They are essential in B cell antibody class switching, in the activation and growth of cytotoxic T cells, and in maximizing bactericidal activity of phagocytes such as macrophages. Mature T h cells express the surface protein CD4 and are referred to as CD4+ T cells.Such CD4 + T cells are generally treated as having a pre-defined role as helper T cells within the immune system.hey are essential in B cell antibody class switching, in the activation and growth of cytotoxic T cells, and in maximizing bactericidal activity of phagocytes such as macrophages. Mature T h cells express the surface protein CD4 and are referred to as CD4+ T cells.
To boil artichokes: 1  Fill a large stainless-steel or enameled pot with lightly salted water; bring to boiling. 2  Add artichokes and return water to boiling. 3  Reduce heat; simmer, covered, for about 20 to 30 minutes or until you can easily pull out a leaf from the center of an artichoke.
Place a couple inches (4 cm) of water into a pot to boil with a steaming basket on top. Add some lemon juice and salt to flavor the water if you prefer. Drop the artichokes into the pot once the water begins to boil and steam for 15 to 20 minutes. Drain artichokes with the stem up before serving.