Immune Surveillance System Research Articles

Adverse event following immunization surveillance systems for pregnant women and their infants: a systematic review.

The World Health Organization's Strategic Advisory Group of Experts on Immunization has declared that maternal immunization is a key priority. Robust adverse event following immunization (AEFI) surveillance systems that capture outcomes in pregnant women and their infants are needed to ensure the safety of maternal immunization programs. We sought to identify the active and passive AEFI surveillance systems for pregnant women and their offspring described in the literature. A systematic literature review was conducted of the MEDLINE, CINAHL, and EMBASE databases from 1990 to 2014. English-language articles were reviewed if they included pregnant women as the population of interest and described the surveillance method used. Of 619 articles retrieved from the search, 16 met the criteria for review. These included reports of AEFI surveillance for pregnant women, their offspring, or both. The majority of reports (11/16) came from the USA and described findings on two active and four passive AEFI surveillance systems, only three of which specifically targeted pregnant women. The remaining five articles described one-time AEFI surveillance programs, all in high-income countries. There are no published reports outside of the USA of ongoing AEFI surveillance systems that specifically target pregnant women or their offspring. There may be AEFI surveillance systems that capture events in these populations that have not been reported in the literature. A survey of immunization program managers and national regulatory authorities is needed to determine the current status of AEFI surveillance for pregnant women and their offspring globally.

Dynamic imaging of the recycling endosomal network in macrophages.

Recycling endosomes (REs) form an extensive and complex network of subcompartmentalized vesicular and tubular elements that connect with the cell surface and other endosomes in macrophages. As surveillance and defense cells of the innate immune system, macrophages are highly dependent on REs for their active and voluminous cell surface turnover and endocytic, exocytic, and recycling of membrane and cargo. Here we set out three approaches for imaging and analyzing REs in macrophages, based on the expression of fluorescently labeled RE-associated proteins and the uptake of fluorescent cargo. Subcompartments of the REs are identified by co-expression and co-localization analysis of RE associated Rab GTPases. Transferrin is a well-known cargo marker as it recycles through REs and it is compared here to other cargo, revealing how different endocytic routes intersect with REs. We show how the movement of transferrin through REs can be modeled and quantified in live cells. Finally, since phagosomes are a signature organelle for macrophages, and REs fuse with the maturing phagosome, we show imaging of REs with phagosomes using a genetically encoded pH-sensitive SNARE-based probe. Together these approaches provide multiple ways to comprehensively analyze REs and the important roles they play in these immune cells and more broadly in other cell types.

Unravelling viral camouflage: approaches to the study and characterization of conformational epitopes

Antibodies are broadly used in clinical and basic research. Many of monoclonal antibodies are successfully adopted for therapeutic and diagnostic targeting of viral pathogens. Efficacy of antiviral neutralizing or protective antibodies depends on their ability to recognize epitopes interfering with viral infection. However, viruses are able to incessantly change their antigenic determinants to escape surveillance of humoral immune system and therefore the successful antiviral therapies require continuous development. Characterization of interactions of antibodies with prevalently conformational viral epitopes is important for understanding antibody mode of action and can help to identify conserved regions that may be exploited in designing new vaccines and virus neutralizing antibodies. In this article, we are reviewing techniques in use for characterization of conformational epitopes of monoclonal antibodies with focus on viruses.

Using Human Cytomegalovirus Glycoproteins to Prevent Graft versus Host Disease through Downregulation of Major Histocompatibility Complex Class I and Class II: A Novel Approach

Graft Versus Host Disease (GVHD) is an immune-mediated disease occurs as a complication of allogeneic Hematopoietic Stem Cell Transplantation (HSCT). Differences between donor and recipient Major Histocompatibility Complex (MHC) antigens initiate the disease. The immunocompetent cells of the donor recognize the cells of the immunocompromised host as non-self, thus commencing an immune response against them. The human Cytomegalovirus (hCMV) is a member of the herpesvirus family that has developed strategies to escape the immune surveillance and defense system via encoding a series of glycoproteins that down regulate host MHC antigens. The Unique Short (US) hCMV glycoproteins US2, US3, US6, US10 and US11 have shown variable capabilities to downregulate MHC class I and II. Theoretically, these capabilities could be utilized to downregulate the expression of host MHC antigens, thus inhibiting the allograft recognition and the subsequent immune response, which would prevent GVHD. In this systematic review, 620 literatures have been identified through a PubMed, Epistemonikos, and Google Scholar search. An inclusion criterion has been applied to these studies, of which 27 have been selected. This review found that the hCMV glycoproteins act as partner to downregulate MHC class I and class II, CMV glycoproteins regulate destruction of class I MHC molecules, and degrade MHC class II. The Preferred Reporting Items for Systematic Reviews (PRISMA) Statement has been used to increase the quality of the review, and thus a Population Intervention Comparison Outcome Study design (PICOS) model has been formulated. The findings of this research could be further studied and validated to offer an alternative approach to the current pharmacological preventive measures of GVHD, possibly without compromising patients’ immunity.

HIV and the gut microbiota, partners in crime: breaking the vicious cycle to unearth new therapeutic targets.

The gut microbiota plays a key role in health and immune system education and surveillance. The delicate balance between microbial growth and containment is controlled by the immune system. However, this balance is disrupted in cases of chronic viral infections such as HIV. This virus is capable of drastically altering the immune system and gastrointestinal environment leading to significant changes to the gut microbiota and mucosal permeability resulting in microbial translocation from the gut into the peripheral blood. The changes made locally in the gut have far-reaching consequences on the other organs of the body starting in the liver, where microbes and their products are normally filtered out, and extending to the blood and even brain. Microbial translocation and their downstream effects such as increased indolamine 2,3-dioxygenase (IDO) enzyme expression and activity create a self-sustaining feedback loop which enhances HIV disease progression and constitute a vicious cycle of inflammation and immune activation combining viral and bacterial factors. Understanding this self-perpetuating cycle could be a key element in developing new therapies aimed at the gut microbiota and its fallout after infection.

Translocator protein 18 kDa (TSPO): old dogma, new mice, new structure, and new questions for neuroprotection.

The normal development and optimal functioning of the brain requires a vigilant immune surveillance system to detect and remove potential risk factors and prevent infection and tissue damage. Microglia are the resident immune cells and the frontline defenders responsible for the immune response of the brain. Resting microglia possess a ramified morphology with numerous thin processes that continuously sample the environment. In response to inflammatory signals, microglia become activated and transform their morphology into a thick, amoeboid-like shape. Activated microglia proliferate, migrate to sites of injury, and mediate a cascade of immune responses which protect tissues and maintain homeostasis. However, sustained activation of microglia in the diseased areas leads to over-production of toxic, pro-inflammatory cytokines, which aggravate neuronal damage. An interplay between environmental and genetic factors seems to be important for the interaction between neurons and microglia. The accumulation of neurotoxins affects microglia as well as neurons, and danger signals released from the degenerating neurons induce the microglia to enter a reactive state and overly recruited activated microglia exacerbatethe neurodegeneration process. Many familial neurodegenerative genes whose mutations cause neuronal toxicity also enhance pro-inflammatory responses in microglia. Therefore, hyper-activation of the immune cells in the nervous system, termed “neuroinflammation”, may not be the initiator of the neuropathologies, but rather may be considered as one of the major contributors to disease progression, intimately implicated in a variety of neuronal diseases. As such, the severity of neurodegeneration is often parallel to the level of neuroinflammation, and suppression of neuroinflammation yields neuroprotection in a broad spectrum of animal models of neurological disorders. These observations suggest that environment-gene interactions induce the vicious cycle of tissue damage through amplification of neuroinflammation. In addition to the characteristic and dynamic morphological changes, inflammatory activation of microglia induces a change in their gene expression profiles. Thus, immunological detection of marker proteins, such as IBA-1 or CD11b, has been commonly used to monitor microglia activation in the nervous system. However, the traditionally used immunohistochemical techniques have limitations and are not easily applicable to in vivo situations. Therefore, there is an imminent need for the development of biological markers and probes to monitor neuroinflammation in vivo. In this regard, high expression levels of translocator protein 18 kDa (TSPO) in the diseased state, which are especially predominant in activated microglia, have attracted increasing interest for its use as an imaging target for the visualization of injured brain areas and the monitoring of microglial activation.

Blinatumomab for the treatment of adult acute lymphoblastic leukemia.

The marker CD19 is frequently expressed on the surface of malignant B cells including non-Hodgkin's lymphoma (NHL), chronic lymphocytic leukemia (CLL) and acute lymphoblastic leukemia (ALL), which makes it an attractive target for antineoplastic therapy (1). T cells are part of the immune surveillance system for malignant cells (2). Blinatumomab is a bispecific T cell engager (BiTE(®)) antibody that binds both CD3-positive T cells and CD19-positive B cells via its two variable antigen-binding domains. Once bound to both the T and B cell, blinatumomab induces T-cell activation and subsequently perforin-mediated malignant B-cell death. It has shown efficacy in ALL with minimal residual disease, relapsed/refractory ALL, and NHL in phase I and II clinical trials. With a favorable safely profile and promising results, blinatumomab was granted accelerated FDA approval to treat B-cell ALL in December 2014. Herein, we will review the most relevant data related to blinatumomab in ALL.

AN IMMUNE SURVEILLANCE MODEL TO MONITOR THE RESPONSE TO NEOADJUVANT CHEMOTHERAPY TREATMENT IN BREAST CANCER PATIENTS

AN IMMUNE SURVEILLANCE MODEL TO MONITOR THE RESPONSE TO NEOADJUVANT CHEMOTHERAPY TREATMENT IN BREAST CANCER PATIENTS

Canadian Adverse Events Following Immunization Surveillance System (CAEFISS) Annual report for vaccines administered in 2012

Canadian Adverse Events Following Immunization Surveillance System (CAEFISS) Annual report for vaccines administered in 2012

Canadian Adverse Events Following Immunization Surveillance System (CAEFISS): Annual report for vaccines administered in 2012.

To describe the adverse event following immunization (AEFI) reporting profile for vaccines administered in Canada during 2012 and surveillance trends relative to reports for vaccines administered from 2005 through 2011. Analysis of data based on AEFI reports received by the Public Health Agency of Canada by April 30, 2013, for vaccines marketed in Canada and administered from January 1, 2005, through December 31, 2012. The AEFI reporting rate was 10.1 per 100,000 population in Canada for vaccines administered in 2012 and was inversely proportional to age. There was a trend of declining rates from 2005 (14.8) to 2012 overall and by age group. The vast majority of reports (94%-95%) were non-serious involving reactions at or near the vaccination site, rash and febrile events. Canada has a strong pharmacovigilance system for vaccines with one of the highest AEFI reporting rates in developed countries. Vaccines marketed in Canada have a very good safety profile. This report enables comparisons across jurisdictions in Canada and globally.

The Overarching Influence of the Gut Microbiome on End-Organ Function: The Role of Live Probiotic Cultures

At the time of birth, humans experience an induced pro-inflammatory beneficial event. The mediators of this encouraged activity, is a fleet of bacteria that assault all mucosal surfaces as well as the skin. Thus initiating effects that eventually provide the infant with immune tissue maturation. These effects occur beneath an emergent immune system surveillance and antigenic tolerance capability radar. Over time, continuous and regulated interactions with environmental as well as commensal microbial, viral, and other antigens lead to an adapted and maintained symbiotic state of tolerance, especially in the gastrointestinal tract (GIT) the organ site of the largest microbial biomass. However, the perplexing and much debated surprise has been that all microbes need not be targeted for destruction. The advent of sophisticated genomic techniques has led to microbiome studies that have begun to clarify the critical and important biochemical activities that commensal bacteria provide to ensure continued GIT homeostasis. Until recently, the GIT and its associated micro-biometabolome was a neglected factor in chronic disease development and end organ function. A systematic underestimation has been to undervalue the contribution of a persistent GIT dysbiotic (a gut barrier associated abnormality) state. Dysbiosis provides a plausible clue as to the origin of systemic metabolic disorders encountered in clinical practice that may explain the epidemic of chronic diseases. Here we further build a hypothesis that posits the role that subtle adverse responses by the GIT microbiome may have in chronic diseases. Environmentally/nutritionally/and gut derived triggers can maintain microbiome perturbations that drive an abnormal overload of dysbiosis. Live probiotic cultures with specific metabolic properties may assist the GIT microbiota and reduce the local metabolic dysfunctions. As such the effect may translate to a useful clinical treatment approach for patients diagnosed with a metabolic disease for end organs such as the kidney and liver. A profile emerges that shows that bacteria are diverse, abundant, and ubiquitous and have significantly influenced the evolution of the eukaryotic cell.

Utilizing regulatory T cells against rheumatoid arthritis.

Regulatory T (Treg) cells are essential for normal immune surveillance systems, and their dysfunction leads to development of diseases, such as autoimmune disorders. CD4+CD25+ Treg cells are well-known suppressive cells, which express the transcription factor Foxp3, are indispensable for the maintenance of immune self-tolerance and homeostasis by suppressing aberrant or excessive immune response. Other Foxp3− Treg cells include Tr1, Th3, CD8+CD28−/−, and Qa1-restricted T cells; however, the contribution of these Treg cells to self-tolerance, immune homeostasis as well as preventing autoimmunity is not well defined. Here, we discuss the phenotypes and function of Foxp3+ Treg cells and the potential use of such Treg cells against rheumatoid arthritis (RA). Of note, even though most expanded populations of Foxp3+ Treg cells exhibit suppressive activity, tissue-associated or antigen-specific Treg cells appear superior in suppressing local autoimmune disorders such as RA. In addition, utilizing tissue-associated Foxp3+ Treg cells from stem cells may stable Foxp3 expression and avoid induction of a potentially detrimental systemic immunosuppression.

Components of priming-induced resistance to Fusarium head blight in wheat revealed by two distinct mutants of Fusarium graminearum.

Two mutants (tri6Δ and noxABΔ) of the fungal pathogen Fusarium graminearum were assessed for their ability to prime immune responses in wheat (cv. Roblin) against challenge with pathogenic F. graminearum. Priming treatments generated Fusarium head blight (FHB)-resistant wheat phenotypes and reduced the accumulation of fungal mycotoxins in infected tissues. Microarray analysis identified 260 transcripts that were differentially expressed during the priming period. Expression changes were observed in genes associated with immune surveillance systems, signalling cascades, antimicrobial compound production, oxidative burst, secondary metabolism, and detoxification and transport. Specifically, genes related to jasmonate, gibberellin and ethylene biosynthesis exhibited differential expression during priming. In addition, the induction of the phenylpropanoid pathways that lead to flavonoid, coumarin and hydroxycinnamic acid amide accumulation was also observed. This study highlights the utility of nonpathogenic mutants to both elicit and delineate stages of defence responses in wheat.

GroEL from the endosymbiont Buchnera aphidicola betrays the aphid by triggering plant defense.

Aphids are sap-feeding plant pests and harbor the endosymbiont Buchnera aphidicola, which is essential for their fecundity and survival. During plant penetration and feeding, aphids secrete saliva that contains proteins predicted to alter plant defenses and metabolism. Plants recognize microbe-associated molecular patterns and induce pattern-triggered immunity (PTI). No aphid-associated molecular pattern has yet been identified. By mass spectrometry, we identified in saliva from potato aphids (Macrosiphum euphorbiae) 105 proteins, some of which originated from Buchnera, including the chaperonin GroEL. Because GroEL is a widely conserved bacterial protein with an essential function, we tested its role in PTI. Applying or infiltrating GroEL onto Arabidopsis (Arabidopsis thaliana) leaves induced oxidative burst and expression of PTI early marker genes. These GroEL-induced defense responses required the known coreceptor BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1. In addition, in transgenic Arabidopsis plants, inducible expression of groEL activated PTI marker gene expression. Moreover, Arabidopsis plants expressing groEL displayed reduced fecundity of the green peach aphid (Myzus persicae), indicating enhanced resistance against aphids. Furthermore, delivery of GroEL into tomato (Solanum lycopersicum) or Arabidopsis through Pseudomonas fluorescens, engineered to express the type III secretion system, also reduced potato aphid and green peach aphid fecundity, respectively. Collectively our data indicate that GroEL is a molecular pattern that triggers PTI.

AB0439 T Cell CD80/Cd86 Co-Stimulatory Blockade Does not Suppress CD8 (+) Subpopulation in the Course of 48-Week Treatment of Patients with Rheumatoid Arthritis

BackgroundRheumatoid arthritis (RA) is a common immflamatory autoimmune disease characterized by persistent synovitis and progressive destruction of cartilage and bone in multiple joints. Biological agents have shown enhanced efficacy in...

Pulp Fibroblasts Synthesize Functional Complement Proteins Involved in Initiating Dentin–Pulp Regeneration

The complement system is an efficient plasma immune surveillance system that controls tissue injury and infection. Although the liver constitutes the primary circulating complement protein synthesis site, extrahepatic synthesis is known to optimize local tissue inflammatory reaction. Because dentin-pulp regeneration is known to be regulated locally, we investigated activation of the local complement system within the dental pulp and its role in initiating the regeneration process. Membrane attack complex (C5b-9) formation and Gram's staining revealed that complement activation is correlated with the presence of Gram-positive bacteria in carious human teeth. RT-PCR analysis demonstrated that cultured human pulp fibroblasts stimulated with lipoteichoic acid produce all the proteins required for efficient complement activation. This was demonstrated in vitro by C5b-9 formation and C5a active fragment production in the absence of plasma proteins. Finally, the dynamic migration assays performed in μ-Slide chemotaxis chambers and use of a C5aR-specific antagonist (W54011) demonstrated that the activation of complement proteins synthesized by pulp fibroblasts and the subsequent release of C5a specifically induced pulp progenitor cell recruitment. Our study reveals human pulp fibroblasts as the first nonimmune cell type capable of synthesizing all complement proteins. These fibroblasts cells contribute significantly to tissue regeneration by recruiting pulp progenitors via complement activation, which suggests to a potential therapeutic strategy of targeting pulp fibroblasts in dentin-pulp regeneration.

A Thermostatted Kinetic Framework with Particle Refuge for the Modeling of Tumors Hiding

Recently, thermostatted kinetic models have been proposed for the modeling of complex systems subjected to external force fields. This paper deals with the derivation of a generalized thermostatted k inetic framework, which incorporates particles refuge. From the qualitative viewpoint, the global in time existence and uniqueness of the so lution to the relative Cauchy problem, the time evolution of the moments of the solution, and the existence of stationary solutions are d iscussed. Applications refer to biological systems and especially to tumor-escape from immune system surveillance, indeed within this framework an mathematical model for the tumor- immune system competition is derived. Further research directions are outlined in the last section of the paper.

Targeted siRNA Silencing of Indoleamine 2, 3-Dioxygenase in Antigen-presenting Cells Using Mannose-conjugated Liposomes

Indoleamine 2, 3-dioxygenase (IDO) expression in dendritic cells (DCs) leads to the inhibition of T-cell activation, induction of T-cell apoptosis, and promotion of T-cell differentiation into regulatory T cells. All of these could promote tumor escapement of the host's immune surveillance system. We hypothesized that DC-targeted gene silencing of IDO would enhance antitumor immunity and thus restrain tumor growth. Mannose receptors are highly expressed in antigen-presenting cells (APCs) including DCs. In this study, we developed a novel APC-targeted small interfering RNA delivery system using mannosed liposomes (Man-lipo) with encapsulated IDO small interfering RNA (Man-lipo-siIDO), which preferentially knocked down IDO expression in draining lymph node and spleen of melanoma-bearing mice. Mice treated with Man-lipo-siIDO displayed a delayed time of onset of implanted murine melanomas, increased survival time, reduced tumor size, and increased reactivity of T cells from spleen and lymph nodes against melanoma antigens. The enhanced antitumor immunity may be linked to inhibition of apoptosis in CD8 and CD4 T cells as well as Treg cells in spleen and lymph nodes. This study is the first to demonstrate that Man-lipo-siIDO can preferentially targets APCs and efficiently silence IDO expression in vitro and in vivo; events expected to enhance antitumor immune reactions against melanoma xenografts. This study supports the hypothesis that Man-lipo-siIDO may possess the potential for development as an immune-targeting therapeutic anticancer agent.

Thinking outside the Osp(G)--kinase activation by E2-ubiquitin

OspG is a secreted effector kinase from the human pathogen Shigella that is required for the reduction of immune responses during Shigella infection. A new study in The EMBO Journal provides a co-crystal structure of OspG bound to UbcH5c~Ub, revealing how a bacterial kinase can be activated by the host ubiquitin conjugation machinery. These results provide molecular insight into an enigmatic microbial virulence factor that thwarts the host immune surveillance system to cause disease.

Chapter Three - Recognition of Tumors by the Innate Immune System and Natural Killer Cells

In recent years, roles of the immune system in immune surveillance of cancer have been explored using a variety of approaches. The roles of the adaptive immune system have been a major emphasis, but increasing evidence supports a role for innate immune effector cells such as natural killer (NK) cells in tumor surveillance. Here, we discuss some of the evidence for roles in tumor surveillance of innate immune cells. In particular, we focus on NK cells and other immune cells that express germline-encoded receptors, often labeled NK receptors. The impact of these receptors and the cells that express them on tumor suppression is summarized. We discuss in detail some of the pathways and events in tumor cells that induce or upregulate cell-surface expression of the ligands for these receptors, and the logic of how those pathways serve to identify malignant, or potentially malignant cells. How tumors often evade tumor suppression mediated by innate killer cells is another major subject of the review. We end with a discussion on some of the implications of the various findings with respect to possible therapeutic approaches.