Consequences of the introduction of a new protein during the recovery period of a chronic intestinal inflammation

Methods and results Male C57BL/6 mice (n=30) were immunized with 100μg of peanut protein. Half received a 30-day raw-peanutchallenge-diet (CD) (inflamed-I) while the other received mouse chow (controls-C)(Teixeira 2008). They were further divided and received sweetened OVA (new protein) (egg white diluted in distilled H2O, 1:5 v/v+5% sucralose) orally for 7 days, on day 0 (I1 C1), 10 (I2 C2) or 20 (I3 C3) post CD. We assessed body weight, food intake, antibodies and T cell phenotype of mesenteric lymph nodes (MLN) and spleen (SPN). ANOVA with Tukey post-test was performed. Statistical significance considered p<0.05. This study was approved by UFF’s Ethical Committee (CEUA #00147-09). During CD groups I2 (-1.94±2.2) and I3 (-1.44±1.8) but not I1 (0.15 ±0.6) showed significant weight loss compared to C. The C groups (37.50±4.6) ingested significantly more kcals compared to I1 (31.20±2.6), I2 (30.78±2.5) and I3 (30.84 ±3.4). OVA consumption was significantly lower in I1 (3.21±1.0) compared to I2 (6.53±1.19), I3 (6.82±2.3) and C (7.5±1.7). In the MLN we observed a significant increase of CD8T cells of I1 (29.49±4.1) and I2 (31.72 ±4.0) compared to I3 (21.53±3.6) and C (25.65±5.4) and CD8CD25T I1 (0.43±0.2) when compared to I2 (0.32 ±0.0), I3 (0.24±0.1) and C (0.30±0.1) with no significant difference in CD4T cells (I 37.34±5.7 and C 38.35±5.1) and CD4CD25 T cells (I 6.86±1.5 and C 7.00±1.9). In SPN, we observed significantly increase of CD4T cells in I1 (38.67±2.5) compared to I2 (25.93±3.48), I3 (24.48±5.9) and C (26.25±12.2) which was not accompanied by the increase of CD4CD25Foxp3T cells. We observed a significant increase in the CD8CD25 T cells in I1 (0.25±0.1) compared to I2 (0.11±0.0), I3 (0.1+0.0) and C (0.1±0.1). The I-1 showed gut inflammation, increased intraepithelial leukocytes and destruction/flatning of the villi and drop of goblet cells. The I-2 and 3 were similar to C.