Peripheral Blood T-cell Research Articles

Peripheral blood T-cell modulation by omalizumab in chronic urticaria patients.

Chronic spontaneous urticaria (CSU) is a highly prevalent and difficult to manage cutaneous disease characterized by the presence of recurrent urticaria, angioedema, or both, for a period of 6 weeks or longer. One of the biological treatments used for patients with CSU with an autoimmune background and bad control of the disease is omalizumab, an anti-IgE monoclonal antibody. The understanding of the mechanism of action of this biological drug in CSU along with the identification of potential biomarkers of clinical response can be helpful in the personalized management of the disease. The purpose of this study was to analyze the effect of omalizumab on peripheral blood lymphocyte subpopulations in patients with CSU in order to identify potential biomarkers of treatment response. We analyzed 71 patients with CSU [33 under omalizumab and 38 under non-immunomodulatory drugs (treated with antihistamines; NID)] and 50 healthy controls. An exhaustive immunophenotyping of whole blood T-cell subpopulations, including naïve, central memory, effector memory, effector cells, Th1, Th2, and Th17 was performed by multiparametric flow cytometry. Moreover, in CSU patients, we analyzed markers of inflammation (ESR, DD, CRP), atopy (prick test, IgE quantification), and autoimmunity (anti-thyroid antibodies and indirect basophil activation test).To evaluate the clinical activity, the Urticaria Activity Score 7 (UAS 7) test was used. In patients with CSU under treatment with omalizumab, there was a significant decrease in the percentage of naïve and an increase in the percentage of central memory CD4 T cells as well as a decrease in the percentage of naïve and increase in the percentage of effector CD8 T-cell subsets. Moreover, patients under treatment with omalizumab had higher percentages of Th1 and Th2 cells than patients under treatment with NID. The immune monitoring of T-cell subpopulations in patients with CSU starting omalizumab, may be a useful strategy to analyze treatment response in the clinical practice.

Associations of circulating T-cell subsets in carotid artery stiffness: the Multi-Ethnic Study of Atherosclerosis.

Arterial stiffness measured by total pulse wave velocity (T-PWV) is associated with increased risk of multiple age-related diseases. T-PWV can be described by structural (S-PWV) and load-dependent (LD-PWV) arterial stiffening. T-cells have been associated with arterial remodeling, blood pressure, and arterial stiffness in humans and animals; however, it is unknown whether T-cells are related to S-PWV or LD-PWV. Therefore, we evaluated the cross-sectional associations of peripheral T-cell subpopulations with T-PWV, S-PWV, and LD-PWV stiffness. Peripheral blood T-cells were characterized using flow cytometry and the carotid artery was measured using B-mode ultrasound to calculate T-PWV at the baseline examination in a subset of the Multi-Ethnic Study of Atherosclerosis (MESA, n=1,984). A participant-specific exponential model was used to calculate S-PWV and LD-PWV based on elastic modulus and blood pressure gradients. The associations between five primary (p-significance<0.01) and twenty-five exploratory (p-significance<0.05) immune cell subpopulations, per 1-SD increment, and arterial stiffness measures were assessed using adjusted, linear regressions. For the primary analysis, higher CD4+CD28-CD57+ T-cells were associated with higher LD-PWV (β=0.04 m/s, p<0.01) after adjusting for co-variates. For the exploratory analysis, T-cell subpopulations that commonly shift with aging towards memory and differentiated/immunosenescent phenotypes were associated with greater T-PWV, S-PWV, and LD-PWV after adjusting for co-variates. In this cross-sectional study, several T-cell subpopulations commonly associated with aging were related with measures of arterial stiffness. Longitudinal studies that examine changes in T-cell subpopulations and measures of arterial stiffness are warranted.

Targeting myeloid-derived suppressor cells promotes antiparasitic T-cell immunity and enhances the efficacy of PD-1 blockade

Immune exhaustion corresponds to a loss of effector function of T cells that associates with cancer or chronic infection. Here, our objective was to decipher the mechanisms involved in the immune suppression of myeloid-derived suppressor cells (MDSCs) and to explore the potential to target these cells for immunotherapy to enhance checkpoint blockade efficacy in a chronic parasite infection. We demonstrated that programmed cell-death-1 (PD-1) expression was significantly upregulated and associated with T-cell dysfunction in advanced alveolar echinococcosis (AE) patients and in Echinococcus multilocularis-infected mice. PD-1 blockade ex vivo failed to reverse AE patients’ peripheral blood T-cell dysfunction. PD-1/PD-L1 blockade or PD-1 deficiency had no significant effects on metacestode in mouse model. This was due to the inhibitory capacities of immunosuppressive granulocytic MDSCs (G-MDSCs), especially in the liver surrounding the parasite pseudotumor. MDSCs suppressed T-cell function in vitro in an indoleamine 2, 3 dioxygenase 1 (IDO1)-dependent manner. Although depleting MDSCs alone restored T-cell effector functions and led to some limitation of disease progression in E. multilocularis-infected mice, combination with PD-1 blockade was better to induce antiparasitic efficacy. Our findings provide preclinical evidence in support of targeting MDSC or combining such an approach with checkpoint blockade in patients with advanced AE.

P-306 GnRH agonists exert a positive influence on regulatory immune cells in the endometrium of women with adenomyosis

Abstract Study question How does treatment with GnRH-agonist (GnRH-a) prior to frozen embryo transfer (FET) in women with adenomyosis affect immune cell populations in endometrium and peripheral blood? Summary answer GnRH-a induces a decrease in monocytes and an increase in CD4+T-cells in peripheral blood and a decrease classical monocytes and T-regulatory cells in the endometrium What is known already Adenomyosis is associated with lower implantation and higher miscarriage rates. Observational studies have reported improved pregnancy outcomes in women with adenomyosis after assisted reproductive technologies (ART) and pre-treatment with GnRH-a prior to FET. However, the specific mechanisms of GnRHa action beyond central hormonal suppression remain unclear, but may be mediated through local and/or systemic immunomodulation. Study design, size, duration Prospective cohort study including infertile women with adenomyosis and GnRH-a treatment ≥3 months prior to FET. Pre- and post-treatment analysis of blood and endometrium samples were compared. Recruitment is ongoing with n = 30 women included thus far, 16 of whom have completed the study, while the remaining are still undergoing GnRH-a therapy. Participants/materials, setting, methods Adenomyosis was diagnosed sonographically if ≥ 2 criteria published by the MUSA group were met. Peripheral blood and endometrial samples were obtained before and after treatment with GnRH-a. Plasma cells and uterine Natural Killer (uNK) cells in endometrial biopsies were quantified with immunhistochemistry (IHC), and leukocyte populations in all samples were analysed using flow cytometry (FC). Pre- and post-treatment levels of immune cells and percentage of leukocyte populations were compared using Wilcoxon rank-sum tests (p &amp;lt; 0.05 significant) Main results and the role of chance Interim analysis of immune cell populations in peripheral blood and endometrium of the 16 women who already completed the study was performed. At baseline, IHC showed elevated plasma cell concentrations indicating chronic endometritis in 3/30 patients (10%), while uNK cells were elevated (&amp;gt;300/mm2) in 13/30 patients (43.3%). FC analysis of peripheral blood showed a significant decrease in percentage of monocytes (p = 0.01) and increase in percentage of T-cells (p = 0.03), specifically concentration of CD4+T-cells (p = 0.03), after treatment with GnRH-a as compared to pre-treatment levels. In the endometrium, following GnRH-a therapy, we observed a decrease in both the percentage of classical monocytes (p = 0.03) and T-regulatory cells (p = 0.03). All 16 participants who completed the study already underwent FET, resulting in ten pregnancies (62.5%), although four resulted in miscarriage, while the outcome of the remaining pregnancies is still pending. Limitations, reasons for caution These are preliminary results whose generalizability needs to be confirmed in a larger study population. No correction for multiple comparisons was performed and significant findings have to be interpreted with caution. Wider implications of the findings Elevated uNK on IHC cells seen at baseline may be associated with implantation failure, miscarriage. CD4+ and DN T-cells are important mediators of reproductive immune tolerance. In women with adenomyosis, GnRH-a may have a positive impact on these regulatory immune cells in peripheral blood as well as in the endometrium. Trial registration number Not applicable

Intergenic risk variant rs56258221 skews the fate of naive CD4+ T cells via miR4464-BACH2 interplay in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is an immune-mediated liver disease of unknown pathogenesis, with a high risk to develop cirrhosis and malignancies. Functional dysregulation of Tcells and association with genetic polymorphisms in Tcell-related genes were previously reported for PSC. Here, we genotyped a representative PSC cohort for several disease-associated risk loci and identified rs56258221 (BACH2/MIR4464) to correlate with not only the peripheral blood Tcell immunophenotype but also the functional capacities of naive CD4+ T (CD4+ TN) cells in people with PSC. Mechanistically, rs56258221 leads to an increased expression of miR4464, in turn causing attenuated translation of BACH2, a major gatekeeper of Tcell quiescence. Thereby, the fate of CD4+ TN is skewed toward polarization into pro-inflammatory subsets. Clinically, people with PSC carrying rs56258221 show signs of accelerated disease progression. The data presented here highlight the importance of assigning functional outcomes to disease-associated genetic polymorphisms as potential drivers of diseases.

Effects of Tongluo Jiedu prescription on immune function and oxidative stress in patients with oral cancer

BACKGROUND Oral cancer, which is caused by mucous membrane variation, represents a prevalent malignant tumor in the oral and maxillofacial region, posing a significant threat to patients’ lives and safety. While surgical intervention stands as a cornerstone treatment for oral cancer patients, it carries the risk of incomplete treatment or high rates of postoperative recurrence. Hence, a multifaceted approach incorporating diverse treatment modalities is essential to enhance patient prognosis. AIM To analyze the application effect of Tongluo Jiedu prescription as adjuvant therapy and its influence on patient prognosis in patients with oral cancer. METHODS Eighty oral cancer patients in our hospital were selected and divided into the observation group and control group by a random number table. The control group was treated with continuous arterial infusion chemotherapy of cisplatin and 5-fluorouracil. The observation group was additionally given Tongluo Jiadu prescription. The inflammatory stress level, peripheral blood T-cell subsets, and immune function of the two groups were subsequently observed. SPSS 21.0 was used for data analysis. RESULTS The observation group demonstrated lower levels of interleukin-6 and C-reactive protein, and a higher level of tumor necrosis factor in comparison to the control group. After treatment, the immune function in the observation group was significantly better than in the control group. CONCLUSION Tongluo Jiedu prescription can improve the immune function and oxidative stress level of patients with oral cancer and accelerate the recovery process.

&lt;i&gt;In vivo&lt;/i&gt; functional assessment of recombinant adeno-associated viruses carrying genes of protectively significant antigens of the African swine fever virus

Relevance. African swine fever (ASF) is a viral hemorrhagic disease with exceptionally high mortality in members of the family Suidae, with serious economic consequences associated with production losses, trade restrictions and eradication programs. To date, no effective commercial vaccine against ASF has been developed. Of particular interest in the design of candidate vaccines are viral vectors, in particular the adenoassociated virus of the 2nd serotype (AAV2), which has successfully proven itself as a gene therapy agent. We previously reported the ability of rAAV2 to effectively deliver ASF virus genes B646L, E183L, CP530R, CP204L into porcine cells in vitro.The aim of the study was to evaluate the in vivo functionality of adenoassociated viruses of the 2nd serotype carrying genes of protectively significant antigens of the African swine fever virus.Methods. By cloning pairwise combined genes B646L-CP530R, E183L-CP204L into the pAAV-MCS vector, bicistronic constructs with the self-cleaving P2A peptide were created. Assembly of rAAV2 was accomplished by calcium phosphate transfection of AAV293 cells. After iodixanol density gradient purification, rAAV2 was administered to pigs at a dose of 3 × 1011 viral particles and humoral and cellular immunity was assessed for 180 days. The dynamics of antibody genesis were assessed by indirect ELISA, and immunophenotyping of peripheral blood T-lymphocytes was assessed by flow cytometry.Results. It was found that the developed bicistronic constructs based on rAAV2 are safe and easily tolerated by animals and cause the induction of both humoral and cellular immune responses: the formation of virus-specific antibodies was observed, which persisted until the end of the experiment, as well as increased expression of CD8+ and CD4+ lymphocytes. The AAV platform we propose is a promising tool for creating a vaccine, however, a comprehensive characterization of rAAV2 can only be compiled after assessing its protective effect.

Epstein-Barr Virus and immune status imprint the immunogenomics of non-Hodgkin lymphomas occurring in immune-suppressed environments.

Non-Hodgkin lymphomas (NHL) commonly occur in immune-deficient (ID) patients, both HIV-infected and transplanted, and are often EBV-driven with cerebral localization, raising the question of tumor immunogenicity, a critical issue for treatment responses. We investigated the immunogenomics of 68 lymphoproliferative disorders from 51 ID (34 posttransplant, 17 HIV+) and 17 immunocompetent patients. Overall, 72% were Large B Cells Lymphoma (LBCL) and 25% were primary central-nervous-system lymphoma (PCNSL) while 40% were EBV-positive. Tumor whole-exome and RNA sequencing, along with a bioinformatics pipeline allowed analysis of tumor mutational burden (TMB), tumor landscape and microenvironment (TME) and prediction of tumor neoepitopes. Both TMB (2.2 vs 3.4/Mb, p=0.001) and neoepitopes numbers (40 vs 200, p=0.00019) were lower in EBVpositive than in EBV-negative NHL, regardless of the immune status. In contrast both EBV and the immune status influenced the tumor mutational profile, with HNRNPF and STAT3 mutations exclusively observed in EBV-positive and ID NHL, respectively. Peripheral blood T-cell responses against tumor neoepitopes were detected in all EBV-negative cases but in only half EBV-positive ones, including responses against IgH-derived MHC-class-II restricted neoepitopes. The TME analysis showed higher CD8 T cell infiltrates in EBVpositive vs EBV-negative NHL, together with a more tolerogenic profile composed of Tregs, type-M2 macrophages and an increased expression of negative immune-regulators. Our results highlight that the immunogenomics of NHL in patients with immunodeficiency primarily relies on the tumor EBV status, while T cell recognition of tumor- and IgH-specific neoepitopes is conserved in EBV-negative patients, offering potential opportunities for future T cell-based immune therapies.

Effect of different inhalant allergens on T-cell subsets in adults with bronchial asthma

Objective We analyzed the impact of different inhalant allergens on T-lymphocyte subsets in patients diagnosed with bronchial asthma. Methods The study included 57 bronchial asthma patients and 22 healthy controls. Asthma patients were categorized into dust mite, animal hair, pollen, and mold groups. Flow cytometry was used to measure the cells in the case group and control group. These T-lymphocyte subset markers were evaluated among patients with bronchial asthma caused by different allergens as well as between the case group and control group. Results Peripheral blood CD4+ T-cells, CD8+ T-cells, CD4/CD8 ratio, and Th17/Treg ratios were all higher in the case group than in the control group (p < 0.05). Peripheral blood T-lymphocyte subsets were compared among the four groups, and it was found that there were statistical differences in the Th17/Treg ratio among the four groups (p < 0.05). There were no significant differences observed among the four groups in terms of CD3+ cells, CD4+ cells, CD8+ cells, Th1 cells, Th2 cells, Th17 cells, Treg cells, Th9 cells, and Th22 cells. Further pairwise comparison was made, and the results suggested that the peripheral blood Th17/Treg ratio in the pollen mixed group was lower than that in the dust mite mixed group, animal hair mixed group, and mold mixed group (p < 0.05). Conclusion Patients with bronchial asthma show varied T-lymphocyte subset responses to different inhalant allergens. Elevated CD4+ T cells and Th17 cells in peripheral blood could indicate asthma risk. However, small sample size may introduce bias to these findings.

Correlation of peripheral blood monocytic myeloid-derived suppressor cells (M-MDSC) and T-cell receptor (TCR) dynamics with clinical outcomes in patients (pts) with metastatic urothelial carcinoma (mUC) treated with nivolumab (NIVO).

4569 Background: Although PD-1 blockade is active in varied mUC treatment settings, predicting response and overcoming resistance remain unmet needs. We hypothesized that immunosuppressive M-MDSCs (CD14+Lin-/HLA-DRlow/-) and TCR dynamics in tumors and blood may correlate with outcomes from NIVO in pts with platinum-refractory mUC (NCT02553642). Methods: 69 pts with mUC were treated with NIVO 240mg intravenously every 2 weeks (wks). Pre-treatment peripheral M-MDSCs among lineage-negative CD14+ monocytes (%) were estimated by flow cytometry using an algorithm that calculates MDSC frequencies based on HLA-DR mean fluorescence intensity (Kitano et al. 2014). High throughput DNA sequencing of the CDR3 region of the TCR beta chain was performed on baseline tumors (N = 57) and pre and post-treatment (wk 2) peripheral blood mononuclear cells using Adaptive Immunosequencing (Adaptive Biotechnologies). M-MDSC levels and TCR metrics were correlated with clinical outcomes: complete or partial response (CR, PR) vs. stable or progressive disease (SD, PD) by RECIST 1.1, clinical benefit (CR + PR + SD), and progression-free and overall survival (PFS, OS). Groups were compared using Wilcoxon signed rank (paired), Wilcoxon rank sum tests (unpaired), and log-rank tests (time-to-event). Cox proportional hazards and logistic regression models were used to analyze binary and time-to-event outcomes, respectively. Results: Higher pre-treatment M-MDSCs were associated with worse PFS and OS univariably (PFS HR 1.07; 95% CI, 1.01-1.14; p = 0.025; OS HR 1.07; 95% CI, 1.00-1.14; p = 0.038), and after adjustment for liver disease and PD-L1 at baseline (PFS HR 1.12; 95% CI, 1.04-1.21, p = 0.004; OS HR 1.11; 95% CI, 1.03-1.20, p = 0.010). Baseline M-MDSCs did not significantly differ between responders and non-responders, but were significantly lower in patients with clinical benefit (median 12.8 [IQR: 10.7-15.9] vs. median 15.6 [IQR: 13.5-18.3]; p = 0.039), and remained significantly associated after adjustment for PD-L1 score in a multivariable model (OR 0.82; 95% CI, 0.67-0.97; p = 0.037). A higher number of tumor-associated clones in the blood (BTACs) at baseline was associated with response (p = 0.049). Overall, BTACs significantly increased at wk 2 (p &lt; 0.001), and wk 2 values were associated with response (p = 0.003). PFS also significantly differed between BTAC high (high: &gt; median 2,012 clones) and low groups at wk 2, with improved PFS in the high group (log-rank p = 0.026). OS rate for the BTAC high group was 34% vs. 16% for the low group at wk 2, but this did not achieve significance (p = 0.098). Conclusions: Peripheral M-MDSCs may promote resistance to PD-1 blockade in pts with mUC. NIVO stimulated tumor-specific TCR clones in the blood, which correlated with improved response and outcomes. Clinical trial information: NCT02553642 .

Determining the relationship of p16INK4a and additional molecular markers of aging with clinical frailty in hematologic malignancy

PurposeOlder adults with hematologic malignancies (HM) have unique challenges due to age and fitness. The primary aim of this pilot study was to benchmark the ability of multiple biomarkers of aging (p16, epigenetic clocks, T cell gene expression profiles, and T cell receptor excision circles (TREC) to identify frailty as measured by a clinical impairment index (I2) in patients with HM.Methods70 patients newly diagnosed with HM had peripheral blood T lymphocytes (PBTL) analyzed for p16INK4a expression using the OSU_Senescence Nanostring CodeSet. PBTL epigenetic age was measured using 7 epigenetic clocks, and TREC were quantified by qRT-PCR. A composite clinical impairment index (I2) was generated by combining values from 11 geriatric metrics (Independent Activities of Daily Living (iADL), physical health score, Short Physical Performance Battery (SPPB), Body Mass Index (BMI), Eastern Cooperative Oncology Group (ECOG) performance status, self-reported KPS, Blessed Orientation Memory Concentration (BOMC), polypharmacy, Mental Health Inventory (MHI)-17, Medical Outcomes Study (MOS) subscales). Clinical frailty was defined as a score of 7 or greater on the I2.ResultsAge-adjusted p16INK4a was similar in newly diagnosed patients and healthy controls (p > 0.1). PBTL p16INK4a levels correlated positively with the Hannum [r = 0.35, 95% CI (0.09–0.75); p adj. = 0.04] and PhenoAge [r = 0.37, 95% CI (0.11–0.59); p adj. = 0.04] epigenetic clocks. The discrimination ability of the I2 model was calculated using the area under the receiver operating characteristic curve (AUC). After adjusting for chronologic age and disease group, baseline p16INK4a [AUC = 0.76, 95% CI (0.56–0.98); p = 0.01], Hannum [AUC = 0.70, 95% CI (0.54–0.85); p = 0.01], PhenoAge [AUC = 0.71, 95% CI (0.55–0.86); p = 0.01], and DunedinPACE [AUC = 0.73, 95% CI (0.57–0.88); p = < 0.01] measures showed the greatest potential to identify clinical frailty using the I2.ConclusionsOur pilot data suggest that multiple blood-based aging biomarkers have potential to identify frailty in older adults with HM.Implications for Cancer SurvivorsWe developed the I2 index to quantify impairments across geriatric domains and discovered that PBTL p16, Hannum, PhenoAge, and DunedinPACE are promising indicators of frailty in HM.

Investigating peripheral blood monocyte and T-cell subsets as non-invasive biomarkers for asymptomatic hepatic steatosis: results from the Multi-Ethnic Study of Atherosclerosis.

Circulating immune cells have gained interest as biomarkers of hepatic steatosis. Data on the relationships between immune cell subsets and early-stage steatosis in population-based cohorts are limited. This study included 1,944 asymptomatic participants of the Multi-Ethnic Study of Atherosclerosis (MESA) with immune cell phenotyping and computed tomography measures of liver fat. Participants with heavy alcohol use were excluded. A liver-to-spleen ratio Hounsfield units (HU) <1.0 and liver attenuation <40 HU were used to diagnose liver fat presence and >30% liver fat content, respectively. Logistic regression estimated cross-sectional associations of immune cell subsets with liver fat parameters adjusted for risk factors. We hypothesized that higher proportions of non-classical monocytes, Th1, Th17, and memory CD4+ T cells, and lower proportions of classical monocytes and naive CD4+ T cells, were associated with liver fat. Exploratory analyses evaluated additional immune cell phenotypes (n = 19). None of the hypothesized cells were associated with presence of liver fat. Higher memory CD4+ T cells were associated with >30% liver fat content, but this was not significant after correction for multiple hypothesis testing (odds ratio (OR): 1.31, 95% confidence interval (CI): 1.03, 1.66). In exploratory analyses unadjusted for multiple testing, higher proportions of CD8+CD57+ T cells were associated with liver fat presence (OR: 1.21, 95% CI: 1.02, 1.44) and >30% liver fat content (OR: 1.34, 95% CI: 1.07, 1.69). Higher circulating memory CD4+ T cells may reflect liver fat severity. CD8+CD57+ cells were associated with liver fat presence and severity, but replication of findings is required.

Investigation of the Clinical Diagnostic Significance of the T-Cell Test for Tuberculosis combined with Erythrocyte Sedimentation Test in Pulmonary Tuberculosis

Objective: To investigate the clinical diagnostic significance of peripheral blood T-cell test (T-spot test) for tuberculosis (TB) infection combined with erythrocyte sedimentation rate (ESR) in pulmonary TB. Methods: 41 patients with a clinical diagnosis of TB during hospitalization from January 2020 to April 2023 in our hospital were selected as the experimental group, and 45 patients without TB (bronchopneumonia patients) were selected as the control group. The diagnostic specificity, sensitivity, and accuracy of the T-spot TB test, ESR test, and the combined test of the two were calculated respectively. Results: The sensitivity, specificity, and accuracy of the T-spot TB test combined with ESR for the diagnosis of TB in the experimental group were significantly higher than the individual results of the T-spot TB test and ESR test alone (P &lt; 0.05). Conclusion: The T-spot TB test combined with the ESR test for TB diagnosis has greater clinical value than carrying out the tests individually.

T-cell count and T-cell telomere length in patients with severe COVID-19.

Lymphocyte telomere length (TL) is highly variable and shortens with age. Short telomeres may impede TL-dependent T-cell clonal expansion with viral infection. As SARS-CoV-2 infection can induce prolonged and severe T-cell lymphopenia, infected adults, and particularly older adults with short telomeres, may display severe T-cell lymphopenia. To examine the relationship between T-cell TL parameters and T-cell counts, we studied 40 patients hospitalized with severe COVID-19. T-cells were isolated from lymphocytes, counted using flow cytometry, and their TL parameters were measured using the Telomere Shortest Length Assay. The cohort (median age = 62 years, 27% female) was racially and ethnically diverse (33% White, 35% Black, and 33% Other). On intensive care unit study day 1, T-cell count (mean=1.03 x109/L) was inversely related to age (p=0.007) and higher in females than males (p=0.025). Mean TL was 3.88 kilobases (kb), and 45.3% of telomeres were shorter than 3 kb. Using multiple regression analysis and adjusting for age and sex, T-cell count decreased with increased proportion of T-cell telomeres shorter than 3 kb (p=0.033) and increased with mean TL (p=0.052). Our findings suggest an association between the buildup of short telomeres within T-cells and explain in part reduced peripheral blood T-cell counts in patients with severe COVID-19. Shortened T-cell telomeres may be a risk factor for COVID-19-associated T-cell lymphopenia.

Application of Blood Lymphocyte Immunophenotype and TCR Gene Rearrangement in the Diagnosis of CTCL.

The immunophenotype of peripheral blood lymphocytes and T-cell receptor (TCR) gene rearrangement of cutaneous T cell lymphoma (CTCL) patients were retrospectively analyzed to explore their value in the diagnosis of CTCL. A total of fifty patients' results were enrolled from 2013 to 2021, including 29 malignant skin disorders and 21 benign skin disorders. The immunophenotype of peripheral blood lymphocytes were analyzed by flow cytometry and TCR gene rearrangement was detected by capillary electrophoresis. Lymphocyte subsets, CD4/CD8 ratio, the percentage of CD3+CD4+CD7- cells and CD45RA/CD45RO ratio was calculated between malignant and benign skin disorders. Peripheral blood lymphocyte immunophenotype and TCR gene rearrangement was compared with skin biopsy to evaluate their sensitivity and specificity. Lymphocyte subsets between malignant and benign groups have no significant difference in percentage of T cell (p > 0.05). The CD4/CD8 ratio is higher in patients with malignant lymphoma than the healthy range. The percentage of CD3+CD4+CD7- cells in malignant groups is higher than that in benign groups and CD45RA/ CD45RO ratio has significant difference between malignant and benign groups (p < 0.05). The sensitivity and specificity of TCR rearrangement for CTCL were 51.7% and 42.9%. The sensitivity and specificity of peripheral blood lymphocyte immunophenotype for CTCL were 44.8% and 33.3%. Combining the two methods, the sensitivity and specificity reached 69.0% and 38.1%, respectively. CD4/CD8 ratio of lymphocyte subsets, the proportion of CD4+CD7-T cells and CD45RA/CD45RO ratio can effectively distinguish benign and malignant dermatosis. TCR rearrangement method combined with lymphocyte immunophenotype can improve the sensitivity and specificity of CTCL diagnosis.

Immunologic Signatures of Peripheral Blood T Cells Reveal the Outcome of p53MVA Vaccine and Pembrolizumab Treatment in Patients with Advanced Ovarian Cancer.

Our previous studies indicated that p53-reactive T cells were associated with clinical benefit in patients with advanced ovarian cancer who were treated with p53-expressing modified vaccinia Ankara (p53MVA) vaccine and gemcitabine chemotherapy. To replace chemotherapy with an approach that will enhance vaccine efficacy and antitumor immunity, we treated patients with p53MVA in combination with PD-1 checkpoint blocker, pembrolizumab. We also attempted to further characterize the activation status of T cells prior to vaccination and during treatment. Patients received up to three triweekly vaccinations concurrent with pembrolizumab, followed by pembrolizumab monotherapy at 3-week intervals. Correlative studies analyzed peripheral blood T-cell phenotypes and profiles of immune function gene expression. We observed 6/28 (21%) patients with a clinical benefit to therapy, including 3 partial responses (PR) and 3 patients with stable disease (SD) for 6+ months. The median progression-free survival was 1.8 months (95% confidence interval: 1.7-3.8) and median overall survival was 15.1 months (9.4-30.4). Two patients remain progression-free at 28 and 33 months. Of the 18 patients evaluable in correlative studies, 6 were immunologic responders of whom 5 had clinical benefit (3 PR, 2 SD). Immunologic non-responders expressed in pretreatment peripheral blood mononuclear cell samples high levels of mRNA for multiple molecules associated with terminally differentiated T cells. p53MVA/pembrolizumab immunotherapy showed promising antitumor activity in patients who demonstrated functionally competent peripheral blood T cells. Detection of markers of terminally differentiated T cells before treatment may identify patients unlikely to respond to p53MVA/pembrolizumab. The activity of a combination immunotherapy of p53 vaccine and PD-1 checkpoint blockade in patients with platinum-resistant ovarian cancer was evaluated in a phase II trial. Clinical benefit was correlated with the responsive immune status of patients before and during the treatment, defining potential predictive markers for immune therapy.

The clinical trajectory of peripheral blood immune cell subsets, T-cell activation, and cytokines in septic patients.

Changes in the immune status of patients with sepsis may have a major impact on their prognosis. Our research focused on changes in various immune cell subsets and T-cell activation during the progression of sepsis. We collected data from 188 sepsis patients at the First Affiliated Hospital of Zhejiang University School of Medicine. The main focus was on the patient's immunocyte subset typing, T-cell activation/Treg cell analysis, and cytokine assay, which can indicate the immune status of the patient. The study found that the number of CD4+ T cells, CD8+ T cells, NK cells, and B cells decreased early in the disease, and the decrease in CD4+ and CD8+ T cells was more pronounced in the death group. T lymphocyte activation was inhibited, and the number of Treg cells increased as the disease progressed. T lymphocyte inhibition was more significant in the death group, and the increase in IL-10 was more significant in the death group. Finally, we used patients' baseline conditions and immunological detection indicators for modeling and found that IL-10, CD4+ Treg cells, CD3+HLA-DR+ T cells, and CD3+CD69+ T cells could predict patients' prognosis well. Our study found that immunosuppression occurs in patients early in sepsis. Early monitoring of the patient's immune status may provide a timely warning of the disease.

T-cell lymphopenia in frequent volunteer platelet donors.

In the United States, more than 2 000 000 apheresis platelet units are collected annually from volunteer donors. Platelet donors in the United States and elsewhere are permitted to donate up to 24 times per year. Recently, frequent apheresis platelet donation has been associated with severe T-cell lymphopenia. Several frequent platelet donors have been found to have peripheral blood CD4+ T-cell counts below 200 cells/µL, the threshold for AIDS in HIV-positive individuals. Independent risk factors for plateletpheresis-associated lymphopenia include lifetime donations, age, and donations on the Trima Accel instrument (Terumo BCT), which uses a leukoreduction system (LRS) chamber to trap white blood cells. Less often, severe lymphopenia can occur in donors collected on the Fenwal Amicus instrument (Fresenius Kabi), which has no LRS. For Trima Accel donors, lymphopenia can be partially mitigated by performing a plasma rinseback step at the end of collection. To date, there is no definitive evidence that plateletpheresis-associated lymphopenia is harmful. In a study of frequent platelet donors with lymphopenia who were administered COVID-19 messenger RNA vaccines, immune responses were normal. The homeostatic mechanisms responsible for maintaining a normal peripheral blood T-cell count remain obscure, as do the causal mechanisms underlying plateletpheresis-associated lymphopenia.

Investigating the Immune Basis of Green Tea Extract Induced Liver Injury in Healthy Donors Expressing HLA-B*35:01.

Epigallocatechin-3-O-gallate (EGCG) is the major component of green tea extract, commonly found in dietary supplements, and has been associated with immune-mediated liver injury. The purpose of this study was to investigate the immunogenicity of EGCG in healthy donors expressing HLA-B*35:01, and characterize EGCG responsive T-cell clones. We have shown that EGCG can prime peripheral blood mononuclear cells and T-cells from donors with and without the HLA-B*35:01 allele. T-cell clones were CD4+ve and capable of secreting Th1, Th2, and cytolytic molecules. These data demonstrate that EGCG can activate T-cells in vitro, suggesting a significant role in the pathogenesis of green tea extract induced liver injury.

АНАЛИЗ РАЗНООБРАЗИЯ Vβ-СЕГМЕНТОВ Т-КЛЕТОЧНОГО РЕЦЕПТОРА У ЖИТЕЛЕЙ ПРИБРЕЖНЫХ СЁЛ РЕКИ ТЕЧИ, ПОДВЕРГШИХСЯ ХРОНИЧЕСКОМУ РАДИАЦИОННОМУ ВОЗДЕЙСТВИЮ, В ОТДАЛЕННОМ ПЕРИОДЕ

Purpose: Study the repertoire of the T-cell receptor in persons chronically exposed to radiation in the long-term period. Material and methods: The study involved 48 people, who were divided into two groups: a group of exposed persons – 31 individuals with the average accumulated dose to red bone marrow (RBM) of 981±130 mGy, and a comparison group – 17 individuals, the average accumulated dose to RBM was 25.3±5.91 mGy. The study groups did not differ significantly in age, gender and ethnicity. The repertoire of Vβ-segments of the T-cell receptor of the peripheral blood T-lymphocytes of exposed persons was analyzed by flow cytometry method. 24 Vβ-segments of the T-cell receptor were studied. Statistical processing of the obtained data was carried out using the Wilcoxon signed-rank test, and a direct description of Vβ-segment repertoire of the T-cell receptor was performed using the Lorenz curve and the Gini-TCR index. Results: The study revealed a statistically significant increase in the number of Vβ3 and Vβ5.2 T-cell receptor segments in exposed individuals relative to the comparison group (p=0.03 and p=0.003, respectively). It was also shown that the distribution of the Vβ-segments of the T-cell receptor is uneven in both study groups. However, there was no significant difference between the repertoires of the T-cell receptor of the studied groups by the Gini-TCR index (p=0.14).