Our immune systems have evolved to recognize certain foreign molecules that are similar in many species of bacteria, such as parts of the bacterial cell wall. Although these immune mechanisms are built to protect us from foreign invaders, the inflammation and cell proliferation that result from exposure to pathogenic bacteria can actually be detrimental to our health if excessive. In a new study, Humann and colleagues have demonstrated for the first time that bacterial cell wall components can cross a mother’s placenta into the developing fetal brain, where they are recognized by the fetus’s immune sensors. The resulting proliferation of fetal neurons can lead to developmental disorders in the fetal brain. This work has important implications for how we treat pregnant women with bacterial infections, as some antibiotics that work by rupturing bacterial cells are more likely to release these harmful components into the bloodstream, while other antibiotics that kill bacteria without lysing them may lead to less inappropriate inflammation and neuron proliferation in the unborn fetus.
- Jeff Maloy
Staff Writer, Signal to Noise Magazine
PhD Candidate, Microbiology
Humann, J., et al. (2016). “Bacterial Peptidoglycan Transverses the Placenta to Induce Fetal Neuroproliferation and Aberrant Postnatal Behavior.” Cell Host & Microbe. 19(3): 388-399.