Cell-to-cell transmission of retroviruses: Innate immunity and interferon-induced restriction factors

Clare Jolly

doi:10.1016/j.virol.2010.12.031

Abstract

It has been known for some time that retroviruses can disseminate between immune cells either by conventional cell-free transmission or by directed cell-to-cell spread. Over the past few years there has been increasing interest in how retroviruses may use cell-to-cell spread to promote more rapid infection kinetics and circumvent humoral immunity. Effective humoral immune responses are intimately linked with innate immunity and the interplay between retroviruses and innate immunity is a rapidly expanding area of research that has been advanced considerably by the identification of cellular restriction factors that provide barriers to retroviral infection. The effect of innate immunity and restriction factors on retroviral cell-to-cell spread has been comparatively little studied; however recent work suggests this maybe changing. Here I will review some recent advances in what is a budding area of retroviral research.

Highlights

Wohl Virion Centre and MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, W1T 4JF, UK article info
Direct cell-to-cell spread of the human retroviruses HIV type-1 (HIV-1) and HTLV-1 (Human T-lymphotropic Virus Type-1) predominantly takes place at specialized contact-induced structures known as virological synapses (VS) that act as “hot-spots” for virus transmission (Igakura et al, 2003; Jolly et al, 2004; Jolly and Sattentau, 2002; McDonald et al, 2003)
It has generally been assumed that cell-to-cell spread of retroviruses at VS might allow escape from neutralizing antibodies either by limiting the window of opportunity for antibody to engage viral antigens, or by providing a relatively protected domain at cell-to-cell interfaces that could physically exclude the relative bulk of antibodies from gaining access to virions before they attach and enter to target cells

Summary

Introduction

Wohl Virion Centre and MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, W1T 4JF, UK article info. Restriction factors are cellular proteins that are constitutively expressed or induced by type-1 interferon and are able to limit viral replication by targeting specific steps of the retroviral viral life cycle (reviewed in (Wolf and Goff, 2008)) rendering cells less permissive or non-permissive to infection.

Results

Conclusion