““The way immunity works is that one's immune system initially learns about a new pathogen when antigen presenting cells (APCs) carry an antigen (fragment of a pathogen) back to your B memory cells, which live in your lymph system. The APC also tells you B cell where it found the antigen. An antigen could be a spike protein, or some other protein in/on the virus, or it could be something else like an oligosaccharide. Each B cell that receives an APC with a payload will try to construct an antigen-specific immunoglobulin (antibody) that should match that antigen fragment. Those antibodies will have two prongs that can grab the pathogen by that fragment, and they will have one opposing prong that will bind to any of several passing immune cells, such as T cells, which will destroy the antibody and its payload.”

The initial claim that APCs carry antigens back to B memory cells in the lymph system is incorrect. APCs such as dendritic cells, macrophages, and B cells themselves present antigens primarily to T cells, not directly to B memory cells. B cells recognize antigens through their B cell receptors independently and can also act as APCs to T helper cells.cwoer.ccbcmd.educwoer.ccbcmd.eduThe Adaptive Immune System: Antigen-Presenting Cells (APCs)sciencedirect.comsciencedirect.comAntigen Presenting Cell+1 more

The statement that APCs "tell" B cells where they found the antigen is a misunderstanding; antigen presentation involves displaying processed antigen fragments on MHC molecules to T cells, not communicating location information to B cells.cwoer.ccbcmd.educwoer.ccbcmd.eduThe Adaptive Immune System: Antigen-Presenting Cells (APCs)sciencedirect.comsciencedirect.comAntigen Presenting Cell

Antigens can indeed be proteins like spike proteins or other molecules such as oligosaccharides; this part is accurate.cwoer.ccbcmd.educwoer.ccbcmd.eduThe Adaptive Immune System: Antigen-Presenting Cells (APCs)sciencedirect.comsciencedirect.comAntigen Presenting Cell

The description of B cells constructing antigen-specific immunoglobulins (antibodies) that match the antigen fragment is broadly correct. However, naive B cells recognize native antigens directly via their B cell receptors before differentiating into plasma cells that secrete antibodies.library.fiveable.melibrary.fiveable.meAntigen-Presenting Cells (APCs) - (Anatomy and Physiology I)+1 more

The explanation of antibody structure is partially inaccurate. Antibodies have two identical antigen-binding sites (prongs) that bind the antigen, but the "one opposing prong" that binds immune cells is a mischaracterization. The Fc region of antibodies binds Fc receptors on immune effector cells (including some T cells), but T cells do not typically destroy antibodies; rather, Fc receptor-bearing cells like macrophages or NK cells mediate antibody-dependent cellular cytotoxicity or phagocytosis.cwoer.ccbcmd.educwoer.ccbcmd.eduThe Adaptive Immune System: Antigen-Presenting Cells (APCs)sciencedirect.comsciencedirect.comAntigen Presenting Cell

The claim that T cells destroy the antibody and its payload is misleading. Cytotoxic T cells kill infected host cells presenting antigen via MHC I but do not destroy free antibodies. Antibody clearance involves other mechanisms such as phagocytosis by macrophages.cwoer.ccbcmd.educwoer.ccbcmd.eduThe Adaptive Immune System: Antigen-Presenting Cells (APCs)sciencedirect.comsciencedirect.comAntigen Presenting Cell