Santa's Little Helper Academy. However, his new crime-fighting job makes him jaded and one day at home he bites Bart. The Simpsons must therefore send the dog away to live with officer Lou. However, he gets to return after saving Bart from a toxic smoke cloud at school and then leaving the police force. In "How Munched is That Birdie in the Window?" (season 22, 2010), after Santa's Little Helper devours a pigeon with a broken leg that Bart was nursing, Bart gets mad at the dog and is unable to forgive him. The Simpsons therefore give him away to an ostrich farm.
T helper cell because such knowledge may be very useful in the treatment of disease and in increasing the effectiveness of vaccination. Proliferating helper T cells that develop into effector T cells differentiate into two major subtypes of cells known as T1 and T2 cells (also known as Type 1 and Type 2 helper T cells, respectively). T1 helper cells lead to an increased cell-mediated response, typically against intracellular bacteria and protozoa. They are triggered by IL-12 and their effector cytokines are IFN-γ and IL-2. The main effector cells of T1 immunity are macrophages as well as CD8 T cells, IgG B cells,