9 research outputs found
Evolution of predator dispersal in relation to spatio-temporal prey dynamics : how not to get stuck in the wrong place!
Peer reviewedPublisher PD
HLA Class I Binding of HBZ Determines Outcome in HTLV-1 Infection
CD8(+) T cells can exert both protective and harmful effects on the virus-infected host. However, there is no systematic method to identify the attributes of a protective CD8(+) T cell response. Here, we combine theory and experiment to identify and quantify the contribution of all HLA class I alleles to host protection against infection with a given pathogen. In 432 HTLV-1-infected individuals we show that individuals with HLA class I alleles that strongly bind the HTLV-1 protein HBZ had a lower proviral load and were more likely to be asymptomatic. We also show that in general, across all HTLV-1 proteins, CD8(+) T cell effectiveness is strongly determined by protein specificity and produce a ranked list of the proteins targeted by the most effective CD8(+) T cell response through to the least effective CD8(+) T cell response. We conclude that CD8(+) T cells play an important role in the control of HTLV-1 and that CD8(+) cells specific to HBZ, not the immunodominant protein Tax, are the most effective. We suggest that HBZ plays a central role in HTLV-1 persistence. This approach is applicable to all pathogens, even where data are sparse, to identify simultaneously the HLA Class I alleles and the epitopes responsible for a protective CD8(+) T cell response
Can the enemy release hypothesis explain the success of invasive alien predators and parasitoids?
Biological invasions are ecologically and economically costly. Understanding the major
mechanisms that contribute to an alien species becoming invasive is seen as essential for limiting the
effects of invasive alien species. However, there are a number of fundamental questions that need
addressing such as why some communities are more vulnerable to invasion than others and, indeed,
why some alien species become widespread and abundant. The enemy release hypothesis (ERH) is
widely evoked to explain the establishment and proliferation of an alien species. ERH predicts that an
alien species introduced to a new region should experience a decrease in regulation by natural enemies
which will lead to an increase in the distribution and abundance of the alien species. At the centre of
this theory is the assumption that natural enemies are important regulators of populations.
Additionally, the theory implies that such natural enemies have a stronger regulatory effect on native
species than they do on alien species in the introduced range, and this disparity in enemy regulation
results in increased population growth of the alien species. However, empirical evidence for the role of
the ERH in invasion success is lacking, particularly for invertebrates. Many studies equate a reduction
in the number of natural enemies associated with an alien species to release without studying
population effects. Further insight is required in relation to the effects of specific natural enemies on
alien and native species (particularly their ability to regulate populations). We review the role of
ecological models in exploring ERH. We suggest that recent developments in molecular technologies
offer considerable promise for investigating ERH in a community context