Stimulation Of Immune Cells Research Articles

Modulation of Toll-like receptor ligands and Candida albicans-induced cytokine responses by specific probiotics

Probiotics have been proposed as modulators of gut inflammation, especially in inflammatory bowel disease (IBD). In order to be able to use them in these clinical conditions, their capacity to modulate immune responses towards other stimuli or microorganisms has to be thoroughly understood. In the present study, three different potentially probiotic strains, Bifidobacterium breve (NumRes 204), Lactobacillus rhamnosus (NumRes1) and Lactobacillus casei (DN-114 001), have been studied for their potential to modulate responses to stimulation with pure pattern-recognition receptor (PRR) ligands or to the gut commensal fungus Candida albicans. Cytokine production induced by PRR ligands or C. albicans was assessed in conditions of simultaneous stimulation or preincubation of primary immune cells with Bifidobacterium or Lactobacillus spp. Results indicate that simultaneous stimulation leads to potentiation of IL-1β and IL-6 production, while the TNFα and IFN-γ production was inhibited. In settings of pre-incubation with these potentially probiotic strains, lower production of TNFα was observed in the presence of B. breve. Moreover, C. albicans-induced IL-17 production was decreased after pre-incubation with both Bifidobacterium or Lactobacillus probiotic strains. Whereas C. albicans induced cytokines are dampened by the tested probiotic strains, TNFα and IL-6 production by pure pattern-recognition receptor ligands are potentiated. Interestingly, an important role of Toll-like receptor 9 signalling that involves JNK kinase in the modulatory effects of these probiotic strains has been identified. In conclusion, specific probiotic strains exhibit cross-tolerance effects towards other inflammatory stimuli, especially C. albicans, which might have beneficial effects on gut inflammation.

Inflammasome-Derived IL-1β Regulates the Production of GM-CSF by CD4+ T Cells and γδ T Cells

Recent findings have demonstrated an indispensable role for GM-CSF in the pathogenesis of experimental autoimmune encephalomyelitis. However, the signaling pathways and cell populations that regulate GM-CSF production in vivo remain to be elucidated. Our work demonstrates that IL-1R is required for GM-CSF production after both TCR- and cytokine-induced stimulation of immune cells in vitro. Conventional αβ and γδ T cells were both identified to be potent producers of GM-CSF. Moreover, secretion of GM-CSF was dependent on IL-1R under both IL-12- and IL-23-induced stimulatory conditions. Deficiency in IL-1R conferred significant protection from experimental autoimmune encephalomyelitis, and this correlated with reduced production of GM-CSF and attenuated infiltration of inflammatory cells into the CNS. We also find that GM-CSF production in vivo is not restricted to a defined CD4(+) T cell lineage but is rather heterogeneously expressed in the effector CD4(+) T cell population. In addition, inflammasome-derived IL-1β upstream of IL-1R is a critical regulator of GM-CSF production by T cells during priming, and the adapter protein, MyD88, promotes GM-CSF production in both αβ and γδ T cells. These findings highlight the importance of inflammasome-derived IL-1β and the IL-1R/MyD88 signaling axis in the regulation of GM-CSF production.

P2X7 receptor-mediated purinergic signaling promotes liver injury in acetaminophen hepatotoxicity in mice

Inflammation contributes to liver injury in acetaminophen (APAP) hepatotoxicity in mice and is triggered by stimulation of immune cells. The purinergic receptor P2X7 is upstream of the nod-like receptor family, pryin domain containing-3 (NLRP3) inflammasome in immune cells and is activated by ATP and NAD that serve as damage-associated molecular patterns. APAP hepatotoxicity was assessed in mice genetically deficient in P2X7, the key inflammatory receptor for nucleotides (P2X7-/-), and in wild-type mice. P2X7-/- mice had significantly decreased APAP-induced liver necrosis. In addition, APAP-poisoned mice were treated with the specific P2X7 antagonist A438079 or etheno-NAD, a competitive antagonist of NAD. Pre- or posttreatment with A438079 significantly decreased APAP-induced necrosis and hemorrhage in APAP liver injury in wild-type but not P2X7-/- mice. Pretreatment with etheno-NAD also significantly decreased APAP-induced necrosis and hemorrhage in APAP liver injury. In addition, APAP toxicity in mice lacking the plasma membrane ecto-NTPDase CD39 (CD39-/-) that metabolizes ATP was examined in parallel with the use of soluble apyrase to deplete extracellular ATP in wild-type mice. CD39-/- mice had increased APAP-induced hemorrhage and mortality, whereas apyrase also decreased APAP-induced mortality. Kupffer cells were treated with extracellular ATP to assess P2X7-dependent inflammasome activation. P2X7 was required for ATP-stimulated IL-1β release. In conclusion, P2X7 and exposure to the ligands ATP and NAD are required for manifestations of APAP-induced hepatotoxicity.

Curcumins Promote Monocytic Gene Expression Related to β-Amyloid and Superoxide Dismutase Clearance

Neurodegenerative diseases are associated with accumulation of modified proteins or peptides including amyloid-β (Aβ) in Alzheimer’s disease (AD), and misfolded superoxide dismutase-1 (SOD-1) in amyotrophic lateral sclerosis (ALS). Clearance of Aβ or SOD-1 by the innate immune system may be important for controlling or preventing disease onset. Curcumins restore Aβ phagocytosis by peripheral blood mononuclear cells (PBMCs) from AD patients and Aβ clearance with upregulation of key genes including MGAT3, vitamin D receptor (VDR) and Toll-like receptors (TLRs). Certain curcumins inhibit inflammatory processes of PBMCs from ALS patients. We developed an in vitro system using human monocytes from patients and monocytic cell lines (i.e. U-937, THP-1) for evaluating curcuminoid potency of innate immune cell stimulation. Bisdemethoxycurcumin and certain analogs potentiated MGAT3,VDR and TLR gene expression 3- to 300-fold in U-937 cells. The effect of curcumins on inflammation in monocytes from patients with ALS was examined. Recursive medicinal chemistry was applied to identify compounds that stimulate the innate immune system for use in the clearance of Aβ in AD and the reversal of neuroinflammation and defective SOD-1 accumulation in ALS.

Local glucocorticoid production in the mouse lung is induced by immune cell stimulation

Glucocorticoids (GC) are potent anti-inflammatory and immunosuppressive steroid hormones, mainly produced by the adrenal glands. However, increasing evidence supports the idea of additional extra-adrenal sources of bioactive GC. The lung epithelium is constantly exposed to a plethora of antigenic stimuli, and local GC synthesis could contribute to limit uncontrolled immune reactions and tissue damage. Expression of steroidogenic enzymes and GC synthesis in ex vivo organ cultures was studied in mouse lung tissue after in vivo stimulation of immune cells. Mouse lung tissue was found to express steroidogenic enzymes required for the synthesis of corticosterone from cholesterol and to synthesize corticosterone in large quantities after immune cell activation by anti-CD3 antibody, lipopolysaccharide, or TNFα. In marked contrast, ovalbumin-induced allergic airway inflammation failed to promote lung GC synthesis. Although the lung expresses all steroidogenic enzymes necessary for de novo synthesis of corticosterone from cholesterol, functional data indicated that inactive serum-derived dehydrocorticosterone is converted to active corticosterone by 11β-hydroxysteroid dehydrogenase 1. Our results support the notion that local GC synthesis represents a novel immunoregulatory mechanism to limit uncontrolled immune responses in the lung and indicate that defective local steroidogenesis may contribute to the pathogenesis of allergic airway inflammation.

Evaluation in Vitro of Synthetic Curcumins As Agents Promoting Monocytic Gene Expression Related to β-Amyloid Clearance

Accumulation of amyloid-beta (Aβ) is one of the hallmarks of Alzheimer's disease (AD), and efficient clearance of Aβ by cells of the innate immune system may be an important mechanism for controlling or preventing disease onset. It was reported that peripheral blood mononuclear cells (PBMCs) of most AD patients are defective in the phagocytosis of soluble Aβ. Natural curcumins were shown to restore Aβ phagocytosis by AD PBMCs and to up-regulate the expression of key genes including MGAT3 and those encoding Toll-like receptors (TLRs). Bisdemethoxycurcumin (BDC), a minor component of natural curcumin, was shown to have the greatest potency for stimulating AD PBMCs. Because natural curcumins have inherent limitations with regard to physicochemical properties, synthetic curcumin analogues were developed that showed improved solubility, stability, and bioavailability. An in vitro system using human monocytic cell lines (U-937, THP-1) was used to evaluate analogues for the potency of innate immune cell stimulation. These cell lines showed responses to curcuminoids and to 1α,25-dihydroxyvitamin D3 (VD3) resembling those seen in human PBMCs. From more than 45 curcuminoids analyzed, the most potent compounds possessing enhanced pharmaceutical properties were identified. The most promising candidates included prodrug versions containing water solubility-enhancing amino acids and stability-increasing modifications near the central diketone. In vivo studies showed compound (5) substantially increased bioavailability by combining several promising structural modifications. Studies examining ex vivo phagocytosis of Aβ and bead particles in mouse microglia showed that BDC and several water-soluble analogues were quite effective compared to curcumin or an unnatural analogue. In vitro studies using monocytic cell lines reported herein complement those using human PBMCs and represent a routinely accessible and uniform cellular resource allowing direct comparisons between compounds.

The role of the sympathetic and sensory nervous system in peritoneal endometriotic lesions

Question: The nervous system (NS) has an influence on the pathogenesis of chronic inflammatory autoimmune diseases (AID). The sympathetic NS exerts an anti-inflammatory effect while the sensory NS promotes inflammatory changes, through a stimulation of immune cells and proinflammatory cytokines. A reduced density of sympathetic nerve fibers (syNF) in inflammatory tissue and an increased density of sensory (se) NF could be seen. Similar to AID, endometriosis (EM) is a chronic inflammatory disease, associated with chronic pelvic pain. In human peritoneal endometriotic lesions (pEL), seNF and syNF are present.

Selective gelatinase blockage ameliorates acute DSS colitis

In the experimental models of intestinal inflammation and humans with inflammatory bowel diseases (IBD), increased levels of the matrix metalloproteinases (MMPs), MMP-2 and -9 (also referred to as gelatinase A and B, respectively), in inflamed tissue sites can be detected. In the presented study, we investigated potential beneficial effects exerted by doxycycline nonselectively blocking MMPs and the selective gelatinase inhibitor RO28-2653 in acute DSS colitis. Treatment with either compound for 8 days ameliorated clinical colitis pathology with a superior outcome in RO28-2653-treated animals. As compared to placebo controls, histopathological changes in the colon were less distinct following MMP blockage and IL-6 secretion in ex vivo biopsies was downregulated, paralleled by a diminished influx of pro-inflammatory immune cells and lack of overgrowth of the colonic lumen by potentially pro-inflammatory Escherichia coli of the commensal colon flora. We conclude that selective gelatinase inhibition not only exerts beneficial effects by disrupting the vicious cycle of positive feedback between immune cell stimulation and MMP induction but also prevents overgrowth of the colonic lumen by pro-inflammatory E. coli despite a lack of direct anti-bacterial properties, thus unaffecting the commensal gut microbiota. These findings put RO28-2653 into a center stage for development of intervention strategies in human IBD.

Cigarette Smoking and Inflammation

Cigarette smoke (CS) causes considerable morbidity and mortality by inducing cancer, chronic lung and vascular diseases, and oral disease. Despite the well-recognized risks associated with smoking, the habit remains unacceptably prevalent. Several toxins present in CS have immunomodulatory effects. CS also contains trace amounts of microbial cell components, including bacterial lipopolysaccharide. These and other CS constituents induce chronic inflammation at mucosal surfaces and modify host responses to exogenous antigens. The effects of CS on immunity are far-reaching and complex; both pro-inflammatory and suppressive effects may be induced. The net effect of CS on immunity depends on many variables, including the dose and type of tobacco, the route and chronicity of exposure, and the presence of other factors at the time of immune cell stimulation, such as Toll receptor ligands or other inflammatory mediators. CS impairs innate defenses against pathogens, modulates antigen presentation, and promotes autoimmunity. CS also impairs immunity in the oral cavity and promotes gingival and periodontal disease and oral cancer. The recognition of specific mechanisms by which CS affects host immunity is an important step toward elucidating mechanisms of tobacco-induced disease and may identify novel therapeutic approaches for the management of diseases that afflict smokers. Abbreviations: AP-1, activator protein-1; CD, cluster of differentiation; COPD, chronic obstructive pulmonary disease; HLA, human leukocyte antigen; IFNγ, interferon gamma; IL, interleukin; LPS, lipopolysaccharide; MAPK, mitogen-activated protein kinase; NF-κB, nuclear factor kappa-B; RAGE, receptors for advanced glycation end-products; ROS, reactive oxidative species; RORγτ, retinoic acid receptor-related orphan receptor transcription factor; STAT, signal transducer and activator of transcription; T-bet, T-box transcription factor; Th, T-helper; TLR, Toll-like receptors; TNFα, Tumor necrosis factor alpha; and TSLP, thymic stromal lymphopoeitin.

Role of Estrogen Supplementation in Boosting the Immune Response and Stress Resistance as Seen in the White Pulp of the Senile Female Albino Rat Spleen

Background: Living organisms face various kinds of environmental stressors every day that affect the immune system. The spleen plays key role in the immune responses. There is increasing interest in the immunological role played by estrogen in females especially in cases of stress and senility. Aim of the work: To study the effect of estrogen administration on the white pulp of the spleen of senile female albino rats and its possible protective role in case of stress exposure on the immune cells, estrogen receptors distribution and cell apoptosis within the white pulp of the spleen. Materials and Methods: Twenty senile female albino rats were divided into four groups (5 rats/group): Group A, negative control that received daily subcutaneous injection (s.c. inj.) of sesame oil for one week, Group B, rats received s.c. estradiol inj. (40µg/kg BW) for one week, Group C, rats were subjected to immobilization stress for three successive days after s.c. sesame oil inj. for one week, Group D, rats received s.c. estradiol inj.one week before the same stress exposure. All rats were sacrificed at the end of the experiment. Spleen samples were processed for light and electron microscopic examination. Paraffin embedded tissues were sectioned and immune stained in the four groups for estrogen receptors detection, CD3 (T lymphocyte immune marker) and CD20 (B lymphocytes immune marker) distribution also immune-staining for apoptosis was performed in the groups subjected to stress. Results: Estrogen administration resulted in immune cell proliferation in lymphoid follicles of the spleen; an increase in both CD3 and CD20 positively stained cells and estrogen receptors. Stress exposure (Group C) resulted in depletion of the splenic lymphoid follicles, weak immune staining for Estrogen Receptors (ER), dense immune staining for apoptosis, weak immune staining for CD3 and CD20 in contrast to the group protected by estrogen (Group D) which showed preserved white pulp follicles, weak staining for apoptosis marker, preserved immune staining for CD3 and CD20 and positive staining for ER. Electron microscopic examination showed the ultrastructure of lymphocytes in Group A, increased plasma cell in Group B, destructed lymphocytes in Group C and preserved lymphocytes in Group D. Conclusion: Estrogen administration showed immune cell stimulation in senile rats. In addition, estrogen injection prior to stress exposure seemed to reduce the hazardous effect of stress on the immune cells of the spleen. Exogenous estrogen treatment may become clinically important to enhance the immune response in senile female patients especially in stress exposure.

Effect of homocysteine on properties of neutrophils activated in vivo

We have found that neutrophils begin to express NMDA receptors on their membranes after in vivo activation. These receptors are the target for action of homocysteine (HC). After incubation of activated neutrophils with HC, the degranulation process is stimulated and generation of reactive oxygen species is increased. We conclude that expression of NMDA receptors on neutrophil membrane makes neutrophils sensitive to HC. Thus, hyperhomocysteinemia may induce additional stimulation of immune competent cells.

Oligomeric procyanidins stimulate innate antiviral immunity (154.9)

Abstract Oligomeric procyanidins (OPCs) have been shown to have antiviral and immunostimulatory effects. OPCs isolated from non-ripe apple peel, found in the dietary supplement Applepoly®, were tested for capacity to reduce dengue virus (DENV) titers. Similar to published accounts, OPCs exhibited direct antiviral activity. OPCs also enhanced expression of critical innate antiviral products during DENV infection of human PBMCs. Specifically, expression of MXI and IFNB transcripts in DENV infected cells, and phosphorylation of STAT2 in response to recombinant type I IFN (IFN I), were increased by OPC treatment. During low MOI infection, addition of OPCs also increased expression of STAT1 transcripts, MHC I and TNFα protein production. Thus, OPCs exhibited innate immune stimulation of DENV-infected human cells, bystander cells in infected cultures, and uninfected cells treated with IFN I. To test the effects of OPC ingestion in vivo, mice were fed a rich source of OPCs and injected with polyIC to mimic innate responses to viral infection. Ingestion of OPCs resulted in enhanced innate antiviral responses in vivo. While OPCs from a number of sources are known to exhibit antiviral effects, their mechanisms are not precisely defined. The capacity of OPCs to enhance innate antiviral immunity could be broadly applicable to many viral infections and two separate antiviral mechanisms, direct and immunomodulatory, suggest that OPCs may represent a novel, robust antiviral therapy.

The type 1 interferon signature: facts, fads and fallacies

Background and objectivesThe type 1 interferon signature (IFN1) has been reported in systemic lupus erythematosus (SLE) and subsequently in many other diseases. It is deduced from the expression of a...

Oligomeric procyanidins stimulate innate antiviral immunity in dengue virus infected human PBMCs

Oligomeric procyanidins (OPCs) have been shown to have antiviral and immunostimulatory effects. OPCs isolated from non-ripe apple peel were tested for capacity to reduce dengue virus (DENV) titers. Similar to published accounts, OPCs exhibited direct antiviral activity. The possibility of enhanced innate immune protection was also tested by measuring and characterizing gene and protein expression induced by OPCs during DENV infection. Treatment of DENV-infected human PBMCs with OPCs decreased viral titers and affected the expression of critical innate antiviral immune products. OPCs enhanced expression of MXI and IFNB transcripts in high MOI DENV infected PBMC cultures, and phosphorylation of STAT2 in response to recombinant type I IFN (IFN I). During low MOI infection, addition of OPCs increased expression of STAT1 transcripts, MHC I and TNFα protein production. Thus, OPCs exhibited innate immune stimulation of cells in DENV-infected cultures and uninfected cells treated with IFN I. While OPCs from a number of sources are known to exhibit antiviral effects, their mechanisms are not precisely defined. The capacity of OPCs to increase sensitivity to IFN I could be broadly applicable to many viral infections and two separate antiviral mechanisms suggest that OPCs may represent a novel, robust antiviral therapy.

A murine model for study of anticryptococcal activity mediated by cytotoxic immune cells: Role in immunization and human vaccine strategies

NK and T cells play a pivotal role in host defense to Cryptococcus neoformans (C. neoformans) fungus which affects especially hosts with impaired cell mediated immunity. The vaccine against cryptococcosus is not developed yet, thus we established an animal BALB/c mice model to analyze anticryprococcal activity of immune cells. We detected that non-stimulated spleen mononuclear cells (MNC) from non-immunized mice have the capacity to exhibit anticriptococcal activity on the incapsulated C. neoformans strain (ATCC 34873) and this activity can be enhanced by non-adherent cells (NAC). In order to obtained antigen-specific anticryprococcal activity, MNC and NAC were stimulated in vitro with corpuscular (Ag1) or soluble (Ag2) C. neoformans antigen prepared from the acapsular strain Cap67 (ATCC 52817). In vitro stimulation of immune cells with both C. neoformans antigens enhanced the anticryptococcal activity of MNC and NAC. NAC fraction expressed the highest anticryptococcal activity, also in the presence and in the absence of accessory cells (AC). The highest anticryptococcal activity of effector cells was detected after immunization of mice with the same C. neoformans antigens and after additional stimulation of immune cells in vitro with the some antigens. These data demonstrated that growth inhibition of C. neoformans mediated by mice effector cells can be enhanced with corpuscular, as well as soluble antigens. Thus designin an animal model which is simple and reproducible and can be used for further studies and development of immunization strategies against human cryptococcosis.

The MushroomAgaricus blazeiMurill Elicits Medicinal Effects on Tumor, Infection, Allergy, and Inflammation through Its Modulation of Innate Immunity and Amelioration of Th1/Th2 Imbalance and Inflammation

The medicinal mushroom Agaricus blazei Murill from the Brazilian rain forest has been used in traditional medicine and as health food for the prevention of a range of diseases, including infection, allergy, and cancer. Other scientists and we have examined whether there is scientific evidence behind such postulations. Agaricus blazei M is rich in the immunomodulating polysaccharides, β-glucans, and has been shown to have antitumor, anti-infection, and antiallergic/-asthmatic properties in mouse models, in addition to anti-inflammatory effects in inflammatory bowel disease patients. These effects are mediated through the mushroom's stimulation of innate immune cells, such as monocytes, NK cells, and dendritic cells, and the amelioration of a skewed Th1/Th2 balance and inflammation.

Microbiota

We have recently demonstrated that microbiota stimulation of innate immune pathways is required for T cell spontaneous proliferation and chronic intestinal inflammation. Microbiota promoted spontaneous proliferation of T cells by activating dendritic cells to produce interleukin (IL)-6 via a TLR/MyD88-dependent pathway. Although both CBir1-specific TCR transgenic (CBir1 Tg) T cells, which are specific for an immunodominant microbiota antigen, and OT-II T cells, which are specific for the model antigen ovalbumin, underwent spontaneous proliferation, only CBir1 Tg T cells but not OT-II T cells induced colitis in specific pathogen-free RAG-/- mice. Blockade of IL-6 or IL-6-mediated spontaneous proliferation of CBir1 Tg T cells abrogated colitis induction in this adoptive transfer model. Our data reveal that microbiota serves as a natural adjuvant for T cell spontaneous proliferation and development of chronic intestinal inflammation, and that both microbiota stimulation of innate immune cells with subsequent T cell spontaneous proliferation and microbiota antigen activation of antigen-specific TCR are required for the induction of experimental colitis

Frizzled1 is a marker of inflammatory macrophages, and its ligand Wnt3a is involved in reprogrammingMycobacterium tuberculosis‐infected macrophages

Wnt/Frizzled signaling, essential for embryonic development, has also recently been implicated in the modulation of inflammatory processes. In the current study, we observed a reciprocal regulation of the Toll-like receptor (TLR)/nuclear factor-κB (NF-κB) and the Wnt/β-catenin pathway after aerosol infection of mice with Mycobacterium tuberculosis: whereas proinflammatory mediators were substantially increased, β-catenin signaling was significantly reduced. A systematic screen of Fzd homologs in infected mice identified Fzd1 mRNA to be significantly up-regulated during the course of infection. In vitro infection of murine macrophages led to a strong induction of Fzd1 that was dependent on TLRs, the myeloid differentiation response gene 88 (MyD88), and a functional NF-κB pathway. Flow cytometry demonstrated an elevated Fzd1 expression on macrophages in response to M. tuberculosis that was synergistically enhanced in the presence of IFN-γ. Addition of the Fzd1 ligand Wnt3a induced Wnt/β-catenin signaling in murine macrophages that was inhibited in the presence of a soluble Fzd1/Fc fusion protein. Furthermore, Wnt3a reduced TNF release, suggesting that Wnt3a promotes anti-inflammatory functions in murine macrophages. The current data support the notion that evolutionarily conserved Wnt/Fzd signaling is involved in balancing the inflammatory response to microbial stimulation of innate immune cells of vertebrate origin.

Animal Ca2+ release-activated Ca2+ (CRAC) channels appear to be homologous to and derived from the ubiquitous cation diffusion facilitators.

BackgroundAntigen stimulation of immune cells triggers Ca2+ entry through Ca2+ release-activated Ca2+ (CRAC) channels, promoting an immune response to pathogens. Defects in a CRAC (Orai) channel in humans gives rise to the hereditary Severe Combined Immune Deficiency (SCID) syndrome. We here report results that define the evolutionary relationship of the CRAC channel proteins of animals, and the ubiquitous Cation Diffusion Facilitator (CDF) carrier proteins.FindingsCDF antiporters derived from a primordial 2 transmembrane spanner (TMS) hairpin structure by intragenic triplication to yield 6 TMS proteins. Four programs (IC/GAP, GGSEARCH, HMMER and SAM) were evaluated for identifying sequence similarity and establishing homology using statistical means. Overall, the order of sensitivity (similarity detection) was IC/GAP = GGSEARCH > HMMER > SAM, but the use of all four programs was superior to the use of any two or three of them. Members of the CDF family appeared to be homologous to members of the 4 TMS Orai channel proteins.ConclusionsCRAC channels derived from CDF carriers by loss of the first two TMSs of the latter. Based on statistical analyses with multiple programs, TMSs 3-6 in CDF carriers are homologous to TMSs 1-4 in CRAC channels, and the former was the precursor of the latter. This is an unusual example of how a functionally and structurally more complex protein may have predated a simpler one.

Ocular treatment of thyroid eye disease

Thyroid eye disease is an autoimmune disease affecting ocular and orbital tissues. The inflammation may or may not parallel systemic thyroid conditions such as Graves’ disease. Disease manifestations result from tissue remodeling within the orbit. The abnormal stimulation of immune cells and orbital fibroblasts is probably involved. Our current understanding of the pathophysiology of the disease is limited and few rational therapies have been designed that target the underlying disease process. Treatment strategies vary depending on disease severity and activity. Recent small-scale studies have shown some promise with B-cell-depleting drugs such as rituximab, but this therapy requires further evaluation. The testing of new treatments is hindered by the lack of a reliable animal model of thyroid eye disease.