Illuminating the host – How RNAi screens shed light on host‐pathogen interactions

Abstract

Over millions of years pathogens have coevolved with their respective hosts utilizing host cell functions for survival and replication. Despite remarkable progress in developing antibiotics and vaccination strategies in the last century, infectious diseases still remain a severe threat to human health. Meanwhile, genomic research offers a new era of data‐generating platforms that will dramatically enhance our knowledge of pathogens and the diseases they cause. Improvements in gene knockdown studies by RNA interference (RNAi) combined with recent developments in instrumentation and image analysis enable the use of high‐throughput screening approaches to elucidate host gene functions exploited by pathogens. Although only a few RNAi‐based screens focusing on host genes have been reported so far, these studies have already uncovered hundreds of genes not previously known to be involved in pathogen infection. This review describes recent progress in RNAi screening approaches, highlighting both the limitations and the tremendous potential of RNAi‐based screens for the identification of essential host cell factors during infection.

Hierarchies of Host Factor Dynamics at the Entry Site of Shigella flexneri during Host Cell Invasion

“…Microscopy-based high-throughput screens have become widely popular to investigate host-pathogen interactions in single cells (33). For the most part, they are performed as endpoint assays yielding only a single time point of the investigated events.…”

“…For the most part, they are performed as endpoint assays yielding only a single time point of the investigated events. Screens performed by different research groups investigating the same phenomenon have yielded different, even opposing, results (33). One possible explanation lies in the limitations of the assays used for the studies.…”

New technology and resources for cryptococcal research

“…In addition, constitutive RNAi can be used for the study of essential genes since expression is merely reduced rather than eliminated and has a distinct advantage over conditional modalities such as temperature-sensitive mutations in that retained phenotypes after RNAi suppression are likely to be unrelated to the targeted mutation because of continual suppression during all stages of growth. Recently the RNAi system has been used for high-throughput screens in cryptococcal genome analysis and to identify genes involved in host-pathogen interactions (Falschlehner et al, 2010; Prudencio and Lehmann, 2009). …”

From experimental setup to bioinformatics: An RNAi screening platform to identify host factors involved in HIV‐1 replication

“…Although each of the three high-throughput screens published thus far reported a large number of potential host cell factors, there is only little overlap between the different sets [7][8][9]. This might be explained by differences in the individual experimental conditions, such as the use of distinct cell lines, siRNA libraries or virus strains, all of which could have significantly affected the results.…”

“…This might be explained by differences in the individual experimental conditions, such as the use of distinct cell lines, siRNA libraries or virus strains, all of which could have significantly affected the results. Importantly, however, it may also be due to the use of different criteria for defining a "hit" or inconsistencies concerning the techniques applied to validate potential hits [9]. This highlights the need for comparable experimental conditions in further studies and for the selection of consistent analytical methods for future screening approaches.…”