Invited Speaker

Protection Against Pathogen Infection By Boosting Host Innate Immunity
Goutam Gupta
USA

Innate immune system is the first line of host defense against the invading pathogens. It has been conserved through evolution across plants, insects, and humans. The abilities of the host to first recognize and then to clear the pathogen are the two essential steps of the innate immune defense. This allows rapid elimination of the pathogen before it can establish infection in the host and cause disease. However, many pathogens have developed resistance either by blocking the recognition or the clearance step of the host innate immune process. We have developed a strategy that overcomes pathogenic resistance against host innate immune defense. The strategy involves the design of a protein chimera in which the functional domains for pathogen recognition and clearance are linked together in the same protein. The feasibility of this approach has been successfully tested against Xylella fastidiosa that is transmitted by sharpshooter vectors in the plant xylem and causes diseases in many economically important plants. The most notable diseases are: Pierce’s Disease in grapes and Variegated Chlorosis in citrus. We have been able to generate a transgenic grape line that produces the chimeric protein in the plant xylem (the very site of infection) and completely protects against Xylella fastidiosa infection. This is the first example in which a chimeric protein is expressed locally at the site of infection in a transgenic plant to protect against pathogen infection. A similar strategy has also been successful in vitro for protection against staphylococcal infection (a human pathogen). The possibility of converting our strategy into a universal therapy against viral, bacterial, and fungal pathogens seems logical and appealing.