![]() In contrast, we found that each individual uses the germ-line–encoded library of antibody components in very similar ways.īecause the immune system is shaped by selective pressures at the population and somatic levels ( 9), we observed statistical evidence that the immune system is equally likely to expend energy on expanding nondiversifying VJ combinations (innate action) as it is on expanding diversifying and class-switching VJ combinations (adaptive action). We found that the VH gene repertoire is highly dynamic, and the response in each vaccination is qualitatively different. The dynamic behavior of the immune repertoire in response to the vaccination was analyzed by RT-PCR of heavy chain V (VH) genes followed by DNA sequencing by using the 454 platform. We vaccinated three individuals with approved subunit vaccines designed to confer protection to viral antigens and banked blood samples at multiple time points before and after the vaccinations. The present study set out to dissect the rapid dynamics of the complete human peripheral antibody response against a controlled immune challenge (vaccination), without the a priori notion of cell state markers or functions. Indeed, NGS has enabled unprecedented views into the immune repertoire, as its immune receptor diversity is genetically encoded within a complex collection of lymphocytes ( 3 – 8). Recent advances in next-generation sequencing (NGS) ( 2) have enabled any DNA-encodable assay to produce massive amounts of data. Specifically, stimulation of B-cell immunity results in the synthesis of antibodies that are secreted into the blood stream or into the mucosa as well as the programming of B memory cells that play a crucial role in the generation of rapid protective responses upon reinfection.Ĭurrently, many immunology studies depend on characterizing lymphocyte subsets (e.g., assaying cell-surface receptors) and the ability to correlate them to encoded genetic information ( 1). Adaptive immune responses rely on the continuous selection and amplification of specific clones from an enormous library of immune receptors (antibodies and T cell receptors). Given the acute nature and diversity of infections, the immune system must be capable of rapid recognition of a pathogen, amplification of the response, and subsequent contraction of the response after the resolution of the infection. Its arsenal contains systems that are immediately effective against commonly seen patterns (innate immunity) and systems that are capable of responding to novel invaders (adaptive immunity). The immune system is able to rapidly sense and respond to a vast array of invading organisms. Altogether, this work presents an additional set of tools for profiling the human antibody repertoire and demonstrates characterization of the fast repertoire dynamics through time in multiple individuals responding to an immune challenge. By using combinatorial phage display, we screened selected VH genes paired with their corresponding VL library for affinity against the vaccine antigens. We found the antibody RNA repertoire in each volunteer to be highly dynamic, with each individual displaying qualitatively different response dynamics. Surprisingly, there appeared to be no correlation between the use level of a particular VJ combination and degree of expansion. By analyzing data from 38 separate blood samples across 2 y, we found that the use of the germ-line library of V and J segments is conserved between individuals over time. In the present work, we describe a set of tools for the analysis of antibody repertoires and their application to elucidating the dynamics of the response to viral vaccination in human volunteers. Next-generation DNA sequencing now provides the opportunity to survey this complex and vast repertoire. The adaptive immune system confers protection by generating a diverse repertoire of antibody receptors that are rapidly expanded and contracted in response to specific targets. ![]()
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