We have recently shown that a semi-purified RBD produces failure to thrive, small intestinal mucosal atrophy and gut barrier dysfunction in mice [31]. We hypothesized that undernutrition caused by the regional basic diet would impair the efficacy of oral rotavirus immunization and that undernutrition exacerbates rotavirus infection in weanling mice. Here we report that: (1) Despite altered antibody responses following murine rotavirus EDIM challenge, oral rotavirus vaccination appears to adequately protect undernourished mice against shedding of rotavirus, (2) In undernourished mice, anti-rotavirus IgA levels are altered in both immunized and

TGFbeta inhibitor unimmunized mice following EDIM challenge, and (3) Unimmunized, undernourished mice produce lower levels of anti-rotavirus IgG in response to EDIM infection. The rhesus rotavirus (RRV) strain used in this study was obtained from Dr. Harry Greenberg (Stanford University, Palo Alto, CA). The murine rotavirus strain EDIM was originally obtained from M. Collins (Microbiological Associates, Bethesda, MD). Both viruses were passaged in the African green monkey kidney MA-104 cell line. Viruses were titered in this same cell line using a fluorescent focus assay as previously described [34]. Timed pregnant BALB/c mice were purchased from Harlan BLZ945 nmr Laboratories (Indianapolis,

IN). All mice were housed in microisolation cages and shown to be rotavirus-negative by serology prior to

use. Adoptions were set up to allocate 6 to 7 pups per cage. Fourteen dams of 3-day-old pups were randomized to an ad lib purified control diet (Control: 15% fat, 20% protein, 65% CHO) or an isocaloric regional basic diet (RBD: 5% fat, 7% protein, 88% CHO) to induce weanling undernutrition, as previously described [29]. Both diets were irradiated prior to administration. Beginning on day of life (DOL) 3, mice were weighed every three days. On DOL 21 pups were weaned to their dams’ diet (3,4 mice per cage) and body weights were recorded weekly. All animal procedures were conducted in accordance with the Cincinnati Children’s Hospital Research Foundation Institutional Animal Care and Use Committee. On DOL 21, Non-specific serine/threonine protein kinase 86 weanlings received a single dose (1.0 × 107 ffu/ml) of RRV by oral gavage (vaccine) or PBS sham. To determine shedding of RRV, two fecal pellets were collected by massage from each mouse individually at days 2, 3, and 4 after immunization and kept in 1 ml of Earle’s balanced salt solution (EBSS). Samples were stored frozen until analyzed, at which time they were homogenized and centrifuged to remove debris. Three weeks later, animals were bled from the orbital sinus and stool was collected for antibody analysis. Serum samples were centrifuged 10 min at 400 × g and the sera was stored at −20 °C.