An antiserum which recognizes lipopolysaccharide-reactive B cells in the mouse

Area of Science:

• Immunology
• Cell Biology

Background:

• Lipopolysaccharide (LPS) is a potent B cell activator in certain mouse strains.
• Identifying specific B cell populations involved in LPS response is crucial for understanding immune mechanisms.

Purpose of the Study:

• To generate and characterize antisera that specifically target B cells responsive to LPS.
• To investigate the role of this B cell marker in LPS reactivity and immune responses.

Main Methods:

• Preparation of rabbit antisera against spleen B cells from LPS-high responder mice (C3H/Tif).
• Absorption of antisera with tissues from LPS non-responder mice (C3H/Hej).
• Flow cytometry and complement-mediated cell killing assays to assess B cell reactivity.
• Analysis of B cell marker expression during ontogeny, in different organs, and across various mouse strains.

Main Results:

• Antisera specifically stained and killed a fraction of B cells from LPS high responder strains, but not from non-responder strains.
• The B cell marker's distribution paralleled LPS reactivity across different strains and developmental stages.
• Frequencies of stained cells correlated with previously determined LPS-reactive B cell precursor frequencies.
• The antigen was expressed on LPS-activated B cell blasts but not on non-activated small B cells.

Conclusions:

• A specific B cell marker associated with lipopolysaccharide (LPS) responsiveness has been identified.
• This marker is present on LPS-reactive B cell precursors and activated blasts.
• Targeting this marker can deplete LPS-reactive B cells, offering insights into immune modulation.