Regulation of germinal center responses, memory B cells and plasma cell formation—an update

cGAS-mediated control of blood-stage malaria promotes Plasmodium-specific germinal center responses

“…The ability to simultaneously identify and analyze endogenous polyclonal antigen-specific CD4 + T cells and B cells responding to Plasmodium has revealed a profound effect of innate immune control of parasitemia. Control of parasitemia is important for timely development of the GC response, a response critical for both the efficient generation of high-affinity antibodies and durable immune memory (59)(60)(61)(62). Furthermore, our ability to track parasitemia throughout the course of infection combined with the potential to rapidly clear blood-stage infection with atovaquone provided us with an elegant system in which the effects of innate control of parasite burden could be disentangled from the effects of early innate signals on the adaptive immune response.…”

“…To examine antigen-specific CD4 + T cells responding to infection, P. yoelii were generated that constitutively express the Lymphocytic choriomeningitis virus-derived (LCMV-derived) glycoprotein (GP) epitope (GP [61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80] ). This allows for the identification and analysis of antigen-specific CD4 + T cells using previously described GP66:I-A B tetramer enrichment strategies (16).…”

The Developmental History of IgE and IgG4 Antibodies in Relation to Atopy, Eosinophilic Esophagitis, and the Modified TH2 Response

“…We will also ignore for the moment the diverse panel of inhibitors (cells and extracellular factors) that may modify the outcome of the interaction between the antigen and the B cell. For recent reviews on this topic, see for example [11–13]. …”

Immune and myodegenerative pathomechanisms in inclusion body myositis

“…Sera from IBM patients contain increased amounts of muscle antigen‐reactive monoclonal antibodies122 and although CD20 + B cells are scarce, substantial numbers of transcriptionally active CD138 + plasma cells can be detected in inflamed muscle of IBM patients 106. Immunoglobulin heavy chain gene transcript analyses in IBM, PM, and DM revealed that these cells undergo isotype switching, oligoclonal expansion and somatic hypermutation which suggests local affinity maturation of antibodies,123 a process that usually occurs in germinal centers under the aid of follicular dendritic cells (fDCs) and follicular B helper T cells 124, 125, 126. In fact, an early study characterized nodular lymphocytic accumulations in inflamed muscle and found microanatomical organization patterns as well as adhesion molecule expression reminiscent of those in secondary lymphoid organs 127.…”

“…B cell maturation is highly dependent on bidirectional interactions with cognate CD4 + T cells 124, 125, 126. Amongst others, ICOS:B7RP‐1 ligation is essential for the successful execution of this crosstalk 129.…”