Adaptive immune system

adaptive immunityadaptive immune responseadaptiveacquired immunityadaptive immuneadaptive immune responsesspecific immunityacquired immune systemactive immunityimmune system
The adaptive immune system, also known as the acquired immune system or, more rarely, as the specific immune system, is a subsystem of the overall immune system that is composed of highly specialized, systemic cells and processes that eliminate pathogens or prevent their growth.wikipedia
414 Related Articles

Immune system

immuneimmune responseimmune function
The adaptive immune system, also known as the acquired immune system or, more rarely, as the specific immune system, is a subsystem of the overall immune system that is composed of highly specialized, systemic cells and processes that eliminate pathogens or prevent their growth.
In many species, there are two major subsystems of the immune system: the innate immune system and the adaptive immune system.

Innate immune system

innate immunityinnateinnate immune response
The acquired immune system is one of the two main immunity strategies found in vertebrates (the other being the innate immune system).
The innate immune system is one of the two main immunity strategies found in vertebrates (the other being the adaptive immune system).

Vaccination

vaccinationsvaccinatedvaccinating
This process of acquired immunity is the basis of vaccination.

Immunity (medical)

immunityimmuneimmune response
The acquired immune system is one of the two main immunity strategies found in vertebrates (the other being the innate immune system).
An immune system may contain innate and adaptive components.

Somatic hypermutation

hypermutationsomatic hypermutation, immunoglobulinadaptation
The system is highly adaptable because of somatic hypermutation (a process of accelerated somatic mutations), and V(D)J recombination (an irreversible genetic recombination of antigen receptor gene segments).
Somatic hypermutation (or SHM) is a cellular mechanism by which the immune system adapts to the new foreign elements that confront it (e.g. microbes), as seen during class switching.

Immune network theory

Formal Immune Networksimmune networkssymmetric immune network theory
A theoretical framework explaining the workings of the acquired immune system is provided by immune network theory.
The immune network theory is a theory of how the adaptive immune system works, that has been developed since 1974 mainly by Niels Jerne and Geoffrey W. Hoffmann.

V(D)J recombination

immunoglobulin genegene rearrangementrearrange TCR genes
The system is highly adaptable because of somatic hypermutation (a process of accelerated somatic mutations), and V(D)J recombination (an irreversible genetic recombination of antigen receptor gene segments).
The process is a defining feature of the adaptive immune system.

B cell

B cellsB-cellB lymphocytes
B cells and T cells are the major types of lymphocytes.
They function in the humoral immunity component of the adaptive immune system by secreting antibodies.

Lymphocyte

lymphocyteslymphocyticlymphoid cells
This mechanism allows a small number of genes to generate a vast number of different antigen receptors, which are then uniquely expressed on each individual lymphocyte. The cells of the acquired immune system are T and B lymphocytes; lymphocytes are a subset of leukocyte.
Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity).

Thymus

thymus glandthymicmedulla
T cells are critical to the adaptive immune system, where the body adapts specifically to foreign invaders.

Genetic recombination

recombinationmeiotic recombinationDNA recombination
The system is highly adaptable because of somatic hypermutation (a process of accelerated somatic mutations), and V(D)J recombination (an irreversible genetic recombination of antigen receptor gene segments).
V(D)J recombination in organisms with an adaptive immune system is a type of site-specific genetic recombination that helps immune cells rapidly diversify to recognize and adapt to new pathogens.

HIV vaccine

AIDS vaccinevaccineHIV vaccines
This theory, which builds on established concepts of clonal selection, is being applied in the search for an HIV vaccine.
However, the classical vaccination approach that is successful in the control of other viral diseases - priming the adaptive immunity to recognize the viral envelope proteins - have failed to work against HIV.

Major histocompatibility complex

MHCmajor histocompatibility complex (MHC)HLA loci
In the lymph node, the dendritic cell displays these non-self antigens on its surface by coupling them to a receptor called the major histocompatibility complex, or MHC (also known in humans as human leukocyte antigen (HLA)).
The major histocompatibility complex (MHC) is a set of genes that code for cell surface proteins essential for the acquired immune system to recognize foreign molecules in vertebrates, which in turn determines histocompatibility.

Dendritic cell

dendritic cellsmyeloid dendritic cellsdendritic
Dendritic cells, B-cells, and macrophages are equipped with special "co-stimulatory" ligands recognized by co-stimulatory receptors on T cells, and are termed professional antigen-presenting cells (APCs).
They act as messengers between the innate and the adaptive immune systems.

Macrophage

macrophagesM2 macrophagesTissue macrophages
Dendritic cells, B-cells, and macrophages are equipped with special "co-stimulatory" ligands recognized by co-stimulatory receptors on T cells, and are termed professional antigen-presenting cells (APCs).
Besides phagocytosis, they play a critical role in nonspecific defense (innate immunity) and also help initiate specific defense mechanisms (adaptive immunity) by recruiting other immune cells such as lymphocytes.

Humoral immunity

humoralhumoral immune responsehumoral response
Like the innate system, the acquired system includes both humoral immunity components and cell-mediated immunity components.
The immune system is divided into a more primitive innate immune system, and acquired or adaptive immune system of vertebrates, each of which contains humoral and cellular components.

Lymphatic system

lymphoidlymphoid tissuelymphatic
The peripheral blood contains 2% of circulating lymphocytes; the rest move within the tissues and lymphatic system.
Secondary or peripheral lymphoid organs, which include lymph nodes and the spleen, maintain mature naive lymphocytes and initiate an adaptive immune response.

Antigen

antigensantigenicantigenic proteins
Antigens are any substances that elicit the acquired immune response (whether adaptive or maladaptive to the organism).
Both T cells and B cells are cellular components of adaptive immunity. The Ag abbreviation stands for an antibody generator.

Human leukocyte antigen

HLAhuman leukocyte antigenshuman leukocyte antigen (HLA)
In the lymph node, the dendritic cell displays these non-self antigens on its surface by coupling them to a receptor called the major histocompatibility complex, or MHC (also known in humans as human leukocyte antigen (HLA)).
HLA genes are highly polymorphic, which means that they have many different alleles, allowing them to fine-tune the adaptive immune system.

White blood cell

leukocyteleukocyteswhite blood cells
The cells of the acquired immune system are T and B lymphocytes; lymphocytes are a subset of leukocyte.

T cell

T cellsT-cellT-cells
B cells and T cells are the major types of lymphocytes.
Natural killer T cells (NKT cells – not to be confused with natural killer cells of the innate immune system) bridge the adaptive immune system with the innate immune system.

Interferon gamma

IFN-γinterferon-gammaIFNγ
The Th1 response is characterized by the production of Interferon-gamma, which activates the bactericidal activities of macrophages, and induces B cells to make opsonizing (marking for phagocytosis) and complement-fixing antibodies, and leads to cell-mediated immunity.
IFNγ, or type II interferon, is a cytokine that is critical for innate and adaptive immunity against viral, some bacterial and protozoal infections.

Clonal selection

clonal selection theoryclonalclonal dynamics
This theory, which builds on established concepts of clonal selection, is being applied in the search for an HIV vaccine.
The idea turned out to be the foundation of molecular immunology, especially in adaptive immunity.

Antigen-presenting cell

antigen-presenting cellsantigen presenting cellantigen presenting cells
Dendritic cells, B-cells, and macrophages are equipped with special "co-stimulatory" ligands recognized by co-stimulatory receptors on T cells, and are termed professional antigen-presenting cells (APCs).
Antigen-presenting cells are vital for effective adaptive immune response, as the functioning of both cytotoxic and helper T cells is dependent on APCs.

Pattern recognition receptor

pattern recognition receptorspattern recognition receptors (PRRs)(PRRs)
On the other hand, however, the various subsets may also be considered part of the innate immune system where a restricted TCR or NK receptors may be used as a pattern recognition receptor.
They are also called primitive pattern recognition receptors because they evolved before other parts of the immune system, particularly before adaptive immunity.