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Objectives Anti-IL-6 receptor antibodies are clinically efficacious in the management of RA with an associated increase in Tregs; however, the role of functional Treg subsets has yet to be clarified. This study aimed to evaluate how functional Treg subsets are altered by IL-6 receptor blockade and to analyse the relationship between these Treg subsets and the clinical outcome of RA. Methods We collected frozen peripheral blood mononuclear cells (PBMCs) from 40 patients with RA who started tocilizumab (TCZ) with or without MTX and 11 healthy controls (HCs). We fractionated Tregs with flow cytometry based on markers of phenotype and function and measured the proportions of detailed Treg subsets sequentially from baseline to week 52. Results The proportions of resting Tregs (rTregs) and rTregs+activated Tregs (aTregs) were significantly lower in RA patients at baseline than in HCs. The proportions of all those CD127low Tregs, rTregs, aTregs and rTregs+aTregs were significantly increased with TCZ treatment. In patients treated with TCZ without MTX, rTreg were increased. Patients with an increase in the proportion of rTregs at week 12 had significantly less arthritis flares during the observation period. Conclusions Blocking the IL-6 receptor with TCZ increased the proportion of rTregs, a functional Treg subpopulation. Patients with an early increase in rTregs showed a favourable treatment course and this increase in rTregs may reflect molecular remission induced by IL-6 signal inhibition. [ABSTRACT FROM AUTHOR]

Background: Local allergic rhinitis (LAR) is defined by chronic nasal symptoms, absence of atopy, positive nasal allergen challenge (NAC) and a good response to subcutaneous allergen immunotherapy (SCIT). We sought to investigate SCIT capacity to induce local and systemic blocking antibodies in LAR patients. Methods: A RDBPC study of grass SCIT was performed, with participants receiving either SCIT (Group A; n = 10) or placebo (Group B; n = 14) in the first 6 months. Both groups subsequently received SCIT for 12 months at Year 2. Nasal and serum antibodies (IgG4, IgA1 and IgA2) and their inhibitory capacity were measured at multiple timepoints. Results: The allergen concentration tolerated increased significantly at 6 months (Group A; p =.047) and 24 months (Group B; p =.049) compared with baseline and persisted until the end of the study. Induction of serum sIgA1 to Phl p was seen in Groups A and B, albeit the former being induced earlier (1.71‐fold, p =.027). A significant induction in sIgG4 to Phl p 1 and 5 was observed in serum of Group A (p =.047 and p =.0039) and sIgA2 to Phl p in Group B (p =.032 and p =.0098) at 18 and 24 months, respectively. Both local and systemic blocking antibodies can inhibit allergen–IgE complexes binding to CD23 on B cells, and this correlated with level of allergen tolerated intra‐nasally in Group A (serum; 휌 = −.47, p =.0006, nasal; 휌 = −.38, p =.0294). Conclusions: Grass pollen SCIT induced functional systemic blocking antibodies that correlate with the concentration of allergen tolerated following NAC, highlighting their potential as a biomarker of SCIT in LAR. [ABSTRACT FROM AUTHOR]

Simple Summary: Human epidermal growth factor receptor-2 (HER2) plays a critical role in breast and gastric cancer. More recently, a growing body of literature demonstrated that HER2 is involved in biliary tract cancers. In this review, we discuss the potential therapeutic utilization of HER2-blocking antibodies and ongoing clinical trials assessing the efficacy of HER2-blocking antibodies in HER2-altered and/or -amplified biliary tract cancers. Despite recent advances, biliary tract cancer (BTC) is traditionally known as being hard to treat with a poor prognosis. Recent state-of-the-art genomic technologies such as next-generation sequencing (NGS) revolutionized cancer management and shed light on the genomic landscape of BTCs. There are ongoing clinical trials to assess the efficacy of HER2-blocking antibodies or drug conjugates in BTCs with HER2 amplifications. However, HER2 amplifications may not be the sole eligibility factor for these clinical trials. In this review, we aimed to comprehensively examine the role of somatic HER2 alterations and amplifications in patient stratification and provide an overview of the current state of ongoing clinical trials. [ABSTRACT FROM AUTHOR]

A birth cohort design was used to understand whether heterotypic ligand-blocking norovirus antibodies provide cross-protection within the GII genogroup. We found that almost one-half of children who experienced a norovirus GII episode had preexisting antibodies heterotypic to the infecting genotype; therefore, these antibodies did not provide cross-protection. [ABSTRACT FROM AUTHOR]

This study aimed to explore the relationship between recurrent reproductive failure (RRF) and blocking antibody (BA) and lymphocytes, to explore the difference of immune status between recurrent spontaneous abortion (RSA) and recurrent implantation failure (RIF) patients. We undertook a retrospective analysis of BA and lymphocyte subsets detected by flow cytometry in 720 RRF patients (411 RSA and 309 RIF patients) who were treated at Shanxi Maternal and Child Health Hospital from April 2015 to October 2019. The BA negative rate of RRF patients was 81.80%, which was significantly higher than that of normal women (23.46%) (p < 0.05). There was no significant difference in BA negative rates between RSA and RIF patients. Compared with the normal value, the percentage of CD3+ T lymphocytes and CD3+CD4+ T lymphocytes in RRF patients were 71.1% (65.9–76.0) and 36.8% (32.5–41.9) respectively, which were significantly lower than the normal value (p < 0.05). The percentage of B cells in RSA patients [11.0 (8.8–13.9)] was significantly lower than that in RIF patients [11.9 (9.4–14.8)]. The occurrence of RRF is related to the lack of BA and the change of lymphoid subsets. There are some differences in immune status between RSA and RIF patients. [ABSTRACT FROM AUTHOR]

Context The thyrotropin (TSH) receptor (TSH-R) autoantibody activity is clinically measured by inhibition of labeled ligand (TSH or M22) binding to the TSH-R (TSH-binding inhibitory immunoglobulin [TBII]) or by stimulation (TSH-R stimulating antibody [TSAb]) or inhibition (TSH-R blocking antibody [TSBAb]) of 3′,5′-cyclic adenosine 5′-monophosphate (cAMP) production in isolated cells. Objective We experienced a patient with hypothyroid Graves disease (GD) having strong positive TBII but with almost neutral bioactivities on the TSH-R. The aim of this study is the characterization of this apparently paradoxical TBII (serum sample S). Methods We first compared the TBII, TSAb, and TSBAb activities of serum sample S with mixtures of stimulating (S-mAb) and blocking monoclonal Ab (B-mAb). Next, we serially measured cAMPs stimulated by various serum samples in the presence or absence of TSH. Results Mixtures of S-mAb and B-mAb did not reproduce the characteristics of serum sample S. Instead, serum sample S had a unique feature that blocked the TSH-stimulated cAMP initially but disappeared the blocking activity thereafter to reach the control level. Conclusion We present here the TBIIs with neutral bioactivities found in the patient with autoimmune thyroid disease, which strongly inhibit TSH binding to the TSH-R but exerts neither TSAb nor TSBAb activity. Differences in the methods of detecting TRAb between TBII in vitro and bioassay may cause the discrepancy. Although serum sample S may be an extreme example, a variety of TRAb that not only stimulates or blocks but also interferes with TSH-R binding for only a short time may exist in the serum samples of GD patients. [ABSTRACT FROM AUTHOR]

Trichomoniasis—caused by the parasite Trichomonas vaginalis—is associated with a high inflammatory process that may contribute to the risk of suffering from other medical complications. Our study focused on the in vitro interaction of T. vaginalis with human neutrophils because these are the most abundant cells implicated in the characteristic inflammatory process of trichomoniasis. This study showed that T. vaginalis and its surface glycoconjugates (lipophosphoglycan and/or lipoglycan) induced the formation of human neutrophil extracellular traps (NETs). After the trichomonad-neutrophil interaction, parasite integrity was at 32.9%, and the subsequent parasite growth was at 35.2% compared to those of control trophozoites (100%) incubated under the same conditions without neutrophils. In the presence of an antibody against the TLR-4 receptor, DNase I or micrococcal nuclease (MNase), neutrophils reduced the DNA fibres of the NETs and the amount of extracellular DNA, allowing a higher subsequent growth of T. vaginalis, at 52% with the anti-TLR-4 antibody and 62.6% with the enzymes. These results indicated that T. vaginalis induced the formation of extracellular traps by human neutrophils and, because of the interaction with neutrophils and NETs, parasite integrity and growth decreased. [ABSTRACT FROM AUTHOR]

The endothelin family of peptides has long been recognized as a physiological regulator of diverse biological functions and mechanistically involved in various disease states, encompassing, among others, the cardiovascular system, the kidney, and the nervous system. Pharmacological blockade of the endothelin system, however, has encountered strong obstacles in its entry into the clinical mainstream, having obtained only a few proven indications until recently. This translational gap has been attributable predominantly to the relevant side effects associated with endothelin receptor antagonism (ERA), particularly fluid retention. Of recent, however, an expanding understanding of the pathophysiological processes involving endothelin, in conjunction with the development of new antagonists of endothelin receptors or adjustment of their doses, has driven a flourish of new clinical trials. The favorable results of some of them have extended the proven indications for ET targeting to a variety of clinical conditions, including resistant arterial hypertension and glomerulopathies. In addition, on the ground of strong preclinical evidence, other studies are ongoing to test the potential benefits of ERA in combination with other treatments, such as sodium-glucose co-transporter 2 inhibition in fluid retentive states or anti-cancer therapies in solid tumors. Furthermore, antibodies providing long-term blockade of endothelin receptors are under testing to overcome the short half-life of most small molecule endothelin antagonists. These efforts may yet bring new life to the translation of endothelin targeting strategies in clinical practice., (© 2024 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Background: Alzheimer's disease (AD) is a devastating age-related neurodegenerative disorder and characterized by progressive loss of memory and cognitive functions, which are associated with amyloid-beta (Aβ) plaques. Immune cells play an important role in the clearance of Aβ deposits. Immune responses are regulated by immune regulators in which the B7 family members play a crucial role. We have recently identified erythroid membrane-associated protein (ERMAP) as a novel B7 family-related immune regulator and shown that ERMAP protein affects T cell and macrophage functions.Methods: We produced a monoclonal antibody (mAb) against ERMAP protein and then determined the ability of the mAb to affect cognitive performance and AD pathology in mice.Results:  We have shown that the anti-ERMAP mAb neutralizes the T cell inhibitory activity of ERMAP and enhances macrophages to phagocytose Aβ in vitro. Administration of the mAb into AD mice improves cognitive performance and reduces Aβ plaque load in the brain. This is related to increased proportion of T cells, especially IFNγ-producing T cells, in the spleen and the choroid plexus (CP), enhanced expression of immune cell trafficking molecules in the CP, and increased migration of monocyte-derived macrophages into the brain. Furthermore, the production of anti-Aβ antibodies in the serum and the macrophage phagocytosis of Aβ are enhanced in the anti-ERMAP mAb-treated AD mice.Conclusions: Our results suggest that manipulating the ERMAP pathway has the potential to provide a novel approach to treat AD patients. [ABSTRACT FROM AUTHOR]

Rationale: Sensitization to Fel d 1 (Felis domesticus allergen 1) contributes to persistent allergic rhinitis and asthma. Existing treatment options for cat allergy, including allergen immunotherapy, are only moderately effective, and allergen immunotherapy has limited use because of safety concerns. Objectives: To explore the relationship among the pharmacokinetic, clinical, and immunological effects of anti-Fel d 1 monoclonal antibodies (REGN1908-1909) in patients after treatment. Methods: Patients received REGN1908-1909 (n = 36) or a placebo (n = 37) in a phase 1b study. Fel d 1-induced basophil and IgE-facilitated allergen binding responses were evaluated at baseline and Days 8, 29, and 85. Cytokine and chemokine concentrations in nasal fluids were measured, and REGN1908-1909 inhibition of allergen-IgE binding in patient serum was evaluated. Measurements and Main Results: Peak serum drug concentrations were concordant with maximal observed clinical response. The anti-Fel d 1 IgE/cat dander IgE ratio in pretreatment serum correlated with Total Nasal Symptom Score improvement. The allergen-neutralizing capacity of REGN1908-1909 was observed in serum and nasal fluid and was detected in an inhibition assay. Type 2 cytokines (IL-4, IL-5, and IL-13) and chemokines (CCL17/TARC, CCL5/RANTES [regulated upon activation, normal T-cell expressed and secreted]) in nasal fluid were inhibited in REGN1908-1909-treated patients compared with placebo (P < 0.05 for all); IL-13 and IL-5 concentrations correlated with Total Nasal Symptom Score improvement. Ex vivo assays demonstrated that REGN1908 and REGN1909 combined were more potent than each alone for inhibiting FcεRI- and FcεRII (CD23)-mediated allergic responses and subsequent T-cell activation. Conclusions: A single, passive-dose administration of Fel d 1-neutralizing IgG antibodies improved nasal symptoms in cat-allergic patients and was underscored by suppression of FcεRI-, FcεRII-, and T-helper cell type 2-mediated allergic responses. Clinical trial registered with www.clinicaltrials.gov (NCT02127801). [ABSTRACT FROM AUTHOR]

Fel d1 is an important allergen produced by cats that causes IgE reactions in up to 95% of cat-allergic adults. Immunotherapy to reduce human allergy to cats has demonstrated that people have the capacity to produce allergen-specific neutralizing antibodies that block IgE-mediated allergic responses. We wished to determine if "blocking" antibodies could be used to reduce the IgE binding ability of cat allergens prior to their exposure to humans. Here, we describe the characterization of Fel d1-specific antibodies. We demonstrated the efficacy of a rabbit polyclonal and an allergen-specific chicken IgY to bind to Fel d1 in cat saliva and block Fel d1-IgE binding and IgE-mediated basophil degranulation. Fel d1 blocking antibodies offer a new and exciting approach to the neutralization of cat allergens. [ABSTRACT FROM AUTHOR]

Abstract Background The distribution of Pooideae species varies across Europe. Especially, Timothy is less represented in Southern than in Northern Europe. Since allergenic cross-reactivity between pollens from different grasses is only partial, grass pollen-allergic patients are expected to display different sensitization profiles, with specific IgE directed against different combinations of allergenic epitopes, depending on their living places in Europe and the grasses they are exposed to. In this context, this study aimed at comparing two tablets commercially available for allergy immunotherapy, namely a 5-grass (Cocksfoot, Meadow-grass, Rye-grass, Sweet vernal-grass and Timothy) and a 1-grass (Timothy) pollen tablets, for their ability to represent the sensitization profiles of patients, depending on whether they live in Southern or Northern Europe. Methods Sera were collected from adult patients living in Spain (n = 19) and Sweden (n = 22). Tablets were compared for their ability to inhibit the binding of patient serum IgE to pollen allergens from twelve grasses commonly distributed throughout Europe, as determined by the areas under the curves obtained by ELISA-inhibition. Tablets were adjusted to an equivalent allergenic activity, based on the CBER/FDA bioequivalent allergy unit. Results Inhibition of the IgE binding to pollen allergens from twelve grasses was significantly stronger with the 5-grass than with the 1-grass pollen tablet (p

Background: Programmed death‐1 (PD‐1) blocking antibodies have been shown to improve progression‐free survival (PFS) and overall survival in a subset of patients with non–small cell lung cancer (NSCLC). However, the objective response rate with these agents remains low, and the vast majority of NSCLC patients require alternative combination treatment regimens to prolong their survival. The purpose of this study was to evaluate the clinical efficacy of autologous cytokine‐induced killer (CIK) cell infusions combined with PD‐1 blocking antibodies in patients with NSCLC. Methods: In this preliminary study, we investigated the safety and immune function effectiveness of PD‐1 blockade antibodies pembrolizumab or nivolumab administered in combination with or without autologous CIK cell infusions in 18 patients with advanced NSCLC. The peripheral blood mononuclear cells were isolated from these patients and the expression level of some cell surface molecules like PD‐1 were detected using flow cytometry to reflect the effectiveness of this combination regimen. Results: No treatment‐related deaths occurred in either cohort. In comparison with the pretreatment level, CD3+CD56+CD16+ T cells were significantly increased with the combination therapy, while myeloid‐derived suppressor cells were significantly increased with PD‐1 blocking antibody therapy alone but not with combination therapy. Although the serum interleukin‐4 level was downregulated following treatment with the combination regimen, interferon‐γ levels were unchanged. Conclusions: The purpose of this clinical study was to report the clinical efficacy and lack of exacerbated autoimmune adverse events with a combination of PD‐1 blockade and CIK cell infusions in patients with advanced NSCLC, further supporting assessments of this combination in future clinical trials. [ABSTRACT FROM AUTHOR]

Preclinical, clinical, and population studies have provided robust evidence for an important role for the insulin-like growth factor (IGF) system in the development of prostate cancer. An overview of the IGF system is provided. The evidence implicating the IGF system in the development of prostate cancer is summarized. The compelling evidence culminated in a number of clinical trials of agents targeting the system; the reasons for the failure of these trials are discussed. Clinical trials of agents targeting the IGF system in prostate cancer were terminated due to limited objective clinical responses and are unlikely to be resumed unless a convincing predictive biomarker is identified that would enable the selection of likely responders. The aging population and increased screening will lead to greater diagnosis of prostate cancer. Although the vast majority will be indolent disease, the epidemics of obesity and diabetes will increase the proportion that progress to clinical disease. The increased population of worried men will result in more trials aimed to reduce the risk of disease progression; actual clinical endpoints will be challenging and the IGFs remain the best intermediate biomarkers to indicate a response that could alter the course of disease. [ABSTRACT FROM AUTHOR]

Conventional allergen‐specific immunotherapy (AIT), based on administrations of allergen extracts, represents up to now the unique protocol for the desensitization of allergic patients. Whereas the effectiveness of AIT was evidenced for the treatment of allergic rhinitis and allergic asthma, such strategy remains experimental for food allergies up to now. However, important issues are commonly associated with AIT as the quality of natural allergen extracts, the long duration and adverse side‐effects which negatively affect successful desensitization together with the patient compliance. The rapid progression of molecular allergology made possible the quest of safer, shorter and more effective immunotherapeutic approaches. The aim of this review was to provide an update on these different innovative recombinant derivatives including their efficacy but also their limitations. Despite promising preclinical and early clinical studies, the absence of convincing data in large phase III trials precludes so far the translation of these immunotherapeutic candidates into the clinic. [ABSTRACT FROM AUTHOR]

Objective: Syndecan-4 (sdc4) is a cell-anchored proteoglycan that consists of a transmembrane core protein and glucosaminoglycan (GAG) side chains. Binding of soluble factors to the GAG chains of sdc4 may result in the dimerisation of sdc4 and the initiation of downstream signalling cascades. However, the question of how sdc4 dimerisation and signalling affects the response of cells to inflammatory stimuli is unknown.Methods: Sdc4 immunostaining was performed on rheumatoid arthritis (RA) tissue sections. Interleukin (IL)-1 induced extracellular signal-regulated kinases (ERK) phosphorylation and matrix metalloproteinase-3 production was investigated. Il-1 binding to sdc4 was investigated using immunoprecipitation. IL-1 receptor (IL1R1) staining on wild-type, sdc4 and IL1R1 knockout fibroblasts was performed in fluorescence-activated cell sorting analyses. A blocking sdc4 antibody was used to investigate sdc4 dimerisation, IL1R1 expression and the histological paw destruction in the human tumour necrosis factor-alpha transgenic mouse.Results: We show that in fibroblasts, the loss of sdc4 or the antibody-mediated inhibition of sdc4 dimerisation reduces the cell surface expression of the IL-1R and regulates the sensitivity of fibroblasts to IL-1. We demonstrate that IL-1 directly binds to sdc4 and in an IL-1R-independent manner leads to its dimerisation. IL-1-induced dimerisation of sdc4 regulates caveolin vesicle-mediated trafficking of the IL1R1, which in turn determines the responsiveness to IL-1. Administration of antibodies (Ab) against the dimerisation domain of sdc4, thus, strongly reduces the expression IL1R1 on arthritic fibroblasts both in vitro and an animal model of human RA.Conclusion: Collectively, our data suggest that Ab that specifically inhibit sdc4 dimerisation may support anti-IL-1 strategies in diseases such as inflammatory arthritis. [ABSTRACT FROM AUTHOR]

The ability to visualize and quantify the spatial arrangement and geographic proximity of immune cells with tumor cells provides valuable insight into the complex mechanisms underlying cancer biology and progression. Multiplexing, which involves immunofluorescence labeling and the visualization of multiple epitopes within formalin-fixed paraffin embedded tissue sections, is a methodology that is being increasingly employed. Despite the power of immunofluorescence multiplex analysis, application of this technology to bone marrow core biopsies has not yet been realized. Given our specific long term goal to identify immune cells in proximity to bone marrow malignant plasma cells in multiple myeloma patients, we describe in this study adaptation of multiplex immunofluorescence analysis to this tissue. We first identified a blocking strategy that quenched autofluorescence. We next employed a multiplex strategy that uses a simple stripping solution to remove primary and secondary antibodies prior to subsequent rounds of staining. This method was found to be highly efficient and did not significantly alter antigenicity or tissue integrity. Our studies illustrate for the first time that immunofluorescence multiplexing is achievable in bone marrow core biopsies and will provide a novel opportunity to analyze the role of the immune contexture in disease progression of the monoclonal gammopathies. [ABSTRACT FROM AUTHOR]

Background: Allergies to cats are the most common animal‐origin allergy, and affect approximately 1 in 5 adults worldwide. The prevalence of allergy to furry animals has been increasing, and allergy to cats is a major risk factor for the development of asthma and rhinitis. The diagnosis of cat allergy is now well established. The exact significance of component‐resolved diagnosis in the diagnosis of cat allergy remains to be fully understood. Allergen avoidance is effective but often has a psychologic impact. Allergen immunotherapy is not well demonstrated. There is a need for innovative approaches to better manage cat allergens. Next‐generation care pathways for asthma and rhinitis will define the place of cat allergen avoidance. Methods and Results: This manuscript, based on content presented at the European Academy of Allergy and Clinical Immunology Congress 2019, provides information on the prevalence and impact of cat allergies and the molecular biology of Fel d 1, the major cat allergen. Discussion: The authors present the scientific basis of a novel care pathway that utilizes anti‐Fel d 1 IgY antibodies to safely and effectively neutralize Fel d 1 after its production by the cat but before human exposure. Conclusion: Efficacy of a feline diet with an egg product ingredient containing anti‐Fel d 1 IgY antibodies was demonstrated in vitro, ex vivo, and in vivo, and further validated by a pilot exposure study involving cat‐allergic human participants. [ABSTRACT FROM AUTHOR]

Background Grass pollen subcutaneous immunotherapy (SCIT) is associated with induction of serum IgG 4 -associated inhibitory antibodies that prevent IgE-facilitated allergen binding to B cells. Objective We sought to determine whether SCIT induces nasal allergen-specific IgG 4 antibodies with inhibitory activity that correlates closely with clinical response. Methods In a cross-sectional controlled study, nasal fluid and sera were collected during the grass pollen season from 10 SCIT-treated patients, 13 untreated allergic patients (with seasonal allergic rhinitis [SAR]), and 12 nonatopic control subjects. Nasal and serum IgE and IgG 4 levels to Phleum pratense components were measured by using the Immuno Solid Allergen Chip microarray. Inhibitory activity was measured by IgE-facilitated allergen binding assay. IL-10+ regulatory B cells were quantified in peripheral blood by using flow cytometry. Results Nasal and serum Phl p 1– and Phl p 5–specific IgE levels were increased in patients with SAR compared to nonatopic control subjects (all, P <.001) and SCIT-treated patients (nasal, P <.001; serum Phl p 5, P =.073). Nasal IgG 4 levels were increased in the SCIT group compared to those in the SAR group (P <.001) during the pollen season compared to out of season. IgG-associated inhibitory activity in nasal fluid and serum was significantly increased in the SCIT group compared to that in the SAR (both, P <.01). The magnitude of the inhibitory activity was 93% (P <.001) in nasal fluid compared to 66% (P <.001) in serum and was reversed after depletion of IgG. Both nasal fluid (r = −0.69, P =.0005) and serum (r = −0.552, P =.0095) blocking activity correlated with global symptom improvement. IL-10+ regulatory B cells were increased in season compared to out of season in the SCIT group (P <.01). Conclusion For the first time, we show that nasal IgG 4 -associated inhibitory activity correlates closely with the clinical response to allergen immunotherapy in patients with allergic rhinitis with or without asthma. Graphical abstract [ABSTRACT FROM AUTHOR]

Abstract Background An increase in allergen-specific IgG 4 (sIgG 4), which serves as a blocking antibody, is associated with acquisition of immune tolerance after immunotherapy. In this study, we developed a rapid, sensitive, and homogeneous immunoassay based on the light-initiated chemiluminescent assay (LICA) technology for quantifying allergen sIgG 4 in serum samples. Methods Allergen sIgG 4 was measured in vitro by incubating the sample with biotinylated allergens and chemiluminescent beads coated with anti-human IgG 4 antibody, followed by the addition of streptavidin-coated sensitizer beads. Multiple tests were performed to optimize the working conditions of the LICA and evaluate its performance. Results We established the optimal concentration of biotinylated allergens (250 ng/mL), the optimal dilution range (1:8 for Gal d 1, Gal d 2 sIgG 4 and 1:4 for Gal d 3, Gal d 4 sIgG 4), and the optimal incubation time (20 min for Gal d 1, Gal d 2 sIgG 4 and 40 min for Gal d 3, Gal d 4 sIgG 4). The lower limit of quantification (LLOQ) was 0.261 ng/mL. The coefficient variation (CV) of the LICA was <10%. The assay was unaffected by general interfering substances at physiological concentrations. It exhibited excellent accuracy to detect allergen-sIgG 4 in human serum. Additionally, we demonstrated that the levels of Gal d 1, Gal d 2, and Gal d 3-sIgG 4 were significantly higher in the egg allergy group (p <.05), but no differences were found between the groups for Gal d 4-sIgG 4. Conclusions The LICA demonstrated satisfactory performance and can be used for quantifying allergen sIgG 4 in clinical practice. Highlights • An increase in allergen specific IgG4 levels indicates acquisition of tolerance. • LICA is a homogeneous bead-based serological assay. • An immunoquantitation kit for allergen sIgG4 is currently lacking in China. • The LICA for allergen sIgG4 exhibited satisfactory performance. • Levels of Gal d 1, Gal d 2, and Gal d 3 sIgG4 are different among allergic, atopic, and healthy subjects. [ABSTRACT FROM AUTHOR]

The aim of this study is to improve our understanding of the mechanisms involved in maternal–fetal immune tolerance. We searched the related literatures and overviewed the major antibodies associated with pregnancy and described in details their possible roles in mediating maternal–fetal interactions. Antibodies classified into different types based on their functional or structural characteristics were summarized, including immunoglobulin G, blocking antibody, nonprecipitating asymmetric antibody, antiphospholipid antibody, antitrophoblast antibody and antipaternal antibody. The presence and levels of various circulating antibodies in pregnancy may play a crucial role in the occurrence, development and termination of pregnancy. [ABSTRACT FROM AUTHOR]

Background: The distribution of Pooideae species varies across Europe. Especially, Timothy is less represented in Southern than in Northern Europe. Since allergenic cross‐reactivity between pollens from different grasses is only partial, grass pollen‐allergic patients are expected to display different sensitization profiles, with specific IgE directed against different combinations of allergenic epitopes, depending on their living places in Europe and the grasses they are exposed to. In this context, this study aimed at comparing two tablets commercially available for allergy immunotherapy, namely a 5‐grass (Cocksfoot, Meadow‐grass, Rye‐grass, Sweet vernal‐grass and Timothy) and a 1‐grass (Timothy) pollen tablets, for their ability to represent the sensitization profiles of patients, depending on whether they live in Southern or Northern Europe. Methods: Sera were collected from adult patients living in Spain (n = 19) and Sweden (n = 22). Tablets were compared for their ability to inhibit the binding of patient serum IgE to pollen allergens from twelve grasses commonly distributed throughout Europe, as determined by the areas under the curves obtained by ELISA‐inhibition. Tablets were adjusted to an equivalent allergenic activity, based on the CBER/FDA bioequivalent allergy unit. Results: Inhibition of the IgE binding to pollen allergens from twelve grasses was significantly stronger with the 5‐grass than with the 1‐grass pollen tablet (p < 0.0001), regardless of whether patients were considered as a whole or by geographical area. This difference between tablets was significantly greater for Southern than Northern European patients (p < 0.05). Conclusions: Compared to the 1‐grass tablet, the 5‐grass tablet generally covers better the sensitization profiles of European patients, especially patients from Southern Europe, in principle less exposed to pollen from Timothy than from other grasses. The 5‐grass tablet is therefore expected to elicit larger spectra of blocking antibodies, which might have implications in light of the generally accepted mechanisms of allergy immunotherapy. [ABSTRACT FROM AUTHOR]

Abstract Measuring the plasma corticotropin (ACTH) concentration is an important step in determining the underlying cause in patients with hypercortisolemia. Interfering substances in immunoassays can lead to erroneous results impacting clinical management. We describe a case series of 12 patients, the majority of whom were being investigated for possible Cushing's syndrome and in whom inconsistencies between the clinical picture and biochemical testing raised concerns of assay interference. ACTH assay interference resulted in falsely elevated ACTH concentrations using the Siemens Immulite assay and consequently led to additional unnecessary testing. Communication between physician and laboratory as well as appropriate investigation (including sample dilution, use of blocking antibodies and testing on an alternate platform) resulted in assay interference identification. Recognition of biochemical results which are clinically discrepant remains an essential step in patient assessment. Highlights • Measurement of adrenocorticotropin is an important step in the assessment of the hypothalamic pituitary axis • The ACTH immunoassay may be subject to interfering substances • When there is a discrepancy between the clinical and biochemical assessment of patient, assay interference should be considered • Communication between clinician and laboratory can facilitate appropriate investigations to assess for interfering substances [ABSTRACT FROM AUTHOR]

Abstract Der p 5 is one of the important house dust mite allergens in Algeria; this allergen is frequently recognized by patients with allergic asthma. However, there is no information on its IgG–binding epitopes. In the present study, rabbits were immunized with recombinant Der p 5 allergen, and serum samples were obtained. Recognition of linear IgG epitopes of Der p 5 was determined using synthesized peptides derived from the allergen sequence. The results showed that serum from immunized rabbits recognized three linear epitopes from Der p 5 (28EDKKHDYQNEFDFLLMERIHEQIK43), (37IHEQIKKGELALFYLQEQ55) and (92LMQRKDLDIFEQYNLEMAKKS112). More interestingly, we observed that the 92L-S112 amino acid sequence is well recognized by both IgE and IgG antibodies. Der p 5 stimulates the synthesis of specific IgG antibodies which recognize common but also novel epitopes compared to IgE antibody binding. Indeed, the potential to induce IgG antibodies can be used to inhibit human IgE binding to allergens which may be part of the mechanism of action of specific immunotherapy. [ABSTRACT FROM AUTHOR]

The thyrotropin receptor (TSHR), the lutropin- (LHR), and the follicotropin receptor (FSHR) belong to glycoprotein hormone receptors (GPHR), a subgroup of the class A G-protein coupled receptors. In this review, the unique features of GPHR have been taken into account for their pharmacological interventions: i) The respective hormone and stimulating or blocking antibodies are binding on the large ectodomain that is ii) via a hinge region, containing iii) an internal tethered agonist linked to the transmembrane domain. iv) Multimerization and mechanisms for negative or positive cooperativity of GPHR upon ligand binding and v) dimer- and oligomeric arrangements enabling trans-activation on GPHR signaling are considered. Available knowledge concerning the modulation of the GPHR (mal)-function and associated structural aspects by diverse entities such as antibodies, chaperones, peptides, small molecule agonists, inverse agonists, and antagonists is summarized. The TSHR is important with respect to autoimmune [Graves' disease (GD), Graves' orbitopathy (GO)] or non-autoimmune thyroid dysfunctions and cancer-development. To date there is neither an agonist nor antagonist modulator of pathogenic such as TSHR signaling in the clinics. However, several different ligands monoclonal stimulating and inhibiting antibodies and small molecule drug-like ligands have been reported in the last decade. In special focus are the most recent findings regarding the development and use of small molecule TSHR ligands. Finally, limitations of current knowledge and lack of information are discussed highlighting the need for intensified efforts towards understanding the interplay of TSHR multimers, especially their interaction with drug-like ligands. Important in this context is the biased ligand development. [ABSTRACT FROM AUTHOR]

Autoantibodies (Ab) against the thyroid-stimulating hormone receptor (TSHR) are frequently found in autoimmune thyroid disease (AITD). Autoantibodies to the TSHR (anti-TSHR-Ab) may mimic or block the action of TSH or be functionally neutral. Measurement of anti-TSHR-Ab can be done either via competitive- binding immunoassays or with functional cell-based bioassays. Antibody-binding assays do not assess anti-TSHR-Ab functionality, but rather measure the concentration of total anti-TSHR binding activity. In contrast, functional cell-based bioassays indicate whether anti-TSHR-Ab have stimulatory or blocking activity. Historically bioassays for anti-TSHR-Ab were research tools and were used to study the pathophysiology of Graves' disease and Hashimoto's thyroiditis. In the past, bioassays for anti-TSHR-Abs were laborious and time-consuming and varied widely in performance from laboratory to laboratory. Recent advances in the development of cell-based assays, including the application of molecular engineering, have led to significant improvements that have enabled bioassays to be employed routinely in clinical laboratories. The prevalence and functional significance of TSHR blocking autoantibodies (TBAb) in autoimmune hypothyroidism has been less well investigated compared to TSHR stimulating Ab. There is an increasing body of data, however, that demonstrate the clinical utility and relevance of TBAb, and thus the importance of TBAb bioassays, in the diagnosis and management of patients with AITD. In the present review, we summarize the different methods used to measure TBAb, and discuss their prevalence and clinical relevance. [ABSTRACT FROM AUTHOR]

There are rapidly emerging efforts to explore tumor-associated macrophages (TAMs) as a tumor therapy target. Tumor cells express CD47, which can interact with the macrophages' SIRPα transmitting a "don't eat me" signal to macrophages. The expression of CD47 increases in various tumors to evade immune attack. However, the expression of CD47 in endometrial cancer (EC) and the role of CD47-SIRPα in the TAMs which mediate the progression of EC remain unclear. Our study shows that there are increased TAMs in EC which dominantly consist of M2 macrophages and contribute to the progression of EC. We confirm that CD47 is highly expressed in EC tissue using the TCGA database, qPCR, and flow cytometry. Instead of directly promoting the apoptosis of EC cells, anti-CD47 blocking antibody promoted phagocytosis of EC cells by macrophages and the increased phagocytosis ability was mediated by M2 macrophages in a coculture assay. Besides, CD47 blockade inhibited the growth of the EC tumors in vivo and increased the infiltration of macrophages with antitumor ability in the tumor microenvironment (TME). These findings might assist in developing promising strategies that blocked the CD47-SIRPa interaction for EC therapy. [ABSTRACT FROM AUTHOR]

Cancer immunotherapy, a treatment that selectively augments a patient's anti-tumor immune response, is a breakthrough advancement in personalized medicine. A subset of cancer patients undergoing immunotherapy have displayed robust and long-lasting therapeutic responses. Currently, the spotlight is on the use of blocking antibodies against the T-cell checkpoint molecules, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programed cell death-1 (PD-1)/programed death-ligand 1 (PD-L1), which have been effectively used to combat many cancers types. Despite the overall enthusiasm, immune checkpoint blockade inhibitors suffer from significant limitations such as high cost, serious toxicity in a substantial proportion of patients, and a response rate as low as 10%-40% in some clinical trials. Consequently, there is an urgent and unmet medical need for companion biomarkers that could both predict the response of individual patients to these therapies, and provide the means for precise monitoring of their therapeutic outcome. In this era of precision medicine, predictive biomarkers are a hot commodity because they can effectively separate responders from non-responders, and spare non-responders from serious therapy-related toxicity. Emerging predictive biomarkers for immune checkpoint blockade are: PD-L1 expression, increased amounts of tumor-infiltrating lymphocytes, increased mutational load and mismatch repair deficiency. Other well-studied biomarkers include inflammatory infiltrate, absolute lymphocyte count and lactate dehydrogenase levels. We review recent progress on predictive cancer biomarkers in immunotherapy, with a special emphasis on serum autoantibodies that have the potential to be personalized for optimal clinical outcomes. [ABSTRACT FROM AUTHOR]

Extensive clinical evidence supports that cytotoxic T lymphocyte antigen-4 (CTLA-4) is expressed in a variety of human malignant tumour cells in addition to T cells. In certain types of cancer, the overexpression of CTLA-4 is associated with poor patient prognosis. However, few studies have demonstrated the effects of tumour-intrinsic CTLA-4 in cancer stem cells, including melanoma stem cells (MSCs). In the present study, it was demonstrated that melanoma cell-intrinsic CTLA-4 induced tumour cell proliferation in vitro and suppressed tumour cell apoptosis. Furthermore, CTLA-4 was expressed in aldehyde dehydrogenase (ALDH)+ MSCs. CTLA-4 inhibited MSCs proliferation in vitro by blocking antibodies and significantly downregulated ALDH1A1, ALDH1A3 and ALDH2 mRNA expression (P<0.01). Functionally, blocking CTLA-4 in melanoma cell lines suppressed the properties of stem-like cells, including ALDH activity and significantly suppressed the ability of these cells to form spheres in vitro (P<0.05). In addition, the blocking of CTLA-4 in melanoma cells suppressed the properties of stem-like cells in vivo, including the capacity for tumourigenesis. The presence of residual ALDH+ MSCs within the tumour was observed, and the blocking CTLA-4 significantly decreased the number of residual ALDH+ MSCs in vivo (P<0.01). Altogether, these results indicate the identification of a novel mechanism underlying melanoma progression in the present study and that CTLA-4-targeted therapy may benefit candidate CTLA-4-targeted therapy by improving the long-term outcome for patients with advanced stages of melanoma. [ABSTRACT FROM AUTHOR]

To investigate the clinical significance of the ratio of T helper cell 17 (Th17) cells to single immunoglobulin IL-1-related receptor (SIGIRR)+ cluster of differentiation (CD4)+ T cells in patients with systemic lupus erythematosus (SLE), novel data and data from previous studies were analyzed. The frequency of Th17 cells in peripheral blood mononuclear cells (PBMCs) and their correlation with clinical data were evaluated in 48 patients with SLE and 38 healthy controls through flow cytometry. Compared with healthy controls, the percentage of Th17 cells was significantly increased in the PBMCs of patients with SLE (Z=−5.82, P<0.001). Compared with inactive SLE (ISLE), the percentage of Th17 cells in active SLE (ASLE) were significantly increased (Z=−4.26, P<0.0001). Compared with patients without lupus nephritis, the frequency of Th17 cells was significant increased (Z=−2.20, P=0.028). The frequency of Th17 cells was inversely correlated with the frequency of SIGIRR+CD4+ T cells (r=−0.61, P<0.001). The ratio of Th17 cells to SIGIRR+CD4+ T cells in ASLE was significantly increased compared with healthy controls or patients with ISLE (P<0.001) and was inversely correlated with complement component 3 and complement component 4, and positively correlated with SLE disease activity index and 24-h proteinuria (P<0.05). In summary, increased numbers of Th17 cells and decreased numbers of SIGIRR+CD4+ T cells in patients with SLE suggested that SIGIRR+CD4+ T and Th17 cells may be involved in the pathogenesis of SLE. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Spontaneously oscillating thyroid function in Graves’ disease is a rare phenomenon. Switching between TSH receptor stimulating antibodies (TSAb) and TSH receptor blocking antibodies (TBAb) most likely accounts for presentations of alternating hyperthyroidism and hypothyroidism. To achieve stability of thyroid function, definitive therapy is recommended to remove the pathological thyroid. [ABSTRACT FROM AUTHOR]

Changes in sialic acids in cancer have been observed for many years. In particular, the increase of sialoglycan density or hypersialylation in tumors has been described. Recent studies have identified mechanisms for immune evasion based on sialoglycan interactions with immunoregulatory Siglec receptors that are exploited by tumor cells and microorganisms alike. Siglecs are mostly inhibitory receptors similar to known immune checkpoints including PD-1 or CTLA-4 that are successfully targeted with blocking antibodies for cancer immunotherapy. Here, we summarize the known changes of sialic acids in cancer and the role Siglec receptors play in cancer immunity. We also focus on potential ways to target these Siglec receptors or sialoglycans in order to improve anti-cancer immunity. [ABSTRACT FROM AUTHOR]

Human and mouse resident memory T cells are present in vitiligo lesions, and blocking IL-15 signaling provides long-lasting reversal of disease in a mouse model of vitiligo. Forcing memory T cells to forget: In vitiligo, autoreactive T cells attack melanocytes, leading to white spots on the skin. Depigmentation typically recurs upon cessation of treatment, so new therapies are needed for permanent patient relief. Richmond and colleagues reasoned that targeting tissue-resident memory T cells may allow for durable therapy. They observed that T cells from patient lesional samples expressed the receptor for IL-15, an important survival cytokine. T cells in a mouse model of vitiligo also expressed the IL-15 receptor, and blocking IL-15 signaling with an antibody was able to reverse disease symptoms. A clinical trial to test this therapy is now in the works. Vitiligo is an autoimmune disease of the skin mediated by CD8+ T cells that kill melanocytes and create white spots. Skin lesions in vitiligo frequently return after discontinuing conventional treatments, supporting the hypothesis that autoimmune memory is formed at these locations. We found that lesional T cells in mice and humans with vitiligo display a resident memory (TRM) phenotype, similar to those that provide rapid, localized protection against reinfection from skin and mucosal-tropic viruses. Interleukin-15 (IL-15)–deficient mice reportedly have impaired TRM formation, and IL-15 promotes TRM function ex vivo. We found that both human and mouse TRM express the CD122 subunit of the IL-15 receptor and that keratinocytes up-regulate CD215, the subunit required to display the cytokine on their surface to promote activation of T cells. Targeting IL-15 signaling with an anti-CD122 antibody reverses disease in mice with established vitiligo. Short-term treatment with anti-CD122 inhibits TRM production of interferon-γ (IFNγ), and long-term treatment depletes TRM from skin lesions. Short-term treatment with anti-CD122 can provide durable repigmentation when administered either systemically or locally in the skin. On the basis of these data, we propose that targeting CD122 may be a highly effective and even durable treatment strategy for vitiligo and other tissue-specific autoimmune diseases involving TRM. [ABSTRACT FROM AUTHOR]