Furthermore, the immune system's enhanced response to invaders that it has seen before makes it difficult for gene therapy to be repeated in patients.

HIV most heavily targets the immune system's white blood cells known as " helper T cells ", and identifies these target cells through T-cell surface receptors designated " CD4 " and " CCR5 ".

This breakage leads to the immune system's mounting an effective and specific immune response against self determinants.

* Artificial immune system, a computational system inspired by the principles and processes of the vertebrate immune system's characteristics of learning and memory

In general, the lower the number of T cells the lower the immune system's function will be.

The shallow implantation is thought to stem from the maternal immune system's response to the placenta and refers to evidence suggesting a lack of established immunological tolerance in pregnancy.

In some cases of pre-eclampsia it is thought that the mother lacks the receptors for the proteins the placenta is using to downregulate the maternal immune system's response to it.

Many viruses ( HIV being the most extreme example ) seem to exploit the immune system's use of tolerance induction to evade the immune system, though the suppression of specific antigens is done by fewer pathogens ( notably Mycobacterium leprae ).

Immunodeficiency ( or immune deficiency ) is a state in which the immune system's ability to fight infectious disease is compromised or entirely absent.

When immune cells encounter the allergenic protein, IgE antibodies are produced ; this is similar to the immune system's reaction to foreign pathogens.

Those that escape the immune system's initial response, however, spread through intracellular mechanisms and are, therefore, guarded against circulating immune factors ( AMI ).

So humoral immunity in forms of IgG and complement proteins is the human immune system's response against bacterial capsules.

On 13 December 2007, the first detailed report of the progress of this transplant after 18 months was released in the New England Journal of Medicine and documents that the patient was happy with the results but also that the journey has been very difficult, especially with respect to her immune system's response.

* Provocation ( medical ), a way of medical testing for conditions such as an allergy by provoking the immune system's response

Immunologic adjuvants are added to vaccines to stimulate the immune system's response to the target antigen, but do not in themselves confer immunity.

The alternative pathway of the complement system is an innate component of the immune system's natural defense against infections.

Adult T-cell leukemia / lymphoma ( ATL ) is a rare cancer of the immune system's own T-cells.

Healthy individuals can be infected with the virus and show no signs or symptoms, due to the immune system's ability to keep the infection in check.

As the body prepares to deal with a threat, blood pressure, heart rate, perspiration, blood flow to the major muscle groups are increased, while immune and digestive functions are inhibited ( the fight or flight response ).

An immunogen is a substance that is able to provoke an adaptive immune response if injected on its own.

An immunogen is able to induce an immune response, whereas an antigen is able to combine with the products of an immune response once they are made.

Immunogenicity is the ability to induce a humoral and / or cell-mediated immune response

Antigenicity is the ability to combine specifically with the final products of the immune response ( i. e. secreted antibodies and / or surface receptors on T-cells ).

Five different antibody isotypes are known in mammals, which perform different roles, and help direct the appropriate immune response for each different type of foreign object they encounter.

These patches may improve the efficiency of the cellular immune response.

Instead of an immune response, the dying cell synthesizes substances to break itself down and places them in a vacuole which ruptures as the cell dies.

Norway saw its first finding in February 2009, when cows at two farms in Vest-Agder in the south of Norway showed an immune response to bluetongue.

Recent research by the Imperial College London has focused on finding new cell wall proteins which trigger an immune response and are suitable for use in a vaccine to provide long-term protection against M. tuberculosis.

# Interference by nontuberculous mycobacteria: Exposure to environmental mycobacteria ( especially M. avium, M. marinum and M. intracellulare ) results in a nonspecific immune response against mycobacteria.

Administering BCG to someone who already has a nonspecific immune response against mycobacteria does not augment the response already there.

Whether this natural immune response is protective is not known.

An alternative explanation is suggested by mouse studies ; immunity against mycobacteria stops BCG from replicating and so stops it from producing an immune response.

# Interference by concurrent parasitic infection: In another hypothesis, simultaneous infection with parasites changes the immune response to BCG, making it less effective.

As Th1 response is required for an effective immune response to tuberculous infection, concurrent infection with various parasites produces a simultaneous Th2 response, which blunts the effect of BCG.

These vaccines will elicit the immune response without the attendant risks of infection.

In one response to Gettier, the American philosopher Richard Kirkham has argued that the only definition of knowledge that could ever be immune to all counterexamples is the infallibilist one.

* Molecular Mimicry-An exogenous antigen may share structural similarities with certain host antigens ; thus, any antibody produced against this antigen ( which mimics the self-antigens ) can also, in theory, bind to the host antigens, and amplify the immune response.

More modern uses of saponins in biotechnology are as adjuvants in vaccines: Quil A and its derivative QS-21, isolated from the bark of Quillaja saponaria Molina, to stimulate both the Th1 immune response and the production of cytotoxic T-lymphocytes ( CTLs ) against exogenous antigens make them ideal for use in subunit vaccines and vaccines directed against intracellular pathogens as well as for therapeutic cancer vaccines but with the aforementioned side-effects of hemolysis.

** An exogenous antigen that stimulates an immune response

CRISPR functions as a prokaryotic immune system, in that it confers resistance to exogenous genetic elements such as plasmids and phages.

Regular administration of exogenous granulocyte colony-stimulating factor ( Filgrastim ) clinically improves neutrophil counts and immune function and is the current mainstay of therapy, although this may increase risk for myelofibrosis and acute myeloid leukemia in the long term.