Even after successful antiretroviral therapy, HIV can hide dormant in a tiny number of immune system cells for decades and re-emerge to threaten the life of its host. Now Yale University researchers have discovered a molecular ...
May 13, 2020
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The latest generation of cancer treatments spring from the discovery that the human immune system is able to beat the disease. Like Dorothy in "The Wizard of Oz," what research teams around the world have spent decades searching ...
Dec 20, 2017
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While treatments for HIV mean that the disease is no longer largely fatal, the world still lacks a true therapy that can eradicate the virus across a globally—and genetically different—population.
Jun 8, 2018
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Researchers at The Westmead Institute for Medical Research have discovered brand new immune cells that are at the frontline of HIV infection. Known as CD11c+ dendritic cells, these new cells are more susceptible to HIV infection ...
Jun 21, 2019
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An international team focused on HIV cure research spearheaded by The Wistar Institute in collaboration with the University of Pennsylvania and Vall d'Hebron Research Institute (VHIR) in Barcelona, Spain, established that ...
Apr 18, 2018
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Messenger-RNA (mRNA) vaccines against the coronavirus that causes COVID-19 provoke a swift and strong response by the immune system's T cells—the heavy armor of the immune system—according to a study from researchers ...
Aug 16, 2021
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Researchers from the University of Copenhagen have discovered autoreactive cells in persons suffering from narcolepsy. This is a new, important proof that the sleep disorder is an autoimmune disease. This knowledge may lead ...
Mar 18, 2019
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In a study, a new HIV drug reduced viral replication and increased immune cells in individuals with advanced, drug-resistant HIV infection. Used in combination with existing HIV medications, the drug is a promising strategy ...
Aug 15, 2018
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391
Treating new born mice with farmyard microbes reduces wheezing and inflammation in the airways, by 'taming' their immune systems.
Sep 24, 2018
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A team of researchers, led by investigators at the University of Colorado School of Medicine, have identified a new class of antigens that may be a contributing factor to type 1 diabetes, according to an article published ...
Feb 11, 2016
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T helper cells (also known as effector T cells or Th cells) are a sub-group of lymphocytes (a type of white blood cell or leukocyte) that play an important role in establishing and maximizing the capabilities of the immune system. These cells are unusual in that they have no cytotoxic or phagocytic activity; they cannot kill infected host (also known as somatic) cells or pathogens, and without other immune cells they would usually be considered useless against an infection. Th cells are involved in activating and directing other immune cells, and are particularly important in the immune system. They are essential in determining B cell antibody class switching, in the activation and growth of cytotoxic T cells, and in maximizing bactericidal activity of phagocytes such as macrophages. It is this diversity in function and their role in influencing other cells that gives T helper cells their name.
Mature Th cells are believed to always express the surface protein CD4. T cells expressing CD4 are also known as CD4+ T cells. CD4+ T cells are generally treated as having a pre-defined role as helper T cells within the immune system, although there are known rare exceptions. For example, there are sub-groups of regulatory T cells, natural killer T cells, and cytotoxic T cells that are known to express CD4 (although cytotoxic examples have been observed in extremely low numbers in specific disease states, they are usually considered non-existent). All of the latter CD4+ T cell groups are not considered T helper cells, and are beyond the scope of this article.
The importance of helper T cells can be seen from HIV, a virus that infects cells that are CD4+ (including helper T cells). Towards the end of an HIV infection the number of functional CD4+ T cells falls, which leads to the symptomatic stage of infection known as the acquired immune deficiency syndrome (AIDS). There are also some rare disorders that result in the absence or dysfunction of CD4+ T cells. These disorders produce similar symptoms, and many of these are fatal.
This text uses material from Wikipedia, licensed under CC BY-SA
