Articles of Significant Interest Selected from This Issue by the Editors

doi:10.1128/IAI.00207-08

DOI: 10.1128/IAI.00207-08

Pseudomonas aeruginosa Biofilms on Cultured Epithelial Cells: a Lifestyle Influenced by Drugs

Analysis of Pseudomonas aeruginosa biofilm formation in the lungs of patients with cystic fibrosis has been hampered by the lack of model systems. Using a novel biofilm-epithelial cell coculture model, Anderson et al. (p. 1423-1433) performed transcriptional analyses that demonstrated unique biofilm antibiotic responses when biofilms were grown on epithelial cells. Mutational studies of biotic biofilms suggested that tobramycin downregulated bacterial virulence and promoted a biofilm lifestyle. These results indicate that the intense antibiotic therapy used to diminish the microbial burden in the lungs of patients with cystic fibrosis might actually enhance the persistent infection of drug-resistant Pseudomonas aeruginosa biofilms in these patients.

Wheat Germ Cell-Free Protein Synthesis System: a Key Tool for Novel Malaria Vaccine Candidate Discovery

One of the bottlenecks in malaria vaccine research is at the recombinant protein production step and is mainly due to the lack of an efficient methodology to enable preparation of quality proteins. Tsuboi et al. (p. 1702-1708) demonstrate the application of the wheat germ cell-free protein synthesis system for the successful production of Plasmodium falciparum antigens Pfs25, PfCSP, and PfAMA1. The system also proved suitable for use as a parallel approach to produce parasite proteins. Thus, the wheat germ cell-free system may be a key tool for decoding genetic information above and beyond malaria vaccine research.

MyD88 Controls Hypergammaglobulinemia during Bacterial Infection

Toll-like receptors (TLR) are necessary sensors for infections, but their activation has also been suggested to generate autoimmunity. MyD88 is the major adaptor of the TLR signalling pathway. Woods et al. (p. 1657-1667) infected MyD88-deficient mice with Borrelia burgdorferi, expecting to observe negative regulation of the pathogen-induced polyclonal B-cell activation in these animals. However, the infected MyD88-deficient mice developed extreme hypergammaglobulinemia and immunoglobulin M autoantibody production. These results are relevant to the development of new therapies aimed at targeting TLR signalling.

Fetal Responses Influence Outcomes during Maternal Malaria

Placental malaria (PM) due to Plasmodium falciparum causes low birth weight, especially during a first pregnancy, but the underlying mechanisms are unclear; notably, the parasite rarely infects the fetus. In Tanzania, where malaria transmission is intense, Kabyemela et al. (p. 1527-1534) surveyed numerous plasma factors in mothers and newborns at delivery. They report that placental gamma interferon (IFN-γ) levels are negatively related and cord ferritin levels are positively related to birth weight in first-time mothers with PM. Because the placenta expresses IFN-γ and ferritin, the results suggest that fetal responses modify outcomes during PM and that the placenta plays a role.