from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The integrated body system of organs, tissues, cells, and cell products such as antibodies that differentiates self from nonself and neutralizes potentially pathogenic organisms or substances.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The system that differentiates self from non-self and protects the body from foreign substances and pathogenic organisms by producing an immune response. It includes organs such as the thymus, the spleen and lymph nodes; tissue such as bone marrow, and lymphoid tissues such as the tonsils; cells such as lymphocytes including the B cells and T cells, and cell products such as antibodies.

from the GNU version of the Collaborative International Dictionary of English

  • n. The complex of cells, cellular processes, and substances within and diffused throughout an organism which allow the organism to counteract or destroy noxious foreign substances introduced into the body, destroy infectious agents such as bacteria and viruses, destroy malignant cells, and remove cellular debris, thus protecting the organism against many of the potentially harmful external agents and internal events that could lead to sickness or death. The system has numerous interacting components, including circulating antibodies, antibody-producing cells, white blood cells and lymphokines, lymph tissue and lymph nodes, and stem cells which may differentiate into other types of cell, together with the thymus and spleen. The system is responsible for the phenomenon of immunity{3}. See also immunoglobulin and antibody.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a system (including the thymus and bone marrow and lymphoid tissues) that protects the body from foreign substances and pathogenic organisms by producing the immune response


Sorry, no etymologies found.


  • To give you some idea of what a challenging job this policing is, consider this: immune system helper cells, known as dendritic cells, present antigens from foreign invader cells to over a million of our T cells in a single day.

    The Autoimmune Epidemic

  • According to Kathleen Gilbert, the current climate for funding federal research into how toxins affect the immune system has never been more dismal.

    The Autoimmune Epidemic

  • In another study, rural farmers who had a lifetime exposure to organochlorine pesticides had a greater likelihood of having a high antinuclear antibody, or ANA, count—the telltale diagnostic sign that the immune system is turning against the organs and tissue of the body itself in the autoimmune disease lupus.

    The Autoimmune Epidemic

  • Since the very concept of autogenicity—that chemical and toxic agents can prod the immune system to overreact, resulting in autoimmunity—is in and of itself new, how can we go about proving there is a cluster of people who have autoimmunity as a result of exposures to toxic waste in their area?

    The Autoimmune Epidemic

  • Silverstone, an unassuming sixty-four-year-old immunologist whose own wife has suffered greatly from rheumatoid arthritis, began to investigate the role of endocrine disruptors on the immune system after developing successful target therapies for childhood leukemia.

    The Autoimmune Epidemic

  • One of the functions of the immune system is to act like a rapid-response SWAT team, reacting to any invading microorganism, such as viruses or bacteria, by producing antibodies—fighter cells—which seek out and destroy those unhealthy and often life-threatening organisms.

    The Autoimmune Epidemic

  • The immune system must now decide whether: Coxsackievirus B3 was named after Coxsackie, New York, where the virus was first isolated from a patient.

    The Autoimmune Epidemic

  • Back then, the little-explored and poorly understood domain of immunology—the study of how the immune system functions in the body—was hardly a bustling field, and few labs existed where a young PhD could go to complete his medical studies in the field, much less support a new wife and coming child.

    The Autoimmune Epidemic

  • Resident enteric bacteria are necessary for development of spontaneous colitis and immune system activation in interleukin-10-deficient mice.

    The Autoimmune Epidemic

  • Like that earlier flu, avian flu unleashes an unusual hurricanelike storm of immune-system signaling proteins called cytokines, which signal the immune system to combat microbial invaders.

    The Autoimmune Epidemic


Log in or sign up to get involved in the conversation. It's quick and easy.