B Cells Are the Dominant Antigen-Presenting Cells that Activate Naive CD4+ T Cells upon Immunization with a Virus-Derived Nanoparticle Antigen

Abstract

Highlights d B cells are the dominant APCs that initiate CD4 + T cell response to VLPs d The few antigen-specific B cells in WT mice are sufficient to activate CD4 + T cells d Innate signaling in B cells is required for the VLP-induced CD4 + T cell polarization d B cell-mediated antigen-presentation can break CD4 + T cell tolerance

B cells are sufficient to prime the dominant CD4+ Tfh response to Plasmodium infection

“…Together, these data demonstrate that B cells play a significant role in directing the expansion of CD4 + T cells responding to Plasmodium infection independently of DCs. These data also support more recent work demonstrating that antigen presentation by B cells alone is sufficient to drive the expansion and formation of prominent Tfh populations in the context of infection (Hong et al, 2018).…”

“…We next examined whether, alternatively, B cells could be priming CD4 + T cells in response to Plasmodium infection. Following activation, B cells upregulate MHC II and costimulatory molecules, demonstrating their capacity to prime naive CD4 + T cells (Barnett et al, 2014;Constant, 1999;Hawrylowicz and Unanue, 1988;Hong et al, 2018;Krieger et al, 1985). Additionally, B cell priming has been demonstrated in vivo using mice that only express MHC II (I-Ab) on CD19 + B cells (B-MHC II).…”

“…Additionally, B cell priming has been demonstrated in vivo using mice that only express MHC II (I-Ab) on CD19 + B cells (B-MHC II). In B-MHC II mice, antigen presentation by B cells was shown to be sufficient to drive the expansion and formation of antigen-specific Tfh cells in response to immunization (Constant, 1999) and during viral infection (Barnett et al, 2014;Evans et al, 2000;Hong et al, 2018). We used these mice to determine whether a similar phenomenon could occur in response to Plasmodium infection.…”

Engineering Biomaterials to Direct Innate Immunity

“…This innate function and the antibody production of B cells make them an interesting target for modulating immunity. [44] Copyright 2018, Elsevier. D) To control MRSA at implant interfaces, encapsulated cells were genetically engineered to elute antibacterial lysotaphin in response to TLR stimulation, which E) prevented MRSA biofilm development.…”

“…[44] VLPs are strongly immunogenic due to their encapsulation of CpG-containing nucleic acids that activate inflammation through TLR signaling. [44] VLPs are strongly immunogenic due to their encapsulation of CpG-containing nucleic acids that activate inflammation through TLR signaling.…”