CD4


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CD4

 
designation for an antigen found on helper T cells; see under antigen.

CD4

a type I transmembrane protein found on helper/inducer T cells, monocytes, macrophages, and dendritic cells that is involved in T-cell recognition of antigens; expressed in mycosis fungoides, Sézary syndrome, and T-cell lymphomas.

CD4

(sē′dē-fôr′)
n.
A glycoprotein predominantly found on the surface of helper T cells. In humans, it is a receptor for HIV, enabling the virus to gain entry into its host.

CD4

(cluster designation 4) symbol for a glycoprotein expressed on the surface of helper T lymphocytes and other immune cells. CD4 serves as a receptor for human immunodeficiency virus envelope glycoprotein gp120. Binding of the viral glycoprotein gp120 to CD4 is the first step in viral entry, leading to the fusion of viral and cell membranes. CD4 count is used as an indicator of treatment timing in HIV patients.

CD4/CD8 count

the ratio of the number of helper T lymphocytes to the number of suppressor and cytotoxic T lymphocytes. The cells are counted with the use of monoclonal antibodies to the surface glycoproteins CD4 on helper T cells and CD8 on suppressor and cytotoxic T cells. In healthy individuals the ratio ranges from 1.6 to 2.2. The ratio is important in monitoring the function of the immune system in patients who have viral infections or who have undergone tissue transplantation, either of which may cause an increase in the number of suppressor T cells.

CD4

A transmembrane glycoprotein present on T helper/inducer cells, which participates in adherence of T cells to target cells, and is involved in thymic maturation and transmission of intracellular signals during T cell activation by the class II MHC; CD4 has inducer or helper activity for T cell, B cell, and macrophage interactions, and evokes T cell proliferation in response to soluble antigens or autologous non-T cells, providing appropriate signals for B cell proliferation and differentiation into Ig-secreting cells; CD4 is also a high-affinity receptor for HIV-1's gp120, binding 42–55 of the NH2 terminal domain amino acids, and has an Ig-like fold similar to the complementarity-determining region of the kappa light chain; CD4 also binds Igs independently of the Fc receptor, and is an accessory to the T-cell receptor

CD4

A type of protein molecule in human blood that is present on the surface of 65% of human T cells. CD4 is a receptor for the HIV virus. When the HIV virus infects cells with CD4 surface proteins, it depletes the number of T cells, B cells, natural killer cells, and monocytes in the patient's blood. Most of the damage to an AIDS patient's immune system is done by the virus' destruction of CD4+ lymphocytes. CD4 is sometimes called the T4 antigen.
Mentioned in: AIDS, AIDS Tests

CD4 (T4) lymphocyte,

n an immunologically important white cell that is responsible for cell-mediated immunity. It is the cell invaded by the human immunodeficiency virus and in which the virus replicates itself.

CD2

cluster of differentiation or cell differentiation glycoproteins.

CD antigen
a group of cell surface molecules which act as markers on T lymphocytes.
CD3
found on T helper (Th) and T cytotoxic (Tc) lymphocytes; associated with signal transduction.
CD4
found on T helper lymphocytes; an adhesion molecule that binds to class II MHC molecules.
CD8
found on T cytotoxic and variably on NK lymphocytes; an adhesion molecule that binds to class I MHC molecules.
References in periodicals archive ?
After the introduction of point-of-care CD4 tests, the proportion of patients lost to follow-up declined significantly, from 64% to 33% (adjusted odds ratio 0.
However, this study had a major limitation in that the study established reference values only for CD4+ T cell percentages and not absolute CD4 counts.
Ensuring accurate CD4 counts has become more important recently, since ART is being initiated at higher CD4 counts, when clinical signs tend to be less sensitive in detecting immune suppression.
Impact of initial CD4 count on expected age at death in 35-year-old men Expected age at death Under 200 71 200 to 349 78 Above 349 77 Without HIV 78 CD4 count before ontiretrovirals Figure 1.
Relationship of the human immunodeficiency virus type 1 gp120 third variable loop to a component of the CD4 binding site in the fourth conserved region.
There has been a lot of progress increasing access to life-saving HIV drugs in the developing world, but the lack of access to essential diagnostics like a CD4 test is a major barrier to providing the best possible care," said Dr.
Our study revealed that radiographic manifestations of HIV related pulmonary tuberculosis have a relationship with the CD4 count; which is an indicator of immune status and stage of HIV infection.
Both opportunistic and nonopportunistic events were less likely in patients with higher CD4 counts.
As part of its ongoing commitment to increasing access to critical diagnostic technologies, BD entered into an agreement with the Clinton Foundation to expand accessibility of advanced CD4 cell-counting technology for immune system monitoring of people living with HIV/AIDS.
Expenditures totaled $13,885 for individuals at the earliest stage of disease but rose steadily across declining strata of CD4 cell counts, reaching $36,532 for those with the most advanced disease.
However, a recent retrospective review suggested that delaying HAART would, particularly in those with CD4 cell counts<100 cells x [10.
The goal, Margolis says, "is to get rid of [all] infected CD4 T cells.