Helminth infection is associated with dampened cytokine responses to viral and bacterial stimulations in Tsimane hunter-horticulturalists

• Published in: bioRxiv 2021-10
• Main Authors: Schneider-Crease, India, Blackwell, Aaron D, Kraft, Thomas S, Melissa Emery Thompson, Ivan Maldonado Suarez, Cummings, Daniel K, Stieglitz, Jonathan, Snyder-Mackler, Noah, Gurven, Michael, Kaplan, Hillard, Trumble, Benjamin C
• Format: Article
• Language: English
• Subjects: Antigens; Colony-stimulating factor; Cytokine storm; Cytokines; Granulocyte-macrophage colony-stimulating factor; Immune response; Infections; Inflammation; Interferon; Interleukin 10; Interleukin 12; Interleukin 13; Interleukin 2; Interleukin 4; Interleukin 5; Interleukin 6; Interleukin 7; Interleukin 8; Leukocytes (eosinophilic); Lipopolysaccharides; Lymphocytes T; Tumor necrosis factor-TNF; Tumor necrosis factor-α; Women
• DOI: 10.1101/2021.09.29.462428

Background: Soil-transmitted helminth (STH) infections can catalyze immunological changes that affect the response to subsequent infections, particularly those that elicit strong inflammatory responses. As globalization heightens the risk that remote communities with high STH prevalence will encounter novel pathogens, understanding how STHs shape immune responses to these downstream infections becomes increasingly crucial. Methodology: We worked with Tsimane forager-horticulturalists in the Bolivian Amazon, where STHs are prevalent. We tested whether STHs and eosinophil levels- most likely indicative of infection in this population- are associated with dampened immune responses to in vitro stimulation with H1N1 and lipopolysaccharide (LPS) antigens. Whole blood samples (n = 179) were treated with H1N1 vaccine and LPS and assayed for 13 cytokines (interferon gamma [INF-γ], interleukin [IL]-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, Granulocyte-macrophage colony-stimulating factor [GM-CSF], and Tumor necrosis factor-α [TNF-α]). We evaluated how STHs and eosinophil levels affected cytokine responses and T helper (Th) 1 and Th2- cytokine suite responses to stimulation. Results: Infection with Ascaris lumbricoides was significantly (p < 0.05) associated with lower response of some cytokines to H1N1 and LPS in women. Eosinophils were significantly negatively associated with some cytokine responses to H1N1 and LPS, with the strongest effects in women, and associated with a reduced Th1- and Th2-cytokine response to H1N1 and LPS in women and men. Conclusions and implications: We find that STHs were associated with dampened cytokine responses to certain viral and bacterial antigens, and suggest that this mitigation of host-induced damage may reduce the incidence of cytokine storms in populations with high STH prevalence. Competing Interest Statement The authors have declared no competing interest.