Evolutionary dynamics of human and avian metapneumoviruses

Abstract

Human (HMPV) and avian (AMPV) metapneumoviruses are closely related viruses that cause respiratory tract illnesses in humans and birds, respectively. Although HMPV was first discovered in 2001, retrospective studies have shown that HMPV has been circulating in humans for at least 50 years. AMPV was first isolated in the 1970s, and can be classified into four subgroups, A-D. AMPV subgroup C is more closely related to HMPV than to any other AMPV subgroup, suggesting that HMPV has emerged from AMPV-C upon zoonosis. Presently, at least four genetic lineages of HMPV circulate in human populations -A1, A2, B1 and B2 -of which lineages A and B are antigenically distinct. We used a Bayesian Markov Chain Monte Carlo (MCMC) framework to determine the evolutionary and epidemiological dynamics of HMPV and AMPV-C. The rates of nucleotide substitution, relative genetic diversity and time to the most recent common ancestor (TMRCA) were estimated using large sets of sequences of the nucleoprotein, the fusion protein and attachment protein genes. The sampled genetic diversity of HMPV was found to have arisen within the past 119-133 years, with consistent results across all three genes, while the TMRCA for HMPV and AMPV-C was estimated to have existed around 200 years ago. The relative genetic diversity observed in the four HMPV lineages was low, most likely reflecting continual population bottlenecks, with only limited evidence for positive selection. INTRODUCTIONHuman metapneumovirus (HMPV) is a respiratory pathogen that was first described in 2001 (van den Hoogen et al., 2001). HMPV causes respiratory illnesses ranging from mild upper respiratory symptoms to severe lower respiratory tract disease (van den Hoogen et al., 2001(van den Hoogen et al., , 2003Williams et al., 2004). HMPV is an enveloped, non-segmented, negative-strand RNA virus and was classified as a member of the family Paramyxoviridae, the subfamily Pneumovirinae, the genus Metapneumovirus. HPMV seroprevalence in the human population reaches 100 % by the age of five (van den Hoogen et al., 2001). Experimental HMPV infections in macaques have been shown to induce transient protection , which is in agreement with relatively frequent occurrences of reinfection in humans (Ebihara et al., 2004). HMPV can be divided in two main genetic lineages (A and B), each consisting of at least two sublineages -A1, A2, B1 and B2 (van den Hoogen et al., 2004). Annual circulation of all four lineages has been observed worldwide, with reports of a predominating strain changing on a yearly basis in some studies, but not in others (Galiano et al., 2006;Sloots et al., 2006;van den Hoogen et al., 2004).The only other member of the genus Metapneumovirus is avian metapneumovirus (AMPV). AMPV has been found to infect domestic poultry worldwide, causing acute respiratory infections (Cook, 2000b). AMPVs have been classified into four subgroups, A through to D (BayonAuboyer et al., 1999;Eterradossi et al., 1995;Juhasz & Easton, 1994;Seal, 1998). AMPV subgroups A and B were first detected in...

Human Metapneumovirus: Lessons Learned over the First Decade

“…Investigations of the evolutionary dynamics of HMPV and AMPV-C, using G, F, and N nucleotide sequences, demonstrated higher substitution rates for the G gene genes (56,259). Such high evolutionary rates are not uncommon for RNA viruses (120).…”

Aberrant T cell immunity triggered by human Respiratory Syncytial Virus and human Metapneumovirus infection

“…1 Genomic and phylogenic analyses suggest that hMPV diverged from avian MPV, a virus that causes serious respiratory diseases in chickens. [15][16][17] Infection caused by hMPV presents a similar symptomatology as other respiratory viruses such as hRSV, parainfluenza virus and influenza, 18 whereby the diagnosis is difficult. Symptoms of hMPV include rhinorrhea, cough, acute otitis media, fever, and, less frequently, conjunctivitis, rash, diarrhea and vomiting.…”

Fusion protein is the main determinant of metapneumovirus host tropism

“…As there is a wider variety of AMPV subgroups compared with HMPV, it has been hypothesized that the direction of transmission was from birds to humans (de Graaf et al, 2008b). Therefore, it is of interest that HMPV did not replicate efficiently in QT6, QT35 (data not shown) and CEF cells (van den Hoogen et al, 2001).…”

“…AMPVs have been classified into four subgroups, A-D (Bayon-Auboyer et al, 1999;Eterradossi et al, 1995;Juhasz & Easton, 1994;Seal, 1998), and AMPV-C is more closely related to HMPV than the other AMPV subgroups (Govindarajan & Samal, 2004Govindarajan et al, 2004). It has been demonstrated that HMPV probably originated from birds and that a common ancestor of AMPV-C and HMPV existed around 200 years ago (de Graaf et al, 2008b).…”