Dataset supporting "Functional antibodies exhibit light chain coherence"

The vertebrate adaptive immune system modifies the genome of individual B cells to encode antibodies binding particular antigens. In most mammals, antibodies are composed of a heavy and a light chain which are sequentially generated by recombination of V, D (for heavy chains), J, and C gene segments. Each chain contains three complementarity-determining regions (CDR1-3), contributing to antigen specificity. Certain heavy and light chains are preferred for particular antigens. We considered pairs of B cells sharing the same heavy chain V gene and CDRH3 amino acid sequence and isolated from different donors, also known as public clonotypes. We show that for naive antibodies (not yet adapted to antigens), the probability that they use the same light chain V gene is ~10%, whereas for memory (functional) antibodies it is ~80%. This property of functional antibodies is a phenomenon we call <em>light chain coherence</em>. We also observe it when similar heavy chains recur <em>within</em> a donor. Thus, though naive antibodies appear to recur by chance, the recurrence of functional antibodies reveals surprising constraint and determinism in the processes of V(D)J recombination and immune selection. For most functional antibodies, the heavy chain determines the light chain.

脊椎动物适应性免疫系统（vertebrate adaptive immune system）会对单个B细胞的基因组进行修饰，以编码能够特异性结合特定抗原的抗体。在大多数哺乳动物体内，抗体由重链与轻链组成，二者分别通过V、D（仅重链携带D基因片段）、J及C基因片段的重排过程依次合成。每条肽链均包含3个互补决定区（complementarity-determining regions，CDR1-3），这些区域是决定抗原结合特异性的核心区域。特定抗原往往偏好识别特定的重链-轻链组合。
我们选取了共享同一重链V基因与CDRH3氨基酸序列、且分离自不同供体的B细胞对，这类细胞对也被称为公共克隆型（public clonotypes）。研究结果表明，对于初始抗体（尚未接触过抗原的抗体）而言，它们使用相同轻链V基因的概率约为10%；而对于记忆性（功能性）抗体来说，该概率可达约80%。我们将功能性抗体的这一特性命名为轻链一致性（light chain coherence）。此外，在单个供体内重复出现的相似重链中，我们也观察到了这一现象。
由此可见，尽管初始抗体的出现看似随机，但功能性抗体的重复出现揭示了V(D)J重排（V(D)J recombination）与免疫选择（immune selection）过程中存在出人意料的约束性与决定性规律。对于绝大多数功能性抗体而言，重链决定了轻链的选择。