ABSTRACT
The immune system is composed of a large number of functionally and phenotypically different cell types which have to cooperate in order for the organism to be able to fight infection. Production of the lymphokines occurs as a consequence of the second messenger cascade triggered by interaction of the cell membrane with infectious agents. Malignant transformation is associated with the dysregulation of the mechanisms which control cell proliferation. The human retrovirus Human T-lymphotropic virus-1 is frequently associated with adult acute T-cell leukemia, in particular in certain regions of Japan. Interleukin 1, previously known as lymphocyte activating factor, was defined as a soluble factor produced by activated monocytes which is required for the T-cell immune response. The development of the normal immune response is based upon the controlled expansion of specific cell subpopulations which have the transient capability to produce and/or respond to the appropriate growth factors via autocrine/paracrine mechanisms.
