Mouse Spleen Cells Research Articles

Central effects of <i>ex vivo</i> caffeine-modulated immune cells in the mechanisms of editing depressive-like behavior

Depression is a serious medical and social problem due to its high prevalence, involvement of people of working age and lack of highly effective therapy. Social stressors contribute to the prevalence of depression. The COVID-19 pandemic and the associated rules of social distancing, military clashes, and a deteriorating economic situation can lead to a painful “breakdown” of socio-biological adaptation mechanisms and contribute to an increase in the prevalence of depressive disorders, which, according to WHO forecasts, may take second place in the world by 2030, which leads to interest in studying this problem and finding new effective approaches to therapy. Decreased cognitive function in depressive disorders is caused by neuroinflammatory and neurodegenerative changes. The latter are predominantly recorded in the hippocampus, numerous changes in the plasticity of which have been observed both in patients with clinical depression and in rodent models of depression. There is also a sufficient amount of data on the significant role of immune cells and their cytokines in depression, including in the development of behavioral phenotype. We have previously shown that spleen cells of depressive-like mice after ex vivo treatment with caffeine, a psychoactive drug with a wide range of immunomodulatory properties, change their functional activity and, after intravenous administration to syngeneic depressive-like recipients, have editing depressive-like behavior effect. The purpose of this work was to investigate the central effects of caffeine-modulated spleen cells in the mechanisms of editing depressive-like behavior. It was found that in depressive-like recipients after transplantation of syngeneic caffeine-modulated splenocytes, there is an increase in the density of neurons in the CA1 and CA3 zones of the hippocampus, accompanied by BDNF level increase in the hippocampus and prefrontal cortex against the background of a decrease of a number of pro-inflammatory (IL-1β, IL-6, IFNγ and TNFα) and increased of anti-inflammatory (IL-10 and IL-4) cytokines in brain structures pathogenetically significant for the state of depression. The mechanisms of the identified structural and functional changes in the recipient’s brain after the caffeine-modulated splenocytes transplantation are discussed, including their possible direct influence, confirmed by visualization of transplanted cells in the brain parenchyma of depressed-like recipients.

Recombinant Hemagglutinin Protein from H9N2 Avian Influenza Virus Exerts Good Immune Effects in Mice.

The H9N2 subtype of avian influenza virus (AIV) causes enormous economic losses and poses a significant threat to public health; the development of vaccines against avian influenza is ongoing. To study the immunogenicity of hemagglutinin (HA) protein, we constructed a recombinant pET-32a-HA plasmid, induced HA protein expression with isopropyl β-D-1-thiogalactopyranoside (IPTG), verified it by SDS-PAGE and Western blotting, and determined the sensitivity of the recombinant protein to acid and heat. Subsequently, mice were immunized with the purified HA protein, and the immunization effect was evaluated according to the hemagglutination inhibition (HI) titer, serum IgG antibody titer, and cytokine secretion level of the mice. The results showed that the molecular weight of the HA protein was approximately 84 kDa, and the protein existed in both soluble and insoluble forms; in addition, the HA protein exhibited good acid and thermal stability, the HI antibody titer reached 6 log2-8 log2, and the IgG-binding antibody titer was 1:1,000,000. Moreover, the levels of IL-2, IL-4, and IL-5 in the immunized mouse spleen cells were significantly increased compared with those in the control group. However, the levels of IL-1β, IL-6, IL-13, IFN-γ, IL-18, TNF-α, and GM-CSF were decreased in the immunized group. The recombinant HA protein utilized in this study exhibited good stability and exerted beneficial immune effects, providing a theoretical basis for further research on influenza vaccines.

Angelica sinensis polysaccharides promote extramedullary stress erythropoiesis via ameliorating splenic glycolysis and EPO/STAT5 signaling-regulated macrophages.

Conventional treatments exhibit various side effects on chronic stress anemia. Extramedullary stress erythropoiesis is a compensatory mechanism, which may effectively counteract anemia. Angelica sinensis polysaccharides (ASP) are the main active ingredient found in Angelica sinensis and exhibit antioxidant and hematopoietic effects. However, the effects of ASP on extramedullary stress erythropoiesis remain to be unclear. Here, we demonstrated the protective effects of ASP on chemotherapeutic drug 5-fluorouracil (5-FU)-induced decline in peripheral blood parameters such as RBC counts, HGB, HCT, and MCH, and the decline of BFU-E colony enumeration in the bone marrow. Meanwhile, ASP promoted extramedullary erythropoiesis, increasing cellular proliferation in the splenic red pulp and cyclin D1 protein expression, abrogating phase G0/G1 arrest of c-kit+ cells in mouse spleen. RT-qPCR and immunohistochemistry further revealed that ASP increased macrophage chemokine Ccl2 genetic expression and the number of F4/80+ macrophages in the spleen. The colony-forming assay showed that ASP significantly increased splenic BFU-E. Furthermore, we found that ASP facilitated glycolytic genes including Hk2, Pgk1, Pkm, Pdk1, and Ldha via PI3K/Akt/HIF2α signaling in the spleen. Subsequently, ASP declined pro-proinflammatory factor IL-1β, whereas upregulating erythroid proliferation-associated genes Gdf15, Bmp4, Wnt2b, and Wnt8a. Moreover, ASP facilitated EPO/STAT5 signaling in splenic macrophages, thus enhancing erythroid lineage Gata2 genetic expression. Our study indicated that ASP may improve glycolysis, promoting the activity of splenic macrophages, subsequently promoting erythroid progenitor cell expansion. Additionally, ASP facilitates erythroid differentiation via macrophage-mediated EpoR/STAT5 signaling; suggesting it might be a promising strategy for stress anemia treatment.

Study of Ridostin Pro and Poly(I:C) as adjuvants that enhance the immunogenicity of an antitumor vaccine

Aim of the study: to compare the antitumor efficacy and immunogenicity of vaccines with the same antigens but different adjuvants: Ridostin Pro or Poly(I:C); to evaluate the effect of Ridostin Pro and Poly(I:C) on the cytokine profile of serum and the immunophenotype of mouse spleen cells. Material and Methods. To evaluate the antitumor efficacy of vaccines with different adjuvants, two transplantable tumor lines were used: melanoma B16-F10 and EG 7-OVA lymphoma (expressing ovalbumin) for C57BL/6 mice. Against melanoma B16-F10, vaccination with the peptide TRP2 180–188 with the studied adjuvants was performed in a mixed (preventive/therapeutic) and therapeutic regimens. Ovalbumin with adjuvants was vaccinated against EG 7 lymphoma in a therapeutic mode. The immunogenicity of vaccines with different adjuvants in mice without tumors was evaluated by the ELISPOT method. In this case, the peptide TRP2 180–188 and the protein ovalbumin also served as antigens. The cytokine profile of blood serum and changes in the immunophenotype of mouse spleen cells after administration of Ridostin Pro or Poly(I:C) were studied using flow cytometry. Results. In the B16-F10 model, vaccination in a mixed mode protected mice from tumor formation, and the mice lived for more than 100 days. For B16-F10 and EG 7, vaccination in the therapeutic mode led only to inhibition of tumor growth. Ridostin Pro and Poly(I:C) showed a similar ability to develop specific immunity to the peptide TRP2 and ovalbumin. Ridostin Pro increased cytokine levels in the blood serum of mice more strongly than Poly(I:C). Both drugs caused similar changes in the immunophenotype of spleen cells, but Ridostin Pro increased the number of CD 69+ T cells more strongly than Poly(I:C). Conclusion. The comparison of two drugs as adjuvants for antitumor vaccines showed that the domestic drug Ridostin Pro did not inferior in effectiveness to Poly(I:C) on mouse models. In this regard, Ridostin Pro can be considered as a promising adjuvant for antitumor vaccines and deserves further study.

Wutou decoction alleviates arthritis inflammation in CIA mice by regulating Treg cell stability and Treg/Th17 balance via the JAK2/STAT3 pathway

Ethnopharmacological relevanceWutou Decoction (WTD) is a classic traditional Chinese medicine formula, which has shown clinical efficacy in treating rheumatoid arthritis (RA). The Treg stability and Th17/Treg imbalance is an important immunological mechanism in RA progression. Whether WTD regulates CD4+ T cell subsets has not been thoroughly investigated yet. Aim of the studyThis study aimed to explore the potential role and mechanisms of WTD in regulating the diminished stability of Treg cells and the imbalance of CD4+ T cell subsets via in vivo and in vitro experiments. Materials and methodsFirstly, the therapeutic effects of WTD on the collagen-induced arthritis (CIA) mouse and its potential regulatory function on CD4+ T cell subsets were evaluated in vivo. Animal specimens were collected after 31 days of treatment with WTD. The anti-arthritic and anti-inflammatory effects of WTD were assessed through arthritis scoring, body weight, spleen index, serum IL-6 levels, and micro-PET/CT imaging. Gene enrichment analysis was performed to evaluate the activation T cell-related signaling pathway. Flow cytometry was used to determine the proportions of CD4+ T cell subsets in vitro and in vitro. Additionally, ELISA was used to assess the secretion of IL-10 and TGF-β by Treg cells under inflammatory conditions. The suppressive function of Treg cells on cell proliferation under inflammatory conditions was examined using CFSE labeling. Immunofluorescence staining was performed to detect the phosphorylation levels of STAT3 in CD4+ T cells from mouse spleen tissues. Western blotting was used to evaluate the phosphorylation levels of JAK2/STAT3 in Treg cells. ResultsWTD significantly alleviated joint inflammation in CIA mice. WTD reduced serum IL-6 levels in CIA mice, improved their body weight and spleen index. WTD treatment inhibited the activation of CD4+ T cell subgroup-related signaling in the joint tissues of CIA mice. In vitro and in vitro experiments showed that WTD increased the proportion of Treg cells and decreased the proportion of Th17 cells in CIA mice spleen. Furthermore, WTD promoted the secretion of IL-10 and TGF-β by Treg cells and enhanced the inhibitory capacity of Treg cells on cell proliferation under inflammatory conditions. Immunofluorescence detected decreased STAT3 phosphorylation levels in CD4+ T cells from CIA mice spleen, while western blotting revealed a decrease in JAK2/STAT3 phosphorylation levels in Treg cells in vitro. ConclusionsInhibiting JAK2/STAT3 phosphorylation is a potential mechanism through which WTD improves Treg cell stability, balances CD4+ T cell subsets, and attenuates RA joint inflammation.

Harnessing Metformin's Immunomodulatory Effects on Immune Cells to Combat Breast Cancer.

Metformin, a medication known for its anti-glycemic properties, also demonstrates potent immune system activation. In our study, using a 4T1 breast cancer model in BALB/C WT mice, we examined metformin's impact on the functional phenotype of multiple immune cells, with a specific emphasis on natural killer T (NKT) cells due to their understudied role in this context. Metformin administration delayed the appearance and growth of carcinoma. Furthermore, metformin increased the percentage of IFN-γ+ NKT cells, and enhanced CD107a expression, as measured by MFI, while decreasing PD-1+, FoxP3+, and IL-10+ NKT cells in spleens of metformin-treated mice. In primary tumors, metformin increased the percentage of NKp46+ NKT cells and increased FasL expression, while lowering the percentages of FoxP3+, PD-1+, and IL-10-producing NKT cells and KLRG1 expression. Activation markers increased, and immunosuppressive markers declined in T cells from both the spleen and tumors. Furthermore, metformin decreased IL-10+ and FoxP3+ Tregs, along with Gr-1+ myeloid-derived suppressor cells (MDSCs) in spleens, and in tumor tissue, it decreased IL-10+ and FoxP3+ Tregs, Gr-1+, NF-κB+, and iNOS+ MDSCs, and iNOS+ dendritic cells (DCs), while increasing the DCs quantity. Additionally, increased expression levels of MIP1a, STAT4, and NFAT in splenocytes were found. These comprehensive findings illustrate metformin's broad immunomodulatory impact across a variety of immune cells, including stimulating NKT cells and T cells, while inhibiting Tregs and MDSCs. This dynamic modulation may potentiate its use in cancer immunotherapy, highlighting its potential to modulate the tumor microenvironment across a spectrum of immune cell types.

Optimization of Cytokine-Induced Killer Cell Generation from Mouse Spleen Cells

Optimization of Cytokine-Induced Killer Cell Generation from Mouse Spleen Cells

Lack of ATP2B1 in CD4+ T Cells Causes Colitis.

The ATP2B1 gene encodes for a calcium pump, which plays a role in removing Ca2+ from cells and maintaining intracellular Ca2+ homeostasis. Reduction of the intracellular Ca2+ concentration in CD4+ T cells is thought to reduce the severity of colitis, while elevation of Ca2+ in CD4+ T cells induces T cell hyperactivity. Our aim was to clarify the role of ATP2B1 in CD4+ T cells and in inflammatory bowel disease development. A murine CD4+ T cell-specific knockout (KO) of ATP2B1 was created using a Cre-loxP system. CD4+ T cells were isolated from thymus, spleen, and blood using fluorescence-activated cell sorting. To quantify messenger RNA levels, quantitative real-time polymerase chain reaction was performed. Although the percentages of CD4+ T cells in both KO mouse spleen and blood decreased compared with those of the control samples, both T-bet (a T helper 1 [Th1] activity marker) and GATA3 (a Th2 activity marker) expression levels were further increased in KO mouse blood CD4+ T cells (vs control blood). Diarrhea and colonic wall thickening (with mucosal changes, including crypt distortion) were seen in KO mice but not in control mice. Prior to diarrhea onset, the KO mouse colon length was already noted to be shorter, and the KO mouse stool water and lipid content were higher than that of the control mice. Tumor necrosis factor α and gp91 expressions were increased in KO mouse colon. Lack of ATP2B1 in CD4+ T cells leads to Th1 and Th2 activation, which contributes to colitis via elevation of tumor necrosis factor α and oxidative stress.

Generation and characterization of mAb 61H9 against junctional adhesion molecule-a with potent antitumor activity.

Junctional adhesion molecule-A (JAM-A) is an adhesion molecule that exists on the surface of certain types of cells, including white blood cells, endothelial cells, and dendritic cells. In this study, the cDNA sequences of JAM-A-Fc were chemically synthesized with optimization for mammalian expression. Afterward, we analyzed JAM-A protein expression through transient transfection in HEK293 cell lines. Mice were immunized with JAM-A-Fc protein, and hybridoma was prepared by fusing myeloma cells and mouse spleen cells. Antibodies were purified from the hybridoma supernatant and four monoclonal strains were obtained and numbered 61H9, 70E5, 71A8, and 74H3 via enzyme-linked immunosorbent assay screening. Immunofluorescence staining assay showed 61H9 was the most suitable cell line for mAb production due to its fluorescence signal being the strongest. Flow cytometric analysis proved that 61H9 possessed high affinity. Moreover, antagonism of JAM-A mAb could attenuate the proliferative, migrative, and invasive abilities of ESCC cells and significantly inhibit tumor growth in mice. By examining hematoxylin-eosin staining mice tumor tissues, we found inflammatory cells infiltrated lightly in the anti-JAM-A group. The expression of BCL-2 and IκBα in the anti-JAM-A group were decreased in mice tumor tissues compared to the control group. Ultimately, a method for preparing high-yield JAM-A-Fc protein was created and a high affinity mAb against JAM-A with an antitumor effect was prepared.

Immunomodulatory activity of heat-killed Lacticaseibacillus paracaseiMCC1849 based on the activation of plasmacytoid dendritic cells in the peripheral blood of healthy adults.

Probiotics are widely used in food for their health benefits to the host. Inactivated probiotics also reportedly improve the intestinal environment and immune regulation. Our previous studies showed that heat-killed Lacticaseibacillus paracasei MCC1849 (hk-MCC1849) effectively induced IL-12 production in mouse spleen cells and significantly reduced cold symptoms in clinical trial subjects. To further elucidate the mechanism of host immune regulation by hk-MCC1849, human peripheral blood mononuclear cells (PBMCs) were cocultured with hk-MCC1849. The Toll-like receptor 9 ligands CpG-ODN 2216 and hk-MCC1849 and the heat-killed Lacticaseibacillus rhamnosus ATCC53103 were used as positive and negative controls, respectively. The results showed that, compared with the control, hk-MCC1849 significantly increased the expression of the plasmacytoid dendritic cell (pDC) marker CD86 (p < .0001) and the pDC marker HLA-DR (p < .001) in PBMCs. The expression levels of the IL-12p40, IFNα, IFNα1, IFNγ, and ISG15 genes were significantly increased after coculture with hk-MCC1849 (p < .05, p < .05, p < .05, p < .05, and p < .05, respectively, vs. control). Furthermore, to confirm whether hk-MCC1849 directly interacted with pDCs, DCs were enriched with PBMCs following 24 h of coculture with hk-MCC1849. Phagocytosis of fluorescently labeled hk-MCC1849 by pDCs was observed, and there were significant increases in CD86 (p < .05) and HLA-DR (p < .0001) expression in pDCs. These results suggest that hk-MCC1849 exerts a potential immunomodulatory effect on the host through the activation of peripheral pDCs.

Kisspeptin prevents pregnancy loss by modulating the immune microenvironment at the maternal-fetal interface in recurrent spontaneous abortion.

Immune factors are crucial in the development of recurrent spontaneous abortion (RSA). This study aimed to investigate whether kisspeptin regulates immune cells at the maternal-fetal interface and whether G protein-coupled receptor 54 (GPR54) is involved in this process, through which it contributes to the pathogenesis of RSA. Normal pregnancy (NP) (CBA/J × BALB/c) and RSA (CBA/J × DBA/2) mouse models were established. NP mice received tail vein injections of PBS and KP234 (blocker of kisspeptin receptor), whereas RSA mice received PBS and KP10 (active fragment of kisspeptin). The changes in immune cells in mouse spleen and uterus were assessed using flow cytometry and immunofluorescence. The expression of critical cytokines was examined by flow cytometry, ELISA, Western blotting, and qPCR. Immunofluorescence was employed to detect the coexpression of FOXP3 and GPR54. The findings revealed that the proportion of Treg cells, MDSCs, and M2 macrophages in RSA mice was lower than that in NP mice, but it increased following the tail vein injection of KP10. Conversely, the proportion of these cells was reduced in NP mice after the injection of KP234. However, the trend of γδT cell proportion change is contrary to these cells. Furthermore, FOXP3 and GPR54 were coexpressed in mouse spleen and uterus Treg cells as well as in the human decidua samples. Our results suggest that kisspeptin potentially participates in the pathogenesis of RSA by influencing immune cell subsets at the maternal-fetal interface, including Treg cells, MDSC cells, γδT cells, and M2 macrophages.

CD4 T-cell aging exacerbates neuroinflammation in a late-onset mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is an adult-onset progressive neurodegenerative disorder characterized by the loss of upper and lower motor neurons in the brain and spinal cord. Accumulating evidence suggests that ALS is not solely a neuronal cell- or brain tissue-autonomous disease and that neuroinflammation plays a key role in disease progression. Furthermore, whereas both CD4 and CD8 T cells were observed in spinal cords of ALS patients and in mouse models of the disease, their role in the neuroinflammatory process, especially considering their functional changes with age, is not fully explored. In this study, we revealed the structure of the CD4 T-cell compartment during disease progression of early-onset SOD1G93A and late-onset SOD1G37R mouse models of ALS. We show age-related changes in the CD4 T-cell subset organization between these mutant SOD1 mouse models towards increased frequency of effector T cells in spleens of SOD1G37R mice and robust infiltration of CD4 T cells expressing activation markers and the checkpoint molecule PD1 into the spinal cord. The frequency of infiltrating CD4 T cells correlated with the frequency of infiltrating CD8 T cells which displayed a more exhausted phenotype. Moreover, RNA-Seq and immunohistochemistry analyses of spinal cords from SOD1G37R mice with early clinical symptoms demonstrated immunological trajectories reminiscent of a neurotoxic inflammatory response which involved proinflammatory T cells and antigen presentation related pathways. Overall, our findings suggest that age-related changes of the CD4 T cell landscape is indicative of a chronic inflammatory response, which aggravates the disease process and can be therapeutically targeted.

In vivo evaluations of Lactobacillus-fermented Eucheuma spinosum polysaccharides on alleviating food allergy activity.

In order to explore the in vivo anti-food allergy activity of Lactobacillus sakei subsp. sakei-fermented Eucheuma spinosum polysaccharides F1-ESP-3, an ovalbumin (OVA)-induced food allergy mouse model was established by ascites immunization and gavage. The weight, temperature, incidence of diarrhea, levels of allergic mediators and inflammatory factors in the serum of mice were analyzed. We analyzed the differentiation of mouse spleen lymphocytes and the proportion of sensitized mast cells by flow cytometry. The intestinal barrier status of mice was analyzed by intestinal pathological tissue sections and microbiota sequencing. The results showed that F1-ESP-3 could alleviate the food allergy symptoms of mice, such as hypothermia and loose stool; levels of OVA-specific immunoglobulin E, mast cell protease and histamine in the serum of sensitized mice and the proportion of dendritic cells and mast cells in mouse spleen were significantly reduced; in addition, F1-ESP-3 may protect the intestinal barrier and further improve the intestinal microenvironment of food-allergic mice by regulating the abundance of Bacteroidetes and Firmicutes. F1-ESP-3 can further improve the intestinal microenvironment of food-allergic mice by upregulating the levels of Lachnospiraceae, and may affect the signal pathways such as NOD-like receptor, MAPK, I kappa B and antigen processing and presentation.

RG7774 (Vicasinabin), an orally bioavailable cannabinoid receptor 2 (CB2R) agonist, decreases retinal vascular permeability, leukocyte adhesion, and ocular inflammation in animal models.

Preclinical studies suggest that cannabinoid receptor type 2 (CB2R) activation has a therapeutic effect in animal models on chronic inflammation and vascular permeability, which are key pathological features of diabetic retinopathy (DR). A novel CB2R agonist, triazolopyrimidine RG7774, was generated through lead optimization of a high-throughput screening hit. The aim of this study was to characterize the pharmacology, absorption, distribution, metabolism, elimination, and toxicity (ADMET) profile of RG7774, and to explore its potential for managing the key pathological features associated with retinal disease in rodents. The in vitro pharmacology of RG7774 was investigated for CB2R binding and receptor activation using recombinant human and mouse CB2R expression in Chinese hamster ovary cells, and endogenous CB2R expression in human Jurkat cells, and rat and mouse spleen cells. The ADMET profile was evaluated and the effects of RG7774 on retinal permeability, leukocyte adhesion, and choroidal neovascularization (CNV) were investigated in rodent models of retinal disease. Pharmacokinetic (PK) parameters and the exposure-response relationship were characterized in healthy animals and in animals with laser-induced CNV. RG7774 was found to be a potent (EC50: 2.8nM and Ki: 51.3nM), selective, and full CB2R agonist with no signs of cannabinoid receptor type 1 (CB1R) binding or activation. The ligand showed a favorable ADMET profile and exhibited systemic and ocular exposure after oral delivery. Functional potency in vitro translated from recombinant to endogenous expression systems. In vivo, orally administered RG7774 reduced retinal permeability and leukocyte adhesion in rodents with lipopolysaccharide (LPS)-induced uveitis and streptozotocin (STZ)-induced DR, and reduced lesion areas in rats with laser-induced CNV with an ED50 of 0.32mg/kg. Anatomically, RG7774 reduced the migration of retinal microglia to retinal lesions. RG7774 is a novel, highly selective, and orally bioavailable CB2R agonist, with an acceptable systemic and ocular PK profile, and beneficial effects on retinal vascular permeability, leukocyte adhesion, and ocular inflammation in rodent animal models. Results support the development of RG7774 as a potential treatment for retinal diseases with similar pathophysiologies as addressed by the animal models.

In situ monitoring of toxic effects of algal toxin on cells by a novel microfluidic flow cytometry instrument

Algal toxins produced by microalgae, such as domoic acid (DA)11(DA) domoic acid, have toxic effects on humans. However, toxicity tests using mice only yield lethal doses of algal toxins without providing insights into the mechanism of action on cells. In this study, a fast segmentation of microfluidic flow cytometry cell images based on the bidirectional background subtraction (BBS)22(BBS) bidirectional background subtraction method was developed to get the visual evidence of apoptosis in both bright-field and fluorescence images. This approach enables mapping of changes in cell morphology and activity under algal toxins, allowing for fast (within 60 s) and automated biological detection. By combining microfluidics with flow cytometry, the intricate cellular-level reaction process can be observed in micro samples of 293 T cells and mouse spleen cells, offering potential for future in vitro experiments.

Optimization and intra-assay validation of a multiparametric flow cytometric test for monitoring circulating TREGs.

Multiparametric flow cytometry (MFC) represents an essential tool for immune monitoring, and validation of MFC panels is a fundamental prerequisite in routine laboratory settings as well as for translational and clinical research purposes. Regulatory T cells (TREGs) constitute a subset of CD4+ effector T cells that modulate the immune response in numerous settings, including autoimmune disease, allergy, microbial infection, tumor immunity, transplantation, and more. These cells comprise a small fraction of total CD4+ T cells in human peripheral blood and mouse spleen. In oncology, TREG cells are highly relevant, as they are involved in the suppression of the anti-tumor response in many types of cancer, to the extent that the first immune checkpoint inhibitor approved for clinical use in humans was a monoclonal antibody directed against CTLA-4, a molecule functionally associated with TREGs. Due to all these factors, robust assays are mandatory to accurately determine TREG cell frequency and function. Here, we describe the validation of an 8-color flow-cytometry protocol for TREG detection and analysis in a real-world laboratory scenario. The entire process includes the workflow plan and the standard operating procedure resembling each phase, from the panel design to the staining, acquisition, and analysis steps. Validation is planned to be performed in replicates on fresh whole blood samples derived from multiple healthy subjects. The analytical validity of the TREG cell assay is ensured by testing the intra-assay accuracy. The detailed procedure for the entire process is accompanied by important troubleshooting suggestions and other useful tips.

Evaluation of The Genoprotective Effect of Curcumin Against Methotrexate in Bone Marrow and Spleen Cells in Mice

Curcumin is a yellow pigment produced from the rhizomes of the Curcuma longa plant and a primary chemo preventive component of turmeric is used as a spice and food coloring ingredient. Curcumin has a large number of pharmacological activities, such as anticancer, anti-diabetic, antioxidant, anti-infectious, and anti-inflammatory properties.Investigation of the geno-protective effect of curcumin on methotrexate induces chromosomal aberrations of spleen and bone marrow cells. In this study, 32 mice were used and divided into four groups (eight mice at each group) as follows: Group1 (negative control): Dimethyl sulfoxide was given intraperitoneally to mice every day for ten days.Group2 (positive control): Mice were received a single dose (20mg/kg) of methotrexate intraperitoneally Group3: Mice were received (200mg/kg) of curcumin solution intraperitoneally for ten successive days.Group4: Mice were received (200mg/kg) of curcumin solution intraperitoneally for ten successive days and on the day 11, a single dose of methotrexate ( 20 mg/kg ) was injected intraperitoneally . In animals treated with methotrexate, significant elevations of the chromosomal aberrations were observed along with a decline in the mitotic index. Meanwhile, there was a considerable elevation of the mitotic index and no detectable chromosomal changes in the curcumin-supplemented mice. The number of abnormal cells was reduced significantly in the curcumin-treated group in comparison with the methotrexate-treated group. The ability of curcumin to inhibit methotrexate's cytotoxic effects was shown by the compound's ability to raise the mitotic index. According to this finding, curcumin approved to be a protective agent against genotoxic effects of methotrexate. Keywords: Curcumin, Chromosomal aberrations, Methotrexate, Mitotic index, Mice

In vitro and in vivo killing effects of methionine enkephalin on osteosarcoma

ObjectiveThis study aimed to investigate the underlying regulatory effects of methionine enkephalin (MENK) on osteosarcoma. MethodsThe Cell Counting Kit-8 assay, clone formation, wound healing, transwell assay, and flow cytometry were performed to measure the effects of MENK on the proliferation, migration, invasion, and apoptosis of MG-63 and Saos-2 cells. Opiate growth factor receptor expression (OGFr) in cells was stably knocked down using siRNA. A tumor model was established by inoculating MG-63 cells into mice. Flow cytometry was performed to identify alterations in mice bone marrow, spleen, and tumor tissue immune cells. The phenotype of tumor-associated macrophages was determined using immunohistochemistry. After OGFr knockdown or/and treatment with MENK, Bax, Bcl-2, caspase 3, caspase 9, and PARP expression levels were characterized using qRT-PCR, western blot, and WES, respectively. ResultsMENK could significantly inhibit the proliferation, invasion, and migration of MG-63 and Saos-2, arrest the cell cycle in the G0/G1 phase, upregulate Bax, caspase 3, caspase 9, and PARP expression, and downregulate Bcl-2 expression. Tumor size and weight were lower in the MENK group than those in the control group. MENK-treated mice exhibited a reduced ratio of CD11b + Gr-1 + myeloid-derived suppressor cells. MENK increased the ratio of M1-type macrophages and decreased the proportion of M2-type macrophages in tumor tissue. Furthermore, the level of TNF-α significantly increased while that of IL-10 decreased in MENK-treated mice. The effect of MENK could be partly reversed by OGFr knockdown. ConclusionMENK reduces the abundance of myeloid-derived suppressor cells, induces M1 polarization of macrophages, and exhibits an inhibitory effect on osteosarcoma.

The Exposure to Lead (Pb) Exacerbates Immunological Abnormalities in BTBR T+ Itpr3tf/J Mice through the Regulation of Signaling Pathways Relevant to T Cells.

Autism spectrum disorder (ASD) is a common neurodevelopmental illness characterized by abnormal social interactions, communication difficulties, and repetitive and limited behaviors or interests. The BTBR T+ Itpr3tf/J (BTBR) mice have been used extensively to research the ASD-like phenotype. Lead (Pb) is a hazardous chemical linked to organ damage in the human body. It is regarded as one of the most common metal exposure sources and has been connected to the development of neurological abnormalities. We used flow cytometry to investigate the molecular mechanism behind the effect of Pb exposure on subsets of CD4+ T cells in the spleen expressing IFN-γ, T-bet, STAT1, STAT4, IL-9, IRF4, IL-22, AhR, IL-10, and Foxp3. Furthermore, using RT-PCR, we studied the effect of Pb on the expression of numerous genes in brain tissue, including IFN-γ, T-bet, STAT1, STAT4, IL-9, IRF4, IL-22, AhR, IL-10, and Foxp3. Pb exposure increased the population of CD4+IFN-γ+, CD4+T-bet+, CD4+STAT1+, CD4+STAT4+, CD4+IL-9+, CD4+IRF4+, CD4+IL-22+, and CD4+AhR+ cells in BTBR mice. In contrast, CD4+IL-10+ and CD4+Foxp3+ cells were downregulated in the spleen cells of Pb-exposed BTBR mice compared to those treated with vehicle. Furthermore, Pb exposure led to a significant increase in IFN-γ, T-bet, STAT1, STAT4, IL-9, IRF4, IL-22, and AhR mRNA expression in BTBR mice. In contrast, IL-10 and Foxp3 mRNA expression was significantly lower in those treated with the vehicle. Our data suggest that Pb exposure exacerbates immunological dysfunctions associated with ASD. These data imply that Pb exposure may increase the risk of ASD.

Threshold Attenuation of Perk Signaling Is Sufficient to Overcome RAS-Mediated FLT3 Inhibitor Resistance

Introduction Acute myeloid leukemia (AML) with activation of FMS-related receptor tyrosine kinase 3 ( FLT3) confers a poor prognosis, principally due to disease relapse. The FLT3 inhibitor (FLT3i) gilteritinib is standard of care in relapsed/refractory FLT3-mutant AML, however its efficacy is limited by drug resistance, primarily due to RAS mutations. This suggests that RAS signaling is the critical mediator of downstream FLT3 signaling, but there is no standardized treatment for patients who relapse on FLT3i due to RAS pathway activation. Efforts to overcome resistance have been limited both by understanding of the optimal RAS effectors to target as well as the potential toxicity of simultaneously targeting FLT3 and RAS. Here, we demonstrate that while RAS-driven resistance to gilteritinib is mediated through MAPK, not PI3K, attenuation of pERK signaling is sufficient to overcome this resistance both in vitro and in vivo. Methods/ Results FLT3-ITD+ cells (Molm14) with transduced NRAS mutations are resensitized to gilteritinib by MEK inhibitor treatment, proving that MAPK signaling is necessary for RAS-driven resistance. Further, expression of a constitutively active MEK construct (MEKDD) in Molm14 confers resistance to gilteritinib, showing MAPK signaling is sufficient for RAS-driven resistance. Conversely, we show that activated PI3K signaling is neither necessary nor sufficient to drive resistance, as AKT inhibition cannot resensitize NRAS-mutants to gilteritinib, and an activated AKT mutant does not confer gilteritinib resistance. We used a doxycycline-inducible system to increase expression of MEKDD, to titrate levels of ERK signaling activation in Molm14 cells. Surprisingly, we found that the relationship between ERK phosphorylation (pERK) and FLT3i resistance was non-linear and appeared to increase at a threshold of pERK (62%). In keeping with this, suppression of pERK levels in Molm14 cells with concurrent RAS mutations to levels below 70% of baseline using the MEK inhibitor (MEKi) trametinib, was sufficient to resensitize to gilteritinib in proliferation assays. A similar phenomenon was seen in apoptosis assays. Molm14 NRAS Q61K mutant cells treated with 500nM gilteritinib plus increasing doses of trametinib showed apoptosis plateaued at the relatively low dose of 5nM trametinib. Western Blot analysis showed residual pERK activation at this dose. Thus, attenuation of MAPK signaling below a threshold, rather than its ablation, can overcome FLT3i resistance. In a patient-derived xenograft (PDX) model of AML with concurrent FLT3-ITD and NRAS Q61K, the combination of low dose MEK inhibition (PD-901 1.5mg/kg) combined with gilteritinib was equivalent to standard dose MEK inhibition (PD-901 5mg/kg) combined with gilteritinib in suppressing outgrowth of human CD45+ cells in spleen, bone marrow, and blood of NSGS mice in comparison to vehicle-treated control. Standard dose MEK inhibition in combination with gilteritinib was also noted to be intolerable in the majority of mice with only 2 of 6 mice surviving 28 days. Given the similar activity of low and high dose MAPK inhibition in combination with gilteritinib, we hypothesized that suppression of ERK activation below a critical level is sufficient to activate a shared transcriptional program to trigger cell cycle arrest and apoptosis. To test this hypothesis, we performed RNAseq analysis of Molm14 NRAS Q61K cells treated with gilteritinib, standard dosing of trametinib, low dose trametinib, or the combination. There is a gene expression signature of MAPK expression unique to the combination of gilteritinib and trametinib that is dose independent of trametinib, which includes MAPK regulators including ETV4 and ETV5. Conclusions MAPK is the critical effector pathway of RAS-driven gilteritinib resistance, but partial attenuation of pERK signaling is sufficient to inhibit proliferation and induce apoptosis, restoring sensitivity to FLT3i. Applied clinically, this suggests feasibility of low dose MAPK inhibition in combination with gilteritinib to treat resistant FLT3-activated AML. This strategy that would improve tolerability, a major concern in clinical use of MAPK pathway inhibitors.