kinase (LCK) is an SRC-family kinase critical for initiation and propagation of T-cell antigen receptor (TCR) signaling through phosphorylation of TCR-associated CD3 chains and recruited downstream molecules. Until now, only one case of profound T-cell immune deficiency with complete LCK deficiency [1] caused by a biallelic missense mutation (c.1022T>C, p.L341P) and three cases of incomplete LCK deficiency [2] caused by a biallelic splice site mutation (c.188-2A>G) have been described. Additionally, deregulated LCK expression has been associated with genetically undefined immune deficiencies and hematological malignancies. Here, we describe the second case of complete LCK deficiency in a 6-month-old girl born to consanguineous parents presenting with profound T-cell immune deficiency. Whole exome sequencing (WES) revealed a novel pathogenic biallelic missense mutation in LCK (c.1393T>C, p.C465R), which led to the absence of LCK protein expression and phosphorylation, and a consecutive decrease in proximal TCR signaling. Loss of conventional CD4+ and CD8+ αβT-cells and homeostatic T-cell expansion was accompanied by increased γδT-cell and Treg percentages. Surface CD4 and CD8 co-receptor expression was reduced in the patient T-cells, while the heterozygous mother had impaired CD4 and CD8 surface expression to a lesser extent. We conclude that complete LCK deficiency is characterized by profound T-cell immune deficiency, reduced CD4 and CD8 surface expression, and a characteristic TCR signaling disorder. CD4 and CD8 surface expression may be of value for early detection of mono- and/or biallelic LCK deficiency.

Legend or Truth: Mature CD4+CD8+ Double-Positive T Cells in the Periphery in Health and Disease.

The expression of CD4 and CD8 co-receptors defines two distinct T cell populations with specialized functions. While CD4+ T cells support and modulate immune responses through different T-helper (Th) and regulatory subtypes, CD8+ T cells eliminate cells that might threaten the organism, for example, virus-infected or tumor cells. However, a paradoxical population of CD4+CD8+ double-positive (DP) T cells challenging this paradigm has been found in the peripheral blood. This subset has been observed in healthy as well as pathological conditions, suggesting unique and well-defined functions. Furthermore, DP T cells express activation markers and exhibit memory-like features, displaying an effector memory (EM) and central memory (CM) phenotype. A subset expressing high CD4 (CD4bright+) and intermediate CD8 (CD8dim+) levels and a population of CD8bright+CD4dim+ T cells have been identified within DP T cells, suggesting that this small subpopulation may be heterogeneous. This review summarizes the current literature on DP T cells in humans in health and diseases. In addition, we point out that strategies to better characterize this minor T cell subset's role in regulating immune responses are necessary.

The use of alpha 1 thymosin as an immunomodulator of the response against SARS-Cov2

BackgroundSince the beginning of SARS-CoV2 pandemic, the mortality rate among elderly patients (60–90 years) has been around 50%, so age has been a determining factor of a worse COVID-19 prognosis. Associated with age, the thymic function involution and depletion plays an important role, that could be related to a dysregulated and ineffective innate and adaptive immune response against SARS-CoV2. Our study aims to further in vitro effect of human Thymosin-alpha-1 (α1Thy) treatment on the immune system in population groups with different thymic function levels in the scenario of SARS-CoV2 infection.ResultsActivation markers such as CD40, CD80 and TIM-3 were upregulated in α1Thy presence, especially in plasmacytoid dendritic cells (pDCs) and, with increased TNFα production was observed compared to untreated condition. Co-cultures of CD4 + and CD8 + T cells with DCs treated with α1Thy in response to SARS-CoV2 peptides showed a decrease in the cytokine production compared to the condition without α1Thy pre-treated. A decrease in CD40L activation co-receptor expression in CD8 + LTs was also observed, as well as an increase in PD1 in CD4 + TLs expression in both age groups. In fact, there are no age-related differences in the immunomodulatory effect of the hormone, and it seems that effector memory and terminally differentiated memory T lymphocyte subsets were the most actively influenced by the immunomodulatory α1Thy effect. Finally, the polyfunctionality measured in SARS-CoV2 Specific-T cells response was maintained in α1Thy presence in total and memory subpopulations CD4 + and CD8 + T-cells, despite decreased proinflammatory cytokines production.ConclusionThe hormone α1Thy could reduce, through the modulation of DCs, the amount of proinflammatory cytokines produced by T cells. Moreover, α1Thy improve lymphocyte functionality and could become a beneficial therapeutic alternative as an adjuvant in SARS-CoV2 treatment either in the acute phase after infection or reinfection. In addition, the effect on the T immune response means that α1Thy can be incorporated into the vaccination regimen, especially in the most immunologically vulnerable individuals such as the elderly.SubjectsThymosin alpha 1, Dendritic cells, SARS-CoV2-specific T cells response, Immunomodulation

Female Sex Hormones Upregulate the Replication Activity of HIV-1 Sub-Subtype A6 and CRF02_AG but Not HIV-1 Subtype B.

More than 50% of all people living with HIV worldwide are women. Globally, HIV/AIDS is the leading cause of death among women aged 15 to 44. The safe and effective methods of hormonal contraception are an essential component of preventive medical care in order to reduce maternal and infant mortality. However, there is limited knowledge regarding the effect of hormones on the rate of viral replication in HIV infection, especially non-B subtypes. The goal of the present work was to study in vitro how the female hormones β-estradiol and progesterone affect the replication of the HIV-1 subtypes A6, CRF02_AG, and B. The findings show that high doses of hormones enhanced the replication of HIV-1 sub-subtype A6 by an average of 1.75 times and the recombinant variant CRF02_AG by 1.4 times but did not affect the replication of HIV-1 subtype B. No difference was detected in the expression of CCR5 and CXCR4 co-receptors on the cell surface, either in the presence or absence of hormones. However, one of the reasons for the increased viral replication could be the modulated TLRs secretion, as it was found that high doses of estradiol and progesterone upregulated, to varying degrees, the expression of TLR2 and TLR9 genes in the PBMCs of female donors infected with HIV-1 sub-subtype A6.

Massively HIV-1-infected macrophages exhibit a severely hampered ability to differentiate into osteoclasts.

Osteoclasts play a crucial role in bone resorption, and impairment of their differentiation can have significant implications for bone density, especially in individuals with HIV who may be at risk of altered bone health. The present study aimed to investigate the effects of HIV infection on osteoclast differentiation using primary human monocyte-derived macrophages as precursors. The study focused on assessing the impact of HIV infection on cellular adhesion, cathepsin K expression, resorptive activity, cytokine production, expression of co-receptors, and transcriptional regulation of key factors involved in osteoclastogenesis. Primary human monocyte-derived macrophages were utilized as precursors for osteoclast differentiation. These precursors were infected with HIV, and the effects of different inoculum sizes and kinetics of viral replication were analyzed. Subsequently, osteoclastogenesis was evaluated by measuring cellular adhesion, cathepsin K expression, and resorptive activity. Furthermore, cytokine production was assessed by monitoring the production of IL-1β, RANK-L, and osteoclasts. The expression levels of co-receptors CCR5, CD9, and CD81 were measured before and after infection with HIV. The transcriptional levels of key factors for osteoclastogenesis (RANK, NFATc1, and DC-STAMP) were examined following HIV infection. Rapid, massive, and productive HIV infection severely impaired osteoclast differentiation, leading to compromised cellular adhesion, cathepsin K expression, and resorptive activity. HIV infection resulted in an earlier production of IL-1β concurrent with RANK-L, thereby suppressing osteoclast production. Infection with a high inoculum of HIV increased the expression of the co-receptor CCR5, as well as the tetraspanins CD9 and CD81, which correlated with deficient osteoclastogenesis. Massive HIV infection of osteoclast precursors affected the transcriptional levels of key factors involved in osteoclastogenesis, including RANK, NFATc1, and DC-STAMP. The effects of HIV infection on osteoclast precursors were found to be dependent on the size of the inoculum and the kinetics of viral replication. These findings underscore the importance of understanding the underlying mechanisms to develop novel strategies for the prevention and treatment of bone disorders in individuals with HIV.

Breast cancer associated CD169+ macrophages possess broad immunosuppressive functions but enhance antibody secretion by activated B cells.

CD169+ resident macrophages in lymph nodes of breast cancer patients are for unknown reasons associated with a beneficial prognosis. This contrasts CD169+ macrophages present in primary breast tumors (CD169+ TAMs), that correlate with a worse prognosis. We recently showed that these CD169+ TAMs were associated with tertiary lymphoid structures (TLSs) and Tregs in breast cancer. Here, we show that CD169+ TAMs can be monocyte-derived and express a unique mediator profile characterized by type I IFNs, CXCL10, PGE2 and inhibitory co-receptor expression pattern. The CD169+ monocyte-derived macrophages (CD169+ Mo-M) possessed an immunosuppressive function in vitro inhibiting NK, T and B cell proliferation, but enhanced antibody and IL6 secretion in activated B cells. Our findings indicate that CD169+ Mo-M in the primary breast tumor microenvironment are linked to both immunosuppression and TLS functions, with implications for future targeted Mo-M therapy.

Preclinical evaluation of oncolytic potential human rotavirus Wt 1-5 in gastric adenocarcinoma.

Despite advances in biomedical research, gastric cancer remains the leading cause of morbidity and mortality worldwide due to the limited efficacy of conventional therapies. In recent decades, oncolytic viruses have emerged as a biological therapeutic alternative to cancer due to their selectivity, effectiveness, and low toxicity. However, clinical trials have shown that developing a virus with selectivity for multiple tumor receptors and the ability to penetrate and diffuse through the tumor microenvironment to reactivate the immune system remains challenging. This study aimed to examine the oncolytic potential of tumor cell-adapted rotavirus Wt1-5 in gastric adenocarcinoma samples. This study focused on determining the propagation capacity of the RV Wt1-5 through the tumor and the importance of the expression of cell surface co-receptors, including integrin β3, protein disulfide isomerase (PDI), and heat shock proteins (Hsp-90, -70, -60, -40, and Hsc 70), during infection of tumor cells. These proteins were found to be differentially expressed in tumor cells compared to adjacent non-tumor cells. Preincubation of gastric tumor cells with antibodies against these proteins decreased rotavirus infections, validating their importance in the binding and entry of RV Wt1-5 into tumor cells, as previously reported. Upon RV infection, apoptosis was one of the types of death that was observed. This was evidenced by evaluating the expression of CASP-3, -9, PARP, cytochrome C, Bax, Bid, p53, and Bcl-2, as well as observing morphological changes such as chromatin margination, nuclear condensation, and fragmentation. Finally, at 60 h.p.i, histological analysis revealed that oncolysis compromised the entire thickness of the tumor. Therefore, the results suggest that RV Wt1-5 could be a novel therapeutic agent co-adjuvant agent for conventional and targeted therapies in managing GC. Ex vivo infection of the tumor tissue model showed characteristics of an immune response that could be explored in future studies.

CD4 co-receptor regulates sexual dimorphic NK cell responses to T. gondiiinfection.

Abstract Immunity to Toxoplasma gondiiis sexually dimorphic in humans and mice with females having higher morbidity and mortality during immune dysfunction and HIV/AIDS. The mechanisms underlying these sex differences are unclear. Since CD4+ T cells are very low during HIV/AIDS and females are more susceptible to Toxoplasmic encephalitis (TE) when they have AIDS, we investigated how a lack of CD4 co-receptor expression (CD4KO) and CD4+ T cells (MHCIIKO) impacted T. gondiisurvival and innate immune responses in mice. Female CD4KO mice succumbed to T. gondiimuch faster than male CD4KO mice. To dissect why female CD4KO mice died faster we tested their NK cell responses to acute T. gondiiinfection compared to male CD4KO mice. Although in wild type (WT) animals both sexes had similar increases in NK cell numbers and IFNg production, infected CD4KO female mice had 50% fewer IFNg+ NK cells than infected WT female mice. However, infected male CD4KO had the same number of NK cells producing IFNg compared to WT male mice. Since CD4 co-receptor deficient mice still have functional helper T cells that are CD4-we next tested survival and NK cell responses in female and male MHCII deficient (MHCIIKO) animals, which have very few helper CD4+T cells. To our surprise survival, NK cell numbers, and IFNg+ NK cells were not significantly different between WT or MHCIIKO female and male mice. These results suggest only in female mice and not in male mice, CD4 co-receptor expression is required for survival via optimal NK cell responses during acute T. gondiiinfection. Our findings reveal an unappreciated sexual dimorphic role of CD4 co-receptor expression in regulation of NK cell responses to acute T. gondiiinfection. National Institute of General Medical Sciences (P20GM103432)

The Synthetic Opioid Fentanyl Increases HIV Replication and Chemokine Co-Receptor Expression in Lymphocyte Cell Lines.

In the United States, the illicit use of synthetic opioids such as fentanyl has led to a serious public health crisis. Synthetic opioids are known to enhance viral replication and to suppress immunologic responses, but their effects on HIV pathogenesis remain unclear. Thus, we examined the impact of fentanyl on HIV-susceptible and HIV-infected cell types. TZM-bl and HIV-infected lymphocyte cells were incubated with fentanyl at varying concentrations. Expression levels of the CXCR4 and CCR5 chemokine receptors and HIV p24 antigen were quantified with ELISA. HIV proviral DNA was quantified using SYBR RT-PCR. Cell viability was detected with the MTT assay. RNAseq was performed to characterize cellular gene regulation in the presence of fentanyl. Fentanyl enhanced expression of both chemokine receptor levels in a dose-dependent manner in HIV-susceptible and infected cell lines. Similarly, fentanyl induced viral expression in HIV-exposed TZM-bl cells and in HIV-infected lymphocyte cell lines. Multiple genes associated with apoptosis, antiviral/interferon response, chemokine signaling, and NFκB signaling were differentially regulated. Synthetic opioid fentanyl impacts HIV replication and chemokine co-receptor expression. Increased virus levels suggest that opioid use may increase the likelihood of transmission and accelerate disease progression.

Cyclic adenosine monophosphate-elevating agents inhibit amyloid-beta internalization and neurotoxicity: their action in Alzheimer's disease prevention.

Cyclic adenosine monophosphate-elevating agents inhibit amyloid-beta internalization and neurotoxicity: their action in Alzheimer's disease prevention.

An opinion on the debatable function of brain resident immune protein, T-cell receptor beta subunit in the central nervous system.

In recent years scientific research has established that the nervous and immune systems have shared molecular signaling components. Proteins native to immune cells, which are also found in the brain, have neuronal functions in the nervous system where they affect synaptic plasticity, axonal regeneration, neurogenesis, and neurotransmission. Certain native immune molecules like major histocompatibility complex I (MHC-I), paired immunoglobulin receptor B (PirB), toll-like receptor (TLR), cluster of differentiation-3 zeta (CD3ζ), CD4 co-receptor, and T-cell receptor beta (TCR-β) expression in neurons have been extensively documented. In this review, we provide our opinion and discussed the possible roles of T-cell receptor beta subunits in modulating the function of neurons in the central nervous system. Based on the previous findings of Syken and Shatz., 2003; Nishiyori et al., 2004; Rodriguez et., 1993 and Komal et., 2014; we discuss whether restrictive expression of TCR-β subunits in selected brain regions could be involved in the pathology of neurological disorders and whether their aberrant enhancement in expression may be considered as a suitable biomarker for aging or neurodegenerative diseases like Huntington's disease (HD).

Pharmacological potentiation of monocyte-derived dendritic cell cancer immunotherapy.

Dendritic cells have been at the forefront of cancer-immunotherapy research for over 2 decades. They elicited that attention by having an unprecedented capacity to mount T cells responses against tumors. However, the clinical use of DC-based vaccination against established malignancies has resulted in limited clinical benefits. Several factors are responsible for limiting the efficacy of DC-based immunotherapy, such as the harmful influence of the tumor microenvironment on DCs activity. New insights into the inner process of DC-mediated T cell activation have supported the development of new strategies that potentiate DCs-based therapies. Herein, we identify signaling cascades that have recently been targeted by small molecules and biologicals to promote the activation of monocyte-derived DCs and decrease their susceptibility to becoming tolerogenic. While Statins can markedly enhance antigen presentation, protein kinase inhibitors can be used to increase the expression of co-receptors and adhesion molecules. STAT3 and IDO can be modulated to limit the production of regulatory factors that work against differentiation and activation. The targeting of multiple pathways simultaneously has also been found to produce synergism and drastically enhance DCs activity. Some of these strategies have recently yielded positive results in clinical settings against established malignancies such as non-small cell lung cancer. The emergence of these approaches opens the door for a new generation of potent dendritic cell-based therapeutics to fight cancer.

Studying the effect of double-stranded RNA upon activity of mouse splenocytes using flow cytometry

Ribonucleic acids (RNA), in particular, double-stranded RNAs, due to their ability to modulate innate immune responses, are of undoubted interest in view of their usage as vaccine adjuvants. However, despite the fact that dsRNA preparations have been known for a long time, the issues of cellular interactions and orientation of immune response upon their exposure have not yet been properly studied. The aim of this work was to evaluate the in vitro response of mouse splenocytes to dsRNA exposure in cell cultures, and after drug administration in vivo. The studies were carried out in female Balb/c mice. Activation status of various splenocyte populations after treatment with yeast dsRNA and reference substance (PolyI:PolyC) was assessed by means of flow cytometry by expression of CD69 and CD86 activation markers on CD19+B lymphocytes and CD11c+ dendritic cells (DC). During in vitro studies, the splenocytes were incubated in DMEM medium containing 10% fetal calf serum for 22 hours following addition of the yeast dsRNA preparations, or PolyI:PolyC (2.5 μg/mL) preparation. Single-stranded high-polymer RNA (hpRNA), which is a component of the substance, was used as an additional control at the dose of 16 μg/mL. Our study has shown that the activating effect of dsRNA and PolyI:PolyC on expression of CD86 and CD69 markers upon the cells of the entire pool of splenocytes, B lymphocytes and DC. Highly polymeric RNA increased the total number of CD86+ cells in the population without changing the expression level of these markers upon B lymphocytes and DCs. When performing the in vivo studies, yeast dsRNA substance was administered intravenously into mice at a dose of 2.5 mg/kg, and hpRNA was used at a dose of 16 mg/kg. The number of CD69+ and CD86+ splenocytes was assessed 4 hours after drug administration. The highest stimulating effect of dsRNA was registered with CD69 expression marker: significantly increased numbers of CD69+ cells were registered for B lymphocytes and the entire cell population. The stimulation of CD86 co-receptor expression on B lymphocytes was less pronounced, but statistically significant. The ability of single-stranded and double-stranded RNAs to cause significant increase in CD86+ cell numbers was demonstrated among dendritic cell population. The results of the study made it possible to evaluate the effect of dsRNA on the immune cell function, with respect of their interaction, maturation, and migration. This approach may be useful for developing optimal strategies for selection and screening of new nucleic acid-based adjuvants.

Immunometabolic Analysis of Synovial Fluid from Juvenile Idiopathic Arthritis Patients.

Juvenile idiopathic arthritis (JIA) is an inflammatory rheumatic disorder. Polymorphonuclear neutrophils (PMNs) are present in JIA synovial fluid (SF), but with variable frequency. SF PMNs in JIA were previously shown to display high exocytic but low phagocytic and immunoregulatory activities. To further assess whether the degree of SF neutrophilia associated with altered immune responses in JIA, we collected SF and blood from 16 adolescent JIA patients. SF and blood leukocytes were analyzed by flow cytometry. SF and plasma were used for immune mediator quantification and metabolomics. Healthy donor blood T cells were cultured in SF to evaluate its immunoregulatory activities. PMN and T cell frequencies were bimodal in JIA SF, delineating PMN high/T cell low (PMNHigh) and PMN low/T cell high (PMNLow) samples. Proinflammatory mediators were increased in SF compared with plasma across patients, and pro- and anti-inflammatory mediators were further elevated in PMNHigh SF. Compared to blood, SF PMNs showed increased exocytosis and programmed death-1/programmed death ligand-1 expression, and SF PMNs and monocytes/macrophages had increased surface-bound arginase-1. SPADE analysis revealed SF monocyte/macrophage subpopulations coexpressing programmed death-1 and programmed death ligand-1, with higher expression in PMNHigh SF. Healthy donor T cells showed reduced coreceptor expression when stimulated in PMNHigh versus PMNLow SF. However, amino acid metabolites related to the arginase-1 and IDO-1 pathways did not differ between the two groups. Hence, PMN predominance in the SF of a subset of JIA patients is associated with elevated immune mediator concentration and may alter SF monocyte/macrophage phenotype and T cell activation, without altering immunoregulatory amino acids.