ICOS-dependent extrafollicular helper T cells
elicit IgG production via IL-21 in systemic autoimmunity.
Liu et al., "Increased frequency of follicular helper T cells
in patients with autoimmune thyroid disease," The Journal of Clinical Endocrinology and Metabolism, vol.
Shimohakamada et al., "The development and fate of follicular helper T cells
defined by an IL-21 reporter mouse," Nature Immunology, vol.
"Our team also showed that these transformed helper T cells
represent a separate and distinct population of cells.
With the use of this technique, the killer T cells would not need the assistance of helper T cells
. So even if a tumor were to put the helper T cells
in a suppressive cage, the killer T cells would still be able to go out and kill cancer cells.
If Ho's model is correct, antiretroviral drugs, which slow the destruction of helper T cells
, reduce the need for production of CD4 cell replacements.
However, it may be possible to remove helper T cells
from a human patient and stimulate them so that all the cells that recognize a given virus grow.
In initial test-tube experiments, the researchers found that leptin increases the ability of helper T cells
, one class of immune cells, to proliferate after being stimulated into activity.
His own work indicates that exposure to lead and various other heavy metals can upset the balance between two classes of the immune system's helper T cells
in favor of cells less able to ward off certain viral infections.