innate immune

(noun)

The innate immune system, also known as non-specific immune system and first line of defense, comprises the cells and mechanisms that defend the host from infection by other organisms in a non-specific manner. This means that the cells of the innate system recognize and respond to pathogens in a generic way, but unlike the adaptive immune system, it does not confer long-lasting or protective immunity to the host.

Related Terms

Examples of innate immune in the following topics:

  • Physical and Chemical Barriers

    • The innate immune response has physical and chemical barriers that exist as the first line of defense against infectious pathogens.
    • The immune system comprises both innate and adaptive immune responses.
    • Both the innate and adaptive levels of the immune response involve secreted proteins, receptor-mediated signaling, and intricate cell-to-cell communication.
    • The skin is considered the first defense of the innate immune system; it is the first of the nonspecific barrier defenses.
    • In the innate immune system, they serve to move pathogens out of the respiratory system via a concerted sweeping motion.

  • The Complement System

    • The innate immune system serves as a first responder to pathogenic threats that bypass natural physical and chemical barriers of the body.
    • Using a combination of cellular and molecular attacks, the innate immune system identifies the nature of a pathogen and responds with inflammation, phagocytosis (where a cell engulfs a foreign particle), cytokine release, destruction by NK cells, and/or a complement system.
    • The complement system is so named because it is complementary to the antibody response of the adaptive immune system.
    • When innate mechanisms are insufficient to clear an infection, the adaptive immune response is informed and mobilized.

  • Primary and Secondary Antibody Responses

    • The immune system protects organisms from infection first with the innate immune system, then with adaptive immunity.
    • If pathogens successfully evade the innate response, vertebrates possess a second layer of protection, the adaptive immune system, which is activated by the innate response.
    • Both innate and adaptive immunity depend on the ability of the immune system to distinguish between self and non-self molecules.
    • Active immunity often involves both the cell-mediated and humoral aspects of immunity as well as input from the innate immune system .
    • Generalize the role of the innate and adaptive immune system in regards to antibody response

  • Pathogen Recognition

    • Upon pathogen entry to the body, the innate immune system uses several mechanisms to destroy the pathogen and any cells it has infected.
    • The innate immune system must respond accordingly by identifying the extracellular pathogen and/or by identifying host cells that have already been infected.
    • Interleukins are involved in bridging the innate and adaptive immune responses.
    • The characteristics and location of cells involved in the innate immune system are described in this chart.
    • Describe the role of PAMPs and PRRs, interferons, and other cytokines in innate immunity

  • Overview of Adaptive Immunity

    • The adaptive immune system works to protect and heal the body when the innate immune system fails.
    • The adaptive immune system starts to work after the innate immune system is activated.
    • If an infection progresses despite the inflammation, fever, NK cell and phagocyte activity of the innate immune system, a more coordinated response is required in order to destroy the pathogen.
    • The adaptive immune response occurs a few days after the innate immune response occurs.
    • Adaptive immunity is triggered when a pathogen evades the innate immune system for long enough to generate a threshold level of an antigen.

  • The Complement System

    • The serum complement system, which represents a chief component of innate immunity, not only participates in inflammation but also acts to enhance the adaptive immune response.
    • The complement system plays a crucial role in the innate defense against common pathogens.
    • More recently, however, the role of the complement in the immune response has been expanded due to observations that link complement activation to adaptive immune responses.
    • It is now understood that the complement is a functional bridge between innate and adaptive immune responses that allows an integrated host defense to pathogenic challenges.
    • It has become increasingly understood that complement functions in host defense extend beyond innate immune responses.

  • Innate Immune Response

    • Mammalian immune systems evolved for protection from such pathogens.
    • The immune response that defends against pathogens can be classified as either innate or active.
    • The innate immune response is present in its final state from birth and attempts to defend against all pathogens.
    • However, we are born with only innate immunity, developing our adaptive immune response after birth.
    • Eosinophils play a variety of roles in the immune response.

  • Overview of the Immune System

    • If a pathogen breaches these barriers, the innate immune system provides an immediate, but non-specific response.
    • If pathogens successfully evade the innate response, vertebrates possess a second layer of protection, the adaptive immune system, which is activated by the innate response.
    • Both innate and adaptive immunity depend on the ability of the immune system to distinguish between self and non-self molecules, where self molecules are those components of an organism's body that can be distinguished from foreign substances by the immune system.
    • Through these approaches, innate immunity can prevent the colonization, entry, and spread of microbes.
    • Adaptive immunity is often sub-divided into two major types depending on how the immunity was introduced.

  • Antigen-presenting Cells: B and T cells

    • The adaptive, or acquired, immune response to an initial infection takes days or even weeks to become established, much longer than the innate response.
    • However, adaptive immunity is more specific to an invading pathogen and can fight back much more quickly than the innate response if it has seen the pathogen before.
    • The adaptive immune response activates when the innate immune response insufficiently controls an infection.
    • In fact, without information from the innate immune system, the adaptive response could not be mobilized.
    • Explain the role played by B and T cells in the adaptive immune system

  • Types of Adaptive Immunity

    • The adaptive immune response is mediated by B and T cells and creates immunity memory.
    • The adaptive immune system mounts a stronger, and antigen specific immune response after the innate immune response fails to prevent a pathogen from causing an infection.
    • There are two subdivisions of the adaptive immune system: cell-mediated immunity, and humoral immunity.
    • Cell mediated immunity is controlled by type 1 helper T-cells (Th1) and cytotoxic T-cells.
    • Antibodies to provide a number of functions in humoral immunity.