Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
B-1 cell
Introduction
B-1 cells are B cells that express CD5, which can bind to another B cell surface protein, CD72. CD5-CD72 is thought to mediate B cell-B cell interaction. B-1 cells express IgM in greater quantities than IgG and its receptors show polyspecificity, meaning that they have low affinities for many different antigens, but have a preference for other immunoglobulins, self antigens and common bacterial polysaccharides. B-1 cells are present in low numbers in the lymph nodes and spleen and are instead found predominantly in the peritoneal and pleural cavities. B-1 cells generate diversity mainly via recombinatorial recombination (there is a preferential recombination between D-proximal VH gene segments). B-1 cells are first produced in the fetus, unlike conventional B-2 cells that are produced after birth and replaced in the bone marrow.
Isolation of peritoneal B1 cells
Isolation of peritoneal B1 cells
In research laboratories, B1 B cells can be easily isolated from a mouse by injecting cell media or PBS into the peritoneal cavity of the mouse and then draining it off via a technique mirroring diagnostic peritoneal lavage. Cells can be identified and placed into 2 categories “B1a” or B1b” using multi-colour Flow cytometry looking for surface expression of CD19, B220, and CD5. B1a expresses high CD5 level, while B1b expresses low CD5 to almost-absent levels; both are CD19+ and B220+.
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]