Search Results (1,981)

Severe respiratory syncytial virus (RSV) infection during early life has been linked to gut dysbiosis, which correlates with increased disease severity and a higher risk of developing asthma later in life. However, the impact of such early-life RSV infections on intestinal immunity in adulthood remains unclear. Herein, we show that RSV infection in 3-week-old mice induced persistent differential natural killer (NK) and T cell profiles within the lungs and gastrointestinal (GI) lymphoid tissues (GALT) in adulthood. Notably, male mice exhibited more pronounced RSV-induced changes in immune cell populations in both the lungs and GALT, while female mice displayed greater resilience. Importantly, early-life RSV infection was associated with the chronic downregulation of CD69-expressing T lymphocytes, particularly T regulatory cells in Peyer’s patches, which could have a significant impact on T cell functionality and immune tolerance. We propose that RSV infection in early life is a trigger for the breakdown in immune tolerance at mucosal surfaces, with potential implications for airways allergic disease, food allergies, and other GI inflammatory diseases. Full article

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. Full article

Gestational diabetes mellitus (GDM) is a public health problem with increasing prevalence. Analyses of metabolic and immune profiles have great potential for discovering new markers and mechanisms related to the development of GDM. We monitored 61 pregnant women during the first and third trimesters of pregnancy, including 13 pregnant women with GDM, 14 pregnant women with elevated glucose in the first trimester and 34 healthy pregnant women. A number of metabolic and immunological parameters were measured, including glucose, insulin, lipid status, fatty acids, lymphocyte profile, adiponectin, IL-6, IL-10 and TNF-a. A higher number of T-helper lymphocytes and a higher ratio of helper/cytotoxic lymphocytes was found in the control group in the first trimester of pregnancy. Pregnant women whose glucose threshold values were measured in the first trimester, but who did not develop GDM, showed a higher percentage of neutrophils and a lower percentage of lymphocytes in the third trimester. Differences in polyunsaturated fatty acids levels were observed between healthy pregnant women and those with glucose metabolism disorders in the first trimester of pregnancy. The results of this pilot study demonstrate that there are differences in the profiles of T lymphocytes, NK cells and polyunsaturated fatty acids between the examined groups of pregnant women, which can serve as a direction for future research. Full article

Patients with chronic myeloid leukemia (CML) respond to tyrosine kinase inhibitors (TKIs); however, CML leukemic stem cells (LSCs) exhibit BCR::ABL kinase-independent growth and are insensitive to TKIs, leading to disease relapse. To prevent this, new therapies targeting CML-LSCs are needed. Rates of mitochondria-mediated oxidative phosphorylation (OXPHOS) in CD34⁺CML cells within the primitive CML cell population are higher than those in normal undifferentiated hematopoietic cells; therefore, the inhibition of OXPHOS in CML-LSCs may be a potential cure for CML. NK-128 (C₃₃H₆₁NO₅S) is a structurally simplified analog of JCI-20679, the design of which was based on annonaceous acetogenins. NK-128 exhibits antitumor activity against glioblastoma and human colon cancer cells by inhibiting OXPHOS and activating AMP-activated protein kinase (AMPK). Here, we demonstrate that NK-128 effectively suppresses the growth of CML cell lines and that the combination of imatinib and NK-128 is more potent than either alone in a CML xenograft mouse model. We also found that NK-128 inhibits colony formation by CD34⁺ CML cells isolated from the bone marrow of untreated CML patients. Taken together, these findings suggest that targeting OXPHOS is a beneficial approach to eliminating CML-LSCs, and may improve the treatment of CML. Full article

While antibody-based immunotherapeutic strategies have revolutionized the treatment of B-cell lymphomas, progress in T-cell lymphomas has suffered from suboptimal targets, disease heterogeneity, and limited effective treatment options. Nonetheless, recent advances in our understanding of T-cell biology, the identification of novel targets, and the emergence of new therapies provide hope for the future. In this review, we explore four areas of current and evolving antibody-based strategies for the treatment of peripheral T-cell lymphoma (PTCL): monoclonal antibodies (mAbs), bispecific antibodies (BsAs), chimeric antigen receptor T-cell therapy (CAR-T), and antibody–drug conjugates (ADCs). As part of this discussion, we will also include limitations, lessons learned, and potential future directions. Full article

Only some subpopulations of natural killer (NK) cells have cytotoxic functionality, and the effects of anesthetics on these subpopulations are unknown. This study aimed to evaluate the in vitro effects of various anesthetics, both alone and in combination, on the distribution and cytotoxic function of NK cells and their subpopulations. Peripheral blood mononuclear cells (PBMCs) from eight healthy volunteers were treated for 4 h in vitro with dexmedetomidine, remifentanil, lidocaine, propofol, sevoflurane, and combinations in clinically relevant concentrations or left untreated. Flow cytometry was used to quantify the percentage of sampled NK cells and evaluate their distribution (CD56^brightCD16^neg, CD56^brightCD16^dim, CD56^dimCD16^neg, CD56^dimCD16^bright, and CD56^negCD16^bright) and cytotoxicity (Granzyme B (GrzB) and perforin) of NK cell subpopulations. Although the percentage of total NK cells did not change following exposure to anesthesia, the most important cytotoxic subpopulation (CD56^dimCD16^bright NK cells) decreased after exposure to both propofol (−3.58%, p = 0.045) and sevoflurane (−16.10%, p = 0.008) alone, and most combinations, especially in combination with lidocaine (propofol with lidocaine (−9.66%, p = 0.002) and sevoflurane with lidocaine (−21.90%, p < 0.001)). Dexmedetomidine and remifentanil had no effect on CD56^dimCD16^bright NK cells. Furthermore, no anesthetic regimen or combination altered the expression of GrzB and perforin in NK cells or NK cell subpopulations. In short, propofol and sevoflurane suppressed the highly cytotoxic phenotype (CD56^dimCD16^bright) of NK cells, with those exposed to sevoflurane combinations showing greater reductions. Immunosuppression was intensified with the inclusion of lidocaine in the anesthetic regimen. Full article

Background/Objective: Current treatments for eosinophilic and mast cell disorders are often ineffective. One promising target to improve outcomes is sialic acid-binding immunoglobulin-like lectin-8 (Siglec-8). As limitations, there are few Siglec-8 monoclonal antibodies (mAbs) available to date, and Siglec-8-directed treatments have so far primarily focused on unconjugated mAbs, which may be inadequate, especially against mast cells. Methods: Here, we used transgenic mice to raise a diverse panel of fully human mAbs that either recognize the V-set domain, membrane-distal C2-set domain, or membrane-proximal C2-set domain of full-length Siglec-8 as a basis for novel therapeutics. Results: All mAbs were efficiently internalized into Siglec-8-expressing cells, suggesting their potential to deliver cytotoxic payloads. Tool T cell-engaging bispecific antibodies (BiAbs) and chimeric antigen receptor (CAR)-modified natural killer (NK) cells using single-chain variable fragments from Siglec-8 mAbs showed highly potent cytolytic activity against Siglec-8-positive cells even in cases of very low target antigen abundance, whereas they elicited no cytolytic activity against Siglec-8-negative target cells. Siglec-8^V-set-directed T cell-engaging BiAbs and Siglec-8^V-set-directed CAR-modified NK cells induced substantially greater cytotoxicity against cells expressing an artificial smaller Siglec-8 variant containing only the V-set domain than cells expressing full-length Siglec-8, consistent with the notion that targeting membrane-proximal epitopes enhances effector functions of Siglec-8 antibody-based therapeutics. Indeed, unconjugated Siglec-8^C2-set mAbs, Siglec-8^C2-set-directed T cell-engaging BiAbs, and Siglec-8^C2-set-directed CAR-modified NK cells showed high antigen-specific cytolytic activity against Siglec-8-positive human cell lines and primary patient eosinophils. Conclusions: Together, these data demonstrate Siglec-8-directed immunotherapies can be highly potent, supporting their further development for eosinophilic and mast cell disorders. Full article

Background: Humanized mice transplanted with CD34⁺ hematopoietic cells (HPCs) are broadly used to study human immune responses and infections in vivo and for testing therapies pre-clinically. However, until now, it was not clear whether interactions between the mouse major histocompatibility complexes (MHCs) and/or the human leukocyte antigens (HLAs) were necessary for human T-cell development and immune reactivity. Methods: We evaluated the long-term (20-week) human hematopoiesis and human T-cell development in NOD Scid Gamma (NSG) mice lacking the expression of MHC class I and II (NSG-DKO). Triplicate experiments were performed with HPCs obtained from three donors, and humanization was confirmed in the reference strain NOD Rag Gamma (NRG). Further, we tested whether humanized NSG-DKO mice would respond to a lentiviral vector (LV) systemic delivery of HLA-A*02:01, HLA-DRB1*04:01, human GM-CSF/IFN-α, and the human cytomegalovirus gB antigen. Results: Human immune reconstitution was detectable in peripheral blood from 8 to 20 weeks after the transplantation of NSG-DKO. Human single positive CD4⁺ and CD8⁺ T-cells were detectable in lymphatic tissues (thymus, bone marrow, and spleen). LV delivery harnessed the detection of lymphocyte subsets in bone marrow (αβ and γδ T-cells and NK cells) and the expression of HLA-DR. Furthermore, RNA sequencing showed that LV delivery increased the expression of different human reactome pathways, such as defense responses to other organisms and viruses. Conclusions: Human T-cell development and reactivity are independent of the expression of murine MHCs in humanized mice. Therefore, humanized NSG-DKO is a promising new model for studying human immune responses, as it abrogates the xenograft mouse MHC interference. Full article

Cryptococcus neoformans is an environmental pathogen that causes life-threatening disease in immunocompromised persons. The majority of immunological studies have centered on CD4⁺ T-cell dysfunction and associated cytokine signaling pathways, optimization of phagocytic cell function against fungal cells, and identification of robust antigens for vaccine development. However, a growing body of literature exists regarding cytotoxic cells, specifically CD8⁺ T-cells, Natural Killer cells, gamma/delta T-cells, NK T-cells, and Cytotoxic CD4⁺ T-cells, and their role in the innate and adaptive immune response during C. neoformans and C. deneoformans infection. In this review, we (1) provide a comprehensive report of data gathered from mouse and human studies on cytotoxic cell function and phenotype, (2) discuss harmonious and conflicting results on cellular responses in mice models and human infection, (3) identify gaps of knowledge in the field ripe for exploration, and (4) highlight how innovative immunological tools could enhance the study of cytotoxic cells and their potential immunomodulation during cryptococcosis. Full article

Background/Objectives: Flow cytometry is a convenient tool in immunophenotyping for monitoring the status of immunological conditions and diseases. The aim of this study was to investigate the effect of isolation and cryopreservation by flow cytometric analysis on subpopulations of CD4⁺ T helper (Th), T regulatory (Treg), CD8⁺ T cytotoxic (Tc), CD56⁺ NK, CD19⁺ B and monocytes. Freshly isolated and cryopreserved peripheral blood mononuclear cells (PBMCs) were compared to fresh whole blood. Methods: Peripheral blood was collected from healthy donors and prepared for flow cytometric analysis using the same panels of antibodies throughout the study. Results: Comparisons between fresh (F)- and cryopreserved (C)-PBMCs showed no major differences in percentages of CD4⁺, Th1, Th2 and CD4⁺CD25⁺CD127^low Treg cells. No differences in percentage of CD8⁺ or subpopulations of naive/stem, central or effector memory cells were observed between F- and C-PBMCs. The percentage of CD56⁺ NK cells, CD19⁺ B cells or classical and nonclassical monocytes did not differ between F-and C-PBMCs either. On the contrary, whole blood had lower percentages of Th and NK cells but higher percentages of Th1, Th17, Th1Th17, Tregs, Tc and B cells compared to C-PBMCs, while it had a higher proportion of Tc compared to F-PBMCs. Conclusions: Flow cytometric immunophenotyping minimally differs between freshly isolated and cryopreserved PBMCs. This implies the possibility of cryostorage of cohorts for later analysis. Importantly, care must be taken when comparing results from whole blood with isolated and cryopreserved PBMCs. Collectively, these results can contribute to the standardization of flow cytometric protocols in both clinical and research settings. Full article

Intrahepatic cholangiocarcinoma (ICC) is a highly heterogeneous malignancy. The reasons behind the global rise in the incidence of ICC remain unclear, and there exists limited knowledge regarding the immune cells within the tumor microenvironment (TME). In this study, a more comprehensive analysis of multi-omics data was performed using machine learning methods. The study found that the immunoactivity of B cells, macrophages, and T cells in the infiltrating immune cells of ICC exhibits a significantly higher level of immunoactivity in comparison to other immune cells. During the immune sensing and response, the effect of antigen-presenting cells (APCs) such as B cells and macrophages on activating NK cells was weakened, while the effect of activating T cells became stronger. Simultaneously, four distinct subpopulations, namely ${\mathrm{B}}^{\mathrm{L}\mathrm{p}}$, ${\mathrm{M}\mathrm{a}\mathrm{c}\mathrm{r}\mathrm{o}\mathrm{p}\mathrm{h}\mathrm{a}\mathrm{g}\mathrm{e}\mathrm{s}}^{\mathrm{L}\mathrm{p}}$, ${\mathrm{B}}^{\mathrm{H}\mathrm{n}}$, and ${\mathrm{T}}^{\mathrm{H}\mathrm{n}}$, have been identified from the infiltrating immune cells, and their corresponding immune-related marker genes have been identified. The immune sensing and response model of ICC has been revised and constructed based on our current comprehension. This study not only helps to deepen the understanding the heterogeneity of infiltrating immune cells in ICC, but also may provide valuable insights into the diagnosis, evaluation, treatment, and prognosis of ICC. Full article

Background/Objectives: Mucin-1 (MUC1) is a transmembrane glycoprotein that is overexpressed and hypoglycosylated in premalignant and malignant epithelial cells compared to normal cells, creating a target antigen for humoral and cellular immunity. Healthy individuals with a history of advanced colonic adenomas and at high risk for colon cancer were enrolled in a clinical trial to evaluate the feasibility of using a MUC1 peptide vaccine to prevent colon cancer. Anti-MUC1 antibodies elicited by this vaccine were cloned using peripheral blood B cells and sera collected two weeks after a one-year booster. Twelve of these fully human monoclonal antibodies (mAb) were tested for binding to MUC1+ target cells, and three with the highest binding were further evaluated for various effector functions important for tumor rejection. Methods: Immune cells were incubated together with target cells expressing variations in the number, distance, and membrane anchoring properties of the MUC1 epitope in the presence of each mAb. Results: All three mAbs mediated antibody-dependent cytokine release (ADCR), antibody-dependent cellular cytotoxicity (ADCC), and antibody-dependent cellular phagocytosis (ADCP). Two also mediated antibody-dependent trogocytosis/trogoptosis (ADCT). None were capable of complement-dependent cytotoxicity (CDC). Conclusions: ADCP and ADCT functions were more efficient when antibodies bound epitopes proximal to and anchored to the membrane, providing insight for future therapeutic antibody validation strategies. Full article

Background/Objectives: Cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC) represent major primary liver cancers, affecting one of the most vital organs in the human body. T regulatory (Treg) cells play an important role in liver cancers through the immunosuppression of antitumor immune responses. The current study focuses on the characterization of circulating natural killer (NK) cells and T cell subsets, including Treg cells, in CCA and HCC patients, before and after surgical tumor resection, in order to understand the effect of tumor resection on the homeostasis of peripheral blood NK cells and T cells. Methods: Whole blood assays were performed to monitor immune alterations and the functional competence of circulating lymphocytes in a group of ten healthy individuals, eight CCA patients, and twenty HCC patients, before and one month after the surgical procedure, using flow cytometry, cell sorting, and qRT-PCR. Results: Before tumor resection, both HCC and CCA patients display increased percentages of CD8⁺ Treg cells and decreased frequencies of circulating CD4⁺ Treg cells. Notwithstanding, no functional impairment was detected on circulating CD4⁺ Treg cells, neither in CCA nor in HCC patients. Interestingly, the frequency of peripheral CD4⁺ Treg cells increased from 0.55% ± 0.49 and 0.71% ± 0.54 (in CCA and HCC, respectively) at T0 to 0.99% ± 0.91 and 1.17% ± 0.33 (in CCA and HCC, respectively) at T1, following tumor resection. Conclusions: Our results suggest mechanisms of immune modulation induced by tumor resection. Full article

Natural killer (NK) cells are multifaceted innate effector cells that critically influence antiviral immunity, and several protective NK cell features that modulate HIV-1 acquisition and viral control have been described. Chronic HIV-1 infection leads to NK cell impairment that has been associated with metabolic dysregulations. Therapeutic approaches targeting cellular immune metabolism represent potential novel interventions to reverse defective NK cell function in people living with HIV. Full article

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. Full article