Santa's Little Helper their old pet. Bart eventually gives Santa's Little Helper away instead of Laddie when repo men take back everything he fraudulently purchased. Feeling guilty about this disloyalty and bored with his too perfect new dog, Bart tries to get him back. When he finally finds him, Santa's Little Helper is serving as a seeing-eye dog for a blind man, but eventually decides to return to the family. In "Stop or My Dog Will Shoot" (season 18, 2007), Santa's Little Helper becomes a local hero after finding a lost Homer, and the Simpsons decide to enroll him in the Animal Police
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,