10779/crick.11357768.v1 Camila H Coelho Camila H Coelho Pedro Henrique Gazzinelli-Guimaraes Pedro Henrique Gazzinelli-Guimaraes Jennifer Howard Jennifer Howard Emma Barnafo Emma Barnafo Nada AH Alani Nada AH Alani Olga Muratova Olga Muratova Ashley McCormack Ashley McCormack Emily Kelnhofer Emily Kelnhofer Joseph F Urban Joseph F Urban David L Narum David L Narum Charles Anderson Charles Anderson Jean Langhorne Jean Langhorne Thomas B Nutman Thomas B Nutman Patrick E Duffy Patrick E Duffy Chronic helminth infection does not impair immune response to malaria transmission blocking vaccine Pfs230D1-EPA/Alhydrogel® in mice The Francis Crick Institute 2019 H. polygyrus bakeri Helminth intestinal infection Immunoregulation Malaria transmission blocking vaccine P. falciparum Pfs230 Langhorne FC001101 06 Biological Sciences 07 Agricultural and Veterinary Sciences 11 Medical and Health Sciences Virology 2019-12-12 17:36:12 Journal contribution https://crick.figshare.com/articles/journal_contribution/Chronic_helminth_infection_does_not_impair_immune_response_to_malaria_transmission_blocking_vaccine_Pfs230D1-EPA_Alhydrogel_in_mice/11357768 INTRODUCTION: Malaria transmission blocking vaccines (TBV) are innovative approaches that aim to induce immunity in humans against Plasmodium during mosquito stage, neutralizing the capacity of the infected vectors to transmit malaria. Pfs230D1-EPA/Alhydrogel®, a promising protein-protein conjugate malaria TBV, is currently being tested in human clinical trials in areas where P. falciparum malaria is coendemic with helminth parasites. Helminths are complex metazoans that share the master capacity to downregulate the host immune response towards themselves and also to bystander antigens, including vaccines. However, it is not known whether the activity of a protein-based malaria TBV may be affected by a chronic helminth infection. METHODS: Using an experimental murine model for a chronic helminth infection (Heligmosomoides polygyrus bakeri - Hpb), we evaluated whether prior infection alters the activity of Pfs230D1-EPA/Alhydrogel® TBV in mice. RESULTS: After establishment of a chronic infection, characterized by a marked increase of parasite antigen-specific IgG1, IgA and IgE antibody responses, concomitant with an increase of systemic IL-10, IL-5 and IL-6 levels, the Hpb-infected mice were immunized with Pfs230D1-EPA/Alhydrogel® and the vaccine-specific immune response was compared with that in non-infected immunized mice. TBV immunizations induced an elevated vaccine specific-antibody response, however Pfs230D1 specific-IgG levels were similar between infected and uninfected mice at days 15, 25 and 35 post-vaccination. Absolute numbers of Pfs230D1-activated B cells generated in response to the vaccine were also similar among the vaccinated groups. Finally, vaccine activity assessed by reduction of oocyst number in P. falciparum infected mosquitoes was similar between Hpb-infected and immunized mice with non-infected immunized mice. CONCLUSION: Pfs230D1-EPA/Alhydrogel® efficacy is not impaired by a chronic helminth infection in mice.