Changes In Lymphocyte Populations Research Articles

Dynamic Changes in Lymphocyte Populations Establish Zebrafish as a Thymic Involution Model.

The thymus is the site of T lymphocyte development and T cell education to recognize foreign, but not self, Ags. B cells also reside and develop in the thymus, although their functions are less clear. During "thymic involution," a process of lymphoid atrophy and adipose replacement linked to sexual maturation, thymocytes decline. However, thymic B cells decrease far less than T cells, such that B cells comprise ∼1% of human neonatal thymocytes but up to ∼10% in adults. All jawed vertebrates possess a thymus, and we and others have shown zebrafish (Danio rerio) also have thymic B cells. In this article, we investigated the precise identities of zebrafish thymic T and B cells and how they change with involution. We assessed the timing and specific details of zebrafish thymic involution using multiple lymphocyte-specific, fluorophore-labeled transgenic lines, quantifying the changes in thymic T- and B-lymphocytes pre- versus postinvolution. Our results prove that, as in humans, zebrafish thymic B cells increase relative to T cells postinvolution. We also performed RNA sequencing on D. rerio thymic and marrow lymphocytes of four novel double-transgenic lines, identifying distinct populations of immature T and B cells. Collectively, this is, to our knowledge, the first comprehensive analysis of zebrafish thymic involution, demonstrating its similarity to human involution and establishing the highly genetically manipulatable zebrafish model as a template for involution studies.

Adipose tissue lymphocytes and obesity.

Obesity is associated with chronic inflammation in adipose tissue (AT), mainly evidenced by infiltration and phenotypic changes of various types of immune cells. Macrophages are the major innate immune cells and represent the predominant immune cell population within AT. Lymphocytes, including T cells and B cells, are adaptive immune cells and constitute another important immune cell population in AT. In obesity, CD8+ effector memory T cells, CD4+ Th1 cells, and B2 cells are increased in AT and promote AT inflammation, while regulatory T cells and Th2 cells, which usually function as immune regulatory or type 2 inflammatory cells, are reduced in AT. Immune cells may regulate the metabolism of adipocytes and other cells through various mechanisms, contributing to the development of metabolic diseases, including insulin resistance and type 2 diabetes. Efforts targeting immune cells and inflammation to prevent and treat obesity-linked metabolic disease have been explored, but have not yielded significant success in clinical studies. This review provides a concise overview of the changes in lymphocyte populations within AT and their potential role in AT inflammation and the regulation of metabolic functions in the context of obesity.

Hematopoietic Stem and Progenitor Cells Improve Survival from Sepsis By Boosting Immunomodulatory Cells

Sepsis is a dysregulated inflammatory syndrome that accounts for as many as 20% of deaths worldwide. Elevated production of pro-inflammatory cytokines during sepsis, such as IL-1, IL-6, interferons (IFNs), and tumor necrosis factor contribute to the development of fever, vasodilation, and multiorgan failure. Novel therapies to treat sepsis are urgently needed.Hematopoietic stem and progenitor cells (HSPC) are responsible for the day-to-day production of blood and immune cells. Recent work from our group and others indicates that during emergency hematopoiesis, inflammatory signals including cytokines, chemokines, and pathogen-derived molecules direct HSPCs to differentiate into effector immune cells. While these signals are essential for a proper immune response, excessive signaling in HSPCs can be detrimental and lead to their depletion. Thus, the interactions between HSPCs and their inflammatory environment may play a deterministic role in immune responses and sepsis.We used a mouse model of Group A Streptococcus (GAS) infection to examine the role of HSPCs in pathogenic infection and sepsis. GAS is a common pathogen that can cause a plethora of diseases from mild skin infections to life-threatening necrotizing fasciitis. We infected mice with 10 6 cfu GAS by intramuscular injection, which typically results in sepsis and death within 7 days, and examined the impact of this infection on peripheral blood (PB) and bone marrow (BM) populations. In just 24 hrs after GAS infection, BM myeloid and HSPC populations are significantly depleted, with myeloid cells being heavily trafficked into circulation following increased levels of monocyte chemoattractant protein-1 (MCP-1). Lineage tracing experiments using KRT18-CreERT2:Rosa26-lox-STOP-lox-TdTomato demonstrated that endogenous HSPCs differentiate toward the myeloid lineage after GAS infection. Based on these data, we hypothesized that the inflammatory environment of GAS infection drives rapid HSPC differentiation resulting in a depletion that could be rescued by the infusion of new HSPCs. To test this hypothesis, we infused GAS-infected mice with 10 4 naïve HSPCs (1.7x10 7 cells per m 2) and evaluated pathogen load and overall survival. This number of HSPCs infused is very low in comparison to the current granulocyte therapies that use ~10 10 cells per m 2 cells per infusion. BM and PB analysis showed that HSPC infusion restored HSPC levels and significantly increased myeloid progenitors and circulating myeloid cells. Strikingly, HSPC infusion in GAS-infected mice significantly increased survival, with 50-75% of mice surviving as opposed to 0-10% of controls. Despite the restoration of hematopoietic populations, surprisingly, GAS-infected mice infused with HSPCs did not show a reduction in pathogen load.Given that HSPC infusion significantly increased survival without impacting pathogen clearance, we sought to determine whether infused HSPCs served an immunomodulatory role. Analysis of BM and PB did not show any changes in lymphocyte populations, suggesting that Tregs and Bregs were not strongly affected. However, BM and PB MDSC populations were severely depleted during GAS sepsis, and HSPC infusion led to a dramatic restoration of these MDSC populations. Interestingly and in accordance with MDSC numbers, the overall cytokine levels of GAS-infected mice are lower after HSPC infusion. Notably, serum levels of cytokines known to drive the symptoms of sepsis, like TNF, IL-12, MIP-1a, IL-6, and IL-1b were dampened in HSPC-rescued mice.In conclusion, while HSPC infusion did not reduce bacterial load, it conferred a significant survival advantage to GAS-infected mice. Our data showing restoration of MDSCs and lower cytokine levels after HSPC infusion suggest that HSPC infusion supports the development of immunomodulatory cells that can prevent sepsis-related hyperinflammation and death. Current work is directed at defining specific HSPC subpopulations that mediate this effect. Importantly, the rescue potential of such low numbers of infused HSPCs highlights the feasibility of this technique and its potential applications. Overall, the information gained in this project may contribute to a new therapeutic strategy to use HSPCs to fight bacterial infections and sepsis where granulocyte infusions have so far produced only mixed results. DisclosuresNo relevant conflicts of interest to declare.

Intraoperative radiation therapy induces immune response activity after pancreatic surgery

BackgroundPancreatic cancer has highly aggressive features, such as local recurrence that leads to significantly high morbidity and mortality and recurrence after successful tumour resection. Intraoperative radiation therapy (IORT), which delivers targeted radiation to a tumour bed, is known to reduce local recurrence by directly killing tumour cells and modifying the tumour microenvironment.MethodsAmong 30 patients diagnosed with pancreatic cancer, 17 patients received IORT immediately after surgical resection. We investigated changes in the immune response induced by IORT by analysing the peritoneal fluid (PF) and blood of patients with and without IORT treatment after pancreatic cancer surgery. Further, we treated three pancreatic cell lines with PF to observe proliferation and activity changes.ResultsLevels of cytokines involved in the PI3K/SMAD pathway were increased in the PF of IORT-treated patients. Moreover, IORT-treated PF inhibited the growth, migration, and invasiveness of pancreatic cancer cells. Changes in lymphocyte populations in the blood of IORT-treated patients indicated an increased immune response.ConclusionsBased on the characterisation and quantification of immune cells in the blood and cytokine levels in the PF, we conclude that IORT induced an anti-tumour effect by activating the immune response, which may prevent pancreatic cancer recurrence.Clinical trial registrationNCT03273374.

Анализ изменений в популяциях лимфоцитов в зависимости от метода обезболивания при хирургическом лечении рака прямой кишки

Цель. Изучение влияния различных методов периоперационного обезболивания на некоторые показатели иммунной системы и уровня иммунодепрессии через количественные изменения в популяциях лимфоцитов и активность Т-лимфоцитов при хирургическом лечении рака прямой кишки. Материалы и методы. В исследование включены 60 пациентов, оперированных по поводу рака прямой кишки. Проведен анализ количественных изменений в популяциях лимфоцитов и активности Т-лимфоцитов при хирургическом лечении рака прямой кишки в раннем и отдаленном послеоперационном периоде в зависимости от метода периоперационного обезболивания. Результаты. В результате исследования установлено, что в группе пациентов с использованием ингаляционного анестетика севоран для общей анестезии отмечалось уменьшение активности Т-лимфоцитов и минимальное влияние на количество всех исследуемых популяций лимфоцитов в раннем послеоперационном периоде. Применение в исследуемой группе пропофола для общей анестезии менее влияло на активность Т-лимфоцитов по сравнению с севораном в раннем послеоперационном периоде. В исследуемой группе с эпидуральной анальгезией для периоперационного обезболивания наблюдали длительный положительный эффект на иммунную систему в отдаленном послеоперационном периоде, что сопровождалось восстановлением и усилением активности Т-лимфоцитов в отдаленном послеоперационном периоде в сравнении с парентеральным опиоидным анальгетиком для обезболивания после операции. Севоран и эпидуральная анальгезия имели минимальное влияние на количественную популяцию лимфоцитов в сравнении с пропофолом в исследуемых группах. Выводы. Использование эпидуральной анальгезии в сочетании с парентеральным декскетопрофеном и парацетамолом для периоперационного обезболивания оказывает меньший иммунодепрессивный эффект на иммунную систему в сравнении с применением парентерального опиоида омнопон. Пропофол лучше сохраняет активность Т-лимфоцитов, чем ингаляционный анестетик севоран, и предпочтителен в качестве гипнотика для общей анестезии у пациентов с факторами риска иммунодепрессии при хирургическом лечении рака прямой кишки.

Effect of Kidney Transplantation on Accelerated Immunosenescence and Vascular Changes Induced by Chronic Kidney Disease.

Kidney transplantation is the best option for patients with end-stage renal disease. Despite the improvement in cardiovascular burden (leading cause of mortality among patients with chronic kidney disease), cardiovascular adverse outcomes related to the inflammatory process remain a problem. Thus, the aim of the present study was to characterize the immune profile and microvesicles of patients who underwent transplantation. We investigated the lymphocyte phenotype (CD3, CD4, CD8, CD19, and CD56) and monocyte phenotype (CD14, CD16, CD86, and CD54) in peripheral blood, and endothelium-derived microvesicles (annexin V+CD31+CD41–) in plasma of patients with advanced chronic kidney disease (n = 40), patients with transplantation (n = 40), and healthy subjects (n = 18) recruited from the University Hospital “12 de Octubre” (Madrid, Spain). Patients with kidney transplantation had B-cell lymphopenia, an impairment in co-stimulatory (CD86) and adhesion (CD54) molecules in monocytes, and a reduction in endothelium-derived microvesicles in plasma. The correlations between those parameters explained the modifications in the expression of co-stimulatory and adhesion molecules in monocytes caused by changes in lymphocyte populations, as well as the increase in the levels of endothelial-derived microvesicles in plasma caused by changes in lymphocyte and monocytes populations. Immunosuppressive treatment could directly or indirectly induce those changes. Nevertheless, the particular characteristics of these cells may partly explain the persistence of cardiovascular and renal alterations in patients who underwent transplantation, along with the decrease in arteriosclerotic events compared with advanced chronic kidney disease. In conclusion, the expression of adhesion molecules by monocytes and endothelial-derived microvesicles is related to lymphocyte alterations in patients with kidney transplantation.

Relationship Between Pregnancy and Acute Disseminated Encephalomyelitis: A Single-Case Study.

The relationship between pregnancy and autoimmune diseases is unclear. This study investigated the possible role of local immune changes and the activation state of the HMGB1/TLR4/Nf-κB/IL-6 pathway at the maternal–fetal interface during pregnancy in the pathogenesis of acute disseminated encephalomyelitis (ADEM). Clinical data and blood samples of a patient with ADEM were collected to observe the dynamic changes in lymphocyte populations after an abortion. The expression of HMGB1, TLR4, Nf-κB, AQP4, IL-2, IL-4, IL-6, and TNF-α in the fetal membrane and placenta was compared between the patient with pregnancy-related ADEM and a woman with a normal pregnancy using Real-time qPCR and western blotting (WB). The patient was diagnosed with ADEM in the early stage of pregnancy after showing limb weakness symptoms. In the third month of gestation, the symptoms worsened, with a disturbance of consciousness and breathing. After the abortion, the patient relapsed with vertigo and visual rotation. Analysis of lymphocyte subsets by flow cytometry showed that B lymphocytes increased, while natural killer T lymphocytes decreased. WB and Real-time qPCR showed that the expression levels of HMGB1, TLR4, Nf-κB, AQP4, and IL-6 in the fetal membrane and placenta were higher in the patient with pregnancy-related ADEM than in the woman with a normal pregnancy, while those of IL-2 were lower in the patient than in the woman with a normal pregnancy. The local immune changes and the activation of the HMGB1/TLR4/Nf-κB/IL-6 pathway at the maternal–fetal interface may be related to the pathogenesis of ADEM.

T and B Cell Receptor Immune Repertoire Analysis using Next-generation Sequencing.

Immunological memory, the hallmark of adaptive immunity, is orchestrated by T and B lymphocytes. In circulation and different organs, there are billions of unique T and B cell clones, and each one can bind a specific antigen, leading to proliferation, differentiation and/or cytokine secretion. The vast heterogeneity in T and B cells is generated by random recombination of different genetic segments. Next-generation sequencing (NGS) technologies, developed in the last decade, enable an unprecedented in-depth view of the T and B cell receptor immune repertoire. Studies in various inflammatory conditions, immunodeficiencies, infections and malignancies demonstrated marked changes in clonality, gene usage, and biophysical properties of immune repertoire, providing important insights about the role of adaptive immune responses in different disorders. Here, we provide a detailed protocol for NGS of immune repertoire of T and B cells from blood and tissue. We present a pipeline starting from DNA isolation through library preparation, sequencing on NGS sequencer and ending with basic analyses. This method enables exploration of specific T and B cells at the nucleotide or amino-acid level, and thus can identify dynamic changes in lymphocyte populations and diversity parameters in different diseases. This technique is slowly entering clinical practice and has the potential for identification of novel biomarkers, risk stratification and precision medicine.

Fingolimod Profoundly Reduces Frequencies and Alters Subset Composition of Circulating T Follicular Helper Cells in Multiple Sclerosis Patients.

Fingolimod is an effective treatment for relapsing-remitting multiple sclerosis. It is well established that fingolimod, a modulator of the sphingosine-1-phosphate pathway, restrains the egress of CCR7+ lymphocytes from lymphatic tissues into the blood, thus resulting in reduced lymphocyte counts in peripheral blood. CXCR5+ T follicular helper (Tfh) cells provide help to B cells, are essential for the generation of potent Ab responses, and have been shown to be critically involved in the pathogenesis of several autoimmune diseases. Besides lymphoid tissue-resident Tfh cells, CXCR5+ circulating Tfh (cTfh) cells have been described in the blood, their numbers correlating with the magnitude of Tfh cells in lymphoid tissues. Although the effect of fingolimod on circulating lymphocyte subsets has been established, its effect on cTfh cells remains poorly understood. In this study, we found that although fingolimod strongly and disproportionally reduced cTfh cell frequencies, frequencies of activated cTfh cells were increased, and the composition of the cTfh cell pool was skewed toward a cTfh1 cell phenotype. The circulating T follicular regulatory cell subset and CXCR5+ CD8+ T cell frequencies were also strongly and disproportionally decreased after fingolimod treatment. In contrast, relative frequencies of CXCR5- memory Th cells as well as regulatory T and B cells were increased. In summary, these data provide new insights into fingolimod-induced compositional changes of lymphocyte populations in the blood, in particular cTfh cells, and thus contribute to a better understanding of the mechanism of action of fingolimod in multiple sclerosis patients.

Th17 and MAIT cell mediated inflammation in antipsychotic free schizophrenia patients

The immune hypothesis of schizophrenia has gained significant popularity in recent years in schizophrenia research. Evidence suggests that the peripheral immune system communicates with central nervous system and the effect propagates through microglial and lymphocyte crosstalk, especially during neuro-inflammation. Although, there is previous literature indicating changes in lymphocyte population in schizophrenia, detailed studies with respect to T and B cells are scarce. Mucosal associated invariant T (MAIT) cells are functionally associated with the gut microbiome. The gut microbiome has been implicated in the pathogenesis of schizophrenia. However, there is no information on the frequency of MAIT cells in schizophrenia. Hence, we investigated changes in proportions of T cells, B cells and MAIT cells in peripheral blood mononuclear cells derived from antipsychotic-free patients with schizophrenia in comparison to healthy controls. In line with earlier reports, we noted perturbations in Th17 cells. This study for the first time reports changes in frequencies of MAIT cells in a homogenous population of antipsychotic-free patients with schizophrenia. These changes, though not common across all patients nevertheless point to the fact that inflammation is prevalent in a significant subset of schizophrenia cases.

Phenotypic changes of lymphocyte populations in psoriasiform dermatitis animal model.

Psoriasis is a T cell mediated, chronic inflammatory autoimmune skin disease that affects up to 2–3% of the global population and leads to a decrease in quality of life. Experimental data accumulated in recent years highlighted the important role played by the immune system in the pathogenesis of this disease. Non-human psoriasis models are an important research tool that attempts to reproduce the clinical features of the disease in order to explain the pathogenesis of psoriasis and to identify possible therapeutic targets. Imiquimod-based murine model of psoriatic dermatitis is an alternative to traditional models of experimental psoriasis in mice and the induced dermatitis closely mimics the pathologic changes in human psoriasis. In order to emphasize changes in immune cell populations involved in lesion pathogenesis, we performed a murine model of psoriasiform dermatitis model by topical IMQ application. The progress and the severity of IMQ-induced skin inflammation were clinically (PASI score) and histopathologically evaluated. The immunological changes induced by IMQ treatment in lymphocyte populations from peripheral blood and spleen were evaluated by flow cytometry. The main changes observed in peripheral blood were the significantly increased T-CD8a+ lymphocyte and NK1.1+ cell percentages and the decreased T-CD4+ and B lymphocyte percentages in IMQ-treated mice. In spleen samples, lymphocytes showed the same tendency of variation as in peripheral blood, but without statistical significance. A significant decrease of B cells percentages was observed in spleen suspensions. Data obtained in skin samples may suggest the involvement of CD3ε+, CD4+ and CD8a+ cells in the lesional process. This murine model was analyzed by performing a basic cellular profile at three levels: peripheral blood, spleen and skin. The evaluation aimed to establish the immune framework of this experimental model that could further be used for etipathogenic mechanism identification and/or for studies regarding targeted therapies.

Evidence for Local and Systemic Immune Activation in Functional Dyspepsia and the Irritable Bowel Syndrome: A Systematic Review.

Subtle histopathologic features such as eosinophilia and increased mast cells have been observed in functional gastrointestinal disorders (FGIDs), including functional dyspepsia (FD) and the irritable bowel syndrome (IBS). The mechanisms that drive recruitment of these cells to the gastrointestinal tract remain unexplained, largely due to the heterogeneity in phenotypes among patients diagnosed with such conditions. We aimed to systematically review the literature and collate the evidence for immune activation in FD and IBS, and where possible, detail the nature of activation. Seven literature databases were searched using the keywords: 'functional gastrointestinal disorder', FGID, 'functional dyspepsia', 'non-ulcer dyspepsia', 'idiopathic dyspepsia', 'irritable bowel syndrome', IBS and 'immun*'. Fifty-one papers reporting discordant immune features met the selection criteria for this review. Changes in lymphocyte populations, including B and T lymphocyte numbers and activation status were reported in IBS and FD, in conjunction with duodenal eosinophilia in FD and increased colonic mast cells in IBS. Increases in circulating α4+β7+ gut-homing T cells appear to be linked to the pathophysiology of both FD and IBS. Studies in the area are complicated by poor phenotyping of patients into subgroups and the subtle nature of the immune activity involved in FD and IBS. Alterations in proportions of gut-homing T lymphocytes in both FD and IBS indicate that a loss of mucosal homeostasis may drive the symptoms of FD and IBS. There is indirect evidence that Th17 responses may play a role in FGIDs, however the evidence for a Th2 immune phenotype in FD and IBS is limited. Although immune involvement is evident, large, well-characterised patient cohorts are required to elucidate the immune mechanisms driving the development of FGIDs.

Immunological Mechanisms of Adsorptive Cytapheresis in Inflammatory Bowel Disease.

Ulcerative colitis and Crohn's disease are the two main forms of inflammatory bowel disease (IBD). The study of immunological pathways involved in the onset of IBD is of fundamental importance to identify potential biological markers of disease activity and specific targets for therapy. Removing excess and activated circulating leukocytes with adsorptive cytapheresis has been shown to be a potentially effective treatment for patients with an inflamed bowel. Adsorptive cytapheresis is a non-pharmacological approach for active IBD, in which known sources of inflammatory cytokines such as activated myeloid lineage leucocytes are selectively depleted from the circulatory system. The decrease in inflammatory load caused by removing these cells is thought to enhance drug therapy and thereby promote disease remission. The benefit of cytapheresis appears to rest upon its ability to reduce levels of certain immune cell populations; however, whether this depletion results in further changes in lymphocyte populations and cytokine production needs further clarification. In this review, we aim to summarize existing evidence on the role of cytapheresis in patients with IBD, its effect on cytokine levels and cellular populations, and to discuss its potential impact on disease activity.

The Immunologic Complexity of Growing Up with Malaria—Is Scientific Understanding Coming of Age?

In the current issue of Clinical and Vaccine Immunology, Mandala et al. report changes in lymphocyte populations in children with uncomplicated malaria, severe malarial anemia, and cerebral malaria compared to controls (W. L. Mandala et al., Clin Vaccine Immunol 23:95-103, 2016, http://dx.doi.org/10.1128/CVI.00564-15). This commentary discusses the importance of understanding both helpful and detrimental aspects of the antimalarial immune response that are critical to malaria vaccine development and considers how these responses may relate to antimalarial vaccine safety and efficacy.

CBM-06IMMUNE BIOMARKER RESULTS FROM A TRIAL OF NIVOLUMAB ± IPILIMUMAB IN PATIENTS WITH RECURRENT GLIOBLASTOMA: CHECKMATE-143

BACKGROUND: The prognosis for patients with glioblastoma (GBM) remains poor despite the availability of first-line therapies including surgery and chemoradiation. Recent evidence suggests that there are varying degrees of lymphocyte infiltration in GBM, and the composition may have prognostic significance. Expansion of regulatory T cells (CD4+FoxP3+, Treg) at the tumor site has been observed and is implicated in cancer-associated immunity in GBM. Immune checkpoint inhibitors, such as the fully human anti-PD-1 monoclonal antibody nivolumab, have shown promising antitumor activity in both solid tumors and preclinical glioma models. The CHECKMATE-143 study is evaluating nivolumab as monotherapy and in combination with ipilimumab (anti-CTLA-4) in patients with recurrent GBM (Cohorts 1 and 1b). As part of the initial phase of this study, T-cell maturation, activation, exhaustion, and effector function, as well as Treg frequencies and function and myeloid-derived suppressor cell frequencies were examined. METHODS: Analyses were performed on peripheral blood drawn from patients at pre-determined time points and upon tumor tissue samples obtained if resection was performed at the time of progression or suspected progression. Baseline and on-treatment samples were obtained from patients (n = 20) randomized 1:1 to receive either nivolumab 3 mg/kg Q2W or nivolumab 1 mg/kg + ipilimumab 3 mg/kg Q3W followed by nivolumab 3 mg/kg Q2W. Phenotypic analysis was determined by CyTOF and flow cytometry; Treg suppressive function by thymidine incorporation; cytokine release by multiplex immunoassay; and gene expression by RNAseq. RESULTS: Treatment-related changes in lymphocyte populations (including but not limited to T, B, and NK cells, granulocytes, and memory and effector T-cell subsets) in peripheral blood and resected tumor will be reported. CONCLUSIONS: Peripheral and tumor biomarker analyses of GBM subjects treated with checkpoint inhibitors will provide insights into treatment-related changes versus tumor progression.

Impact of MDSC emergence during ovarian cancer in cytokine-deficient mice. (TUM6P.1011)

Abstract We have been studying the emergence of myeloid-derived suppressor cells (MDSCs) following i.p. transfer of ID8 cells (mouse ovarian surface epithelial cell carcinoma) into intact, syngeneic, C57BL/6J (wild type, WT) mice. Our current work studies the impact of the cytokine (CK) environment on ID8 expansion and MDSC emergence in the peritoneal cavity (PerC). We wanted to determine if particular pro- (IFNg) or anti- (IL4, IL10) inflammatory CKs were drivers of disease in this model. We found that, relative to WT mice, the development of hemorrhagic ascites was accelerated in IL10-/-, IL4-/-, and IFNgR-/- mice. The greatest percentage and number of MDSCs was observed in IL10-/- mice, which also had the greatest expansion of ID8 cells. ID8 triggered a marked increase in PerC Mfs, particularly in the IL10-/- mice, and lymphocytes, particularly in the IFNgR-/- and IL4-/- mice. However, for all mice, the percent representation of B cells in the total PerC cell pool declined markedly, particularly in the IL10-/- mice (> 70%). Interestingly, beyond the peritoneal locus of disease, both B and T lymphocyte percentages dropped in the spleens of all mice. This was seen without a concomitant increase in the number of MDSCs or appearance of ID8 in the spleen. These observations reinforce that inflammation drives MDSC emergence and suggest that changes in lymphocyte populations could serve as biomarkers for assessing ovarian cancer.

Changes in immune cell populations in the periphery and liver of GBV-B-infected and convalescent tamarins (Saguinus labiatus)

Flaviviruses related to hepatitis C virus (HCV) in suitable animal models may provide further insight into the role that cellular immunity contributes to spontaneous clearance of HCV. We characterised changes in lymphocyte populations in tamarins with an acute GBV-B infection, a hepatitis virus of the flaviviridae. Major immune cell populations were monitored in peripheral and intra-hepatic lymphocytes at high viraemia or following a period when peripheral virus was no longer detected. Limited changes in major lymphocyte populations were apparent during high viraemia; however, the proportions of CD3+ lymphocytes decreased and CD20+ lymphocytes increased once peripheral viraemia became undetectable. Intrahepatic lymphocyte populations increased at both time points post-infection. Distinct expression patterns of PD-1, a marker of T-cell activation, were observed on peripheral and hepatic lymphocytes; notably there was elevated PD-1 expression on hepatic CD4+ T-cells during high viraemia, suggesting an activated phenotype, which decreased following clearance of peripheral viraemia. At times when peripheral vRNA was not detected, suggesting viral clearance, we were able to readily detect GBV-B RNA in the liver, indicative of long-term virus replication. This study is the first description of changes in lymphocyte populations during GBV-B infection of tamarins and provides a foundation for more detailed investigations of the responses that contribute to the control of GBV-B infection.

The comparative immunotoxicity of mesoporous silica nanoparticles and colloidal silica nanoparticles in mice

BackgroundMesoporous silica (MPS) nanoparticles (NPs), which have a unique pore structure and extremely large surface area and pore volume, have received much attention because of their biomedical application potential. Using MPS NPs for biomedical devices requires the verification of their biocompatibility because the surface area of NPs is one of the most important determinants of toxicity, including the cellular uptake and immune response. We have previously reported that the cytotoxicity and inflammation potential of MPS NPs have been shown to be lower than those of general amorphous colloidal silica (Col) NPs in macrophages, but the low cytotoxicity does not guarantee high biocompatibility in vivo. In this study, we compared the in vivo immunotoxicity of MPS and Col NPs in the mouse model to define the effects of pore structural conditions of silica NPs.Materials and methodsBoth MPS and Col NPs (2, 20, and 50 mg/kg/day) were intraperitoneally administered in female BALB/c mice for 4 weeks, and clinical toxicity, lymphocyte population, serum IgG/IgM levels, and histological changes were examined.ResultsThere was no overt sign of clinical toxicity in either MPS- or Col-treated mice. However, MPS NPs led to significant increases in liver and spleen weight and splenocyte proliferation. Mice treated with MPS NPs showed altered lymphocyte populations (CD3+, CD45+, CD4+, and CD8+) in the spleen, increased serum IgG and IgM levels, and histological changes. Despite slight changes in lymphocyte populations in the spleen, Col NPs did not alter other immunological factors.ConclusionThe results indicate that in vivo exposure to MPS NPs caused more damage to systemic immunity than that of Col NPs through the dysregulation of the spleen. The results for in vivo data are inconsistent with those for in vitro data, which show lower cytotoxicity for MPS NPs. These results suggest the importance of verifying biocompatibility both in vitro and in vivo during the design of new nanomaterials.

Impact of organic and conventional carrots on intestinal and peripheral immunity

Studies on health effects of organic (ORG) products are still limited and often contradictory. We have investigated the impact of ORG and conventional (CV) carrots from two consecutive harvest years on mouse peripheral and intestinal immunity. Danish carrots (Bolero variety) were grown in three ORG (O1, O2 and O3) and one CV cropping system (D-CV). Italian carrots (Maestro and Excelso varieties) were grown in one ORG and one CV field for each variety. Immune phenotypes of blood, spleen and intestinal lymphocytes, and cytokine serum levels were analyzed in mice fed the different carrots for 30 days. Principal component analysis (PCA) was performed in mice fed the Danish carrots. The consumption of the 'more organic' O2 and O3 carrots induced some changes in lymphocyte populations, including an increase in regulatory T cells. In Italian carrots more differences between ORG and CV were observed in the first as compared to the second year. No relevant differences were observed in cytokine secretion. PCA showed a clear separation among mice fed the O1, O2, O3 and D-CV carrots. Although a great variability was observed between the two years, an immune stimulation was found after the ORG carrot consumption.

Elevation of circulating HLA DR+ CD8+ T-cells and correlation with chromium and cobalt concentrations 6 years after metal-on-metal hip arthroplasty

Background and purpose Following metal-on-metal hip arthroplasty (THA), immunological reactions including changes in lymphocyte populations, aseptic loosening, and lymphocytic pseudotumors occur. We hypothesized that changes in lymphocyte subpopulations would be associated with elevated metal ion concentrations.Methods A randomized trial involving 85 patients matched for age and sex and randomized to receiving metal-on-metal (n = 41) or metal-on-polyethylene total hip arthroplasty (n = 44) was conducted. 36 patients were eligible for follow-up after mean 7 (6–8) years. Concentrations of chromium and cobalt were analyzed by high-resolution inductively coupled plasma mass spectrometry. Leukocyte subpopulations and immunoglobulins in patient blood were measured using standard laboratory methods.Results Patients with a metal-on-metal hip had higher serum concentrations of chromium (1.05 vs. 0.36 μg/L; p < 0.001) and cobalt (0.86 vs. 0.24 μg/L; p < 0.001) than those with metal-on-polyethylene. The percentage of HLA DR+ CD8+ T-cells was higher in the metal-on-metal group (10.6 vs. 6.7%; p = 0.03) and correlated positively with chromium and cobalt concentrations in patient blood (Pearson's correlation coefficient: 0.39, p = 0.02; 0.36, p = 0.03, respectively). The percentage of B-cells was lower in the metal-on-metal group (p = 0.01). The two groups were similar with respect to immunoglobulin concentrations and Harris hip scores, and there were no radiographic signs of loosening.Interpretation We conclude that immunological alterations appear to be associated with increased cobalt and chromium concentrations. It is tempting to speculate that HLA DR+ CD8+ T-cells are involved in the pathogenesis of allergic reactions, implant loosening, and lymphocytic pseudotumors.