According to Nankai University, Professor Wang Lei's team has for the first time revealed the molecular mechanism by which the three main bacteria causing bacterial meningitis use the same mechanism to cross the blood-brain barrier, which is of great significance for the prevention and treatment of bacterial meningitis. The research findings were recently published online in the international academic journal PNAS. Bacterial meningitis is an inflammatory reaction caused by pathogenic bacteria infection, including meninges, arachnoid membranes and pia mater. It has a high incidence rate and mortality. Even after treatment, it may also be accompanied by cerebral palsy, mental retardation, epilepsy and other neurological sequelae. It has become one of the global public health problems. The in-depth study of the pathogenic mechanism of bacterial meningitis pathogens and the search for effective treatment and prevention and control methods for bacterial infections has always been a research hotspot in the field of microbiology. The blood-brain barrier can protect the central nervous system from harmful substances or bacteria in the blood entering the brain. However, the pathogenic bacteria of bacterial meningitis can cross the blood-brain barrier, invade the brain, and cause inflammation. The molecular mechanism of this crossing mechanism has not been elucidated. The research team at Nankai University has focused on this key issue and, after years of research, discovered that the main pathogenic bacteria of bacterial meningitis - Streptococcus pneumoniae, Group B Streptococcus, and Escherichia coli of neonatal meningitis - cross the blood-brain barrier by hijacking the intracellular transport of iron transporter receptor (TfR). Wang Lei explained that after entering the blood-brain barrier, these three bacteria mainly form cells (human brain microvascular endothelial cells) and reside in intracellular vesicles, activating Toll like receptors (TLRs) on the vesicle membrane. The activated TLR recruits multiple effector proteins to the vesicles of bacteria, forming a protein complex, and then ties the vesicles of bacteria and TfR together, triggering vesicular fusion. The intercellular transport of TfR vesicles is one of the few active pathways in human brain microvascular endothelial cells that cross the blood-brain barrier. Therefore, pathogenic bacteria hijack the intracellular transport of TfR vesicles to cross the blood-brain barrier. Wang Lei stated that the research results suggest that the main pathogenic bacteria of bacterial meningitis use a common mechanism to cross the blood-brain barrier. The discovery of this mechanism provides a theoretical basis and potential targets for the development of broad-spectrum drugs for the prevention and treatment of bacterial meningitis, as well as new ideas for delivering drugs across the blood-brain barrier. Reporter: Chen Xi (Xinhua News Agency)