We are memory: B‐cell responses in allergy and tolerance

Abstract

The significance of B‐cell memory in sustaining IgE‐mediated allergies but also ensuring the development of long‐term allergen tolerance has remained enigmatic. However, well‐thought murine and human studies have begun to shed more light on this highly disputed subject. The present mini review highlights important aspects, like the involvement of IgG1 memory B cells, the meaning of low‐ or high‐affinity IgE antibody production, the impact of allergen immunotherapy, or the relevance of local memory established by ectopic lymphoid structures. Based on recent findings, future investigations should lead to deeper knowledge and the development of improved therapies treating allergic individuals.

Single‐cell RNA sequencing reveals the landscape of biomarker in allergic rhinitis patient undergoing intracervical lymphatic immunotherapy and related pan‐cancer analysis

“…Shamji's findings showed elevated specific‐IgA1/2 levels in nasal secretions during SLIT at years 2 and 3, whereas allergen‐specific IgG4 levels increased during SCIT at years 1, 2, and 3 7 . Both allergen‐specific IgG and IgA antibodies were detected in the nasal mucosa of AR patients undergoing AIT 6 …”

“…Allen proposed that enhanced or prolonged GC responses could maintain the suppression of IgE‐producing CSR, consequently decreasing the production of the high‐affinity allergen‐specific IgE 27 . During the immune response triggered by allergens, GC‐derived memory B cells functioned as the primary reservoir of antibody‐secreting cells within the humoral memory B cells response 6,27,28 . As the precursor of IgE maturation, IgG1 memory B cells arising from repeated allergen encounters contribute to the differentiation of either high‐affinity IgE PC by direct isotype switch (from IgM to IgE) or low‐affinity IgE PC by indirect switching (from IgM over IgG1 to IgE).…”

“…27 During the immune response triggered by allergens, GC-derived memory B cells functioned as the primary reservoir of antibody-secreting cells within the humoral memory B cells response. 6,27,28 As the pre- Generally, IgG is the predominant isotype in serum, followed by IgA in peripheral blood. 7 In contrast, detecting IgE antibody-secreting cells in peripheral blood and human bone marrow is challenging due to their short half-life in the serum, as opposed to their prominent presence in local tissues and organs.…”

“…Upon the stimulation of the cognate antigen, B cells become activated and differentiated into plasmablasts, plasma cells, or germinal center (GC)‐independent memory B cells 5 . The long‐lasting immune tolerance induced by repeated allergen exposure after AIT was a procedure in which memory B cells exhibited its protective role by re‐entering into the GC, where the correlative immunoglobulins underwent somatic hypermutation (SHM) in the dark zone and affinity maturation in the light zone regarding B cell receptor (BCR) gene 6 . Among the immunoglobulins, specific allergen‐induced IgE decrease after AIT in the maintenance phase is considered successful, coming with an increase in IgA and IgG4 functioning as “blocking antibodies” 7 .…”

“…5 The long-lasting immune tolerance induced by repeated allergen exposure after AIT was a procedure in which memory B cells exhibited its protective role by reentering into the GC, where the correlative immunoglobulins underwent somatic hypermutation (SHM) in the dark zone and affinity maturation in the light zone regarding B cell receptor (BCR) gene. 6 Among the immunoglobulins, specific allergen-induced IgE decrease after AIT in the maintenance phase is considered successful, coming with an increase in IgA and IgG4 functioning as "blocking antibodies". 7 AITinduced IgG2, IgG4, and IgA display a protective role in competitively binding specific allergens with IgE, consequently inhibiting the activation and degranulation of effector cells, reaching clinically effective protection in pollen season and food allergy.…”