Hookworm infection: Toward development of safe and effective peptide vaccines

Next-generation immunotherapeutic strategy and clinical advances of vaccines against nicotine addiction

Smoking causes death of millions of people every year. However, available therapies for nicotine addiction are partially effective and exhibit frequent side effects. Thus vaccines targeted at drug nicotine not brain offer a promising strategy to treat nicotine addiction. They cannot pass blood-brain barrier, avoiding serious side effects relevant with central nervous system. The specific nicotine antibody produced by vaccines would convert to complex after combined with nicotine in serum, decreasing or even blocking the distribution of nicotine in brain. This review summarizes the pre-clinical and clinical advances of nicotine vaccines and then addresses future directions of nicotine vaccine and the practical aspects of deployments.

The impact of multiple infections and community knowledge on engagement with a historical deworming programme: hookworm and Ascaris in Jamaica, 1913-1936

INTRODUCTION

Community engagement with public health efforts often depends on existing knowledge of a health issue.

METHODS

Here, qualitative analysis of archival material from the Jamaica Hookworm Commission (1919-1936) and quantitative analysis of prevalence data are used to assess knowledge of and ecological interactions between different helminths during a historical hookworm eradication campaign.

RESULTS

Archival sources demonstrate that Jamaicans were familiar with Ascaris lumbricoides. Surveys revealed a high prevalence of hookworm (62% of individuals infected), Ascaris (30%) and Trichuris trichiura (32%) in communities targeted for hookworm control. Community prevalence of Trichuris was positively associated with the prevalence of Ascaris and hookworm. Many individuals were infected with more than one parasite. At an individual level, data from hospital patients and soldiers showed significant associations between all three parasites. The co-occurrence of hookworm and Ascaris, alongside folk treatment of Ascaris with the same plant used by the Hookworm Commission (Chenopodium ambrisoides) to treat hookworm, made biomedical claims about hookworm credible and biomedical treatment more acceptable. Expulsions of Ascaris following treatment also provided dramatic proof of the effectiveness of treatment, further facilitating engagement.

DISCUSSION/CONCLUSION

Knowledge of Ascaris and other helminths directly shaped engagement with hookworm treatment, demonstrating how folk medical knowledge, grounded in the biology of the worms, aided a biomedical public health program.

Helminth induced monocytosis conveys protection from respiratory syncytial virus infection in mice

BACKGROUND

Respiratory syncytial virus (RSV) infection in infants is a major cause of viral bronchiolitis and hospitalisation. We have previously shown in a murine model that ongoing infection with the gut helminth Heligmosomoides polygyrus protects against RSV infection through type I interferon (IFN-I) dependent reduction of viral load. Yet, the cellular basis for this protection has remained elusive. Given that recruitment of mononuclear phagocytes to the lung is critical for early RSV infection control, we assessed their role in this coinfection model.

METHODS

Mice were infected by oral gavage with H. polygyrus. Myeloid immune cell populations were assessed by flow cytometry in lung, blood and bone marrow throughout infection and after secondary infection with RSV. Monocyte numbers were depleted by anti-CCR2 antibody or increased by intravenous transfer of enriched monocytes.

RESULTS

H. polygyrus infection induces bone marrow monopoiesis, increasing circulatory monocytes and lung mononuclear phagocytes in a IFN-I signalling dependent manner. This expansion causes enhanced lung mononuclear phagocyte counts early in RSV infection that may contribute to the reduction of RSV load. Depletion or supplementation of circulatory monocytes prior to RSV infection confirms that these are both necessary and sufficient for helminth induced antiviral protection.

CONCLUSIONS

H. polygyrus infection induces systemic monocytosis contributing to elevated mononuclear phagocyte numbers in the lung. These cells are central to an anti-viral effect that reduces the peak viral load in RSV infection. Treatments to promote or modulate these cells may provide novel paths to control RSV infection in high risk individuals.

Hookworm genomics: dusk or dawn?

Hookworms are parasites, closely related to the model nematode Caenorhabditis elegans, that are a major economic and health burden worldwide. Primarily three hookworm species (Necator americanus, Ancylostoma duodenale, and Ancylostoma ceylanicum) infect humans. Another 100 hookworm species from 19 genera infect primates, ruminants, and carnivores. Genetic data exist for only seven of these species. Genome sequences are available from only four of these species in two genera, leaving 96 others (particularly those parasitizing wildlife) without any genomic data. The most recent hookworm genomes were published 5 years ago, leaving the field in a dusk. However, assembling genomes from single hookworms may bring a new dawn. Here we summarize advances, challenges, and opportunities for studying these neglected but important parasitic nematodes.