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Influence of recombination on acquisition and reversion of immune escape and compensatory mutations in HIV-1

Nagaraja, Pradeep and Alexander, Helen K and Bonhoeffer, Sebastian and Dixit, Narendra M (2016) Influence of recombination on acquisition and reversion of immune escape and compensatory mutations in HIV-1. In: EPIDEMICS, 14 . pp. 11-25.

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Official URL: http://dx.doi.org/10.1016/j.epidem.2015.09.001

Abstract

Following transmission, HIV-1 adapts in the new host by acquiring mutations that allow it to escape from the host immune response at multiple epitopes. It also reverts mutations associated with epitopes targeted in the transmitting host but not in the new host. Moreover, escape mutations are often associated with additional compensatory mutations that partially recover fitness costs. It is unclear whether recombination expedites this process of multi-locus adaptation. To elucidate the role of recombination, we constructed a detailed population dynamics model that integrates viral dynamics, host immune response at multiple epitopes through cytotoxic T lymphocytes, and viral evolution driven by mutation, recombination, and selection. Using this model, we compute the expected waiting time until the emergence of the strain that has gained escape and compensatory mutations against the new host's immune response, and reverted these mutations at epitopes no longer targeted. We find that depending on the underlying fitness landscape, shaped by both costs and benefits of mutations, adaptation proceeds via distinct dominant pathways with different effects of recombination, in particular distinguishing escape and reversion. When adaptation at a single epitope is involved, recombination can substantially accelerate immune escape but minimally affects reversion. When multiple epitopes are involved, recombination can accelerate or inhibit adaptation depending on the fitness landscape. Specifically, recombination tends to delay adaptation when a purely uphill fitness landscape is accessible at each epitope, and accelerate it when a fitness valley is associated with each epitope. Our study points to the importance of recombination in shaping the adaptation of HIV-1 following its transmission to new hosts, a process central to T cell-based vaccine strategies. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.

Item Type: Journal Article
Publication: EPIDEMICS
Publisher: ELSEVIER SCIENCE BV
Additional Information: Copy right for this article belongs to the ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Keywords: Multi-locus adaptation; Immune escape; Cytotoxic T lymphocytes; Waiting time; Fitness landscape
Department/Centre: Division of Mechanical Sciences > Chemical Engineering
Date Deposited: 02 Apr 2016 06:04
Last Modified: 02 Apr 2016 06:04
URI: http://eprints.iisc.ac.in/id/eprint/53584

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