Circulating T cells in sarcoidosis have an aberrantly activated phenotype that correlates with disease outcome

RATIONALE

Disease course in sarcoidosis is highly variable. Bronchoalveolar lavage fluid and mediastinal lymph nodes show accumulation of activated T cells with a T-helper (Th)17.1 signature, which correlates with non-resolving sarcoidosis. We hypothesize that the peripheral blood (PB) T cell phenotype may correlate with outcome.

OBJECTIVES

To compare frequencies, phenotypes and function of circulating T cell populations in sarcoidosis patients with healthy controls (HCs) and correlate these parameters with outcome.

METHODS

We used multi-color flow cytometry to quantify activation marker expression on PB T cell subsets in treatment-naïve patients and HCs. The disease course was determined after 2-year follow-up. Cytokine production was measured after T cell stimulation in vitro.

MEASUREMENTS AND MAIN RESULTS

We observed significant differences between patients and HCs in several T cell populations, including CD8+ and CD4+ T cells, Th1/Th17 subsets, CD4+ T memory stem cells, regulatory T cells (Tregs) and γδ T cells. Decreased frequencies of CD4+ T cells and increased frequencies of Tregs and CD8+ γδ T cells correlated with worse outcome. Naïve CD4+ T cells displayed an activated phenotype with increased CD25 expression in patients with active chronic disease at 2-year follow-up. A distinctive Treg phenotype with increased expression of CD25, CTLA4, CD69, PD-1 and CD95 correlated with chronic sarcoidosis. Upon stimulation, both naïve and memory T cells displayed a different cytokine profile in sarcoidosis compared to HCs.

CONCLUSIONS

Circulating T cell subpopulations of sarcoidosis patients display phenotypic abnormalities that correlate with disease outcome, supporting a critical role of aberrant T cell activation in sarcoidosis pathogenesis.

Immune regulation by activation markers at feto-maternal interface in infection-associated spontaneous preterm birth

BACKGROUND

Spontaneous preterm birth (sPTB) is a global health concern. Studies reveal infections are majorly responsible for sPTB and immune activation markers play a role in regulation of maternal immune responses against pathogens during sPTB.

AIM

To study the mRNA expression and correlation of activation markers (CD66a, ICAM1, ITGB1, TIM3, CD25, CD95) and associated cytokines (IL-1β and IL-17)/prostaglandin receptors (EP2 and IP) in the placenta of Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum-infected sPTB women.

METHODS

Placental samples were collected from 160 sPTB and 160 term birth women. PCR was used for the detection of C. trachomatis, M. hominis, U. urealyticum. The mRNA expression of activation markers, cytokines and prostaglandin receptors was evaluated by real-time qPCR.

RESULTS

The fold-change expression of CD66a, ICAM1, TIM3, CD25 and CD95 was 2.89, 5.5, 4.95, 6.44 and 6.95-fold (p < 0.001), respectively; while for cytokines- IL-1β and IL-17 was 5.41 and 4.71-fold (p < 0.001), respectively and for prostaglandin receptors- EP2 and IP was 5.5 and 5-fold (p < 0.001) upregulated, respectively in infected sPTB women. Significant positive correlation was obtained among ICAM-1 and IL-1β/EP2/IL-17, TIM3 and IP/IL-17. Significant negative correlation was obtained between CD66a and EP2/IL-17, CD25 and IL-1β/EP2, CD95 and IL-1β/EP2 in infected sPTB women.

CONCLUSIONS

CD66a, ICAM1 and TIM3 may play role in inflammation and have potential for the clinical beginning of preterm labour during infection while CD25 and CD95 are possibly involved in immunotolerance at feto-maternal interface during C. trachomatis, M. hominis and U. urealyticum infection.

Rapid activation of hematopoietic stem cells

Adult hematopoietic stem cells (HSCs) in the bone marrow (BM) are quiescent. Following perturbations, such as blood loss or infection, HSCs may undergo activation. Surprisingly, little is known about the earliest stages of HSCs activation. We utilize surface markers of HSCs activation, CD69 and CD317, revealing a response as early as 2 h after stimulation. The dynamic expression of HSCs activation markers varies between viral-like (poly-Inosinic-poly-Cytidylic) or bacterial-like (Lipopolysaccharide) immune stimuli. We further quantify dose response, revealing a low threshold, and similar sensitivity of HSCs and progenitors in the BM. Finally, we find a positive correlation between the expression of surface activation markers and early exit from quiescence. Our data show that the response of adult stem cells to immune stimulation is rapid and sensitive, rapidly leading HSCs out of quiescence.

Optimized flow cytometry assays to monitor neutrophil activation in human and mouse whole blood samples

Polymorphonuclear neutrophils (PMNs) protect the host from invading microorganisms. However, excessively activated PMNs can also cause damage to host tissues under inflammatory conditions. Here we developed simple assays to determine the activation state of PMNs in human whole blood that contains soluble mediators known to influence PMN functions. Because mouse models are widely used to study the role of PMNs in infectious and inflammatory diseases, we adapted these assays for the rapid and reliable assessment of PMN functions in murine blood samples. Freshly collected whole blood samples were stimulated with agonists of the formyl peptide receptors (FPR) of PMNs and changes in reactive oxygen species (ROS) production and the expression of CD11b, CD62L (L-selectin), CD66b, and CD63 on the cell surface were analyzed with flow cytometry. We optimized these assays to minimize inadvertent interferences such as cell stress generated during sample handling and the loss of plasma mediators that regulate PMN functions. Human PMNs readily responded to the FPR agonist N-formyl-methionyl-leucyl-phenylalanine (fMLP). The most sensitive responses of human PMNs to fMLP were CD11b, CD62L, and CD66b expression with half maximal effective concentrations (EC₅₀) of 5, 8, and 6 nM fMLP, respectively. CD63 expression and ROS production required markedly higher fMLP concentrations with EC₅₀ values of 19 and 50 nM fMLP, respectively. Mouse PMNs did not respond well to fMLP and required significantly higher concentrations of the FPR agonist WKYMVm (W-peptide) to achieve equivalent cell activation. The most sensitive response of mouse PMNs was ROS production with an EC₅₀ of 38 nM W-peptide. Because mice do not express CD66b, we only assessed the expression of CD62L, CD11b, and CD63 with EC₅₀ values of 54, 119, and 355 nM W-peptide, respectively. Validation of our optimized assays showed that they sensitively detect the responses of human PMNs to priming with endotoxin in vitro as well as the corresponding responses of murine PMNs to bacterial infection in a sepsis model. We conclude that these optimized assays could be useful tools for the monitoring of patients with infections, sepsis, and other inflammatory conditions as well as for the design and interpretation of preclinical studies of these diseases in mouse models.

Different aspects of platelet evaluation in dengue: Measurement of circulating mediators, ability to interact with the virus, the degree of activation and quantification of intraplatelet protein content

Platelets play a role in hemostasis, coagulation, angiogenesis, inflammation and immune response is one of the most affected cells in dengue. Here we describe some aspects of platelets by observing their specific circulating mediators, the ability to interact with the virus and morphological consequences of this interaction, activation markers and intraplatelet protein contents in dengue. We conducted this study using dengue-patients as well as healthy donors. Immunoenzymatic assay, flow cytometry, transmission electron microscopy and intraplatelet proteins expression assays were carried out. Briefly, we found an increase in sCD62L, NO or TBX2 ratio in platelet count, mostly in patients with the worse clinical outcome. After in vitro DENV infection or during natural infection, platelets underwent morphological alteration with increased expression of platelet activation markers, particularly in natural infections. Analysis of intraplatelet protein contents revealed different angiogenic and inflammatory profiles, maintaining or not extracellular matrix integrity between DF and DFWS patients. Thus, platelets are frequently affected by dengue, either by altering their own functionality, as "carrier" of the virus, or as an antiviral and mediator-secreting effector cell. Thus, strategies aimed at recovering platelet amounts in dengue seem to be essential for a better clinical outcome of the patients.

Age determines response to anti-TNFα treatment in patients with ankylosing spondylitis and is related to TNFα-producing CD8 cells

Younger age is a predictor of good clinical response to treatment with tumour necrosis factor (TNF) α inhibitors in ankylosing spondylitis (AS) patients; therefore, the aim of the study was to determine age-related differences in cellular functions, which can predict the response. High disease activity AS patients were treated with TNFα inhibitors for 12 weeks. Based on the percentage of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) improvement, patients were divided into responding or non-responding groups. Cytometric and clinical assessment were determined at baseline, 4, and 12 weeks after initiation of anti-TNFα treatment. Expression of activation markers on T cells and intracellular cytokine staining was performed. Baseline percentage of TNFα-producing CD8 cells was lower in responders than in non-responders (20.8 ± 2.9 vs 40.7 ± 8.2; P = 0.04 in T test) and increased in the responding group during the first month of treatment (20.8 ± 2.9 vs 30.3 ± 2.5; P = 0.02). Moreover, its baseline level correlated with age (r = 0.7; P = 0.0009) but not with BASDAI improvement adjusted for age. There were no differences in the baseline percentage of IL-4, IL-17A, and IFNγ within CD4 and CD8 cells nor in the expression of CD25, CD28, and CD69 on these cells between responders and non-responders. However, baseline level of CD4+CD28null cells correlated with the percentage of BASDAI improvement while analysed as a continuous variable adjusted for age (r = − 0.4; P = 0.048). Clinical predictors of response were also determined. Influence of age on the response to anti-TNFα treatment in AS patients could be mediated by TNFα-producing CD8 cells.

Platelet populations and priming in hematological diseases

In healthy subjects and patients with hematological diseases, platelet populations can be distinguished with different response spectra in hemostatic and vascular processes. These populations partly overlap, and are less distinct than those of leukocytes. The platelet heterogeneity is linked to structural properties, and is enforced by inequalities in the environment. Contributing factors are variability between megakaryocytes, platelet ageing, and positive or negative priming of platelets during their time in circulation. Within a hemostatic plug or thrombus, platelet heterogeneity is enhanced by unequal exposure to agonists, with populations of contracted platelets in the thrombus core, discoid platelets at the thrombus surface, patches of ballooned and procoagulant platelets forming thrombin, and coated platelets binding fibrin. Several pathophysiological hematological conditions can positively or negatively prime the responsiveness of platelet populations. As a consequence, in vivo and in vitro markers of platelet activation can differ in thrombotic and hematological disorders.

CD11a and CD49d enhance the detection of antigen-specific T cells following human vaccination

BACKGROUND

Determining the efficacy of human vaccines that induce antigen-specific protective CD4 T cell responses against pathogens can be particularly challenging to evaluate. Surface expression of CD11a and CD49d has been shown to identify antigen-specific CD4 T cells against viral pathogens in mice. We hypothesized that CD11a and CD49d would also serve as markers of human antigen-specific T cells responding to vaccination.

METHODS

A phase I vaccine trial enabled us to evaluate a novel gating strategy based on surface expression of CD11a and CD49d as a means of detecting antigen-specific, cytokine producing CD4 and CD8 T cells induced after vaccination of naïve individuals against leishmaniasis. Three study groups received LEISH-F3 recombinant protein combined with either squalene oil-in-water emulsion (SE) alone, SE with the synthetic TLR-4 ligand glucopyranosyl lipid adjuvant (GLA-SE), or SE with Salmonella minnesota-derived monophosphoryl lipid A (MPL-SE). Individuals were given 3 vaccine doses, on days 0, 28 and 168.

RESULTS

Starting after the first vaccine dose, the frequency of both CD11a^hiCD49d⁺ CD4 and CD11a^hiCD49d⁺ CD8 T cells significantly increased over time throughout the 24-week trial. To confirm the role of CD11a^hiCD49d⁺ expression in the identification of the antigen-specific T cells, cytokine production was measured following LEISH-F3 stimulation. All of the IFN-γ, TNF-α, and IL-2 producing cells were found within the CD11a^hiCD49d⁺ population.

CONCLUSIONS

Our results suggest that the change in the frequency of CD11a^hiCD49d⁺ T cells can be used to track antigen-specific CD4 and CD8 T cell responses following T cell-targeted vaccination.

Blood derived products in pediatrics: New laboratory tools for optimizing potency assignment and reducing side effects

Neonates and children can develop rare bleeding disorders due to congenital/acquired coagulation Factor deficiencies, or allo-immune/autoimmune complications, or can undergo surgeries at high haemorrhagic risk. They then need specialized transfusion of blood components/products, or purified blood extracted products or recombinant proteins. Blood-derived therapies conventionally used for management of affected infants with genetic/acquired deficiencies, bleeding problems (coagulation Factor reduced or missing) or thrombotic disorders (reduced or missing anticoagulant proteins) pose some additional risks. These remedial therapies can cause tolerance when used very early in life and, sometimes needed, repeatedly. The introduction of recombinant proteins has allowed manufacturers to produce large amounts of the proteins usually present at very low concentration in blood. This has also changed the risk pattern of plasma-extracted products, especially in terms of continual reduction of viral transmission. Many efforts have been made over these past decades to reduce the risks associated with the use of all these products in terms of viral and bacterial safety, as well as immune disorders but they are not the objective of this article. Other associated side effects are the presence of undesired activities in blood products, which can produce thrombotic events or adverse reactions. The progressive introduction of blood derived products has greatly improved the prognosis and quality of life of affected patients. This concerns whole blood, but also blood cell concentrates, mainly platelets and red blood cells, plasma, while the blood extracted products are increasingly replaced by recombinant proteins. All these therapeutic products, i.e. blood extracted drugs, improve health and quality of life for hemophiliac's A or B, or patients with auto/allo-immune thrombocytopenias or with rare bleeding disorders, and those with thrombotic events occurring in childhood, which are mainly due to Protein C or Protein S deficiencies (congenital or acquired). Progress in analytical methods and biotechnology allow better control of the manufacturing processes for all blood derived or plasma extracted products and recombinant proteins, and contribute to improved manufacturing processes to minimize the occurrence of side effects. These adverse events can be due to the aging of the blood cell concentrate with release of their granule content, and generation of EVs, which can produce anaphylactic reactions and risk of thrombosis, but also to the presence of activated coagulation Factors in purified products, such as Factor Xia as recently identified in immunoglobulin concentrates. Characterization and measurement of contaminant products is of special usefulness during product preparation and for optimization of manufacturing processes for purified extracted products, but also for recombinant proteins. The pharmaceutical industry introduces these new methods for validating manufacturing processes, or for quality control assessments. The objective is first to warrant the full quality and safety of the lots produced, and assure the highest efficacy with the lowest risks when used in patients. For cell concentrates and fresh blood, storage conditions are critical and measurement of analytes such as EVs or Annexin V allows evaluation of quality of each individual transfused pouch. In addition to all the rules around viral and bacterial transmission risk, and immune tolerance, our available laboratory methods contribute to reducing the side effects of blood cell concentrates and derived plasma products, as well as those of the therapeutic recombinant proteins.

CD38+CD8+ and CD38+CD4+ T Cells and IFN Gamma (+874) Polymorphism Are Associated with a Poor Virological Outcome

The main objective of the work was to evaluate the use of CD38 on T lymphocytes, IFNγ (+874 A/T), and IL-10 (-1082 A/G) polymorphisms in HIV-infected patients under antiretroviral (ARV) therapy. Sixty-one patients were selected at the outpatient clinic for HIV infection at the Hospital São José de Doenças Infecciosas, Fortaleza, Ceará, Brazil. The patients were classified into two groups, according to viral load after one year of ARV therapy. In the aviremic group (group I), a reduction of 35.5% of CD38+CD4+ T cells was observed (p = 0.02) and 49.3% of CD38+CD8+ T cells (p = 0.001). In the viremic group (group II), a reduction of 37.2% of CD38+CD4+ T cells (p = 0.067), and 21.4% of CD38+CD8+ T cells (p = 0.60) occurred. No association was found between IL-10 (-1082) polymorphism and the type of response to ARV therapy. Regarding the gene polymorphism on IFNγ (+874 T/A), 73.34% of group I and 33.3% of group II presented the AA genotype. The relative risk of the individuals carrying AA genotype or the A allele and not being able to suppress the viral load level after one year of ARV therapy was 3.44 (1.25-9.45; p = 0.014) or 2.35 (1.05-5.26; p = 0.027), respectively. Our data suggested that an augmented frequency of activated CD38+CD8+ T cells as well as the presence of the A allele of IFNγ polymorphism could contribute to a reduced virological suppression in patients under antiretroviral therapy.

Sodium benzoate, a food preservative, affects the functional and activation status of splenocytes at non cytotoxic dose

Sodium benzoate (SB) is a widely used food preservative due to its bacteriostatic and fungistatic properties. The acceptable daily intake of SB is 5 mg/kg-bw, however, it has been found to be used in the food commodities at relatively high levels (2119 mg/kg). Earlier studies on SB have shown its immunosuppressive properties, but comprehensive immunotoxicity data is lacking. Our studies have shown that SB was non cytotoxic in splenocytes up to 1000 μg/ml for 72 h, however at 2500 μg/ml it was found to be cytotoxic. Thus, 1000 μg/ml dose of SB was chosen for the subsequent experiments. SB significantly suppresses the proliferation of Con A and LPS stimulated splenocytes at 72 h, while allogenic response of T cells was significantly decreased after 96 h. SB did not affect the relative expression of CD3e or CD4 molecules following 72 h exposure, however, it downregulated the relative expression of CD8 co-receptor. Further, exposure of splenocytes to SB for 72 h led to reduced expression of CD28 and CD95, which play a vital role in T cell activation. SB also suppresses the relative expression of CD19, CD40 and CD95 receptors on B cells after 72 h. In addition to the functional responses, SB lowered the expression of IL4, IL6, IFNγ and IL17 cytokines in Con A stimulated splenocytes; and IL6, IFNγ and TNFα in LPS stimulated splenocytes following 48 h of exposure. Taken together, the present study is suggestive of the immunomodulatory potential of SB.

Reduced iNKT cells numbers in type 1 diabetes patients and their first-degree relatives

Type 1 diabetes (T1D) is an autoimmune disease that is characterized by the specific destruction of insulin-producing pancreatic β cells. Invariant natural killer T (iNKT) cells have been associated with development of T1D. Class I MHC-restricted T cell-associated molecule (CRTAM) is expressed on activated iNKT, CD8(+), and CD4(+) T cells, and it is associated with the pro-inflammatory profiles of these cells. Crtam gene expression in CD3(+) lymphocytes from non-obese diabetic (NOD) mice is associated with T1D onset. However, expression of CRTAM on T cells from patients with T1D has not yet been evaluated. We compared iNKT cell (CD3(+)Vα24(+)Vβ11(+)) numbers and CRTAM expression in a Mexican population with recent-onset T1D and their first-degree relatives with control families. Remarkably, we found lower iNKT cell numbers in T1D families, and we identified two iNKT cell populations in some of the families. One iNKT cell population expressed high iTCR levels (iNKT(hi)), whereas another expressed low levels (iNKT(lo)) and also expressed CRTAM. These findings support a probable genetic determinant of iNKT cell numbers and a possible role for these cells in T1D development. This study also suggests that CRTAM identifies recently activated iNKT lymphocytes.

Primary central nervous system diffuse large B-cell lymphoma in the immunocompetent: Immunophenotypic subtypes and Epstein-Barr virus association

INTRODUCTION

Primary central nervous system diffuse large B-cell lymphoma (PCNSL DLBCL) in the immunocompetent is an uncommon tumor that has an activated B-cell immunophenotype resembling germinal center exit B cells. They also differ from primary central nervous diffuse large B-cell lymphomas in the immunocompromised as they show no association with the Epstein-Barr virus.

OBJECTIVE

To determine if immunophenotypic subtyping of PCNS DLBCL from Asian subcontinent are also different similar to its systemic counterpart is unclear, as there are only limited studies from Asia, and none from India.

MATERIAL AND METHODS

The immunohistochemical profile of 24 South Indian patients with primary central nervous system diffuse large B-cell lymphoma was studied using germinal center markers - CD10 and Bcl-6, and activation markers - MUM1 and CD138, which are markers for late/post germinal centre B cells. Insitu hybridization for EBV genome and LMP1 by immunohistochemistry was carried out in all cases to determine association with EBV.

RESULTS

Centroblastic morphology and uniform activated B-cell phenotype with positivity for MUM1 was seen in 91.6% of tumors. Co-expression of Bcl-6 and MUM1 was evident in 50%, which is more frequent than in systemic diffuse large B-cell lymphomas. All cases were negative for Epstein-Barr virus using EBER in-situ hybridization and LMP1 immunohistochemistry.

CONCLUSION

Primary diffuse large B-cell lymphoma in the immunocompetent is a distinct clinicopathological entity with centroblastic morphology, a uniform activated B-cell immunophenotype that is not associated with the Epstein-Barr virus regardless of geographic origin.

Comparison of chosen activation markers of human monocytes/macrophages isolated from the peripheral blood of young and elderly volunteers

BACKGROUND

The immune system of humans is strongly affected by the processes of aging and what is called immunosenescence and inflammaging. Aging processes are also associated with altered macrophage functions and their ability to undergo differential activation. As a result, the risk of macrophage-related disorders like atherosclerosis is increased in the elderly.

METHODS

Human monocyte-derived macrophages obtained from young and elderly healthy volunteers were stimulated with either lipopolysaccharide (LPS) or interleukin-4 (IL-4), and the expression of classical and alternative activation markers was assessed. The concentrations of nitric oxide (NO), reactive oxygen species (ROS) and IL-1β were measured in addition to the expression of genes and relevant proteins of inducible nitric oxide synthase, IL-1β, arginase-1 and suppressor of cytokine signaling-1.

RESULTS

We showed that the macrophages isolated from the young generally demonstrated higher responsiveness to introduced stimuli and balanced the classical activation state. The cells from the elderly showed stronger generation of nitric oxide (NO) and reactive oxygen species (ROS), which contribute to stress and damage reactions.

CONCLUSIONS

The changes observed in the macrophages isolated from the elderly indicate that these cells could contribute to the development of metabolic disorders like atherosclerosis and diabetes. The cells from the young volunteers are less likely to present such properties.

A novel gold nanoparticle-doped polyaniline nanofibers-based cytosensor confers simple and efficient evaluation of T-cell activation

A rapid, easy assay for monitoring dynamics of T-cell activation should help to guide potential medical evaluation of immune responses or immunopathogenesis. Here, we report development of novel electrochemical cytosensors for dynamic analyses of T-cell activation markers on living cells. Gold nanoparticles-doped polyaniline nanofiber (Au/PANI-NFs) composite was greenly prepared by in situ one-step chemical inertness of PANI-NFs with gold nanoparticles to fabricate impedance-based electrochemical biosensors. Transmission electron micrographs indicated that the gold nanoparticles were uniformly anchored along with the structure of PANI-NF surface, displaying fibrillar morphology with a ~60 nm diameter. Au/PANI-NFs-based cytosensors coated with anti-CD Ab molecules could provide biomimetic interface for multiple immunosensing of T-cell surface activation markers (CD69, CD25, and CD71). The dual signal amplification of Au nanoparticle and PANI-NFs-based electrochemical impedance spectroscopic (EIS) measurements enabled the cytosensors considerably sensitive, with a detection limit of 1×10(4) cells/ml of activated T-cells. The activation-targeted cytosensors detected early, middle and late stages for expression of activation markers CD69, CD25, and CD71 at 8 h, 24 h, and 36 h, respectively, after concanvalin A stimulation of T cells. The quantitative results consisted with those derived from flow cytometric analysis. Furthermore, activation-targeted cytosensor allowed for dynamic analysis of the immune inhibition of T-cell activation by immune regulatory drug icariin (ICA). Thus, Au/PANI-NFs-based cytosensors offer simple and fast approach for non-destructive, quantitative evaluation of T-cell activation markers, with considerable specificity, reproducibility, and low background noise.