TLR5 expression marks brain boarder associated macrophages and protects neonatal mice from bacterial meningitis

Meningitis is one of the major threats to prenatal and newborn babies, causing more than 300,000 infant deaths worldwide annually. Survivors often suffer from long-term neuron-developmental disorders caused by the infection [[1], [2], [3]]. Bacterial meningitis, a prevalent form of this condition, remains a major global public health challenge, despite significant progress in combating specific pathogens [4]. In infants, where systemic adaptive immunity is not fully developed, brain macrophage plays a crucial role in defensing pathogen infection in this vital organ [5,6]. However, our understanding of the precise markers that reflect the distinct contributions of various macrophage populations in the neonatal brain remains incomplete.