Santa's Little Helper the show in minor appearances, although there have been some episodes that feature him heavily, including the first episode of "The Simpsons". In that episode, "Simpsons Roasting on an Open Fire" (season one, 1989), Homer discovers that he has no money to buy Christmas presents for the family. Desperate for a miracle, he and Bart go to the greyhound racing track on Christmas Eve in hopes of winning some money. Although Homer has inside information on which dog is the most likely to win, he instead bets on a last-minute entry, Santa's Little Helper (here despite being brown), believing the
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,