Lymphocyte Apoptosis Research Articles

The impact of ulinastatin on lymphocyte apoptosis and autophagy in sepsis patients

This study aimed to assess the influence of ulinastatin (UTI) on lymphocyte apoptosis and autophagy in sepsis patients, as well as its effect on inflammatory factors and vital organ function, with the goal of providing insights for improved clinical management of sepsis. A total of 40 sepsis patients were randomly assigned to the UTI group or the control group. The UTI group received standard treatment plus intravenous UTI, while the control group received standard treatment alone. Peripheral blood samples were collected at multiple time points for analysis of lymphocyte apoptosis, autophagy, inflammatory markers, and organ function. Various experimental techniques including Hoechst staining, transmission electron microscopy, and Western blot analysis were utilized to assess lymphocyte apoptosis, autophagy, and related protein expression levels. The study revealed that UTI treatment significantly inhibited lymphocyte apoptosis and promoted autophagy in sepsis patients. The levels of autophagy-related proteins LC3-II and Beclin-1 were substantially elevated, while the ratio of anti-apoptotic Bcl-2 to pro-apoptotic Bax was increased following UTI treatment. Furthermore, the levels of inflammatory markers IL-6, procalcitonin, and C-reactive protein were markedly reduced in the UTI group compared to the control group. Additionally, UTI treatment led to improved liver, kidney and cardiac function as evidenced by reduced levels of liver enzymes and creatinine, and cardiac enzymes. The findings of this study demonstrate that UTI exerts a protective effect on septic patients by inhibiting lymphocyte apoptosis, promoting autophagy, and attenuating systemic inflammation. Moreover, UTI treatment was associated with improved liver, kidney, and cardiac function in septic patients. These results contribute to a better understanding of the clinical management of sepsis and underscore the potential of UTI as a therapeutic intervention in septic patients.

Involvement of canine parvovirus in mRNA expression levels of key lectins and caspases in blood leukocytes.

Canine parvovirus disease (CPVD) is one of the most common causes of viral diarrhea in dogs. The disease has a mortality rate of up to 90% if left untreated, and can cause gastroenteritis, vomiting, mucoid/hemorrhagic diarrhea, lymphopenia and even immunosuppression. Based on the effects of canine parvovirus type 2 (CPV-2) on the immune system, we investigated the effects of the CPV-2 on hematological indices and the expression of certain immune molecules in blood leukocytes of CPV-positive and non-CPV dogs. The dogs were (para)clinically evaluated, and their disease status was confirmed by antigen rapid detection kits and polymerase chain reaction (PCR). To elucidate the nature of the immunosuppression seen in CPVD, we investigated the expression of caspases 3/7 and 9, and some lectin family molecules such as galectin-1 (important in viral adhesion) and Mincle (macrophage‑inducible C‑type lectin receptor), in blood leukocytes using reverse transcription quantitative PCR (RT-qPCR). We observed remarkable lymphopenia, lower Hb concentration and higher red blood cell distribution width (RDW) value in CPV-positive dogs. No significant changes in expression of caspases 3/7 and 9 were detected, but galectin-1 and Mincle showed remarkable down and up-regulation, respectively. This proves that the immunosuppression seen in most CPVD is not caused by lymphocyte apoptosis in blood, and that Mincle is partially involved in the immune response to CPV-2. The observed changes in galectin-1 and Mincle may be a defense mechanism against parvovirus by potentially preventing the parvovirus from adhering to the cells. Further research is, nonetheless, needed to elucidate the possible roles of these molecules in CPV-2 pathogenesis and the immune system's response to parvovirus.

In vivo Study of the Anti/Prooxidant Activity of a Metal-Organic Coordination Polymer Modified with Iron Oxides and Ascorbic Acid

Experiments on 39 male Wistar rats were performed. A metal-organic coordination polymer modified with iron oxide and ascorbic acid (composite) was administered intravenously to healthy rats at doses of 25 and 50 mg/kg. The anti/prooxidant activity of the composite was assessed 3 and 24 hours after administration. The composite in both doses was shown to have no significant effect on the homeostasis of prooxidants/antioxidants in the blood serum in healthy animals. In high doses, the composite enhances apoptosis of lymphocytes, which indicates its possible use as a catalyst for free radical processes for further use in biomedicine.

Mechanism of Shashen-Maidong herb pair in treating hepatocellular carcinoma using network pharmacology and experimental validation

Ethnopharmacological relevanceHepatocellular carcinoma (HCC) is among the most prevalent malignant tumors globally and represents a significant public health issue worldwide. Immune cell dysfunction is the crucial factor for the formation of immunosuppression microenvironment of HCC. Glehnia littoralis (A.Gray) F.Schmidt ex Miq. (Shashen) and Ophiopogon japonicus (Thunb.) Ker Gawl. (Maidong) are classic herb pair in traditional Chinese medicine (TCM) of nourishing Yin, and is widely applied in the treatment of HCC and possesses multiple immunomodulatory functions. However, the role of the Shashen-Maidong herb pair (SS-MD) for the management of HCC and the potential mechanisms has not been explicated. Aim of the studyThe purpose of the research is to investigate the potential mechanism of the SS-MD herb pair for the management of HCC. Materials and methodsThe known components of the SS-MD herb pair were preliminarily identified using UPLC-Q-Orbitrap-MS/MS. The active ingredients of SS-MD herb pair in treating HCC were screened by constructing herb-component-target network, and the key therapeutic targets were explored by constructing a protein-protein interaction (PPI) network. The binding affinity of the key targets and components were validated through molecular docking and molecular dynamics simulations. GO biological function and KEGG pathway analyses were operated to elucidate the potential mechanisms of the SS-MD herb pair for the management of HCC. And the mechanism was verified in the tumor bearing mice model and cell co-culture experiments. ResultsNetwork pharmacology prediction revealed 39 active components and 138 targets of the SS-MD herb pair for the treatment of HCC. KEGG analysis mainly focused on Notch signaling pathway and Apoptosis signaling pathway. The targets were enriched in biological functions of lymphocyte effector function and lymphocyte apoptosis. In vivo and in vitro experiments proved that the SS-MD herb pair can improve the proportion of CD8+T cells in the HCC immune microenvironment, regulate its subgroup distribution. SS-MD herb pair promoted CD8+T cells to secrete IL-2, TNF-α, IFN-γ, Granzyme B and Perforin, and inhibited apoptosis by regulating Notch signaling pathway. ConclusionsThis study identified the key components, targets, and signaling pathways of the SS-MD herb pair, confirm that SS-MD herb pair play an immunomodulatory role in treating HCC, provides theoretical support for the collaborative treatment of HCC with TCM.

Peptide-directed interference of PD-1/PD-L1 binding increases B lymphocyte function after infectious bursal disease viral infection

Programmed cell death protein 1 (PD-1)/PD-1 ligand 1 (PD-L1) binding contributes to immune evasion mechanisms responsible for B lymphocyte exhaustion and apoptosis. This facilitates immunosuppression in chronic viral infections, including infectious bursal disease virus (IBDV). Our previous study showed that PD-1 and PD-L1 expression increases in the peripheral blood mononuclear cells of chickens infected with IBDV. However, due to their high production costs and immune-related adverse events, monoclonal antibodies targeting PD-1 or PD-L1 are unsuitable therapeutic agents. Thus, in the current study, we designed peptides with optimized binding sites for PD-1 and investigated their ability to disrupt PD-1/PD-L1 binding and restore B lymphocyte function in vitro. The peptide gCK-16 exhibited a high affinity for PD-1 (KD: 3.37 nM) and effectively inhibited the PD-1/PD-L1 interaction in vitro. Moreover, gCK-16 significantly enhanced B lymphocyte proliferation. Remarkably, gCK-16 treatment abrogated the IBDV-induced upregulation of PD-1/PD-L1, NF-κB activation, and B lymphocyte apoptosis. Additionally, IBDV infection attenuated PI3K/AKT pathway activation in B lymphocytes, while gCK-16 treatment increased immunoglobulin M (IgM) production in IBDV-infected B lymphocytes. Together, these results demonstrate that gCK-16 treatment can potentially enhance B lymphocyte function against IBDV infection, guiding the development of vaccine adjuvants to effectively prevent IBDV-induced avian immunosuppression.

Antiretroviral therapy combined with Shenling Guben Granules for the treatment of HIV infection with immune reconstitution deficiency: A randomized, double-blind, placebo-controlled study

Background: Even with long-term complete suppression of the virus through Antiretroviral therapy (ART), people infected with HIV cannot attain optimal immune reconstitution. This phenomenon is called immune reconstitution deficiency, there are no effective therapeutic interventions for immune reconstitution deficiency in modern medicine. Objective: To evaluate the efficacy and safety of ART with Shenling Guben Granules Traditional Chinese medicine in boosting immunological reconstitution compared with ART alone. Methods: This was a randomized, double-blind, placebo-controlled, multi-center clinical trial evaluating the efficacy and safety of ART combined with Chinese medicine. The individuals aged 18–65 years with poor immune reconstitution following ART were included in this trial. The primary outcome was a change in the absolute value of CD4+ T lymphocytes after 72 weeks of combined ART and Chinese medicine administration. Secondary outcomes included changes in CD4+ T lymphocyte functional subpopulations, activated T lymphocyte subpopulations, CD4+ T lymphocyte proliferation, and T lymphocyte apoptosis from baseline to after 72 weeks. We also evaluated efficacy at 24- and 48-week intervals to better understand the dynamics of the trial drug’s efficacy. Results: There was a significant increase in CD4+ cell counts in groups treated with the Shenling Guben Granules after 24 weeks, 48 weeks, and 72 weeks of treatment (P<0.05), and the difference in CD4+ cell counts at 24 weeks of treatment was statistically significant (P=0.010). After 48 and 72 weeks of therapy, the CD4+CD38+ cell counts in the Shenling Guben Granules group were significantly higher than in the control group (P<0.05). In the subgroup analysis of CD4+ cell counts ≥200 cells/mm3, the CD4+ cell counts in the treatment group were higher than the control group after treatment for 24, 48, and 72 weeks (P<0.05). Discussion: CD4 cell counts in HIV/AIDS patients with immunological reconstitution insufficiency can be improved to a certain extent using Shenling Guben Granules. The greater the CD4 cell count at the start, the better the therapy response. Furthermore, Shenling Guben Granules have the efficacy and safety to prevent aberrant immunological activation. A large sample size, long-term follow-up, and multiple efficacy indicators were employed to assess the therapy’s safety. Our findings will lead to new therapeutic alternatives for HIV/AIDS patients suffering from immune reconstitution deficiency. Clinical Trial Registry: Name of the registry: Sundy on promote the reconstruction of Inadequate responders in HIV/AIDS patients after combined antiretroviral therapy by Shen Ling Gu Ben Granules;Chictr.org.cn Identifier: ChiCTR1800015290, registered on March 21, 2018( http://www.chictr.org.cn/registry.aspx).

Analysis of immunopathogenesis of psoriasis in the dynamics of treatment

Оbjective — to analyze the parameters of the immune system of the organism in patients with psoriasis before and after treatment. Materials and methods. The parameters of cellular immunity in an organism estimated after the change of relative and absolute amount of T- (CD3+) and B- (CD19+) of lymphocytes and subpopulations (CD4+, CD8+, CD16+, CD25+, CD71+, CD30+, CD95+). To identify of surface structures of lymphocytes the method of direct immune fluorescence was used where fluorescent label was attached to anti-CD of mononuclear antibodies of series Leu of the firm «Becton Dikinson» (USA). Calculations were conducted on the laser instantaneous cytofluorometer of the firm «Baston» (USA). Results and discussions. The most positive influence on the parameters of the cellular link of the immune system of the organism was found in patients with psoriasis who received immunobiological therapy with the medication etanercept in combination with narrowband (311 nm) phototherapy. After treatment in patients of this group, due to a significant decrease in the production of TNF and its serum concentration, the pro-inflammatory changes in the cellular link of the immune system decreased, the number of lymphocytes with the an early activation marker, which initiated a further cytokine cascade of development and prolongation of inflammation decreased significantly. In addition, the established reduction in the number of CD30+ lymphocytes is an indirect factor indicating the switching of the Tx2 response (autoimmune manifestations) to Tx1, and hence the achievement of the clinical and immunological remission of the psoriatic process. It is extremely important for the functioning of the immune system the decrease in the content of activated lymphocytes that express the Fas-receptor as due to the increased lymphocyte apoptosis, namely, T-cytotoxic lymphocytes, and autoimmune and proliferative changes took place inherent in the exacerbation of the psoriatic process. Conclusions. It was established that all our schemes of psoriasis treatment have immunorehabiting properties but their degree of severity was different. The most effective treatment scheme is the combined use of etanercept and UVB therapy, thus proliferative and inflammatory changes in the skin reduced, antigenic loading decreased, the level of CICs, autosensibilization and autoimmune disorders also decreased.

Comparison the impact of mesenchymal stromal cells, their microvesicles and plasma enriched with soluble platelet factors on survival and apoptosis of rat spleen lymphocytes <i>in vitro</i>

BACKGROUND: The trophic function is one of the important but insufficiently studied features of mesenchymal stromal cells (MSCs), their microvesicles (MVs), and plasma enriched with soluble platelet factors (PRPs), which ensure the viability of target cells. AIM: To analyze the capability of MSCs, MVs, and PRP to affect the viability and spontaneous and activation-induced apoptosis of rat spleen lymphocytes during culturing in vitro. MATERIALS AND METHODS: MSCs were isolated from the mononuclear cell fraction of the femoral bone marrow of Wistar rats using the plastic adhesion method. MVs were obtained from the conditioned medium of MSCs by centrifugation at 14,500 g. PRP was prepared by freezing/thawing rat peripheral blood platelet concentrate. Rat spleen lymphocytes were isolated on a density gradient of 1.077 g/cm3. The viability and degree of lymphocyte apoptosis in vitro were assessed by flow cytometry for 7-AAD incorporation and binding to annexin V. RESULTS: The presence of MSCs at 10 and 20% concentrations caused an increase in the number of living intact and PMA-activated lymphocytes by the end of 3-day in vitro cultivation. Compared with controls, the amount of necrotic cells decreased 8.3–13.5 times, and the number of apoptotic cells decreased 2.3–4.0 times, mainly due to lymphocytes at the late stage of apoptosis. MVs of MSCs at the indicated concentrations did not significantly affect the viability of lymphocytes cultured in vitro but reduced the level of apoptosis of intact and PMA-activated lymphocytes by 3.6 (р=0.03) and 4.8–5.2 (р=0.048; р=0.03) times respectively. Studies have shown that 1.25% rat PRP has a growth-stimulatory activity against MSCs but not against lymphocytes cultured in vitro. In the culture of intact lymphocytes, PRPs did not significantly affect cell viability with a slight decrease (2.7–2.9 fold, p 0.05) in the number of necrotic cells. In the culture of PMA-activated lymphocytes, 1.25–2.50% PRP increased the number of living cells by 1.6–2.2 times (р=0.002; р=0.01) and the number of necrotic cells by two times (р=0.02). CONCLUSION: MSCs, MVs of MSCs, and PRP, in decreasing order, enhanced the viability of rat spleen lymphocytes and suppressed late apoptosis during in vitro cultivation. Lymphocytes activated by phorbol myristate acetate are more sensitive to their vital action compared with resting cells.

Investigating the relationship between lymphocyte cells apoptosis and DNA damage and oxidative stress and therapeutic and clinical outcomes of COVID-19 elderly patients

BackgroundWhile COVID-19 has been controlled and deaths have decreased, the long-term consequences of COVID-19 remain a challenge we face today. This study was conducted to determine the relationship between the apoptosis of lymphocyte cells with DNA damage and oxidative stress and the therapeutic and clinical outcomes of elderly patients with COVID-19.MethodsThis study was conducted from April 2020 to May 2021 (the period of severe attacks of the epidemic peak of COVID-19) and September 2022 (the post-COVID-19 period). The study groups included elderly patients with COVID-19 hospitalized in the ICU and normal wards of the hospital as well as elderly patients with influenza. A polymerase chain reaction was used to check the validity of the studied diseases. The Annexin V/Propidium Iodide method was used to evaluate the level of apoptosis. Genotoxic effects and DNA damage were assessed by the comet assay method. Total antioxidant status (TAS), total oxidant status (TOS), and myeloperoxidase activity (MPO) were measured by photometric methods.ResultsThe highest level of apoptosis in peripheral blood lymphocytes and the highest level of DNA damage were observed at both times in the intubated-ICU and non-intubated-ICU groups. In all groups, there was a significant increase in peripheral blood lymphocyte apoptosis levels and DNA damage levels compared to the healthy control group (p < 0.01). The level of apoptosis and DNA damage decreased significantly in the post-COVID-19 period (p < 0.01). In the investigation of oxidative stress biomarkers, the oxidative stress index, including TOS and MPO levels, increased in patients (p < 0.01), and the TAS level decreased (p < 0.01).ConclusionIt shows that the apoptosis of lymphocyte cells, DNA damage, and oxidative stress can be effective in prognostic decisions and is a suitable predictor for diagnosing the condition of patients with viral infections such as COVID-19 and influenza.

Low-Dose Radiotherapy Attenuates Experimental Autoimmune Arthritis by Inducing Apoptosis of Lymphocytes and Fibroblast-Like Synoviocytes.

Low-dose radiotherapy (LDRT) has been explored as a treatment option for various inflammatory diseases; however, its application in the context of rheumatoid arthritis (RA) is lacking. This study aimed to elucidate the mechanism underlying LDRT-based treatment for RA and standardize it. LDRT reduced the total numbers of immune cells, but increased the apoptotic CD4+ T and B220+ B cells, in the draining lymph nodes of collagen induced arthritis and K/BxN models. In addition, it significantly reduced the severity of various pathological manifestations, including bone destruction, cartilage erosion, and swelling of hind limb ankle. Post-LDRT, the proportion of apoptotic CD4+ T and CD19+ B cells increased significantly in the PBMCs derived from human patients with RA. LDRT showed a similar effect in fibroblast-like synoviocytes as well. In conclusion, we report that LDRT induces apoptosis in immune cells and fibro-blast-like synoviocytes, contributing to attenuation of arthritis.

The histone methyltransferase KMT2D maintains cellular glucocorticoid responsiveness by shielding the glucocorticoid receptor from degradation

Because of their ability to induce lymphocyte apoptosis, glucocorticoids (GC) are widely used to treat hematological malignancies such as lymphomas and multiple myeloma. Their effectiveness is often limited, however, due to the development of glucocorticoid resistance by a variety of molecular mechanisms. Here we performed an unbiased genome-wide CRISPR screen with the human T cell leukemia cell line Jurkat to find previously unidentified genes required for GC-induced apoptosis. One such gene was KMT2D (also known as MLL2 or MLL4), which encodes a histone lysine methyltransferase whose mutations are associated with a variety of cancers, blood malignancies in particular, and are considered markers of poor prognosis. Knockout of KMT2D by CRISPR/Cas9 gene editing in Jurkat and several multiple myeloma cell lines downregulated GR protein expression. Surprisingly, this was not due to a reduction in GR transcripts, but rather to a decrease in the protein's half-life, primarily due to proteasomal degradation. Reconstitution of KMT2D expression restored GR levels. In contrast to the known ability of KMT2D to control gene transcription through covalent histone methylation, KMT2D-mediated upregulation of GR levels did not require its methyltransferase activity. Co-immunoprecipitation and proximity ligation assays found constitutive binding of KMT2D to the GR, which was enhanced in the presence of GC. These observations reveal KMT2D to be essential for stabilization of cellular GR levels, and suggest a possible mechanism by which KMT2D mutations may lead to GC resistance in some malignancies.

The effect of aluminum- and silicon-containing enterosorbent on the thymic cellular composition in mice kept under two-week all-night lighting

Background. Continuous lighting contributes to the development of desynchronosis, which is stressful for the body. As a result, the normal functioning of the immune system is disrupted, which in turn can shift the physiological balance towards pathology and endotoxemia. It is relevant to develop innovative drugs based on a sorbent matrix, which can be modified with biologically active molecules that extendedly leave the sorbent surface. At the same time, the sorbent retains the properties of a detoxifier, fixing toxic agents on the surface and removing them from the body, which helps restore the internal environment and normalizes the overall reactivity of the body in extreme conditions.The aim. To study the effect of aluminum- and silicon-containing enterosorbent (based on aluminum oxide and polydimethylsiloxane) on the cellular composition of the thymus and the distribution of thymocytes in the organ according to the cell cycling state in C57Bl/6 mice kept under the all-night lighting.Materials and methods. Animals received sorbent (0.665 g per 1 kg of body weight in 200 μl of distilled water) through an intragastric tube once a day for 14 days against the background of continuous lighting. Intact mice and placebo animals composed control group. We used flow cytometry to assess the percentage of CD3hi and CD3low lymphocytes of the thymus, the CD3low/CD3hi ratio, viability and distribution of cells across according to the cell cycling state.Results. Continuous lighting inhibited the differentiation and maturation of young CD3low lymphocytes into mature forms of CD3hi, reduced the proliferation of thymic epithelial cells, and activated apoptosis of lymphocytes and epithelial cells in the organ. The introduction of the sorbent restored the content and viability of young CD3low lymphocytes and contributed to the preservation of the viability and proliferation of thymic epithelial cells.Conclusion. Using an enterosorbent based on aluminum oxide and polydimethylsiloxane under conditions of continuous lighting helps maintain the functional activity of the thymus, preventing its involution, and is advisable against the background of circadian disruption.

Enhanced autophagy and phagocytosis of apoptotic lymphocytes in splenic macrophages of acute ethanol-treated rats: Light and electron microscopic studies.

Autophagy is a prosurvival mechanism for the clearance of damaged cellular components, specifically upon exposure to various stressors. In lymphoid organs, excessive ethanol consumption increases lymphocyte apoptosis, resulting in immunosuppression. However, ethanol-induced autophagy and related phagocytosis of apoptotic lymphocytes in the spleen have not been studied yet. Adult male Wistar rats were injected intraperitoneally either with 5 g/kg ethanol or phosphate-buffered saline (as a control group) and then sacrificed 0, 3, 6, and 24 hours after injection. Light and transmission electron microscopy (TEM) findings indicated enhanced T cell apoptosis in the white pulps of ethanol-treated rats (ETRs) compared with the control group, which peaked at 6 h and was associated with the accumulation of tingible body macrophages (TBMs). These macrophages exhibited an upregulated autophagic response, as evidenced by enhanced LC3-II (a specific marker of autophagosomes) expression, which peaked at 24h. In addition, double labeling immunofluorescence of LC3-II with lysosomal markers revealed the enhanced formation of autolysosomes in TBMs of ETRs, which was associated with suppression of p62 immunostaining, indicating the enhanced autophagic flux. Interestingly, this elevated autophagic response in ETR TBMs was accompanied by evidence of LC3-associated phagocytosis (LAP) of apoptotic splenocytes. This is based on TUNEL/LC3-II double labeling and TEM observations of phagosomes containing apoptotic bodies, enclosed within phagosomal membranes adjacent to the autophagic vacuoles. It can be concluded that enhanced prosurvival autophagy in splenic TBMs of ETRs and clearing of apoptotic lymphocytes via LAP may contribute to preventing secondary necrosis and autoimmune diseases.

9-cis-retinoic acid signaling in Sertoli cells regulates their immunomodulatory function to control lymphocyte physiology and Treg differentiation

BackgroundTestis is an immune privileged organ, which prevents the immune response against sperm antigens and inflammation. Testicular cells responsible for immune tolerance are mainly Sertoli cells, which form the blood-testis barrier and produce immunosuppressive factors. Sertoli cells prevent inflammation in the testis and maintain immune tolerance by inhibiting proliferation and inducing lymphocyte apoptosis. It has been shown that 9-cis-retinoic acid (9cRA) blocks ex vivo apoptosis of peripheral blood lymphocytes and promotes the differentiation of Treg cells in the gut. However, the role of retinoid signaling in regulating the immune privilege of the testes remains unknown.ObjectiveThe aim of this study was to determine whether 9cRA, acting via the retinoic acid receptors (RAR) and the retinoic X receptors (RXR), controls the immunomodulatory functions of Sertoli cells by influencing the secretion of anti-inflammatory/pro-inflammatory factors, lymphocyte physiology and Treg cell differentiation.MethodsExperiments were performed using in vitro model of co-cultures of murine Sertoli cells and T lymphocytes. Agonists and antagonists of retinoic acid receptors were used to inhibit/stimulate retinoid signaling in Sertoli cells.ResultsOur results have demonstrated that 9cRA inhibits the expression of immunosuppressive genes and enhances the expression of pro-inflammatory factors in Sertoli cells and lymphocytes, increases lymphocyte viability and decreases apoptosis rate. Moreover, we have found that 9cRA blocks lymphocyte apoptosis acting through both RAR and RXR and inhibiting FasL/Fas/Caspase 8 and Bax/Bcl-2/Caspase 9 pathways. Finally, we have shown that 9cRA signaling in Sertoli cells inhibits Treg differentiation.ConclusionCollectively, our results indicate that retinoid signaling negatively regulates immunologically privileged functions of Sertoli cells, crucial for ensuring male fertility. 9cRA inhibits lymphocyte apoptosis, which can be related to the development of autoimmunity, inflammation, and, in consequence, infertility.

Lymphocyte radiosensitivity: An extension to the linear-quadratic model?

Background and purposeThe linear-quadratic (LQ) model has been pivotal for evaluating the effects of radiation on cells, but it is primarily characterized by linear responses, which has exhibited limitations when applied to lymphocyte data. The present research aims to address these limitations and to explore an alternative model extended from the conventional LQ model. Materials and methodsLiterature providing lymphocyte counts from assays investigating apoptosis and survival after in vitro irradiation was selected. To address the nonlinearity in lymphocyte responses to radiation, we developed a saturation model characterized by a negative exponential relationship between radiation dose and cellular response. We compared the performance of this saturation model against that of conventional models, including the LQ model and its variants (linear model LM and linear-quadratic-cubic model LQC), as well as the repair-misrepair (RMR) model. The models were evaluated based on prediction-residual plots, residual standard errors, and the Akaike information criterion (AIC). We applied the saturation model to two additional datasets: (1) a dataset from the existing literature that assessed stimulated and unstimulated human lymphocytes exposed to gamma irradiation in vitro and (2) a novel dataset involving T lymphocytes from rodent spleens after exposure to various radiation types (X-rays and protons). ResultsThe literature (n = 15 out of 2342) showed that lymphocyte apoptosis varies with dose, time and experimental conditions. The saturation model had a lower AIC of 718 compared to the LM, LQ, LQC and RMR models (AIC of 728, 720, 720 and 734, respectively). The saturation model had a lower residual error and more consistent error distribution. Integrating time as a covariate, the saturation model also had a better AIC for demonstrating time-dependent variations in lymphocyte responses after irradiation. For datasets involving unstimulated lymphocytes before irradiation, the saturation model provided a more accurate fit than did the LM, LQ, and RMR models. In these cases, the fit of the saturation model was comparable to that of the LQC model but offered an advantage when extrapolating to higher doses, where the LQC model might underestimate survival. For stimulated lymphocytes, which are radioresistant, all the models approximated the LM. Both the LQ and saturation models indicated greater radiosensitivity to protons in vitro. ConclusionThe new “saturation model” performed better than the LQ model in quantifying lymphocyte apoptosis and survival, estimating time dependency and assessing the role of radiation modalities or lymphocyte stimulation. Further experiments are warranted to experimentally explore the validity of the saturation model as a promising alternative in the clinical setting.

Expression of FoxO3a in sepsis mice and its association with lymphocyte apoptosis.

This study investigated forkhead box O3a (FoxO3a) expression in peripheral blood of sepsis mice and its correlation with lymphocyte apoptosis. Sixty male C57 mice were randomly assigned to sham, model, and intervention groups. Sepsis was induced via cecal ligation in the model and intervention groups, while sham mice underwent similar procedures excluding cecal ligation. Apoptosis proteins in lymphocytes were assessed by Western blotting, reactive oxygen species (ROS) levels by 2,7-Dichlorodi-hydrofluorescein diacetate (DCFH-DA), and serum interleukin-1β (IL-1β) and IL-10 content. The model group exhibited elevated mortality, increased lymphocyte apoptosis, higher Caspase3 expression, and lower Bcl-2/Bax ratio compared to sham and intervention groups. Additionally, the model group displayed decreased serum IL-10, elevated IL-1β, heightened lymphocytic ROS, reduced FoxO3a expression, and increased levels of p-FoxO3a, p-PI3K, and p-Akt compared to sham. In sepsis mice, inhibited FoxO3a signaling in lymphocytes leads to enhanced apoptosis, elevated ROS, and immune cell dysfunction, contributing to increased mortality.

Network pharmacology combined with an experimental validation study to reveal the effect and mechanism of Lonicera japonica Thunb. extracts against immunomodulation.

Lonicera japonica Thunb. (LJT) is known for its valuable medicinal properties that highlight its potential application in the pharmaceutical and health food industry. We predict that LJT polyphenols by network pharmacology may be involved in immunomodulation, and the study of LJT polyphenols regulating immunity is still insufficient; therefore, we experimentally found that LJT enhances immunity by promoting the proliferation and phagocytic activity of RAW246.7 cells. A model of an immunosuppressed mouse was constructed using cyclophosphamide-induced, and LJT was extracted for the intervention. We found that LJT restored immune homeostasis in immune deficiency mice by inhibiting the abnormal apoptosis in lymphocytes, enhancing natural killer cell cytotoxicity, promoting T lymphocyte proliferation, and increasing the CD4+ and CD8+ T lymphocytes in quantity. Moreover, LJT treatment modulates immunity by significantly downregulating lipopolysaccharide-induced inflammation and oxidative stress levels. We verified the immunomodulatory function of LJT through both cell and animal experiments. The combination of potential-protein interactions and molecular docking later revealed that LJT polyphenols were associated with immunomodulatory effects on MAPK1; together, LJT intervention significantly modulates the immune, with the activation of MAPK1 as the underlying mechanism of action, which provided evidence for the utilization of LJT as a nutraceutical in immune function.

Comparing the pharmacological effects of the prepared folium of Epimedium brevicornu Maxim. and Epimedium sagittatum Maxim. on kidney-Yang deficiency syndrome and liver injury complications

Yinyanghuo, a famous herb, includes the folium of Epimedium brevicornu Maxim. and Epimedium sagittatum Maxim. It is believed that their processed products, the prepared slices of the folium of Epimedium brevicornu Maxim. (PFEB) and Epimedium sagittatum Maxim. (PFES) have greater efficacy in tonifying kidney Yang to treat kidney-Yang deficiency syndrome (KDS). However, there are few studies comparing the pharmacological effects of PFEB and PFES, and the underlying mechanisms. This study compared their effects on improving hypothalamic-pituitary-adrenal (HPA) axis, immune system and sexual characteristic, as well as repairing liver injury complications in the KDS model mice. Additionally, the mechanisms of the effects relevance to their main components were explored. It was found that PFEB was more effective than PFES in increasing cAMP/cGMP ratio, SOD activity, CRH and ACTH levels, eNOS and testosterone levels, splenic lymphocytes proliferation, while in decreasing MDA content, atrophy of spleen and thymus, splenic lymphocytes apoptosis, and PDE5 level. PFES showed stronger protection than PFEB in decreasing triglyceride and hepatic lipid. The contents of baohuoside I and epimedin A, B were much higher in PFEB, while Epimedin C, Icariin, 2-O″-rhamnosylicaridide II were higher in PFES. Consequently, PFEB exhibits superior efficacy over PFES in tonifying the kidney-Yang by improving the neuroendocrine-immune network, including HPA axis, immune systems, and corpus cavernosum. However, PFES has better recovery effect on mild hepatic lipid caused by KDS. The efficacy difference between PFEB and PFES in kidney-Yang and liver may be attributed to the content variations of baohuoside I.

HMGB1 promotes neutrophil PD-L1 expression through TLR2 and mediates T cell apoptosis leading to immunosuppression in sepsis

Neutrophils and T lymphocytes are closely related to occurrence of immunosuppression in sepsis. Studies have shown that neutrophil apoptosis decreases and T lymphocyte apoptosis increases in sepsis immunosuppression, but the specific mechanism involved remains unclear. In the present study, we found Toll-like Receptor 2 (TLR2) and programmed death-ligand 1 (PD-L1) were significantly activated in bone marrow neutrophils of wild-type mice after LPS treatment and that they were attenuated by treatment with C29, an inhibitor of TLR2. PD-L1 activation inhibits neutrophil apoptosis, whereas programmed death protein 1 (PD-1)activation promotes apoptosis of T lymphocytes, which leads to immunosuppression. Mechanistically, when sepsis occurs, pro-inflammatory factors and High mobility group box-1 protein (HMGB1) passively released from dead cells cause the up-regulation of PD-L1 through TLR2 on neutrophils. The binding of PD-L1 and PD-1 on T lymphocytes leads to increased apoptosis of T lymphocytes and immune dysfunction, eventually resulting in the occurrence of sepsis immunosuppression. In vivo experiments showed that the HMGB1 inhibitor glycyrrhizic acid (GA) and the TLR2 inhibitor C29 could inhibit the HMGB1/TLR2/PD-L1 pathway, and improving sepsis-induced lung injury. In summary, this study shows that HMGB1 regulates PD-L1 and PD-1 signaling pathways through TLR2, which leads to immunosuppression.

Patients with STAT1 Gain-of-function Mutations Display Increased Apoptosis which is Reversed by the JAK Inhibitor Ruxolitinib

IntroductionThe signal transducer and activator of transcription (STAT1) gain-of-function (GOF) syndrome accounts for most cases of chronic mucocutaneous candidiasis but is characterized by a broader clinical phenotype that may include bacterial, viral, or invasive fungal infections, autoimmunity, autoinflammatory manifestations, vascular complications, or malignancies. The severity of lymphopenia may vary and influence the infectious morbidity.MethodsIn our cohort of seven STAT1-GOF patients, we investigated the mechanisms that may determine T lymphopenia, we characterized the interferon gene signature (IGS) and analyzed the effect of ruxolitinib in reverting the immune dysregulation.ResultsSTAT1-GOF patients exhibited increased T lymphocyte apoptosis that was significantly augmented in both resting conditions and following stimulation with mitogens and IFNα, as evaluated by flow cytometry by Annexin V/ Propidium iodide assay. The JAK inhibitor ruxolitinib significantly reduced the IFNα-induced hyperphosphorylation of STAT1 and reverted the stimulation-induced T-cell apoptosis, in vitro. In two adult STAT1-GOF patients, the JAKinib treatment ameliorated chronic mucocutaneous candidiasis and lymphopenia. Most STAT1-GOF patients, particularly those who had autoimmunity, presented increased IGS that significantly decreased in the two patients during ruxolitinib treatment.ConclusionIn STAT1-GOF patients, T lymphocyte apoptosis is increased, and T lymphopenia may determine higher risk of severe infections. The JAKinib target therapy should be evaluated to treat severe chronic candidiasis and lymphopenia, and to downregulate the IFNs in patients with autoinflammatory or autoimmune manifestations.