In previous works we demonstrated that subcutaneous sensitization with Ovalbumin (OVA) induce generation of specific IgE antibodies and modifications of immune cells populations from bronchial mucosa in rabbit. The aim of the study is characterization of CD4 and CD5 positive cell population in tracheal mucosa from OVA sensitized and aerosolized challenged rabbits.
New Zealand white rabbits were divided into three groups: G1 (n = 8): normal control; G2 (n = 10): subcutaneous sensitized with OVA; G3 (n = 10): subcutaneous sensitized and inhalatory challenged with OVA. Four hours after challenge animals were sacrificed and obtained samples were processed for immunohistochemistry with the following monoclonal antibody: mouse anti-rabbit CD4 and CD5. Avidin-biotin-peroxidase system was used as detection kit. Cells were counted in 200 high power fields per group.
Data were expressed as arithmetic mean and standard deviation. CD4: G1: 5.2 (SD 1.9); G2: 6.4 (SD 2.1); G3: 11.2 (SD 2.8). (G3 vs G1 and G2 p < 0.001). CD5: G1: 3.6 (SD 1.9); G2: 13.6 (SD 1.9); G3: 10.9 (SD 3.9). (G3 vs. G1 p < 0.001; G2 vs G1 p < 0.001). Specific anti-OVA-IgE levels were evaluated by positive passive cutaneous anaphylaxis test (PCA) at 160 fold dilutions.
An increase in number of CD4-positive cell after inhalatory challenge is observed as compared to normal control and sensitized animals without challenge. A different pattern is expressed by CD5-cells which showed augmentation after sensitization and number is still increased after challenge. We conclude that systemic sensitization with soluble antigen and inhalatory challenge induces modifications in number of immune cells populations in tracheal mucosa infiltrate from rabbits.
Sensitization with soluble food allergen as OVA induced modifications in tracheal mucosa infiltrate that could generate functional alterations.
Miguel Vinuesa, No Financial Disclosure Information; No Product/Research Disclosure Information