Number Of NK Cells Research Articles

TLR3 activation enhances antitumor effects of sorafenib in hepatocellular carcinoma by activating NK cell functions through ERK and NF-κB pathways

Background Sorafenib is a standard therapeutic agent for advanced hepatocellular carcinoma (HCC). However, its efficacy is moderate, as the survival of patients is prolonged for only a few months, and the response rate is low. The mechanism of low efficacy remains unclear. In this study, we investigated the effect of Toll-like receptor 3 (TLR3) on the effects of sorafenib on HCC. Methods Polyinosinic-polycytidylic acid [poly(I: C)] was used as a double-stranded RNA analog and TLR3 agonist in subsequent experiments. After orthotopic implantation of HCC tumors in BALBc nu/nu or C57BL/6 mice, survival time, tumor growth, and metastasis in the abdomen and lungs were analyzed. Flow cytometry and cytotoxicity assays were used to analyze NK cells isolated from the spleen or peripheral blood. ELISA was used to detect the expression of plasma interferon (IFN)-γ and monocyte chemoattractant protein (MCP)-1. In addition, the expression of phosphorylated-extracellular regulated kinase 1/2 (pERK1/2), phosphorylated-protein kinase B (pAKT), ERK1/2 and AKT was analyzed by Western blotting. Results Sorafenib reduced the number and activity of NK cells in tumor-bearing mice and simultaneously decreased the levels of MCP-1 and IFN-γ in the plasma. The combination of sorafenib and poly(I: C) synergistically inhibited tumor growth and metastasis in tumor xenograft mice and prolonged survival. Poly(I: C) not only exerts a direct inhibitory effect on tumor growth and metastasis by targeting the TLR3 receptor on tumor cells but also facilitates the proliferation and activation of NK cells, indirectly impeding tumor progression. Mechanistically, poly(I: C) decreased the sorafenib-induced inhibition of ERK phosphorylation and increased the phosphorylation of IκB in NK cells, thereby enhancing NK cell function. Conclusion Activation of TLR3 can enhance the antitumor effect of sorafenib on HCC. The combination of a TLR3 activator and sorafenib may be a new strategy for the treatment of HCC.

New concept for the prevention of acute respiratory infections

Medical personnel and family members of patients with acute respiratory diseases (ARD) are at increased risk of infection during epidemics or pandemics. In this regard, it is necessary to develop and implement accessible preventive measures. The aim of the study was to evaluate the effectiveness of the use of IFNα-2b for the prevention of acute respiratory viral infections in persons located at the source of infection (medical personnel and members of their families). Patients (n = 31) with acute respiratory infections and 117 people from their environment (family members in constant contact with patients) were examined. The subjects underwent a clinical examination and laboratory tests a clinical blood test and a study of the content of the main populations and subpopulations of lymphocytes in the blood. Persons in contact with ARD patients were divided into three groups: persons who received the drug “Grippferon” for 7 days; persons who received the drug “Grippferon” in a prophylactic dose for 7 days; persons in contact with patients with ARD but who have not received the drug “Grippferon”. When assessing the state of the immune system, it was found that the most common type of immune reaction in patients and their people around was activation of innate immunity (48.39% and 66.67%, respectively). At the same time, immunodeficiency in the group of patients with ARD was detected much more often than in persons in contact with them. In addition, patients were more likely to have monocytosis (1.4 times), T lymphocytopenia (2.1 times) and an increase in the number of regulatory T lymphocytes (7.6 times). More than 50% of those examined in both groups showed an increase in the number of NK cells in the blood. An examination of persons in contact with patients with ARD after 7 days of using the “Grippferon” in different doses revealed that the lowest frequency of acute respiratory viral infections symptoms was found in the group receiving IFN at a therapeutic dose. In the group receiving IFN in a prophylactic dose, the frequency of acute respiratory viral infection (ARVI) symptoms was detected in almost 40% of those examined. More than 80% of people from the group who did not receive the “Grippferon” had symptoms of ARVI after a week of contact with patients with ARD. Thus, the use of IFN in therapeutic doses during the epidemic for persons in contact with patients is proposed as a new concept for the prevention of ARD.

Some Glycoproteins Expressed on the Surface of Immune Cells and Cytokine Plasma Levels Can Be Used as Potential Biomarkers in Patients with Colorectal Cancer

Colorectal cancer (CRC) is a leading cause of mortality worldwide. Its incidence holds a major position among the most common life-threatening diseases. Hence, the early identification and precise characterization of disease activity based on proper biomarkers are of utmost importance for therapeutic strategy and patient survival. The identification of new biomarkers for colorectal cancer or disease-specific levels/combinations of biomarkers will significantly contribute to precise diagnosis and improved personalized treatment of patients. Therefore, the present study aims to identify colorectal cancer-specific immunological biomarkers. The plasma levels of several cytokines (interleukin-1β /IL-1β/, IL-2, IL-4, IL-10, IL-12, IL-15, TGFβ and IFNγ) of 20 patients with colorectal cancer and 21 healthy individuals were determined by ELISA. The expression of several types of glycoproteins on the surface of peripheral blood leukocytes isolated from CRC patients and healthy volunteers was evaluated by flow cytometry. Correlations between cytokine levels and cell surface glycoprotein expression were analyzed. The obtained results demonstrated significantly elevated levels of CD80, CD86, CD279 and CD274 expressing leukocyte populations in the cancer patient group, while the numbers of NK cells and CD8- and CD25-positive cells were decreased. Based on these data and the correlations with cytokine levels, it can be concluded that CD25, CD80, CD86, CD274 and CD279 glycoproteins combined with specific plasma levels of IL-1β, IL-2, IL-15 and TGFβ could represent potential biomarkers for colorectal cancer.

STYK1 mediates NK cell anti-tumor response through regulating CCR2 and trafficking

The serine/threonine/tyrosine kinase 1 (STYK1) is a receptor protein-tyrosine kinase (RPTK)-like molecule that is detected in several human organs. STYK1 plays an important role in promoting tumorigenesis and metastasis in various cancers. By analyzing the expression of RTKs in immune cells in the database of 2013 Immunological Genome Project, we found that STYK1 was principally expressed in NK cells. In order to investigate the function of STYK1, we used CRISPR/Cas9 technology to generate STYK1-deleted mice, we found STYK1 deletion mice have normal number, development, and function of NK cells in spleen and bone marrow in tumor-free resting state. To examine the tumor surveillance of STYK1 in vivo, we utilized a variety of tumor models, including NK cell-specific target cell (ß2M and RMA-S) clearance experiments in vivo, subcutaneous and intravenous injection of B16F10 melanoma model, and the spontaneous breast cancer model MMTV-PyMT. Surprisingly, we discovered that deletion of the oncogenic STYK1 promoted the four-model tumor progression, and we observed a reduction of NK cell accumulation in the tumor tissues of STYK1 deletion mice compared to WT mice. In order to study the mechanism of STYK1 in NK, RNA sequence of STYK1−/− and WT NK have unveiled a disparity in the signaling pathways linked to migration and adhesion in STYK1−/− NK cells. Further analysis of chemokine receptors associated with NK cell migration revealed that STYK1-deficient NK cells exhibited a significant reduction in CCR2 expression. The STYK1 expression was negatively associated with tumor progression in glioma patients. Overall, our study found the expression of STYK1 in NK cell mediates NK cell anti-tumor response through regulating CCR2 and infiltrating into tumor tissue.

Targeting CD3-CD16+CD56+ NK Cells and NK Cell Activity by Intralipid in the Management of Reproductive Failure

Immunological risk factors in recurrent pregnancy loss include autoantibodies, alterations in NK cell number and function, regulatory T cells, the human leukocyte antigen system (HLA), etc., where the treatment options aim to regulate immune dysfunction. Intralipid is a synthetic product traditionally used as a dietary supplement consisting of soybean oil combined with refined egg phospholipids. It has been shown that intralipid exerts physiologic activities, including altering immunological functions, that may benefit patients with certain types of infertility. In this review, we summarize the current state of the art of targeting NK cells and NK cell activity in women with implantation failure or/and recurrent pregnancy loss. We focus on intralipid mechanisms of action and outcomes of clinical trials regarding the efficacy and safety of intralipid infusions in women with reproductive failure. More studies are needed to reveal all the aspects of the safety and effectiveness of intralipid administration in reproductive failure treatment.

Increased CRHR1 expression on monocytes from patients with AA enables a pro-inflammatory response to corticotrophin-releasing hormone.

Stress may play a key role in alopecia areata (AA), though the exact interactions of stress with AA remain undefined. Corticotropin-releasing hormone (CRH), the proximal regulator of the stress axis, has been recognized as an immunomodulatory factor in tissues and peripheral blood mononuclear cells (PBMCs). We used multicolour flow cytometry to identify receptor CRHR1 expression on PBMC subsets in AA patients (n = 54) and controls (n = 66). We found that CRHR1 was primarily expressed by circulating monocytes. CRHR1 expression on monocytes was enhanced in AA compared with controls (3.17% vs. 1.44%, p = 0.002, chi-squared test). AA incidence was correlated to elevated CD14+ monocyte numbers (R = 0.092, p = 0.036) and markedly independently correlated with increased CRHR1 expression (R = 0.215, p = 0.027). High CRHR1 expression was significantly related to chronic AA (disease duration >1 year; p = 0.003, chi-squared test), and large lesion area (AA area >25%; p = 0.049, chi-squared test). We also observed enhanced percentages of active monocytes and reduced CD16+ CD3- NK cell numbers in AA patients' PBMCs (p = 0.010; 0.025, respectively). Invitro CRH treatment of PBMCs and human monocyte cell line THP-1 promoted CD86 upregulation. The findings imply that stress-related factors CRH and CRHR1 contribute to AA development and progression where higher CRHR1 expression is associated with chronic AA and larger lesions.

The impact of supervised and home exercise activity intervention on circulating immune cell numbers in cancer patients

IntroductionMalignant diseases challenge clinicians to balance treatment intensity and patient quality of life. Regular physical activity positively impacts mental and physical health, benefiting sleep patterns, heart rate, and overall health. Moreover, telehealth physical exercise training represents a viable option for maintaining intrinsic capacity. The American Cancer Society highlights exercise's role in helping patients cope with anti-cancer treatment side effects. In the Czech Republic, there is no fitness-promoting protocol for cancer patients, despite recognized benefits. Exercise may also enhance immune function, with moderate-intensity exercise potentially positively affecting immune cell counts. ObjectiveThis study aimed to analyze the long-term effects of exercise on circulating immune cells in patients undergoing treatment for solid malignancies. Patients and methods49 participants were recruited at the Masaryk Memorial Cancer Institute, Czech Republic, starting September 2021. Participants were randomized into an experimental (SAPA = undergoing monitored exercise program) group (N = 16; madian age: 46,6; median BMI: 25,1) and a control (CO) group (N = 33; madian age: 52,0; median BMI: 25,3). Flow cytometry was used to examine cellular immunological profiles. The exercise program involved thrice-weekly sessions conducted online. ResultsSAPA group showed stable lymphocyte counts post-exercise (percentage chance: +0,5 %; p = 0,256; effect size r = −0,284), while the CO group exhibited a significant drop (percentage chance: −23,0 %; p = 0,015; effect size r = −0,423). B lymphocyte numbers were significantly higher in the SAPA group post-exercise compared to the CO group (p = 0,003; effect size r = −0,422). The number of Th-lymphocytes, T-c lymphocytes, T-gamma/delta lymphocytes, and NK cells remained stable in SAPA but dropped in CO group. ConclusionExercise's impact on the immune system in cancer patients shows promise, with differences noted between acute and chronic exercise effects. Previous studies on acute exercise indicate a rise in immune cell counts, supporting our findings of stable or increased immune cells with controlled exercise in cancer patients. Controlled physical activity stabilizes or increases certain immune cell populations in patients undergoing chemotherapy for solid malignancies, highlighting the potential benefits of incorporating exercise into cancer treatment protocols.

A CD38/CD3xCD28 trispecific T‐cell engager as a potentially active agent in multiple myeloma patients relapsed and/or refractory to anti‐CD38 monoclonal antibodies

SummaryThere is accumulating evidence of BCMA and GPRC5D loss after treatment with T‐cell redirecting therapies in patients with relapsed/refractory multiple myeloma (RRMM). While complete CD38 loss is not observed upon relapses after treatment with anti‐CD38 monoclonal antibodies (mAb), there is downregulation of surface CD38 expression and decreased number and function of NK cells, which renders these patients resistant to retreatment with anti‐CD38 mAb. Here, we provide preclinical evidence that RRMM patients previously exposed to anti‐CD38 mAb could benefit from T‐cell‐based immunotherapy that depend less on CD38 antigen density and NK‐cell activity, such as the novel CD38/CD3xCD28 trispecific T‐cell engager, SAR442257.

A mechanistic study of radiotherapy on intratumoral NK cell infiltration augmentation by regulating the EZH2/CXCL10 pathway in hepatocellular carcinoma cells

Objective: To investigate the effect and associated mechanism of tumor tissue-infiltrating NK cells after receiving radiotherapy for hepatocellular carcinoma (HCC). Methods: A HCC tumor-bearing mouse model was constructed using human hepatocellular carcinoma cell line (SK-Hep-1) and divided into four groups: control, radiotherapy, NK cell clearance, and NK clearance combined with radiotherapy. Tumor growth condition was simultaneously recorded. The NK cell ratio in peripheral blood and the NK cell intratumoral infiltration condition were detected by flow cytometry and immunohistochemistry. Lentiviral-constructed SK-Hep-1 cells was used to detect the effect of radiotherapy on the regulation of CXCL10 and NK cell chemotaxis following EZH2 overexpression. SK-Hep-1 cells were irradiated in vitro and in vivo. The expression levels of EZH2 and CXCL10 mRNA and protein in the two groups of cell lines and mouse tumor tissues were detected by reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), western blotting (WB), and immunohistochemistry. The chemotaxis and blocking experiments were used to validate the chemotaxis effect of CXCL10 on NK cells. The independent sample t-test was used to compare the groups. P<0.05 was considered statistically significant. Results: The HCC tumor-bearing mouse model experiment showed that HCC tumor growth was most remarkable in the NK clearance combined with the radiotherapy group compared to the radiotherapy group (P<0.05). Compared with the control group, the number of NK cells in the peripheral blood of nude mice in the radiotherapy group was significantly reduced, while the NK cell intratumoral infiltration was significantly increased (P<0.05). Flow cytometry and immunohistochemistry showed in vitro and in vivo expressional alterations. The average expression levels of EZH2 mRNA and protein in hepatocellular carcinoma cell lines and tumor tissues were decreased in the radiotherapy group than the control group and mouse tumor tissues (P<0.05), while the mRNA and protein expression levels of CXCL10 increased (P<0.05). The cell supernatant following radiotherapy enhanced NK cell chemotaxis but inhibited CXCL10 neutralization. EZH2 overexpression validated that radiotherapy up-regulated CXCL10 mRNA and down-regulated protein expression levels in in vitro and in vivo experiments (P<0.05). The chemotactic effect on NK cells was significantly weakened with EZH2 overexpression following radiotherapy. Conclusion: NK cells, as immune effector cells, are directly involved in radiotherapy- activated anti-HCC immunity. Importantly, radiotherapy inhibits EZH2 expression in hepatocellular carcinoma, thereby upregulating CXCL10 expression and enhancing intratumoral NK cell invasion.

Speleoclimatoterapy: psychophysiological mechanisms of influence on the organism of a healthy person

The article considers some psychophysiological mechanisms of the impact of speleoclimate on the human body. The mechanisms of increasing the reserves of the human neuroimmunoendocrine system as a result of a 10-day course of speleotherapy were revealed. Under the influence of speleoclimate, the content of T-lymphocytes, T-helpers, T-cytotoxic lymphocytes increased, an increase in early and late activation of T-lymphocytes and T-regulatory cells, an increase in the number of B-cells and NK cells with the CD3-CD16-CD56+ phenotype; the frequency of occurrence of epithelial cells of the oral cavity with nuclear aberrations decreased. It is noted that the influence of the speleoclimate on the human body is mainly limited by intrasystemic influences, affecting the regulatory system at the level of vagosympathetic interaction. It was revealed that the course of speleotherapy improves the speed of the visual signal, the speed of primary processing of information and the speed of analysis of visual information in terms of the parameters of the sEP. The mechanisms of influence of speleotherapy on the neuroimmunoendocrine system are determined by the initial psychophysiological state of a person. Under the influence of speleotherapy, the vegetative status is restored.

Proliferation capability of natural killer cells upon cytokines stimulation correlated negatively with serum lactate dehydrogenase level in coronary artery disease patients.

Natural killer (NK) cells are proposed to participate in coronary artery disease (CAD) development. However, little is known about how CAD patients' NK cells respond to different stimulatory factors in terms of proliferation capability. Twenty-nine CAD patients' peripheral blood NK cells were isolated and individually treated with IL-2, IL-12, IL-15, IL-18, IL-21, cortisone acetate, hydrocortisone, or ascorbic acid for 36 hours, followed by cell cycle analysis using flow cytometry. The ratio of S and G2/M phase cell number to total cell number was defined as a proliferation index (PrI) and used for proliferative capability indication. The results showed that these eight factors resulted in different life cycle changes in the 29 NK cell samples. Remarkably, 28 out of 29 NK cell samples showed an obvious increase in PrI upon ascorbic acid treatment. The serum lactate dehydrogenase (LDH) level of the 29 CAD patients was measured. The results showed a negative correlation between serum LDH level and the CAD patients' NK cell PrI upon stimulation of interleukins, but not the non-interleukin stimulators. Consistently, a retrospective analysis of 46 CAD patients and 32 healthy donors showed that the circulating NK cell number negatively correlated with the serum LDH level in CAD patients. Unexpectedly, addition of LDH to NK cells significantly enhanced the production of IFN-γ, IL-10 and TNF-α, suggesting a strong regulatory role on NK cell's function. Ascorbic acid could promote the proliferation of the CAD patients' NK cells; LDH serum level may function as an indicator for NK cell proliferation capability and an immune-regulatory factor.

Establishment of NK Cell Natural Immunotherapy for Cancer Prevention and Treatment Using the Natural Terpenes Derived from Forest Phytoncide

The active ingredient of forest phytoncide has many remarkable biological activities, especially in the aspect of anti-tumor. It can activate NK cells, increase the number of NK cells and the expression level of anti-cancer protein in NK cells, induce the self-apoptosis of cancer cells, and help the human body effectively complete the cellular immune anti-cancer mechanism. If we replace ordinary air with natural forest air as a new pressurizing medium and input it into the hyperbaric oxygen chamber, after being processed by hyperbaric oxygen chamber oxygen production technology, the high pressure oxygen of forest phytoncide is generated. At this time, the high pressure oxygen inhaled into the body is different from natural forest air or ordinary air. The fundamental difference is that the high pressure oxygen inhaled into the body at this time contains both high concentration of oxygen and high concentration of phytoncide, moreover the phytoncide concentration and oxygen concentration are much higher than the natural forest air or ordinary air. After it is inhaled by the human body into the alveoli, it can reach the peripheral blood through the pulmonary circulation and systemic circulation, and the high concentration of the active component terpene of phytoncide has an opportunity to directly contact NK cells and fully play the biological activity of activating NK cells. The high pressure oxygen that enters the alveoli simultaneously with phytoncide gas also passes through the pulmonary and systemic circulation, reaches the peripheral blood, Oxygen is released from the oxygenated hemoglobin, passes through the cell membrane and enters the mitochondria in the cells to provide sufficient energy for the physiological activities of NK cells. By applying this basic principle, we can establish a satisfactory NK cell natural immunotherapy for cancer prevention and treatment that can be accepted by humanity in the long run.

The different paradigms of NK cell death in patients with severe trauma

Lymphocyte decline, particularly the depletion of NK cells, is a prominent feature of immunosuppression following severe tissue injury, heightening the susceptibility of severe trauma patients to life-threatening infections. Previous research indicates that the reduction in the number of NK cells is closely associated with the process of cell death. Nonetheless, the precise mechanism of NK cell death remains unknown. Here, we discovered that following severe traumatic injury, NK cells undergo several cell death pathways, dominated by apoptosis and pyroptosis with coexistence of necrotic cell death, immunogenic cell death, ferroptosis, and autophagy. These NK cells with different paradigms of death have diverse cytokine expression profiles and diverse interactions with other immune cells. Further exploration revealed that hypoxia was strongly associated with this diverse paradigm of NK cell death. Detailed investigation of paradigms of cell death may help to enhance comprehension of lymphopenia post-severe trauma, to develop new strategy in preventing immunosuppression, and then to improve outcome for severe trauma population.

Potential role of B- and NK-cells in the pathogenesis of pediatric aplastic anemia through deep phenotyping.

Pediatric patients with unexplained bone marrow failure (BMF) are often categorized as aplastic anemia (AA). Based on the accepted hypothesis of an auto-immune mechanism underlying AA, immune suppressive therapy (IST) might be effective. However, due to the lack of diagnostic tools to identify immune AA and prognostic markers to predict IST response together with the unequaled curative potential of hematopoietic stem cell transplantation (HSCT), most pediatric severe AA patients are momentarily treated by HSCT if available. Although several studies indicate oligoclonal T-cells with cytotoxic activities towards the hematopoietic stem cells, increasing evidence points towards defective inhibitory mechanisms failing to inhibit auto-reactive T-cells. We aimed to investigate the role of NK- and B-cells in seven pediatric AA patients through a comprehensive analysis of paired bone marrow and peripheral blood samples with spectral flow cytometry in comparison to healthy age-matched bone marrow donors. We observed a reduced absolute number of NK-cells in peripheral blood of AA patients with a skewed distribution towards CD56bright NK-cells in a subgroup of patients. The enriched CD56bright NK-cells had a lower expression of CD45RA and TIGIT and a higher expression of CD16, compared to healthy donors. Functional analysis revealed no differences in degranulation. However, IFN-γ production and perforin expression of NK-cells were reduced in the CD56bright-enriched patient group. The diminished NK-cell function in this subgroup might underly the auto-immunity. Importantly, NK-function of AA patients with reduced CD56bright NK-cells was comparable to healthy donors. Also, B-cell counts were lower in AA patients. Subset analysis revealed a trend towards reduction of transitional B-cells in both absolute and relative numbers compared to healthy controls. As these cells were previously hypothesized as regulatory cells in AA, decreased numbers might be involved in defective inhibition of auto-reactive T-cells. Interestingly, even in patients with normal distribution of precursor B-cells, the transitional compartment was reduced, indicating partial differentiation failure from immature to transitional B-cells or a selective loss. Our findings provide a base for future studies to unravel the role of transitional B-cells and CD56bright NK-cells in larger cohorts of pediatric AA patients as diagnostic markers for immune AA and targets for therapeutic interventions.

Recombinant Human Interleukin-2 Corrects NK Cell Phenotype and Functional Activity in Patients with Post-COVID Syndrome

Post-COVID syndrome develops in 10–20% of people who have recovered from COVID-19 and it is characterized by impaired function of the nervous, cardiovascular, and immune systems. Previously, it was found that patients who recovered from infection with the SARS-CoV-2 virus had a decrease in the number and functional activity of NK cells. The aim of the study was to assess the effectiveness of recombinant human IL-2 (rhIL-2) administered to correct NK cell phenotype and functional activity in patients with post-COVID syndrome. Patients were examined after 3 months for acute COVID-19 of varying severity. The phenotype of the peripheral blood NK cells was studied by flow cytometry. It was found that disturbances in the cell subset composition in patients with post-COVID syndrome were characterized by low levels of mature (p = 0.001) and cytotoxic NK cells (p = 0.013), with increased release of immature NK cells (p = 0.023). Functional deficiency of NK cells in post-COVID syndrome was characterized by lowered cytotoxic activity due to the decreased count of CD57+ (p = 0.001) and CD8+ (p 0.001) NK cells. In the treatment of patients with post-COVID syndrome with recombinant IL-2, peripheral blood NK cell count and functional potential were restored. In general, the effectiveness of using rhIL-2 in treatment of post-COVID syndrome has been proven in patients with low levels of NK cells.

Immune status of patients with community-acquired pneumonia associated with a new coronavirus infection and other viral and bacterial pathogens

Despite the fact that the state of the individual’s immune system plays an important role in developing community-acquired pneumonia, its clinical features are determined not only by immune response characteristics, but also by the nature of the infectious agent. The aim of the work was to assess immune status of patients with community-acquired pneumonia with lung damage ranging from 2 to 12%, in whom pathogens of a viral, bacterial and fungal nature were verified (n = 96, aged 46,3±20,5) who were admitted to the hospital 5–7 days after disease onset. Materials and methods. The selection of smears and sputum specimens was carried out on day 1 after admission. COVID-19 pathogen was analyzed in smears by PCR using the Vector-PCRR-2019-nCoV-RG kit (SSC Vector of Rospotrebnadzor, Russia). Biochemical activity, colony morphology, and pathogen concentration (in the amount of ≥ 105 CFU/ml) were also evaluated. Based on the results of preliminary studies, target patients groups were formed: with a new coronavirus infection caused by the SARS-CoV-2 gene variant B.1.1.529 (Omicron) (n = 33); with COVID-19 and bacterial pathogens (n = 17); with COVID-19 and combined bacterial and fungal infection (n = 16); patients with identified pathogens of bacterial infections (n = 13); patients with combined bacterial and fungal infection (n = 17). The relative and absolute level of CD45+CD3+ lymphocytes, CD45+CD3+CD4+ cells, CD45+CD3+CD8+ lymphocytes, CD45+CD3-CD16+CD56+ cells, CD45+CD3+CD16+CD56+ lymphocytes, CD45+CD45RO–CD45RA+ and CD45+CD45RO+CD45RA– lymphocytes, CD45+CD19+ cells, CD45+CD5+CD19–CD27– and CD45+CD19+CD5–CD27– lymphocytes, CD45+CD19+CD5–CD27+ cells was assessed in all volunteers. Results. The analysis of the immune status of patients with community-acquired pneumonia associated with Omicron gene variant new coronavirus infection revealed T-lymphocytopenia, a decreased number of CD8+ lymphocytes, an increased relative and absolute number of NK cells. In COVID-19 patients, who also had bacterial pathogens verified, there was a decrease in relative and absolute number of T-helper cells, an increased relative and absolute number of B and B2 lymphocytes. In COVID-19-negative volunteers with bacterial and bacterial-fungal community-acquired pneumonia, the relative and absolute level of B and B2 lymphocytes, as well as the general memory B cell population, was increased. In contrast to COVID-19-positive patients, in the absence of T-lymphocytopenia, a decreased number of CD4+ cells and rise in number of cytotoxic lymphocytes were recorded in patients of these groups. Conclusions. The data obtained indicate that in the immune status of patients with community-acquired pneumonia, depending on the nature of the infectious agent, changes in relative and absolute level of T-helper cells, cytotoxic lymphocytes, as well as in the qualitative and quantitative B-lymphocyte population composition are recorded.

O-254 The relationship between dysbiosis of vaginal microbiome and proinflammatory cytokine levels in vaginal fluid in recurrent implantation failure patients

Abstract Study question Is there any relation between vaginal fluid cytokine levels and the composition of the vaginal microbiome in recurrent implantation failure (RIF) patients? Summary answer IL-1β and IL-2 levels are higher in patients with greater alpha diversity in vaginal microbiome, which associates dysbiotic bacteria with cytokine imbalance towards inflammation. What is known already In recent years, the development of sequencing-based technologies has enabled the evaluation of the vaginal microbiome. Studies have shown that a vaginal microbiota with less than 90% Lactobacillus is predictive of a poor IVF outcome, suggesting that dysbiosis in the reproductive tract negatively affects reproductive outcomes compared to women with a Lactobacillus-dominated microbiome. Furthermore, it is known that pregnancy is characterized by an anti-inflammatory cytokine pattern. In contrast, an altered Th1/Th2 ratio, and altered NK cell and macrophage numbers are more prevalent in women with RIF. Also, interleukin-1 system and interleukin-2 are involved in human implantation and pregnancy. Study design, size, duration 35 patients with RIF were included in a prospective study between November 2022 and July 2023. 21 had normal microbiome and 14 had dysbiotic microbiome. In all of them, two vaginal swabs were obtained to analyze microbiome composition and the levels of cytokines IL-2, IL-4, IL- 6, IL-8, IL-10, VEGF, IFNγ, TNFα, IL-1α, IL-1β, MCP-1 and EGF, respectively. Patients with uterine malformations, uterine surgery or other known factors which may influence RIF were excluded. Participants/materials, setting, methods To measure cytokine levels, one vaginal swab was resuspended in 500 μl PBS and a sandwich immunoassay with specific antibodies was performed for the cytokines IL-2, IL-4, IL-6, IL-8, IL-10, VEGF, IFNγ, TNFα, IL -1α, IL-1β, MCP-1 and EGF. Vaginal microbiome was analyzed by mass sequencing of the V3V4 region of 16S rRNA. Statistical analysis was performed with R Statistical Software and bioinformatic analysis of vaginal microbiome was performed using QIIME2, Phyloseq and MicrobiomeAnalyst packages. Main results and the role of chance For the cytokines measured in vaginal fluid, we observe that IL-1β levels (p = 0.040) are higher in patients with dysbiotic microbiome, which have an imbalance towards inflammation. Comparing levels of cytokines with respect to alpha diversity, this is greater in patients with higher levels of IL-1β (p = 0.005) and IL-2 (p = 0.032). Furthermore, the multivariate model that predicts alpha diversity does consider IL-1β and IL-2 levels (p = 0.036; AIC=45.123). Alpha diversity, moreover, is higher in vaginal samples from patients with dysbiotic microbiome (p &amp;lt; 0.001). Regarding beta diversity, it is also higher in patients with altered microbiome (p = 0.001). Considering the relative abundance of each bacteria, we can predict the levels of the aforementioned cytokines: for IL-2, the multivariate model reaches 88.1% of prediction including the relative abundance of Aerococcus, Burkholderia, Dialister, Escherichia, Lactobacillus, Megasphaera, Porphyromonas, Streptococcus and Ralstonia. For IL-1β, the multivariate model reaches 76.0% of prediction including Aerococcus, Dialister, Enterobacter, Lactobacillus, Megasphaera, Porphyromonas, Streptococcus, Veillonella and Ureaplasma. Some of these genera cause dysbiotic microbiome, which suggests that the relative abundance of some pathogenic bacteria is what alters the production of cytokines. Limitations, reasons for caution The dysbiotic microbiome group includes patients with various vaginal microbiome compositions, which can make it difficult to observe the specific effects of certain bacteria. Additionally, the sample size in the dysbiotic microbiome group is limited. Further studies, incorporating a metagenomic approach, might be able to identify functional groups of bacteria. Wider implications of the findings These results indicate that dysbiotic bacteria, such as Aerococcus or Streptococcus, induce an imbalance in cytokine levels, resulting in inflammation associated with lower implantation rates. When the vaginal microbiome is altered, the administration of antibiotics or probiotics may improve the immunologic environment, thus, avoiding the use of immunosuppressants. Trial registration number -

Abstract PO-003: Peripheral blood and tumor tissue biomarkers associated with epcoritamab response in patients with relapsed or refractory diffuse large B-cell lymphoma: Data from the dose-expansion cohort of the phase 1/2 EPCORE NHL-1 trial (NCT03625037)

Abstract Introduction: Epcoritamab, a CD3xCD20 bispecific antibody, demonstrated deep and durable clinical responses in patients (pts) with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). We evaluated the correlation of peripheral blood (PB) and tumor tissue biomarkers with clinical response to epcoritamab. Methods: Pts received priming (0.16 mg), intermediate (0.8 mg) and full epcoritamab doses (48 mg). Absolute lymphocyte count (ALC) was analyzed locally. Blood immunophenotyping was assessed by flow cytometry, plasma cytokines by MSD assay, and %CD20+ in tumors by immunohistochemistry (n=117). Gene expression in baseline tumor biopsies was evaluated using HTG EdgeSeq (n=70). Microenvironment scores were estimated from gene expression as a sum of immune (B/T, NK, dendritic, and myeloid cells) and stromal scores (adipocytes, fibroblasts, and endothelial cells). Best overall response as of April 21, 2023 was assessed by independent review committee using Lugano criteria. P values were based on Wilcoxon rank-sum test. Results: In PB at baseline, significantly higher ALC (P=0.031), CD4+ (P=0.0038), and CD8+ (P=0.043) T-cell levels were observed in responders (R) vs nonresponders (NR). Similarly, CD4+ (P=0.02) and CD8+ (P=0.03) signatures and immune and microenvironment scores were higher in baseline tumor tissue in R vs NR. In PB CD8+ T cells, NR showed higher %PD1+ (P=0.016), %TIM3+ (P=0.048), and %TIM3+TIGIT+ (P=0.045). High tumor %CD20+ (≥90%) was observed in most pts (n=97/117); lower %CD20+ (&amp;lt;50%) was observed only in 6 NRs and 1 R. Epcoritamab treatment caused a rapid decline in circulating B cells irrespective of clinical response. Transient reductions in PB CD4+ and CD8+ T cells (ie, margination) were observed within 24 hours (H) after each dose during cycle (C) 1 and were more pronounced in R vs NR. Magnitude of margination for CD8+ T cells after the priming and intermediate doses was significantly lower in NR (reduced by median 22 &amp; 41%) vs R (57 &amp; 70%), while the difference in CD4+ T cells was not as pronounced in NR vs R, resulting in a substantially lower CD4+/CD8+ ratio in NR vs R. In C1, epcoritamab led to an increase of PB CD4+ and CD8+ T cells expressing activation/proliferation markers, with significantly higher fold change from baseline in R vs NR, especially within 24H post-priming dose. Early cytokine peaks of IFNy and IL-10 were more pronounced 6–24H post-priming dose and 6–14H post-first full dose in complete R vs pts with progressive disease. Epcoritamab also appeared to modulate NK cell numbers (under further investigation). Conclusions: In pts with R/R DLBCL, T-cell abundance and increased margination, activation, proliferation, and modulation of cytokines differed in R vs NR. These findings are consistent with epcoritamab’s mechanism of action and demonstrate the dependency on proper T-cell engagement for clinical benefit. Our findings also revealed differences in the dynamics of CD4+ and CD8+ T-cell margination in R vs NR, warranting further investigation. Previously submitted in part to EHA 2024. Citation Format: Monica Wielgos-Bonvallet, Jimin Zhang, Han Si, Kubra Karagoz, Melih Acar, Yasmin Karimi, Herve Ghesquieres, Michael Roost Clausen, Iş?l Alt?ntaş, Binhuan Wang, Wissam Assaily, Matthew Loya, Gregg Masters, Anantharaman Muthuswamy, Brandon Higgs, Mariana Sacchi, Tahi Ahmadi, Mark Fereshteh, Edith Szafer-Glusman, David Soong, Maria Jure-Kunkel, Andrew J Steele. Peripheral blood and tumor tissue biomarkers associated with epcoritamab response in patients with relapsed or refractory diffuse large B-cell lymphoma: Data from the dose-expansion cohort of the phase 1/2 EPCORE NHL-1 trial (NCT03625037) [abstract]. In: Proceedings of the Fourth AACR International Meeting on Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2024 Jun 19-22; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2024;5(3_Suppl):Abstract nr PO-003.

Specific binding sites on Rhesus rotavirus capsid protein dictate the method of endocytosis inducing the murine model of biliary atresia.

Biliary atresia (BA) is the leading indication for pediatric liver transplantation. Rhesus rotavirus (RRV)-induced murine BA develops an obstructive cholangiopathy that mirrors the human disease. We have previously demonstrated the "SRL" motif on RRV's VP4 protein binds to heat shock cognate 70 protein (Hsc70) facilitating entry into cholangiocytes. In this study, we analyzed how binding to Hsc70 affects viral endocytosis, intracellular trafficking, and uniquely activates the signaling pathway that induces murine BA. Inhibition of clathrin- and dynamin-mediated endocytosis in cholangiocytes following infection demonstrated that blocking dynamin decreased the infectivity of RRV, whereas clathrin inhibition had no effect. Blocking early endosome trafficking resulted in decreased viral titers of RRV, whereas late endosome inhibition had no effect. After infection, TLR3 expression and p-NF-κB levels increased in cholangiocytes, leading to increased release of CXCL9 and CXCL10. Infected mice knocked out for TLR3 had decreased levels of CXCL9 and CXCL10, resulting in reduced NK cell numbers. Human patients with BA experienced an increase in CXCL10 levels, suggesting this as a possible pathway leading to biliary obstruction. Viruses that use Hsc70 for cell entry exploit a clathrin-independent pathway and traffic to the early recycling endosome uniquely activating NF-κB through TLR3, leading to the release of CXCL9 and CXCL10 and inducing NK cell recruitment. These results define how the "SRL" peptide found on RRV's VP4 protein modulates viral trafficking, inducing the host response leading to bile duct obstruction.NEW & NOTEWORTHY In this study, we have determined that the presence of the "SRL" peptide on RRV alters its method of endocytosis and intracellular trafficking through viral binding to heat shock cognate 70 protein. This initiates an inflammatory pathway that stimulates the release of cytokines associated with biliary damage and obstruction.

Photobiomodulation in the infrared spectrum reverses the expansion of circulating natural killer cells and brain microglial activation in Sanfilippo mice.

Sanfilippo syndrome results from inherited mutations in genes encoding lysosomal enzymes that catabolise heparan sulfate (HS), leading to early childhood-onset neurodegeneration. This study explores the therapeutic potential of photobiomodulation (PBM), which is neuroprotective and anti-inflammatory in several neurodegenerative diseases; it is also safe and PBM devices are readily available. We investigated the effects of 10-14 days transcranial PBM at 670 nm (2 or 4 J/cm2/day) or 904 nm (4 J/cm2/day) in young (3 weeks) and older (15 weeks) Sanfilippo or mucopolysaccharidosis type IIIA (MPS IIIA) mice. Although we found no PBM-induced changes in HS accumulation, astrocyte activation, CD206 (an anti-inflammatory marker) and BDNF expression in the brains of Sanfilippo mice, there was a near-normalisation of microglial activation in older MPS IIIA mice by 904 nm PBM, with decreased IBA1 expression and a return of their morphology towards a resting state. Immune cell immunophenotyping of peripheral blood with mass cytometry revealed increased pro-inflammatory signalling through pSTAT1 and p-p38 in NK and T cells in young but not older MPS IIIA mice (5 weeks of age), and expansion of NK, B and CD8+ T cells in older affected mice (17 weeks of age), highlighting the importance of innate and adaptive lymphocytes in Sanfilippo syndrome. Notably, 670 and 904 nm PBM both reversed the Sanfilippo-induced increase in pSTAT1 and p-p38 expression in multiple leukocyte populations in young mice, while 904 nm reversed the increase in NK cells in older mice. In conclusion, this is the first study to demonstrate the beneficial effects of PBM in Sanfilippo mice. The distinct reduction in microglial activation and NK cell pro-inflammatory signalling and number suggests PBM may alleviate neuroinflammation and lymphocyte activation, encouraging further investigation of PBM as a standalone, or complementary therapy in Sanfilippo syndrome.