Cells In Individuals Research Articles

Separation of Immune Cell Subpopulations in Peripheral Blood Samples from Children with Infectious Mononucleosis.

Infectious mononucleosis (IM) is an acute syndrome mostly associated with primary Epstein-Barr virus (EBV) infection. The main clinical symptoms include irregular fever, lymphadenopathy, and significantly increased lymphocytes in peripheral blood. The pathogenic mechanism of IM is still unclear; there is no effective treatment method for it, with mainly symptomatic therapies being available. The main question in EBV immunobiology is why only a small subset of infected individuals shows severe clinical symptoms and even develop EBV-associated malignancies, whilemost individuals are asymptomatic for life with the virus. B cells are first involved in IM because EBV receptors are presented on their surface. Natural killer (NK) cells are cytotoxic innate lymphocytes that are important for killing EBV-infected cells. The proportion of CD4+ T cells decreases while that of CD8+ T cells expands dramatically during acute EBV infection, and the persistence of CD8+ T cells is important for lifelong control of IM. Those immune cells play important roles in IM, and their functions need to be identified separately. For this purpose, monocytes are separated first from peripheral blood mononuclear cells (PBMCs) of IM individuals using CD14 microbeads, a column, and a magnetic separator. The remaining PBMCs are stained with peridinin-chlorophyll-protein (PerCP)/Cyanine 5.5 anti-CD3, allophycocyanin (APC)/Cyanine 7 anti-CD4, phycoerythrin (PE) anti-CD8, fluorescein isothiocyanate (FITC) anti-CD19, APC anti-CD56, and APC anti-CD16 antibodies to sort CD4+ T cells, CD8+ T cells, B cells, and NK cells using a flow cytometer. Furthermore, transcriptome sequencing of five subpopulations was performed to explore their functions and pathogenic mechanisms in IM.

Unique and common TCR repertoire features of Ni2+ -, Co2+ -, and Pd2+ -specific human CD154+ CD4+ T cells.

Apart from Ni2+ , Co2+ , and Pd2+ ions commonly trigger T cell-mediated allergic contact dermatitis. However, in vitro frequencies of metal-specific T cells and the mechanisms of antigen recognition remain unclear. Here, we utilized a CD154 upregulation assay to quantify Ni2+ -, Co2+ -, and Pd2+ -specific CD4+ T cells in peripheral blood mononuclear cells (PBMC). Involved αβ T cell receptor (TCR) repertoires were analyzed by high-throughput sequencing. Peripheral blood mononuclear cells incubation with NiSO4 , CoCl2 , and PdCl2 increased frequencies of CD154 + CD4+ memory T cells that peaked at ~400 μM. Activation was TCR-mediated as shown by the metal-specific restimulation of T cell clones. Most abundant were Pd2+ -specific T cells (mean 3.5%, n=19), followed by Co2+ - and Ni2+ -specific cells (0.6%, n=18 and 0.3%, n=20) in both allergic and non-allergic individuals. A strong overrepresentation of the gene segment TRAV9-2 was unique for Ni2+ -specific TCR (28% of TCR) while Co2+ and Pd2+ -specific TCR favorably expressed TRAV2 (8%) and the TRBV4 gene segment family (21%), respectively. As a second, independent mechanism of metal ion recognition, all analyzed metal-specific TCR showed a common overrepresentation of a histidine in the complementarity determining region 3 (CDR3; 15% of α-chains, 34% of β-chains). The positions of the CDR3 histidine among metal-specific TCR mirrored those in random repertoires and were conserved among cross-reactive clonotypes. Induced CD154 expression allows a fast and comprehensive detection of Ni2+ -, Co2+ -, and Pd2+ -specific CD4+ T cells. Distinct TCR repertoire features underlie the frequent activation and cross-reactivity of human metal-specific T cells.

Impact of antiretroviral therapy in primary HIV infection on natural killer cell function and the association with viral rebound and HIV DNA following treatment interruption.

Natural Killer (NK) cells play a key role in controlling HIV replication, with potential downstream impact on the size of the HIV reservoir and likelihood of viral rebound after antiretroviral therapy (ART) cessation. It is therefore important to understand how primary HIV infection (PHI) disrupts NK cell function, and how these functions are restored by early ART. We examined the impact of commencing ART during PHI on phenotypic and functional NK cell markers at treatment initiation (baseline), 3 months, 1 year, and 2 years in seven well-characterised participants in comparison to HIV seronegative volunteers. We then examined how those NK cell properties differentially impacted by ART related to time to viral rebound and HIV DNA levels in 44 individuals from the SPARTAC trial who stopped ART after 48 weeks treatment, started during PHI. NK cell markers that were significantly different between the seven people with HIV (PWH) treated for 2 years and HIV uninfected individuals included NKG2C levels in CD56dim NK cells, Tim-3 expression in CD56bright NK cells, IFN-γ expressed by CD56dim NK cells after IL-12/IL-18 stimulation and the fraction of Eomes-/T-bet+ in CD56dim and CD56bright NK cells. When exploring time to viral rebound after stopping ART among the 44 SPARTAC participants, no single NK phenotypic marker correlated with control. Higher levels of IL-12/IL-18 mediated NK cell degranulation at baseline were associated with longer times to viral rebound after treatment interruption (P=0.028). Additionally, we found higher fractions of CD56dim NK cells in individuals with lower levels of HIV DNA (P=0.048). NKG2A and NKp30 levels in CD56neg NK cells were higher in patients with lower HIV DNA levels (p=0.00174, r=-0.49 and p=0.03, r= -0.327, respectively) while CD27 levels were higher in those with higher levels of HIV DNA (p=0.026). These data show NK cell functions are heterogeneously impacted by HIV infection with a mixed picture of resolution on ART, and that while NK cells may affect HIV DNA levels and time to viral rebound, no single NK cell marker defined delayed viral rebound.

Protective Immunity of COVID-19 Vaccination with ChAdOx1 nCoV-19 Following Previous SARS-CoV-2 Infection: A Humoral and Cellular Investigation.

Infections caused by SARS-CoV-2 induce a severe acute respiratory syndrome called COVID-19 and have led to more than six million deaths worldwide. Vaccination is the most effective preventative measure, and cellular and humoral immunity is crucial to developing individual protection. Here, we aim to investigate hybrid immunity against SARS-CoV-2 triggered by the ChAadOx1 nCoV-19 vaccine in a Brazilian cohort. We investigated the immune response from ChAadOx1 nCoV-19 vaccination in naïve (noCOVID-19) and previously infected individuals (COVID-19) by analyzing levels of D-dimers, total IgG, neutralizing antibodies (Nabs), IFN-γ (interferon-γ) secretion, and immunophenotyping of memory lymphocytes. No significant differences in D-dimer levels were observed 7 or 15 days after vaccination (DAV). All vaccinated individuals presented higher levels of total IgG or Nabs with a positive correlation (R = 0.88). Individuals in the COVID-19 group showed higher levels of antibody and memory B cells, with a faster antibody response starting at 7 DAV compared to noCOVID-19 at 15 DAV. Further, ChAadOx1 nCoV-19 vaccination led to enhanced IFN-γ production (15 DAV) and an increase in activated T CD4+ naïve cells in noCOVID-19 individuals in contrast with COVID-19 individuals. Hence, our data support that hybrid immunity triggered by ChAadOx1 nCoV-19 vaccination is associated with enhanced humoral response, together with a balanced cellular response.

Mutagenicity in oral cells of individuals exposed to radiofrequency generated by different smartphones

Aim: This study aimed to investigate whether non-ionizing radiation emitted by smartphones is likely to cause genotoxic effects on oral epithelial cells. Methods: Thirty adults were distributed into two groups according to the mobile phone brand used, namely Samsung (Samsung, Seoul, South Korea) and Apple (Apple, California, USA). The material was collected with gentle swabbing of the right and left buccal mucosa using a cervical brush, then the micronucleus test was performed. Results: The Mann-Whitney test with a 5% significance level did not reveal statistically significant differences in micronuclei frequency between the exposed and non-exposed sides (p=0.251). The different brands do not seem to cause risks of inducing genetic damage because there were no statistically significant differences between them (p=0.47). Conclusion: Therefore, our results suggest no correlations of micronuclei frequency in the exposed buccal cells of mobile phone users at the exposure standard levels observed.

ALS mutations in both human skeletal muscle and motoneurons differentially affects neuromuscular junction integrity and function

There is evidence for the involvement of human skeletal muscle (hSKM) in ALS neuromuscular junction (NMJ) dysfunction. However, the specific avenue by which the hSKM contributes to NMJ disruption is not well understood due to limited human-based studies performed to investigate the subject. Thus, hSKM and human motoneurons (hMN) generated from induced pluripotent stem cells of healthy individuals (WT) and ALS patients with two different SOD1 mutations were integrated into functional NMJ systems to investigate and compare the pathological contribution of the hSKM and hMN to ALS NMJ disruption. Morphological assessment of ALS NMJs demonstrated reduced acetylcholine receptor clustering in the post-synaptic membrane of co-cultures with ALS hSKM (hSKMSOD1-hMNWT and hSKMSOD1-hMNSOD1). Significantly reduced functional NMJ numbers, NMJ stability, contraction fidelity and increased fatigue index were observed in all ALS co-cultures compared to WT. However, these disease phenotypes were comparatively more severe in microphysiologic systems with hSKMSOD1-hMNWT or hSKMSOD1-hMNSOD1 than those with hSKMWT-hMNSOD1 co-cultures. Results from this study affirm that the inherent pathological defects in ALS hSKM, independent of motoneurons, significantly contributes to NMJ dysfunction. As such, therapeutically targeting the ALS hSKM may be just as, if not more critical than, the hMN in alleviating disease phenotypes and attenuating disease progression.

High baseline expression of IL-6 and IL-10 decreased CCR7 B cells in individuals with previous SARS-CoV-2 infection during BNT162b2 vaccination.

The current pandemic generated by SARS-CoV-2 has led to mass vaccination with different biologics that have shown wide variations among human populations according to the origin and formulation of the vaccine. Studies evaluating the response in individuals with a natural infection before vaccination have been limited to antibody titer analysis and evaluating a few humoral and cellular response markers, showing a more rapid and intense humoral response than individuals without prior infection. However, the basis of these differences has not been explored in depth. In the present work, we analyzed a group of pro and anti-inflammatory cytokines, antibody titers, and cell populations in peripheral blood of individuals with previous SARS-CoV-2 infection using BNT162b2 biologic. Our results suggest that higher antibody concentration in individuals with an earlier disease could be generated by higher production of plasma cells to the detriment of the presence of memory B cells in the bloodstream, which could be related to the high baseline expression of cytokines (IL-6 and IL-10) before vaccination.

Reduced expression of the tumor necrosis factor gene in blood mononuclear cells in radiologically isolated syndrome – validation of transcriptome analysis results

Radiologically isolated syndrome (RIS) is a nosological form in which magnetic resonance imaging (MRI) reveals lesions of the white matter ofthe brain and/or spinal cord characteristic of multiple sclerosis (MS) in individuals in the absence of clinical symptoms of the disease. Amongthe studies devoted to RIS, the number of works aimed at studying the molecular mechanisms underlying its formation is very small. Previously,using next generation sequencing (NGS), we for the first time revealed significant differences in the expression profiles of several genes in peripheral blood mononuclear cells (MNCs) of individuals with RIS and healthy controls.Objective:to conduct a validation analysis of changes in the expression of the CCR2, CX3CR1, and TNF genes that were observed during NGSin the MNCs of individuals with RIS compared with healthy individuals.Patients and methods.Analysis of the expression of the CCR2, CX3CR1, and TNF genes was performed on independent validation cohorts (inMNCs of 14 subjects with RIS and 14 without RIS) by reverse transcription followed by real-time PCR.Results and discussion.In MNCs of subjects with RIS, the TNF gene expression was significantly reduced compared to healthy controls(p=0.035; FC=0.78). No significant differences in expression levels were found for other genes.Conclusion.The obtained data shows that disturbances of TNF gene expression preceding the clinical manifestations of MS, at least in individuals with RIS, which can lead to further dysregulation of several processes.

Identification of key genes and their association with immune infiltration in adipose tissue of obese patients: a bioinformatic analysis

ABSTRACT Immune cell-mediated adipose tissue (AT) inflammation contributes to obesity-related metabolic disorders, but the precise underlying mechanisms remain largely elusive. In this study, we used the R software to screen key differentially expressed genes (DEGs) in AT from lean and obese individuals and conducted function enrichment analysis. We then analysed their PPI network by using the STRING database. Hub genes were screened by cytohubba plugin. Subsequently, CIBERSORTx was used to predict the proportion of immune cells in AT from lean and obese subjects. Finally, the correlation between hub genes and immune cell proportions was analysed. These studies identified 290 DEGs in the AT between lean and obese subjects. Among them, IL6, CCL19, CXCL8, CXCL12, CCL2, CCL3, CCL4, CXCL2, IL1B, and CXCL1 were proved to be hub genes in regulating the protein-protein interaction (PPI) network. We also found that CXCL8 is positively correlated with resting NK cells, monocytes, activated mast cells, and eosinophils, but negatively correlated with CD8+ T cells and activated NK cells in obese individuals. Taken together, our study identified key genes in AT that are correlated with immune cell infiltration, uncovering potential new targets for the prevention and treatment of obesity and its related complications via regulating the immune microenvironment.

Complement factor B inhibitor LNP023 improves lupus nephritis in MRL/lpr mice

BackgroundLupus nephritis (LN) is the most common complication of systemic lupus erythematosus (SLE), and the abnormal activation of the alternative complement pathway is associated with the pathogenesis of LN. As an inhibitor of complement factor B (CFB) in the alternative pathway, LNP023 has been used in the treatment of a variety of renal diseases with abnormal complement system involvement, such as paroxysmal nocturnal hemoglobinuria, IgA nephropathy, and membranous nephropathy. The aim of our study was to explore whether LNP023 improved LN in MRL/lpr mice by inhibiting the activation of the alternative complement pathway. MethodsThe mice were divided into a normal control group (Normal group) (n = 6), MRL/lpr model group (n = 6), and LNP023 group (n = 6). The LNP023 group was administered LNP023 for 2 weeks by gavage; the MRL/lpr model group was administered saline for 2 weeks by gavage; and the Normal group was administered saline for 2 weeks by gavage. External signs, renal pathology, renal function, renal immune complex and complement deposition, serum anti-dsDNA, serum ANA concentration, and the expression of core complement factors in the alternative complement pathway were analyzed in the 3 groups of animals. The core targets of LNP023 in the treatment of LN were screened using network pharmacology. The pathogenicity of the core targets in LN was verified by analyzing the mRNA expression of the core targets in the peripheral blood mononuclear cells (PBMCs) of normal individuals, SLE patients, and LN patients. The mRNA and protein expression of core targets in the Normal group, MRL/lpr group, and LNP023 group were analyzed to verify whether LNP023 exerted it LN therapeutic effect through the regulation of core targets. ResultsCompared with the MRL/lpr group, the LNP023 group had reduced lupus-like signs, improved renal function, decreased serum anti-dsDNA and ANA concentrations, and reduced renal IgM, IgG, IgG1, C1q, C3, and C4 deposition. Renal pathology showed that LNP023 attenuated pathological damage in the kidneys of MRL/lpr mice. Compared with the MRL/lpr model group, the treatment group had no crescent formation, less immune deposition, no nuclear fragmentation, and less inflammatory cell infiltration. The expression of complement proteins C3, C3b, CR1, CFB, and C5b-9 in kidney tissues and liver was decreased, and the expression of C5 was increased. Network pharmacology screening indicated that AKT, TNF-α, MDM2, UBC, STST3, ESR1, and TP53 were core targets of LNP023 in the treatment of LN. Compared with that in the Normal group, the mRNA expression of the core target in the SLE and LN groups was different; compared with the MRL/lpr group, the LNP023 treatment group showed different mRNA and protein expression levels of AKT, TNF-α, and STST3. ConclusionLNP023 improves LN in MRL/lpr mice. The mechanism is as follows: LNP023 binds to CFB to inhibit the activation of the alternative complement pathway. LNP023 treatment for LN may also play a role in regulating the protein expression of AKT, TNF-α, and STST3.

Regulatory T cells in erythema nodosum leprosum maintain anti-inflammatory function

The numbers of circulating regulatory T cells (Tregs) are increased in lepromatous leprosy (LL) but reduced in erythema nodosum leprosum (ENL), the inflammatory complication of LL. It is unclear whether the suppressive function of Tregs is intact in both these conditions. A longitudinal study recruited participants at ALERT Hospital, Ethiopia. Peripheral blood samples were obtained before and after 24 weeks of prednisolone treatment for ENL and multidrug therapy (MDT) for participants with LL. We evaluated the suppressive function of Tregs in the peripheral blood mononuclear cells (PBMCs) of participants with LL and ENL by analysis of TNFα, IFNγ and IL-10 responses to Mycobacterium leprae (M. leprae) stimulation before and after depletion of CD25+ cells. 30 LL participants with ENL and 30 LL participants without ENL were recruited. The depletion of CD25+ cells from PBMCs was associated with enhanced TNFα and IFNγ responses to M. leprae stimulation before and after 24 weeks treatment of LL with MDT and of ENL with prednisolone. The addition of autologous CD25+ cells to CD25+ depleted PBMCs abolished these responses. In both non-reactional LL and ENL groups mitogen (PHA)-induced TNFα and IFNγ responses were not affected by depletion of CD25+ cells either before or after treatment. Depleting CD25+ cells did not affect the IL-10 response to M. leprae before and after 24 weeks of MDT in participants with LL. However, depletion of CD25+ cells was associated with an enhanced IL-10 response on stimulation with M. leprae in untreated participants with ENL and reduced IL-10 responses in treated individuals with ENL. The enhanced IL-10 in untreated ENL and the reduced IL-10 response in prednisolone treated individuals with ENL was abolished by addition of autologous CD25+ cells. The findings support the hypothesis that the impaired cell-mediated immune response in individuals with LL is M. leprae antigen specific and the unresponsiveness can be reversed by depleting CD25+ cells. Our results suggest that the suppressive function of Tregs in ENL is intact despite ENL being associated with reduced numbers of Tregs. The lack of difference in IL-10 response in control PBMCs and CD25+ depleted PBMCs in individuals with LL and the increased IL-10 response following the depletion of CD25+ cells in individuals with untreated ENL suggest that the mechanism of immune regulation by Tregs in leprosy appears independent of IL-10 or that other cells may be responsible for IL-10 production in leprosy. The present findings highlight mechanisms of T cell regulation in LL and ENL and provide insights into the control of peripheral immune tolerance, identifying Tregs as a potential therapeutic target.

Immunodeficiency syndromes differentially impact the functional profile of SARS-CoV-2-specific T cells elicited by mRNA vaccination

Many immunocompromised patients mount suboptimal humoral immunity after SARS-CoV-2 mRNA vaccination. Here, we assessed the single-cell profile of SARS-CoV-2-specific T cells post-mRNA vaccination in healthy individuals and patients with various forms of immunodeficiencies. Impaired vaccine-induced cell-mediated immunity was observed in many immunocompromised patients, particularly in solid-organ transplant and chronic lymphocytic leukemia patients. Notably, individuals with an inherited lack of mature B cells, i.e., X-linked agammaglobulinemia (XLA) displayed highly functional spike-specific T cell responses. Single-cell RNA-sequencing further revealed that mRNA vaccination induced a broad functional spectrum of spike-specific CD4+ and CD8+ T cells in healthy individuals and patients with XLA. These responses were founded on polyclonal repertoires of CD4+ T cells and robust expansions of oligoclonal effector-memory CD45RA+ CD8+ T cells with stem-like characteristics. Collectively, our data provide the functional continuum of SARS-CoV-2-specific T cell responses post-mRNA vaccination, highlighting that cell-mediated immunity is of variable functional quality across immunodeficiency syndromes.

Effect of aging on immune cells in male HIV-infected and -uninfected healthy individuals.

HIV induces immunologic dysfunction in T cells of infected individuals. However, the impact of aging on T cell phenotypes in HIV-infected individuals receiving antiretroviral therapy (ART) has not been fully delineated. We evaluated the relationship between aging and the expression of immune activation and exhaustion markers on CD8 + T cells of age-matched HIV-infected and -uninfected male participants. Levels of immune activation and exhaustion markers on peripheral blood CD8 + T cells of HIV-infected and -uninfected participants were examined. 110 HIV-infected aviremic male participants receiving ART and 146 HIV-uninfected male participants were studied. The levels of TIGIT, PD-1, CD38, and CD226 on CD8 + T cells of the study participants were determined by flow cytometry. The level of TIGIT on CD8 + T cells was higher in aviremic HIV-infected compared to uninfected participants ( P < 0.0001). In contrast, no significant differences were found in the levels of PD-1 and CD38 on CD8 + T cells between the two groups. Statistically significant correlations were observed between age and the levels of TIGIT + and CD38 + CD8 + T cells in both groups; however, no correlation was found between age and the level of PD-1 + CD8 + T cells in HIV-infected participants. Age-stratification of HIV-infected and -uninfected groups did not show any significant differences in the level of PD-1 expression on CD8 + T cells. The findings of our study highlight the role of aging in the expression of immune markers on CD8 + T cells and have important implications for therapies that target immune checkpoints in HIV-infected individuals.

SARS-CoV-2-specific T cells in unexposed adults display broad trafficking potential and cross-react with commensal antigens.

The baseline composition of T cells directly impacts later response to pathogens, but the complexity of precursor states remains poorly defined. Here, we examined the baseline state of SARS-CoV-2-specific T cells in unexposed individuals. SARS-CoV-2-specific CD4+ T cells were identified in pre-pandemic blood samples by class II peptide-MHC tetramer staining and enrichment. Our data revealed a substantial number of SARS-CoV-2-specific T cells that expressed memory phenotype markers. Integrated phenotypic analyses demonstrated diverse pre-existing memory states that included cells with distinct polarization states and trafficking potential to barrier tissues. T cell clones generated from tetramer-labeled cells cross-reacted with antigens from commensal bacteria in the skin and gastrointestinal tract. Direct ex vivo tetramer staining for one spike-specific population showed a similar level of cross-reactivity to sequences from endemic coronavirus and commensal bacteria. These data highlight the complexity of precursor T cell repertoire and implicate non-infectious exposures to common microbes as a key factor that shapes human pre-existing immunity to SARS-CoV-2.

Human CD38 regulates B cell antigen receptor dynamic organization in normal and malignant B cells.

CD38 is a multifunctional protein expressed on the surface of B cells in healthy individuals but also in B cell malignancies. Previous studies have suggested a connection between CD38 and components of the IgM class B cell antigen receptor (IgM-BCR) and its coreceptor complex. Here, we provide evidence that CD38 is closely associated with CD19 in resting B cells and with the IgM-BCR upon engagement. We show that targeting CD38 with an antibody, or removing this molecule with CRISPR/Cas9, inhibits the association of CD19 with the IgM-BCR, impairing BCR signaling in normal and malignant B cells. Together, our data suggest that CD38 is a new member of the BCR coreceptor complex, where it exerts a modulatory effect on B cell activation upon antigen recognition by regulating CD19. Our study also reveals a new mechanism where α-CD38 antibodies could be a valuable option in therapeutic approaches to B cell malignancies driven by aberrant BCR signaling.

Phenotypic Changes of Peripheral γδ T Cell and Its Subsets in Patients With Coronary Artery Disease.

Coronary atherosclerotic heart disease (CAD) is a chronic inflammatory cardiovascular disease with high morbidity and mortality. Growing data indicate that many immune cells are involved in the development of atherosclerosis. However, the immunological roles of γδ T cells in the initiation and progression of CAD are not fully understood. Here, we used flow cytometry to determine phenotypical changes of γδ T cells and their subpopulations in peripheral blood samples collected from 37 CAD patients. The Pearson correlation coefficient was used to analyze the relationship between the clinical parameter (serum LDL-C level) and the changes of immunophenotypes of γδ T cells. Our results demonstrated that the frequencies and absolute numbers of total γδ T cells and Vδ2+ T cells were significantly decreased in CAD patients when compared to healthy individuals. However, the proportion of Vδ1+ T cells was much lower in CAD patients than that of healthy individuals. Most importantly, a significant alteration of the Vδ1/Vδ2 ratio was found in CAD patients. In addition, a series of surface markers that are associated with costimulatory signals (CD28, CD40L, CD80, CD86), activation levels (CD69, CD25, HLA-DR), activating NK cell receptors (NKp30, NKp46, NKG2D) and inhibitory receptors (PD-1, CTLA-4, PD-1, Tim-3) were determined and then analyzed in the total γδ T cells, Vδ2+T cells and Vδ2-T cells of CAD patients and healthy individuals. The data demonstrated that immunological activities of total γδ T cells, Vδ2+T cells, and Vδ2-T cells of CAD patients were much lower than those in healthy individuals. Moreover, we found that there were positive correlations between the serum LDL-C levels and frequencies of CD3+γδ+ T cells, CD69+Vδ2+T cells, NKG2D+Vδ2+T cells, and NKp46+Vδ2+T cells. By contrast, there was an inverse correlation between the levels of serum LDL-C and the frequencies of CD69+Vδ2-T cells and NKp46+Vδ2-T cells. Accordingly, these findings could help us to better understand the roles of γδ T cells in the CAD, and shed light on the development of novel diagnostic techniques and therapeutic strategies by targeting γδ T cells for CAD patients.

The Role of Beta Cell Recovery in Type 2 Diabetes Remission.

Type 2 diabetes (T2D) has been considered a relentlessly worsening disease, due to the progressive deterioration of the pancreatic beta cell functional mass. Recent evidence indicates, however, that remission of T2D may occur in variable proportions of patients after specific treatments that are associated with recovery of beta cell function. Here we review the available information on the recovery of beta cells in (a) non-diabetic individuals previously exposed to metabolic stress; (b) T2D patients following low-calorie diets, pharmacological therapies or bariatric surgery; (c) human islets isolated from non-diabetic organ donors that recover from “lipo-glucotoxic” conditions; and (d) human islets isolated from T2D organ donors and exposed to specific treatments. The improvement of insulin secretion reported by these studies and the associated molecular traits unveil the possibility to promote T2D remission by directly targeting pancreatic beta cells.

Evaluation of natural chronic low dose radiation exposure on telomere length and transcriptional response of shelterin complex in individuals residing in Kerala coast, India

The high level natural radiation areas (HLNRA) of Kerala coast provide unique opportunity to study the biological effect of chronic low dose ionizing radiation (LDIR) on human population below 100 mSv. The radiation level in this area varies from < 1.0–45 mGy /year due to patchy distribution of monazite in the sand, which contains 232Th (8–10%), 238U (0.3%), and their decay products. Telomere length attrition has been correlated to DNA damage due to genotoxic agents. The objective of the present study is to evaluate the effect of natural chronic LDIR exposure on telomere length and transcriptional response of telomere specific and DNA damage repair genes in peripheral blood mononuclear cells (PBMCs) of individuals from normal level natural radiation areas (NLNRA) and HLNRA of Kerala coast, southwest India. Blood samples were collected from 71 random male donors (24–80 years) from NLNRA (≤1.50 mGy/year; N = 19) and two HLNRA dose groups [1.51–10 mGy/year (N = 17); > 10 mGy/year, (N = 35)]. Genomic DNA was isolated from PBMCs and relative telomere length (RTL) was determined using real time q-PCR. Radio-adaptive response (RAR) study was carried out in PBMCs of 40 random males from NLNRA (N = 20) and HLNRA (>10 mGy/year; N = 20), where PBMCs were given a challenged dose of 2.0 Gy gamma radiation at 4 h. Transcriptional profile of telomere specific (TRF1, TRF2, POT1, TIN2, TPP1, RAP1), DNA damage response (RAD17, ATM, CHEK1) and base excision repair pathway (BER) (OGG1, XRCC1, NTH1, NEIL1, MUTYH, MBD4) genes were analysed at basal level and after a challenge dose of 2.0 Gy at 4 h. Our results did not show any significant effect of chronic LDR on RTL among the individuals from NLNRA and two HLNRA groups (p = 0.195). However, influence of age on RTL was clearly evident among NLNRA and HLNRA individuals. At basal level, TRF1, TRF2, TIN2, MBD4, NEIL1 and RAD17 showed significant up-regulation, whereas XRCC1 was significantly down regulated in HLNRA individuals. After a challenge dose of 2.0 Gy, significant transcriptional up-regulation was observed at telomere specific (TRF2, POT1) and BER (MBD4, NEIL1) genes in HLNRA individuals as compared to NLNRA suggesting their role in RAR. In conclusion, elevated level of natural chronic LDR exposure did not have any adverse effect on telomere length in Kerala coast. Significant transcriptional response at TRF2, MBD4 and NEIL1 at basal level and with a challenge dose of 2.0 Gy suggested their active involvement in efficient repair and telomere maintenance in individuals from HLNRA of Kerala coast.

MRNA Booster Vaccination Enhances Antibody Responses against SARS-CoV2 Omicron Variant in Individuals Primed with mRNA or Inactivated Virus Vaccines

The advent of the Omicron variant globally has hastened the requirement for a booster vaccination dose to confer continuous protection against symptomatic SARS-CoV2 infection. However, different vaccines are available in different countries, and individuals who had adverse reactions to certain vaccine types require heterologous vaccine boosters. To understand the efficacy of different vaccination regimens in inducing humoral responses to SARS-CoV2, we examined plasma antibodies and frequencies of Omicron RBD-specific B cells in individuals who had different priming-booster vaccination regimens. We found that individuals with three homologous doses of mRNA vaccines had higher levels of IgG of all subclasses against RBD of Omicron than individuals with three homologous doses of inactivated virus vaccine. A booster with mRNA vaccine resulted in significant increases in median levels of RBD-reactive IgG1 (17–19 fold) and IgG3 (2.3–3.3 fold) as compared to individuals receiving inactivated virus booster shots regardless of priming vaccine types. More importantly, individuals who received a booster dose of mRNA vaccine, irrespective of the priming vaccine, had antibodies with higher neutralizing capability against the Omicron variant than those who received a booster dose of inactivated virus vaccine. Corroborating the antibody results, boosting with the mRNA vaccine increased the frequencies of Omicron RBD-binding B cells by (1.5–3.3 fold) regardless of priming vaccine types. Together, our data demonstrate that an mRNA vaccine (BNT162b2 or mRNA-1273) booster enhances humoral responses against the Omicron variant in individuals vaccinated with either two prior doses of mRNA or inactivated virus vaccine (CoronaVac or BBIBP-CorV), potentially providing more effective protection against SARS-CoV-2 infection, particularly by the Omicron variant.

A miR-125/Sirtuin-7 pathway drives the pro-calcific potential of myeloid cells in diabetic vascular disease

Aims/hypothesisEctopic calcification is a typical feature of diabetic vascular disease and resembles an accelerated ageing phenotype. We previously found an excess of myeloid calcifying cells in diabetic individuals. We herein examined molecular and cellular pathways linking atherosclerotic calcification with calcification by myeloid cells in the diabetic milieu.MethodsWe first examined the associations among coronary calcification, myeloid calcifying cell levels and mononuclear cell gene expression in a cross-sectional study of 87 participants with type 2 diabetes undergoing elective coronary angiography. Then, we undertook in vitro studies on mesenchymal stem cells and the THP-1 myeloid cell line to verify the causal relationships of the observed associations.ResultsCoronary calcification was associated with 2.8-times-higher myeloid calcifying cell levels (p=0.037) and 50% elevated expression of the osteogenic gene RUNX2 in mononuclear cells, whereas expression of Sirtuin-7 (SIRT7) was inversely correlated with calcification. In standard differentiation assays of mesenchymal stem cells, SIRT7 knockdown activated the osteogenic program and worsened calcification, especially in the presence of high (20 mmol/l) glucose. In the myeloid cell line THP-1, SIRT7 downregulation drove a pro-calcific phenotype, whereas SIRT7 overexpression prevented high-glucose-induced calcification. Through the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, high glucose induced miR-125b-5p, which in turn targeted SIRT7 in myeloid cells and was directly associated with coronary calcification.Conclusions/interpretationWe describe a new pathway elicited by high glucose through the JAK/STAT cascade, involving regulation of SIRT7 by miR-125b-5p and driving calcification by myeloid cells. This pathway is associated with coronary calcification in diabetic individuals and may be a target against diabetic vascular disease.Data availabilityRNA sequencing data are deposited in GEO (accession number GSE193510; https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE193510).Graphical abstract