Taurine promotes B cell activation by interaction with the V H /V L framework regions of B cell receptor.

Taurine (Tau) is a special sulfur-containing amino acid and has been widely used as a dietary supplement. Although taurine exists in lymphocytes in large quantities, the physiological significance of taurine to modulate human immunity is unknown. In the present study, we first found that taurine regulates the B cell receptor (BCR) mediated signal transduction and induces the B cells activation. The IgG production of mice after OVA immunization was also increased by taurine administration. Moreover, the ITC and SPR analysis have shown that taurine specifically bound to the IgG2a-BCR. The taurine could bind to IgG F(ab') 2 regions via fluorescence spectroscopy analysis. In the molecular docking analysis, taurine bound to the framework regions of variable region of the heavy chains (V H ) and in the light chains (V L ) of IgG2a-BCR. Our results suggested that taurine could improve the activation of B cells by interaction with the V H /V L framework regions of BCR.