Human metapneumovirus induces more severe disease and stronger innate immune response in BALB/c mice as compared with respiratory syncytial virus.

Background: Human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) are members of the Pneumovirinae subfamily of Paramyxoviridae and can cause severe respiratory disease, especially in infants and young children. Some differences in the clinical course of these infections have been described, but there are few comparative data on pathogenesis in humans and animal models. In this study, HMPV and RSV were compared for replication, pathogenesis and immune induction in BALB/c mice infected with equivalent inocula of either virus.

Novel human metapneumovirus sublineage.

In a pediatric surveillance network, 287 (5.1%) of 5,580 specimens from patients with acute respiratory infections tested positive for human metapneumovirus (HMPV). Phylogenetic analysis of N- and F-gene sequences of identified HMPV showed that 30% belonged to a novel phylogenetic cluster.

Pregnancy associated hormones modulate the cytokine production but not the phenotype of PBMC-derived human dendritic cells.

Objective: Dendritic cells (DC) play a central role in initiating and polarizing immune responses. As effects of pregnancy associated hormones on phenotype and function of DC are unknown, our objective was to test the influence of progesterone, beta-estradiol and betaHCG on immature (iDC) and mature (mDC) DC.

Study Design: DC generated from peripheral-blood-monocytes were exposed to different doses of hormones.