Search Results (14)

Aim: This study aimed to characterize and compare the composition of central (TCM), effector (TEM), tissue-resident (TRM), and terminally differentiated (TEMRA) memory T cells in mid-luteal endometrium during the window of implantation (WOI) in women with and without a previous miscarriage. Methods: Stromal lymphocytes from endometrial samples (P + 5) were analyzed by multicolor flow cytometry to quantify total, CD4⁺ and CD8⁺ TCM (CD45RA⁻CCR7⁺), TEM (CD45RA⁻CCR7⁻), TRM (CD69⁺), and TEMRA (CD45RA⁺CCR7⁻) subsets. Participants were grouped as having no previous miscarriage (n = 38) or ≥1 previous miscarriage (n = 33), and the relative distribution of these memory subsets was compared between groups. Correlations, PCA and logistic regression were used to assess global memory network organization. Results: Women with prior miscarriage exhibited higher TCM proportions among total and CD8⁺ lymphocytes (p < 0.01), alongside lower CD8⁺ TEM (p = 0.02) and higher CD4⁺ TEM (p = 0.01). TRM showed a mild, non-significant increase (p = 0.18), while TEMRA remained stable. TRM correlated positively with both TCM (r = 0.51) and CD4⁺ TEM (r = 0.40), indicating coordinated organization among memory subsets. Multivariate analyses (PCA and logistic regression) confirmed these trends and identified the TCM/TEM ratio as the most discriminative parameter. Conclusions: Endometrial memory T-cell composition during the WOI differs in women with miscarriage history, characterized by central memory expansion and reduced effector memory proportions, with parallel increases in tissue-resident cells. These changes suggest persistent remodeling of the local immune memory network toward a long-lived, less differentiated phenotype that may influence implantation readiness in subsequent cycles. Full article

Background: Venetoclax-based combination therapies have provided treatment options for patients with acute myeloid leukemia (AML) who are unfit for intensive chemotherapy. However, venetoclax resistance is common, and for such patients, the prognosis is dismal, and treatment approaches with different mechanisms of action are urgently needed. γδ T cells are a promising candidate owing to their good safety profile and cytotoxic effects in various types of cancers but are mostly unstudied in AML. Methods: Here we used flow cytometry to profile the subtype and memory phenotype of peripheral blood γδ T cells in AML patients and investigate the feasibility of using donor-derived Vγ9Vδ2 T cells to treat AML as both a single agent and in combination with venetoclax. Additionally, we used bioluminescence imaging to examine the effect of donor-derived Vγ9Vδ2 T cells on AML xenograft models alone and in combination with venetoclax. Results: We observed that Vδ2 T cells were less abundant and the TEMRA (terminally differentiated effector memory) phenotype was more prevalent as compared with that of healthy donors, suggesting that replenishing patients with Vδ2 T cells may be an effective treatment option. We found that donor-derived Vγ9Vδ2 T cells that Vγ9Vδ2 T cells efficiently induced apoptosis in AML cells from eight cell lines and three primary cultures in an effector-to-target cell ratio-dependent manner. Moreover, Vγ9Vδ2 T cells showed potent cytotoxicity against the venetoclax-resistant OCI-AML3 cell line and remained potent in the presence of venetoclax. Treatment with Vγ9Vδ2 T cells significantly extended survival in two AML xenograft models established with the aggressive Molm-13 and the venetoclax-resistant OCI-AML3 cell lines. An additive effect of venetoclax and Vγ9Vδ2 T cells was observed in the latter model. Conclusions: Overall, these findings suggest Vγ9Vδ2 T cells as a promising “off-the-shelf” immunotherapy approach for AML patients, especially for patients with venetoclax-resistant disease. Full article

Recently, senescent T cells in the peripheral blood have been detected using senescence-associated β-galactosidase (SA-βGal) activity and have been used as an endpoint in clinical trials. However, the epidemiological association between the abundance of SA-βGal-stained senescent CD8+ T cells and chronological age has not been fully elucidated. To examine the correlation between the proportion of SA-βGal^high CD8+ T cells and age, we analyzed previously collected clinical trial data. We conducted a cross-sectional analysis of 632 Japanese adults aged 40–59 years who participated in the screening phase of a clinical trial. To characterize senescent CD8+ T cells, we measured the proportion of SA-βGal^high in total CD8+ T cells and each subset—naïve, central memory (TCM), effector memory (TEM), and terminally differentiated effector memory (TEMRA). We then calculated the correlation coefficients between the proportion of SA-βGal^high CD8+ T cells and age. The proportion of SA-βGal^high cells in total CD8+ T cells, naïve, TCM, TEM, and TEMRA CD8+ T cells increased significantly with age. In Japanese adults, the proportion of SA-βGal^high in CD8+ T cells may serve as a useful biomarker of immune senescence. Full article

Hepatic viruses, such as hepatitis B and C (HBV and HCV), evade immune defenses and drive liver cirrhosis and cancer. They remain a major global health burden, requiring deeper research into immune responses; specifically, adaptive immunity. This study aims to analyze T cellular subsets in chronic HBV and HCV infection and investigate their potential role in the immunopathogenesis of these conditions. Methods: For our study, we collected 123 blood samples taken from patients infected with HCV (n = 36) and HBV (n = 34) and healthy volunteers (n = 53). With the use of flow cytometry, we assessed levels of CD4+ and CD8+ minor T cell subpopulations (naïve, central, and effector memory cells (CM and EM), terminally differentiated EM (TEMRA), Th1, Th2, Th17, Tfh, Tc1, Tc2, Tc17, Tc17.1). Results: Despite similar total CD4+ T cell frequencies across chronic HCV, HBV, and healthy groups, patients with hepatitis showed elevated TEMRA, EM, and CM subsets alongside depleted naïve Th cells and specific CM subpopulations compared to controls. Patients with chronic HCV and HBV showed elevated CD8+ T cell frequencies versus controls, with disease-specific shifts: reduced EM CTLs but increased TEMRA CTLs, Tc1/Tc17.1 depletion (notably Tc17.1 in HCV), and higher Tc2 levels. Conclusions: Viral clearance in HBV and HCV requires a delicate balance between immunity and viral activity. Despite similar T cell frequencies (CD3+/CD4+/CD8+), minor subsets revealed distinct patterns differentiating HCV, HBV, and healthy controls. Full article

Recent concerns regarding the safety of Janus kinase inhibitors (JAKis) have prompted investigation into their impact on immune cell subsets in rheumatoid arthritis (RA) patients. This study aims to analyse alterations in immune cell populations induced by JAKis that may contribute to adverse events, such as infections or malignancies. This study included 78 RA patients meeting ACR/EULAR criteria with an established treatment with JAKis (tofacitinib, baricitinib, upadacitinib, or filgotinib), 20 healthy donors, and 20 RA patients treated with biological disease-modifying antirheumatic drugs (bDMARDs). Peripheral blood mononuclear cells (PBMCs) were immunophenotyped directly after isolation using multiparametric flow cytometry to characterise innate and adaptive immune-cell subsets. JAKi-treated patients showed a significant reduction in cytotoxic NK Dim (CD3−CD56+CD16+) cells and in the percentage of NK Dim cells expressing the activation marker Nkp30. In CD4+ T cells, the percentage of Th17 (CD3+CD4+CD45RA+CCR6+CXCR3−), Th1-17 (CD3+CD4+CD45RA+CCR6+CXCR3+), and central memory (CM, CD3+CD4+CD45RA+CD62L+) cells was lower in the JAKi group, while effector memory (EM, CD3+CD4+CD45RA−CD62L−) and terminally differentiated CD45RA (TEMRA, CD3+CD4+CD45RA+CD62L−) T helper cells were increased compared to healthy and bDMARD-treated controls. The reduction in NK Dim and Th1-17 cells and the increase in exhausted Th subsets suggest a potential compromise in antiviral immunity and balanced immune responses in JAKi-treated RA patients. These alterations may contribute to an increased risk of infections or malignancies. Full article

COVID-19, caused by SARS-CoV-2, triggers a complex immune response, with T regulatory cells (Tregs) playing a crucial role in maintaining immune homeostasis and preventing excessive inflammation. The current study investigates the function of T regulatory cells during COVID-19 infection and the subsequent recovery period, emphasizing their impact on immune regulation and inflammation control. We conducted a comprehensive analysis of Treg subpopulations in peripheral blood samples from COVID-19 patients at different stages: acute infection, early convalescence, and long-term recovery. Flow cytometry was employed to quantify Tregs including “naïve”, central memory (CM), effector memory (EM), and terminally differentiated CD45RA⁺ effector cells (TEMRA). Additionally, the functional state of the Tregs was assessed by the expression of purinergic signaling molecules (CD39, CD73). Cytokine profiles were assessed through multiplex analysis. Our findings indicate a significant decrease in the number of Tregs during the acute phase of COVID-19, which correlates with heightened inflammatory markers and increased disease severity. Specifically, we found a decrease in the relative numbers of “naïve” and an increase in EM Tregs, as well as a decrease in the absolute numbers of “naïve” and CM Tregs. During the early convalescent period, the absolute counts of all Treg populations tended to increase, accompanied by a reduction in pro-inflammatory cytokines. Despite this, one year after recovery, the decreased subpopulations of regulatory T cells had not yet reached the levels observed in healthy donors. Finally, we observed the re-establishment of CD39 expression in all Treg subsets; however, there was no change in CD73 expression among Tregs. Understanding these immunological changes across different T regulatory subsets and adenosine signaling pathways offers important insights into the disease’s pathogenesis and provides a broader view of immune system dynamics during recovery. Full article

IgG4-RD is a multisystem fibroinflammatory disease characterized by the infiltration of tissues by IgG4 plasma cells. Combined skin and biliary tract involvement in IgG4-RD has not been described. We present perhaps the most comprehensive analysis of lymphocyte subsets in the first case of IgG4-related generalized skin rash and first case of combined skin and biliary tract manifestations. A 55-year-old male presented with painful jaundice and generalized macular pigmented pruritic eruptions, and CT abdomen revealed biliary obstruction. Ampulla and skin biopsies were subjected to histology and immunostaining. Naïve, central memory (T_CM), effector memory (T_EM), terminally differentiated effector memory (T_EMRA) subsets of CD4+ and CD8+ T cells, T follicular helper subsets, naïve, transitional, marginal zone (MZ), germinal center (GC), IgM memory, and class-switched memory (CSM) B cells, and T follicular regulatory, regulatory B cells, CD4 Treg, and CD8 Treg were analyzed. Serum IgG4 was elevated at 448 mg/dL. Ampula biopsy showed lamina propria fibrosis and increased IgG4-positive plasma cells. Skin punch biopsy showed lymphoplasmacytic infiltrates with a 67% ratio of IgG4+:IgG+ plasma cells. CD4+T_N and CD4+T_CM decreased, whereas CD4+T_EM increased. Naïve B cells increased; transitional, MZ, CSM, GC B cells, and plasmablasts decreased compared to control. CD4 Treg increased, whereas CD8 Treg and Breg decreased. In conclusion, IgG-RD may present with combined biliary tract and generalized dermatological manifestations. Changes in regulatory lymphocytes suggest their role in the pathogenesis of IgG4-RD. Full article

Pathogenic microbes use arginine-metabolizing enzymes as an immune evasion strategy. In this study, the impact of streptococcal arginine deiminase (ADI) on the human peripheral blood T lymphocytes function in vitro was studied. The comparison of the effects of parental strain (Streptococcus pyogenes M49-16) with wild type of ArcA gene and its isogenic mutant with inactivated ArcA gene (Streptococcus pyogenes M49-16delArcA) was carried out. It was found that ADI in parental strain SDSC composition resulted in a fivefold decrease in the arginine concentration in human peripheral blood mononuclear cell (PBMC) supernatants. Only parental strain SDSCs suppressed anti-CD2/CD3/CD28-bead-stimulated mitochondrial dehydrogenase activity and caused a twofold decrease in IL-2 production in PBMC. Flow cytometry analysis revealed that ADI decreased the percentage of CM (central memory) and increased the proportion of TEMRA (terminally differentiated effector memory) of CD4+ and CD8+ T cells subsets. Enzyme activity inhibited the proliferation of all CD8+ T cell subsets as well as CM, EM (effector memory), and TEMRA CD4+ T cells. One of the prominent ADI effects was the inhibition of autophagy processes in CD8+ CM and EM as well as CD4+ CM, EM, and TEMRA T cell subsets. The data obtained confirm arginine’s crucial role in controlling immune reactions and suggest that streptococcal ADI may downregulate adaptive immunity and immunological memory. Full article

Background: Various studies have reported associations between frequencies of total peripheral blood lymphocytes and prostate cancer prognosis, but none so far has addressed the prognostic role of CD8+ T-lymphocyte subsets. Methods: A total of 43 prostate cancer patients with metastatic disease and 81 patients with non-metastatic disease were included in this study. Flow cytometry analyses were employed for determining the frequencies of peripheral CD8+ T-lymphocyte subsets. Results: Statistically significant lower levels of terminally differentiated effector (TEMRA) cells in patients with non-metastatic disease vs. patients with metastatic disease were observed. Central memory (CM) and effector memory (EM) CD8+ subsets, were found to be significantly higher in patients with non-metastatic disease vs. patients with metastatic disease. A similar profile was revealed when these CD8+ subsets were analyzed based on the patients’ Gleason scores, as well as by combined disease stage (i.e., non-metastatic vs. metastatic disease) and Gleason score. Conclusions: Peripheral blood-derived CD8+ T-lymphocyte memory subsets could function as biomarkers for the prognosis of PCa. Full article

Introduction: Severe COVID-19 can result in a significant and irreversible impact on long-term recovery and subsequent immune protection. Understanding the complex immune reactions may be useful for establishing clinically relevant monitoring. Methods: Hospitalized adults with SARS-CoV-2 between March/October 2020 (n = 64) were selected. Cryopreserved peripheral blood mononuclear cells (PBMCs) and plasma samples were obtained at hospitalization (baseline) and 6 months after recovery. Immunological components’ phenotyping and SARS-CoV-2-specific T-cell response were studied in PBMCs by flow cytometry. Up to 25 plasma pro/anti-inflammatory cytokines/chemokines were assessed by LEGENDplex immunoassays. The SARS-CoV-2 group was compared to matched healthy donors. Results: Biochemical altered parameters during infection were normalized at a follow-up time point in the SARS-CoV-2 group. Most of the cytokine/chemokine levels were increased at baseline in the SARS-CoV-2 group. This group showed increased Natural Killer cells (NK) activation and decreased CD16^high NK subset, which normalized six months later. They also presented a higher intermediate and patrolling monocyte proportion at baseline. T cells showed an increased terminally differentiated (TemRA) and effector memory (EM) subsets distribution in the SARS-CoV-2 group at baseline and continued to increase six months later. Interestingly, T-cell activation (CD38) in this group decreased at the follow-up time point, contrary to exhaustion markers (TIM3/PD1). In addition, we observed the highest SARS-CoV-2-specific T-cell magnitude response in TemRA CD4 T-cell and EM CD8 T-cell subsets at the six-months time point. Conclusions: The immunological activation in the SARS-CoV-2 group during hospitalization is reversed at the follow-up time point. However, the marked exhaustion pattern remains over time. This dysregulation could constitute a risk factor for reinfection and the development of other pathologies. Additionally, high SARS-CoV-2-specific T-cells response levels appear to be associated with infection severity. Full article

Human ageing is accompanied by poor responses to infection and decreased vaccine efficacy. While the causes of this can be attributed to defects in the immune system that increase with age, it is unknown whether mitochondrial dysfunction may also contribute to these phenomena. This study aims to assess mitochondrial dysfunction in CD4+ terminal effector memory T cells re-expressing CD45RA (TEMRA) cells and other CD4+ memory T cell subtypes, which are increased in number in the elderly population, with respect to how their metabolic responses to stimulation are altered compared to CD4+ naïve T cells. In this study, we show that CD4+ TEMRA cells exhibit altered mitochondrial dynamics compared to CD4+ naïve cells and CD4+ central and effector memory cells, with a 25% reduction in OPA1 expression. CD4+ TEMRA and memory cells show increased upregulation of Glucose transporter 1 following stimulation and higher levels of mitochondrial mass compared to CD4+ naïve T cells. Additionally, TEMRA cells exhibit a decrease in mitochondrial membrane potential compared to other CD4+ memory cell subsets by up to 50%. By comparing young to aged individuals, more significant mitochondria mass and lower membrane potential were observed in CD4+ TEMRA of young individuals. In conclusion, we suggest that CD4+ TEMRA cells may be impaired with respect to their metabolic response to stimulation, possibly contributing to impaired responses to infection and vaccination. Full article

Extracellular vesicles (EVs) are formed in physiological and pathological conditions by almost all mammalian cells. They are known as submicron “molecules” that transport and horizontally transfer their cargo from maternal cells to donor cells. Moreover, cancer cells produce tumor-derived EVs (TEVs), which are present in blood of patients with solid tumors and those with hematological malignancies. Their role in evading immune system surveillance and induction of immunosuppression in hematological cancer is limited. According to the authors’ best knowledge, there is no information about the impact of TEVs from canine lymphoma (CLBL-1) and leukemia (CLB70) on lymphocytes isolated from peripheral blood mononuclear cells (PBMCs). In conclusion, we demonstrate in in vitro experiments that CLBL-1 EVs and CLB70 EVs are effectively taken up by T and B lymphocytes. TEVs decrease the percentage of B lymphocytes and increase that of T lymphocytes, and change T cells’ phenotype into the effector memory (EM) or terminally differentiated effector memory (TEMRA) subtype after in vitro co-culturing. Moreover, CLBL70 EVs have pro-tumorogenic properties by inhibiting the production of CD8⁺IL-17⁺ cells. Full article

Phenotypic characterization of γδ T cells in the MALs (malignant ascites lymphocytes), TILs (tumor infiltrating lymphocytes), and PBLs (peripheral blood lymphocytes) of ovarian cancer (OvCA) patients is lacking. Therefore, we quantified γδ T cell prevalence in MAL, TIL, and PBL specimens from n = 18 OvCA patients and PBL from age-matched healthy donors (HD, n = 14). Multicolor flow cytometry was performed to evaluate the expression of inhibitory receptors (TIGIT, PD-1 and TIM-3), stimulatory receptors (Ox40), and purinergic ectoenzymes (CD39 and CD73) on γδ T cell subsets. We identified an abundant infiltration of Vδ1 T cells in the MALs and TILs. These cells varied in their differentiation: The majority of Vδ1 TILs displayed an effector memory (EM) phenotype, whereas Vδ1 MALs had a more mature phenotype of terminally differentiated effector memory cells (TEMRA) with high CD45RA expression. TIGIT and TIM-3 were abundantly expressed in both MALs and PBLs, whereas Vδ1 TILs exhibited the highest levels of PD-1, CD39, and Ox40. We also observed specific clusters on mature differentiation stages for the analyzed molecules. Regarding co-expression, Vδ1 TILs showed the highest levels of cells co-expressing TIGIT with PD-1 or CD39 compared to MALs and PBLs. In conclusion, the Vδ1 T cell population showed a high prevalence in the MALs and primary tumors of OvCA patients. Due to their (co-)expression of targetable immune receptors, in particular TIGIT with PD-1 and CD39 in TILs, Vδ1 T cell-based approaches combined with the inhibition of these targets might represent a promising strategy for OvCA. Full article

Viral infections and reactivations remain a serious obstacle to successful hematopoietic stem cell transplantation (HSCT). When antiviral drug treatment fails, adoptive virus-specific T-cell transfer provides an effective alternative. Assuming that naive T cells (T_N) are mainly responsible for GvHD, methods were developed to generate naive T-cell-depleted products while preserving immune memory against viral infections. We compared two major strategies to deplete potentially alloreactive T cells: CD45RA and CD62L depletion and analyzed phenotype and functionality of the resulting CD45RA⁻/CD62L⁻ naive T-cell-depleted as well as CD45RA⁺/CD62L⁺ naive T-cell-enriched fractions in the CMV pp65 and IE1 antigen model. CD45RA depletion resulted in loss of terminally differentiated effector memory T cells re-expressing CD45RA (T_EMRA), and CD62L depletion in loss of central memory T cells (T_CM). Based on these differences in target cell-dependent and target cell-independent assays, antigen-specific T-cell responses in CD62L-depleted fraction were consistently 3–5 fold higher than those in CD45RA-depleted fraction. Interestingly, we also observed high donor variability in the CD45RA-depleted fraction, resulting in a substantial loss of immune memory. Accordingly, we identified donors with expected response (DER) and unexpected response (DUR). Taken together, our results showed that a naive T-cell depletion method should be chosen individually, based on the immunophenotypic composition of the T-cell populations present. Full article