Inefficient Toll-Like Receptor-4 Stimulation Enables Bordetella parapertussis to Avoid Host Immunity

The recognition of bacterial lipopolysaccharide (LPS) by host Toll-like receptor (TLR)4 is a crucial step in developing protective immunity against several gram negative bacterial pathogens. Bordetella bronchiseptica and B. pertussis stimulate robust TLR4 responses that are required to control the infection, but a close relative, B. parapertussis, poorly stimulates this receptor, and TLR4 deficiency does not affect its course of infection. This led us to hypothesize that inefficient TLR4 stimulation enables B. parapertussis to evade host immunity. In a mouse model of infection, B. parapertussis grew rapidly in the lungs, but no measurable increase in TLR4-mediated cytokine, chemokine, or leukocyte responses were observed over the first few days of infection. Delivery of a TLR4 stimulant in the inoculum resulted in a robust inflammatory response and a 10- to 100-fold reduction of B. parapertussis numbers. As we have previously shown, B. parapertussis grows efficiently during the first week of infection even in animals passively immunized with antibodies. We show that this evasion of antibody-mediated clearance is dependent on the lack of TLR4 stimulation by B. parapertussis as co-inoculation with a TLR4 agonist resulted in 10,000-fold lower B. parapertussis numbers on day 3 in antibody-treated wild type, but not TLR4-deficient, mice. Together, these results indicate that inefficient TLR4 stimulation by B. parapertussis enables it to avoid host immunity and grow to high numbers in the respiratory tract of naïve and immunized hosts

Genetic engineering to enhance crop-based phytonutrients (nutraceuticals) to alleviate diet-related diseases.

Nutrition studies have provided unambiguous evidence that a number of human health maladies including chronic coronary artery, hypertension, diabetes, osteoporosis, cancer and age- and lifestyle-related diseases are associated with the diet. Several favorable and a few deleterious natural dietary ingredients have been identified that predispose human populations to various genetic and epigenetic based disorders. Media dissemination of this information has greatly raised public awareness of the beneficial effects due to increased consumption of fruit, vegetables and whole grain cereals-foods rich in phytonutrients, protein and fiber. However, the presence of intrinsically low levels of the beneficial phytonutrients in the available genotypes of crop plants is not always at par with the recommended daily allowance (RDA) for different phytonutrients (nutraceuticals). Molecular engineering of crop plants has offered a number of tools to markedly enhance intracellular concentrations of some of the beneficial nutrients, levels that, in some cases, are closer to the RDA threshold. This review brings together literature on various strategies utilized for bioengineering both major and minor crops to increase the levels of desirable phytonutrients while also decreasing the concentrations of deleterious metabolites. Some of these include increases in: protein level in potato; lysine in corn and rice; methionine in alfalfa; carotenoids (beta-carotene, phytoene, lycopene, zeaxanthin and lutein) in rice, potato, canola, tomato; choline in tomato; folates in rice, corn, tomato and lettuce; vitamin C in corn and lettuce; polyphenolics such as flavonol, isoflavone, resveratrol, chlorogenic acid and other flavonoids in tomato; anthocyanin levels in tomato and potato; alpha-tocopherol in soybean, oil seed, lettuce and potato; iron and zinc in transgenic rice. Also, molecular engineering has succeeded in considerably reducing the levels of the offending protein glutelin in rice, offering proof of concept and a new beginning for the development of super-low glutelin cereals for celiac disease patients