Comparison of clonotypic IgH repertoires in the pronephros and spleen of a Teleost fish upon sytemic viral infection

A barcoded 5' RACE sequencing approach used to characterize modifications of the complete IgHμ repertoire, giving access to the use of VH in the expressed V(D)J rearrangements and clonal diversity. Viral infection led to important modifications in B cells of the pronephros, implicating several VH subgroups after primary infection. Modest changes persisted five months later, leading to "public" clonal expansions (cad shared by all individuals). the public IgM response implicating the genes ighv1-18 and ighj5, described previously in the spleen, was also observed in the pronephros of the infected fish. However, distribution of the most frequent clonotypes showed that the B cells of the pronephros and the spleen make up distinct compartments. Interestingly, after the boost, the frequency of the anti-VHSV clonotypes decreased in both the pronephros and the spleen, raising new questions on the circulation of B cells.

A better monitoring of B cell response kinetics in lympohoid tissues will be an essential step to understanding B memory an plasmocyte formation mechanisms in fish.

Scientific Contact:

• Pierre Boudinot