B Cells At Work: The Makers of Antibodies, Day 15

In adaptive immunity, B cells are architects of humoral defense. Their journey from naïve B cell to antibody-secreting plasma cell is highly regulated. 

𝗙𝗿𝗼𝗺 𝗔𝗰𝘁𝗶𝘃𝗮𝘁𝗶𝗼𝗻 𝘁𝗼 𝗣𝗹𝗮𝘀𝗺𝗮 𝗖𝗲𝗹𝗹𝘀 
𝘈𝘯𝘵𝘪𝘨𝘦𝘯 𝘌𝘯𝘤𝘰𝘶𝘯𝘵𝘦𝘳 Naïve B cells recognize native antigen via their B cell receptor (BCR), often internalizing and presenting fragments to helper T cells [1]. 

𝘛 𝘊𝘦𝘭𝘭 𝘏𝘦𝘭𝘱  CD4⁺ T follicular helper cells provide critical co-stimulation through CD40–CD40L interactions and cytokines (IL-4, IL-21), driving B cell proliferation and class switching [2]. 

𝘎𝘦𝘳𝘮𝘪𝘯𝘢𝘭 𝘊𝘦𝘯𝘵𝘦𝘳 𝘙𝘦𝘢𝘤𝘵𝘪𝘰𝘯  Within secondary lymphoid tissues, B cells undergo somatic hypermutation and affinity maturation, refining their antibody specificity. 

𝘋𝘪𝘧𝘧𝘦𝘳𝘦𝘯𝘵𝘪𝘢𝘵𝘪𝘰𝘯  The outcome is either long-lived plasma cells, producing antibodies for years, or memory B cells, ensuring rapid responses upon re-exposure. 

𝗚𝗲𝗿𝗺𝗮𝗻 𝗖𝗼𝗻𝘁𝗿𝗶𝗯𝘂𝘁𝗶𝗼𝗻𝘀 
Thomas Winkler (Erlangen): Investigated genetic recombination processes essential for B cell receptor diversity [3]. 
Hedda Wardemann (Heidelberg): Focuses on B cell fate decisions during vaccination, providing key insights into germinal center and plasmablast responses [4]. 
Klaus Rajewsky (Berlin): Pioneered conditional knockout mouse models to study B cell biology and germinal center dynamics [5]. 

𝗕 𝗖𝗲𝗹𝗹𝘀 𝗶𝗻 𝗜𝗺𝗺𝘂𝗻𝗼𝘁𝗵𝗲𝗿𝗮𝗽𝘆 
Engineered B cells could, in theory, serve as ´living antibody factories´, and currently engineered as monoclonals and bispecifics. 

𝗦𝗽𝗲𝗰𝘂𝗹𝗮𝘁𝗶𝘃𝗲 𝗛𝘆𝗽𝗼𝘁𝗵𝗲𝘀𝗶𝘀 
If CAR-T and CAR-NK represent cellular ´weapons´, could CAR-B cells be engineered as modular antibody factories, secreting highly specific immunoglobulins directly in patients? Such a strategy might 𝘣𝘺𝘱𝘢𝘴𝘴 𝘳𝘦𝘱𝘦𝘢𝘵𝘦𝘥 𝘢𝘯𝘵𝘪𝘣𝘰𝘥𝘺 𝘪𝘯𝘧𝘶𝘴𝘪𝘰𝘯𝘴 𝘢𝘯𝘥 𝘤𝘳𝘦𝘢𝘵𝘦 𝘢 𝘴𝘦𝘭𝘧-𝘳𝘦𝘯𝘦𝘸𝘪𝘯𝘨 𝘵𝘩𝘦𝘳𝘢𝘱𝘦𝘶𝘵𝘪𝘤 𝘳𝘦𝘴𝘦𝘳𝘷𝘰𝘪𝘳. 

Stay tuned for 𝗗𝗮𝘆 𝟭𝟲: 𝗧 𝗛𝗲𝗹𝗽𝗲𝗿 (𝗖𝗗𝟰+) 𝗖𝗲𝗹𝗹𝘀: 𝗖𝗼𝗻𝗱𝘂𝗰𝘁𝗼𝗿𝘀 𝗼𝗳 𝘁𝗵𝗲 𝗜𝗺𝗺𝘂𝗻𝗲 𝗢𝗿𝗰𝗵𝗲𝘀𝘁𝗿𝗮 

𝗥𝗲𝗳𝗲𝗿𝗲𝗻𝗰𝗲𝘀 
1. DOI: 10.1038/nri2454 
2. DOI: 10.1146/annurev-immunol-031210-101400 
3. https://www.ncbi.nlm.nih.gov/books/NBK27113/ 
4. https://www.dkfz.de/en/b-cell-immunology 
5. https://doi.org/10.1172/JCI118828   

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