The term ZBA (Zero Balance Account) is sometimes used to describe a transit account. In reality, ZBAs are a completely different story and are usually used in an acquiring and merchant account context, where one party opens the account and another sweeps (clears) it daily.
Helper T cells are the major driving force and the main regulators of the immune defense. Their primary task is to activate B cells and killer T cells. However, the helper T cells themselves must be activated.
When a helper T cell encounters a B cell that has itself encountered an antigen, the helper T cell releases cytokines that activate the B cell so that it can divide and form a clone. 3. Some of the B cells become plasma cells, producing and secreting antibodies. G. Types of Antibodies (p.