Whose Turn? Chromosome Research and the Study of the Human Genome

A common account sees the human genome sequencing project of the 1990s as a “natural outgrowth” of the deciphering of the double helical structure of DNA in the 1950s. The essay aims to complicate this neat narrative by putting the spotlight on the field of human chromosome research that flourished at the same time as molecular biology. It suggests that we need to consider both endeavors – the human cytogeneticists who collected samples and looked down the microscope and the molecular biologists who probed the molecular mechanisms of gene function – to understand the rise of the human genome sequencing project and the current genomic practices. In particular, it proposes that what has often been described as the “molecularization” of cytogenetics could equally well be viewed as the turn of molecular biologists to human and medical genetics – a field long occupied by cytogeneticists. These considerations also have implications for the archives that are constructed for future historians and policy makers.     

Characterising the Mucosal and Systemic Immune Responses to Experimental Human Hookworm Infection

The mucosal cytokine response of healthy humans to parasitic helminths has never been reported. We investigated the systemic and mucosal cytokine responses to hookworm infection in experimentally infected, previously hookworm naive individuals from non-endemic areas. We collected both peripheral blood and duodenal biopsies to assess the systemic immune response, as well as the response at the site of adult worm establishment. Our results show that experimental hookworm infection leads to a strong systemic and mucosal Th2 (IL-4, IL-5, IL-9 and IL-13) and regulatory (IL-10 and TGF-β) response, with some evidence of a Th1 (IFN-γ and IL-2) response. Despite upregulation after patency of both IL-15 and ALDH1A2, a known Th17-inducing combination in inflammatory diseases, we saw no evidence of a Th17 (IL-17) response. Moreover, we observed strong suppression of mucosal IL-23 and upregulation of IL-22 during established hookworm infection, suggesting a potential mechanism by which Th17 responses are suppressed, and highlighting the potential that hookworms and their secreted proteins offer as therapeutics for human inflammatory diseases.