T Lymphocytes are involved in non-specific cell mediated immunity. T-helper cells are one such T lymphocyte is a cell used in specific immune responses. It takes no part in the actual production of antibodies,T Helper cells are T cells which are cell mediators. They are predominantly used when a new pathogen is encountered. The T Helper cells collect antigenic fragments which are displayed on a marcophage's Class II MHC markers. It then presents these fragments to an immature B cell, so the B cell can read the fragment and mature into a B plasma cell to produce antibodies. With out this T cell the specific immune system would be hindered and would lead to autoimmune diseases and leave a person vulnerable to new antigens, as the antigenic fragments could not be received and read by immature B cell.
Natural killers are a cytotoxic cell which is used in non-specific immunity. They have two receptors, activation and inhibition receptor. Cells such as self cells have both an activation and inhibition complementary receptor. Foreign cells also called non-self cells don’t have an inhibition receptor, which is a Class I MHC marker. The lack of this MCH marker causes the natural killer cell to release its granules which when they come in contact with the target cell cause the target cell to either lyse or trigger apoptosis.
Suppressor or Regulatory T cells are so called as they neutralise or help suppress an immune response. These T cells help in maintaining homeostasis and tolerance to self-antigens.