In this paper it is presented and discussed the info-operability of the human immune system, according to the informational concept defined as matter-related information, operating at microstructural level of cell and body, based on the interactions between the micro-material components under a permanent dynamic process, as complex compounds or decomposing systems in constitutive components, with absorption and release of information. It is possible thus to describe coherently the metabolic and genetic processes, for the body maintenance and its growth/development or the plasticity of parts of it, and the info-relation with the brain, the central managing operator/processor of the entire organism. The identification of the specific distinct components of the informational system of the human body and of the eukaryotic composing cells themselves allows to describe the communication between the brain and body, performed mainly by YES/NO binary Bit-type mechanisms, both at the macro and microscopic levels of the constitutive cells, and to approach within the frame of the defined informational model of human and of the composing eukaryotic cells, the info-operability of the immune system, composed both by mobile cells and fixed macro-components of the body, a critical issue in Immunology not yet understood up to date. It is emphasized the high informational operability of the components of the immune system, according to the informational model of the human body and the composing cellular components, experimentally proved, and its great capability/versatility of expression, highly supporting the informational model.