AIDS: our research illness
The Human Immunodeficiency Virus
Introduction
Infectious diseases are one of the leading causes of death worldwide and nowadays more than 15 million people per year die for this reason. One of the most important and extended infectious disease in the world is HIV (Human Immunodeficiency Virus) with its derivation to AIDS (Acquired Immunodeficiency Syndrome).
IMMUNE SYSTEM
The immune system is a host defence system comprising many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, and distinguish them from the organism's own healthy tissue. In many species, the immune system can be classified into subsystems, such as the innate immune system versus the adaptive immune system, or humoral immunity versus cell-mediated immunity.
In front of the invasion of microorganisms, the organism presents three forms of defense:
• First line of defense: The first barrier that must be overcome is that of physical and chemical barriers, that is, skin, mucous membranes, hair, urine, saliva, hyaluronic acid ... This first line It is a nonspecific barrier.
• Second line of defense: If you manage to overcome these barriers you will find a non-specific immune response that will destroy invaders in a generalized manner. These secondary barriers are formed by phagocytic cells, the inflammatory response and the fever.
• Third line of defense: If the infection has not been overcome, the last response, most effective, is the specific immune response. This system is based on the ability to recognize strange molecules in the organism, the antigens, which triggers a series of cellular and molecular processes that lead to its neutralization or destruction. This process is called immune response and can be of two types: cellular response or cellular immunity, which is caused by cells; and humoral response or humoral immunity, developed by other molecules called antibodies (immunoglobulins). The two responses are related to a type of white blood cells called lymphocytes.