Effect of immunobiotic Lactobacillus rhamnosus nasal treatment on the recovery of T lymphopoiesis in malnourished mice

HERRERA MATÍAS, SALVA SUSANA, BARBIERI NATALIA, AGÜERO GRACIELA, ALVAREZ SUSANA

Buenos Aires, Argentina

Congreso; First French - Argentine Immunology Congress. LVIII Reunión Anual de la Sociedad Argentina de Inmunología. XIII Jornada Científica del Grupo Rioplatense de Citometría de Flujo. 3º Jornadas Argentinas de Inmunodeficiencias Primarias (SAP); 2010

Sociedad Argentina de Inmunología. Grupo Rioplatense de Citometría de Flujo

Thymus produces T cells throughout life but it has no self-renewing ability and requires replenishment and recruitment of progenitors derived from the bone marrow (BM). In this work we evaluated the effect of the Lactobacillus rhamnosus CRL1505 nasal administration on recovery of T lymphopoiesis in malnourished mice. Weaned mice were malnourished after consuming protein-free diet for 21d. Malnourished mice were repleted for 7d with balanced conventional diet (BD) or BD with nasal administration of Lr05 (108 cells/d/mouse) on d 6 and 7 (Lr05). Well-nourished (WC) and malnourished mice (MC) were used as control. At the end of treatments we determined body weight and studied the total cell number and T cells (CD3, CD4, CD8) in BM and thymus. Malnutrition induced a significant decrease in total cells and lymphocytes (FSC vs SSC) number in the BM and thymus (p<0.05). Both repletion treatments normalized total cells number in BM, but only Lr05 treatment was able to normalize lymphocytes number (WC=10.5±2.3; MC=5.5±0.4; BD=5.1±0.7; BD+Lr05=11.7±2.4 106 cells/mouse). In addition, repletion with BD or Lr05 induced a significant improvement in the number of these cells in thymus. Malnutrition significantly reduced CD3+CD4+, CD3+CD8+ and CD4+CD8+ cells, while CD4-CD8- cells were not affected in thymus. Both repletion treatments recovered the number of CD3+CD4+ cells, reaching higher values than WC. Lr05 group showed higher CD3+CD8+ cells number than BD group (WC=78.0±14.0; MC=2.1±0.7; BD=22.4±2.0; BD+Lr05=36.9±5.3 106 cells/mouse). In addition, we found that the number of immature T cells (CD4+CD8+ and CD4-CD8-) in BD group was higher than Lr05 group. Malnutrition increased CD3+CD4+ and CD3+CD8+ cells in BM. Repletion treatments significantly decreased these cells that reached lower values than WC. Hence, the nasal treatment with immunobiotic Lr05 is able to induce thymus replenishment and it should be considered in therapeutic approaches in malnutrition.