A Novel Nonhuman Primate Model for Influenza Transmission

Citation: Moncla LH, Ross TM, Dinis JM, Weinfurter JT, Mortimer TD, et al. ( A Novel Nonhuman Primate Model for Influenza Transmission Louise H. Moncla 0 1 Ted M. Ross 0 1 Jorge M. Dinis 0 1 Jason T. Weinfurter 0 1 Tatum D. Mortimer 0 1 Nancy Schultz-Darken 0 1 Kevin Brunner 0 1 Saverio V. Capuano III 0 1 Carissa Boettcher 0 1 Jennifer Post 0 1 Michael Johnson 0 1 Chalise E. Bloom 0 1 Andrea M. Weiler 0 1 Thomas C. Friedrich 0 1 Andrew Pekosz, Johns Hopkins University - Bloomberg School of Public Health, United States of America 0 Current address: Vaccine and Gene Therapy Institute of Florida , Port St. Lucie, Florida , United States of America 1 1 Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, Wisconsin, United States of America, 2 Wisconsin National Primate Research Center, Madison, Wisconsin, United States of America, 3 University of Wisconsin Microbiology Doctoral Training Program, Madison, Wisconsin, United States of America, 4 Center for Vaccine Research, Dept. of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America, 5 Vaccine and Gene Therapy Institute of Florida , Port St. Lucie, Florida , United States of America Studies of influenza transmission are necessary to predict the pandemic potential of emerging influenza viruses. Currently, both ferrets and guinea pigs are used in such studies, but these species are distantly related to humans. Nonhuman primates (NHP) share a close phylogenetic relationship with humans and may provide an enhanced means to model the virological and immunological events in influenza virus transmission. Here, for the first time, it was demonstrated that a human influenza virus isolate can productively infect and be transmitted between common marmosets (Callithrix jacchus), a New World monkey species. We inoculated four marmosets with the 2009 pandemic virus A/California/07/2009 (H1N1pdm) and housed each together with a nave cage mate. We collected bronchoalveolar lavage and nasal wash samples from all animals at regular intervals for three weeks post-inoculation to track virus replication and sequence evolution. The unadapted 2009 H1N1pdm virus replicated to high titers in all four index animals by 1 day post-infection. Infected animals seroconverted and presented human-like symptoms including sneezing, nasal discharge, labored breathing, and lung damage. Transmission occurred in one cohabitating pair. Deep sequencing detected relatively few genetic changes in H1N1pdm viruses replicating in any infected animal. Together our data suggest that human H1N1pdm viruses require little adaptation to replicate and cause disease in marmosets, and that these viruses can be transmitted between animals. Marmosets may therefore be a viable model for studying influenza virus transmission. - Funding: This work was supported by PATH Vaccine Solutions in a sponsored research award to Ted M. Ross. Louise H. Moncla and Tatum D. Mortimer were supported by NIH National Research Service Award T32 GM07215. Jorge M. Dinis was supported by National Science Foundation Graduate Research Fellowship DGE-0718123. This study was conducted in a facility supported in part by NIH grant RR000167/OD011106, which was constructed with additional support from Research Facilities Improvement Program grants RR015459-01 and RR020141-01The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. . These authors contributed equally to this work. Studies of influenza virus transmission, pathogenesis and immunity rely on animal models to understand processes that are difficult or impossible to investigate in humans. Mice, ferrets, guinea pigs and rhesus macaques have all been used to study various aspects of human infection with influenza viruses [1]. For transmission studies, ferrets are a favored model system due to their susceptibility to unadapted human influenza strains, their development of human-like symptoms during infection and their susceptibility to respiratory droplet transmission. However, ferrets are evolutionarily distant from humans, and a lack of reagents makes immunological studies difficult [2]. Nonhuman primates (NHP) have closer immunological and physiological resemblances to humans; a NHP model may therefore provide the closest possible model for immunity to, and transmission of, influenza viruses in humans. Although macaque monkeys have been used in studies of influenza pathogenesis and immunity [1], transmission of influenza viruses between macaques has not been documented, and there is currently no NHP model for influenza transmission studies. The common marmoset (Callithrix jacchus) is an attractive potential model due to its small size and reduced dosing requirements for potential drug and vaccine studies in comparison to macaques. Marmosets are small New World monkeys native to eastern Brazil that breed well in captivity and are already used as models for other viral pathogens, including hepatitis A virus, GB virus B, measles virus, and several hemorrhagic fever and herpesviruses [3]. An understanding of the factors that determine transmissibility of a virus within the human population is indispensible for making informed predictions about the pandemic potential of emerging influenza viruses. Although influenza virus transmission has been studied in a number of models, several questions remain unanswered. The dose required to start a new infection, an important parameter for predicting transmission rates within the human population, is still unknown. Although a few amino acid substitutions have been linked to transmissibility in various influenza subtypes [4], the kinetics by which transmissible variants arise and persist in a population remain unclear. Additionally, the degree to which natural selection may affect transmission between animal hosts is poorly understood. These facets of transmission merit further study because they inform how and why certain influenza viruses are able to emerge and cause pandemics, while others are not. Animal models that mimic human transmission offer a controlled way to study transmission and answer questions, like these, that are impossible to study in humans. Development of a system that is capable of simultaneously modeling human transmission, pathogenesis and immunity would allow combined studies of all of these aspects of influenza infection in a way that is not currently feasible. Here we sought to determine whether a human influenza A virus could cause disease in, and be transmitted between, marmosets. A human H1N1pdm isolate, A/California/07/2009 (CA/07/09), replicated to high titers in all inoculated animals by 1 day post-infection and, in one instance, was transmitted between cohoused animals. Infected marmosets showed several human-like sy (...truncated)