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This article discusses the need for a better understanding of allergen immunotherapy (AIT) and the identification of early biomarkers that can predict treatment outcomes. The authors propose that changes in specific surface proteins on allergen-specific memory B cells can serve as biomarkers for successful AIT. They conducted a study using recombinant protein tetramers and single-cell RNA sequencing to identify changes in transcriptional profiles and surface protein expression on allergen-specific B cells. The authors found that the expression of CD23, CD29, and CD124 on allergen-specific B cells can be prognostic biomarkers for AIT effects after 2-4 months of treatment. These biomarkers can be used to evaluate the effectiveness of new treatments or treatment combinations in clinical trials. The functional relevance of these proteins in the context of AIT is still unclear and requires further investigation. The study was supported by grants and in-kind support from various organizations. The authors also disclose that they are inventors on the presented patent application. [Extracted from the article]

Background: Sublingual immunotherapy (SLIT) for grass pollen allergy can modify the natural history of allergic rhinitis and is associated with increased allergen‐specific IgG4. IgG4 competitively inhibits functional IgE on the surface of effector cells, such as mast cells and basophils, from binding to allergens. To further understand the important role memory B‐cell (Bmem) responses play in mediating the beneficial effects of SLIT, we assessed changes in allergen‐specific Bmem subsets induced by SLIT for grass pollen allergy. Methods: Blood samples were collected twice outside the pollen season from twenty‐seven patients with sensitization to ryegrass pollen (RGP; Lolium perenne) and seasonal rhinoconjunctivitis. Thirteen received 4‐month pre‐seasonal SLIT for grass pollen allergy, and 14 received standard pharmacotherapy only. Single‐cell RNA sequencing was performed on FACS‐purified Lol p 1‐specific Bmem before and after SLIT from four patients, and significant genes were validated by flow cytometry on the total cohort. Results: Four months of SLIT increased RGP‐specific IgE and IgG4 in serum and induced two Lol p 1‐specific Bmem subsets with unique transcriptional profiles. Both subsets had upregulated expression of beta 1 integrin ITGB1 (CD29), whereas IGHE (IgE), IGHG4 (IgG4), FCER2 (CD23), and IL13RA1 were upregulated in one subset. There was an increase in the proportion of Lol p 1+ Bmem expressing surface IgG4, CD23, and CD29 after SLIT. Conclusions: A clinically successful 4 months course of SLIT for grass pollen allergy induces two transcriptionally unique Bmem fates. Associated changes in surface‐expressed proteins on these Bmem subsets can be used as early biomarkers for treatment effects. [ABSTRACT FROM AUTHOR]

Background: While treatment for atopic rhinitis is aimed mostly to relieve symptoms, only allergen‐specific immunotherapy (AIT) is targeted to modify the natural history of allergic diseases. This results in sustained clinical tolerance, even when treatment has stopped. The immunomodulatory effects of AIT are attributed mainly to increased regulatory T‐cell function and increased allergen‐specific IgG4, yet little is known about the effect on the memory B‐cell compartment. Objective: We aimed to examine the effects of AIT on the IgE‐ and IgG subclass‐expressing memory B cells. Methods: We recruited 29 patients with atopic seasonal rhinoconjunctivitis and performed a longitudinal analysis of the peripheral immune compartment before, during, and after sublingual immunotherapy (SLIT) for allergy to temperate grass pollen, predominantly to ryegrass pollen (RGP; Lolium perenne). Using flow cytometry on peripheral blood mononuclear cells and serum immunoassays, we analyzed the effects of a 4 months preseasonal treatment regimen comprising two or three courses in consecutive years on circulating IgE+ and IgG+ memory B cells and allergen‐specific Ig levels. Results: SLIT increased RGP‐specific serum IgG2 and IgG4, as well as the frequencies of IgG2+ and IgG4+ memory B cells, whereas no effect was observed on the IgE+ memory B‐cell compartment. Furthermore, SLIT enhanced proportions of regulatory T cells specific to RGP. These changes were associated with clinical improvement. Conclusion: Our data provide evidence for immunological effects of SLIT on B‐cell memory. Skewing responses toward IgG2 and IgG4 subclasses might be a mechanism to suppress IgE‐mediated allergic responses. [ABSTRACT FROM AUTHOR]

This article discusses a study on the effects of allergen immunotherapy (AIT) on type 2 memory B cells (Bmem) in patients with bee venom and ryegrass pollen allergies. The study found that successful AIT led to an increase in allergen-specific type 2 Bmem expressing certain proteins. The study also observed changes in the phenotype of type 2 Bmem after AIT. The authors suggest that these changes may contribute to the effectiveness of AIT, but more research is needed to understand the long-term effects. The document also provides acknowledgments, funding information, author affiliations, references, and contact information for the corresponding author. The data from the study are available upon request. [Extracted from the article]

Background: While treatment for atopic rhinitis is aimed mostly to relieve symptoms, only allergen-specific immunotherapy (AIT) is targeted to modify the natural history of allergic diseases. This results in sustained clinical tolerance, even when treatment has stopped. The immunomodulatory effects of AIT are attributed mainly to increased regulatory T-cell function and increased allergen-specific IgG 4 , yet little is known about the effect on the memory B-cell compartment., Objective: We aimed to examine the effects of AIT on the IgE- and IgG subclass-expressing memory B cells., Methods: We recruited 29 patients with atopic seasonal rhinoconjunctivitis and performed a longitudinal analysis of the peripheral immune compartment before, during, and after sublingual immunotherapy (SLIT) for allergy to temperate grass pollen, predominantly to ryegrass pollen (RGP; Lolium perenne). Using flow cytometry on peripheral blood mononuclear cells and serum immunoassays, we analyzed the effects of a 4 months preseasonal treatment regimen comprising two or three courses in consecutive years on circulating IgE + and IgG + memory B cells and allergen-specific Ig levels., Results: SLIT increased RGP-specific serum IgG 2 and IgG 4 , as well as the frequencies of IgG 2 + and IgG 4 + memory B cells, whereas no effect was observed on the IgE + memory B-cell compartment. Furthermore, SLIT enhanced proportions of regulatory T cells specific to RGP. These changes were associated with clinical improvement., Conclusion: Our data provide evidence for immunological effects of SLIT on B-cell memory. Skewing responses toward IgG 2 and IgG 4 subclasses might be a mechanism to suppress IgE-mediated allergic responses., (© 2019 The Authors. Allergy published by John Wiley & Sons Ltd.)

Allergic diseases are the most common chronic immune-mediated disorders and can manifest with an enormous diversity in clinical severity and symptoms. Underlying mechanisms for the adverse immune response to allergens and its downregulation by treatment are still being revealed. As a result, there have been, and still are, major challenges in diagnosis, prediction of disease progression/evolution and treatment. Currently, the only corrective treatment available is allergen immunotherapy (AIT). AIT modifies the immune response through long-term repeated exposure to defined doses of allergen. However, as the treatment usually needs to be continued for several years to be effective, and can be accompanied by adverse reactions, many patients face difficulties completing their schedule. Long-term therapy also potentially incurs high costs. Therefore, there is a great need for objective markers to predict or to monitor individual patient's beneficial changes in immune response during therapy so that efficacy can be identified as early as possible. In this review, we specifically address recent technical developments that have generated new insights into allergic disease pathogenesis, and how these could potentially be translated into routine laboratory assays for disease monitoring during AIT that are relatively inexpensive, robust and scalable., (© 2019 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Background: Signal transducer and activator of transcription 3 hyper-IgE syndrome (STAT3-HIES) is caused by heterozygous mutations in the STAT3 gene and is associated with eczema, elevated serum IgE, and recurrent infections resembling severe atopic dermatitis, while clinically relevant specific IgE is almost absent., Methods: To investigate the impact of STAT3 signaling on B-cell responses, we assessed lymph node and bone marrow, blood B and plasma cell subsets, somatic hypermutations in Ig genes, and in vitro proliferation and antibody production in STAT3-HIES patients and healthy controls., Results: Lymph nodes of STAT3-HIES patients showed normal germinal center architecture and CD138 + plasma cells residing in the paracortex, which expressed IgE, IgG, and IgM but not IgA. IgE + plasma cells were abundantly present in STAT3-HIES bone marrow. Proliferation of naive B cells upon stimulation with CD40L and IL-4 was similar in patients and controls, while patient cells showed reduced responses to IL-21. IgE, IgG1, IgG3 and IgA1 transcripts showed reduced somatic hypermutations. Peripheral blood IgE + memory B-cell frequencies were increased in STAT3-HIES, while other memory B-cell frequencies except for IgG4 + cells were decreased., Conclusions: Despite impaired STAT3 signaling, STAT3-HIES patients can mount in vivo T-cell-dependent B-cell responses, while circulating memory B cells, except for those expressing IgG4 and IgE, were reduced. Reduced molecular maturation demonstrated the critical need of STAT3 signaling for optimal affinity maturation and B-cell differentiation, supporting the need for immunoglobulin substitution therapy and explaining the high IgE serum level in the majority with absent allergic symptoms., (© 2019 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)