PT - JOURNAL ARTICLE AU - Razvan C. Stan AU - Katia S. Françoso AU - Rubens P.S. Alves AU - Luís Carlos S. Ferreira AU - Irene S. Soares AU - Maristela M. de Camargo TI - Febrile temperatures increase <em>in vitro</em> antibody affinity for malaria and dengue antigens AID - 10.1101/345553 DP - 2018 Jan 01 TA - bioRxiv PG - 345553 4099 - http://biorxiv.org/content/early/2018/06/12/345553.short 4100 - http://biorxiv.org/content/early/2018/06/12/345553.full AB - Fever is a regulated elevation in the body setpoint temperature and may arise as a result of infectious and noninfectious causes. While beneficial in modulating immune responses to infection, the potential of febrile temperatures in regulating antigen binding affinity to antibodies has not been explored. We have investigated this process under in vitro conditions using selected malaria or dengue antigens and specific monoclonal antibodies, and observed a marked increase in the affinity of these antibody-antigen complexes at 40°C, compared to physiological (37°C) or pathophysiological temperatures (42°C). Induced thermal equilibration of the protein partners at these temperatures, prior to measurements, further increased their binding affinity. These results may indicate an unexpected beneficial and adaptive role for fever in vivo, and highlight the positive role of thermal priming in enhancing protein-protein affinity for samples of scarce availability.