B cell chronic lymphocytic leukemia (CLL) is a disease of expanding monoclonal B cells whose B cell receptor (BCR) mutational status defines 2 subgroups; patients with mutated BCRs have a more favorable prognosis than those with unmutated BCRs. CLL B cells express a restricted BCR repertoire including antibodies with quasi-identical complementarity-determining region 3 (CDR3), which suggests specific antigen recognition. The antigens recognized by CLL antibodies may include autoantigens since about half of CLL B cells produce autoreactive antibodies. However, the distribution of autoreactive antibodies between Ig heavy-chain variable–unmutated (IgV-unmutated) CLL (UM-CLL) and IgV-mutated CLL (M-CLL) is unknown. To determine the role of antibody reactivity and the impact of somatic hypermutation (SHM) on CLL antibody specificity, we cloned and expressed in vitro recombinant antibodies from M- and UM-CLL B cells and tested their reactivity by ELISA. We found that UM-CLL B cells expressed highly polyreactive antibodies whereas most M-CLL B cells did not. When mutated nonautoreactive CLL antibody sequences were reverted in vitro to their germline counterparts, they encoded polyreactive and autoreactive antibodies. We concluded that both UM-CLLs and M-CLLs originate from self-reactive B cell precursors and that SHM plays an important role in the development of the disease by altering original BCR autoreactivity.
Maxime Hervé, Kai Xu, Yen-Shing Ng, Hedda Wardemann, Emilia Albesiano, Bradley T. Messmer, Nicholas Chiorazzi, Eric Meffre
The Editorial Board will only consider comments that are deemed relevant and of interest to readers. The Journal will not post data that have not been subjected to peer review; or a comment that is essentially a reiteration of another comment.