M cells and Mucosal Immune Surveillance
Mucosal surfaces in the lung and intestine are exposed to environmental antigens and allergens and, in the case of the intestine, abundant food antigens. They are also exposed to a variety of infectious organisms such as viruses (influenza, polio, SARS, HIV), bacteria (Staphylococcus, Streptococcus, Anthrax), and parasites (Toxoplasma). The mucosal immune system must be able to identify pathogenic infectious agents and respond to them without reacting to beneficial commensal bacteria, or developing allergic responses to food or environmental antigens.
At mucosal surfaces, epithelial cells provide a tight barrier to entry into the body, but the immune system also induces the development of specialized epithelial cells called M cells to detect the presence of infectious organisms. These M cells are selective gatekeepers that capture particles such as viruses and bacteria for delivery to cells of the immune system waiting below the epithelial layer. Our laboratory has been studying the development of M cells, and the mechanisms used by M cells in their selective uptake of particles. We are also using the information we have learned about M cell function to engineer a novel technology for needle-free vaccine delivery that we hope to use against influenza and other infectious organisms.
Air Quality and Health Impacts
Mucosal tissues such as the intestine and lung provide our main interface with the environment. While mucosal immune systems monitor these tissues for pathogens, they also respond to environmental triggers. In the lung, exposure to aerosol particulates containing complex components including inert particles, allergens, pollutants and other materials can induce tissue responses that may negatively affect our health. While it is well established that pollutants such as diesel exhaust and smoke for cigarettes and fires have harmful effects, other environmental exposures can have significant effects that are not as well understood. One notable example is the high aerosol particulate concentration in regions of inland California including the Central Valley and Coachella Valley. In the Eastern Coachella Valley near the Salton Sea, high particulates produced at the exposed playa (lakebed) are thought to contribute to the unusually high incidence of childhood asthma in the region. Along with collaborating faculty in our BREATHE Center (Bridging Regional Ecology Aerosolized Toxins and Health Effects - we are working to identify the mechanisms behind the serious health impacts in the region.
“In 1736 I lost one of my sons, a fine boy of four years old, by the small-pox, taken in the common way. I long regretted bitterly, and still regret that I had not given it to him by inoculation. This I mention for the sake of parents who omit that operation, on the supposition that they should never forgive themselves if a child died under it; my example showing that the regret may be the same either way, and that, therefore, the safer should be chosen.”
Meet David D. Lo, Distinguished Professor of Biomedical Sciences
Professor David D. Lo joined UCR in 2006 from prior positions at the La Jolla Institute for Allergy and Immunology, the biotech company Digital Gene Technologies, and the Scripps Research Institute. He is a fellow of the American Association for the Advancement of Sciences (2007) and a 2005 recipient of a "Grand Challenges in Global Health" award, Bill and Melinda Gates Foundation and the Foundation for the National Institutes of Health.