Age, calorie restriction, and age of calorie restriction onset reduce maturation of natural killer cells in C57Bl/6 mice.

Calorie restriction (CR), also known as energy restriction, has been shown to have a deleterious impact on both adult and aged mouse survival during influenza virus infection. Natural killer (NK) cell phenotypic differences contribute to increased susceptibility of adult CR mice. We hypothesized NK cell phenotype from adult and aged C57Bl/6 mice fed NIH-31 diet ad libitum (AL) would be different from NK cell phenotype from adult and aged mice fed NIH-31/NIA fortified diet at 40% CR. We hypothesized NK cell phenotype from mice consuming 40% CR initiated at 20 months of age would not be different from 40% CR initiated at 3 months of age. We initiated the 40% restriction either at the standard 12 weeks of age or at 78 weeks of age. NK cells were isolated and quantified from various tissues using flow cytometry. Aged CR mice had significantly reduced levels of terminally mature (CD27-CD11b+) NK cells, increased expression of the immature marker CD127, and decreased expression of the mature marker DX5. Total number of NK cells among cells was significantly lower in the lung and spleen of old-onset aged CR mice compared to aged AL mice, while there was no significant difference between young-onset aged CR and aged AL mice. Old-onset aged CR mice had significantly less early mature (DX5+ and CD27+CD11b+) NK cells compared to young-onset aged CR and aged AL fed mice. Overall, we found that CR in aged mice is detrimental to maturation of NK cells, which is exacerbated when CR is initiated in old age.

Validation of MAX Aqueous Extraction on Veratox® for Total Aflatoxin ELISA Test Kit.

Neogen Corp. (Lansing, MI) has developed a common aqueous extraction method for the detection of mycotoxins in the ELISA or lateral flow format. The Veratox® for Total Aflatoxin ELISA extraction method uses a MAX 2 extraction packet and water in replacement of traditionally used organic solvents. Veratox for Total Aflatoxin has a detection range of 5-50 ppb neat or up to 300 ppb with dilution. The kit development focused on superior cross-reactivity, ability to accurately detect naturally contaminated samples, and utilization of an aqueous extraction method. In two separate validation studies, the Veratox for Total Aflatoxin test kit resulted in average yields of 91-114% in naturally contaminated mycotoxin reference material corn. The cross-reactivity profiles for aflatoxins B1, B2, G1, and G2 were 100, 113, 103, and 93%, respectively. This kit is approved by the Grain Inspection, Packers, and Stockyards Administration.

Short-term supplementation with active hexose correlated compound improves the antibody response to influenza B vaccine.

Administration of bioactive nutritional supplements near or at the time of immunization has been a recent approach to stimulate human immune response to vaccination. Active hexose correlated compound (AHCC), a mushroom extract, has been shown to protect mice against lethal primary influenza infection. Moreover, when AHCC was administered pre-vaccination in mice, they showed improved protection from lethal avian flu infection when compared to mice vaccinated alone. In this study, we hypothesized that AHCC will also improve the immune responses of healthy individuals to influenza vaccine. A randomized controlled study was performed with 30 healthy adults to evaluate the effects of AHCC supplementation on the immune response to the 2009-2010 seasonal influenza vaccine. Blood was drawn pre-vaccination and 3 wk post-vaccination. Immediately post-vaccination, the AHCC group began supplementation with AHCC (3 g/d). Flow cytometric analysis of lymphocyte subpopulations revealed that AHCC supplementation increased NKT cells (P < .1), and CD8 T cells (P < .05) post-vaccination compared to controls. Analysis of antibody production 3 weeks post-vaccination revealed that AHCC supplementation significantly improved protective antibody titers to influenza B, while the improvement was not significant in the control group. Overall, our study showed that AHCC supplementation improved some lymphocyte percentages and influenza B antibody titers over the control. Future studies are required to determine the kinetics of AHCC supplementation to improve the overall response to influenza vaccination.