Abstract
BackgroundIt can be difficult to register a weak proliferative response of T lymphocytes to an antigen, particularly in a simple culture system of peripheral blood mononuclear cells (PBMC). Here we assess the usefulness of the cytokine IL-2 in amplifying such a response.MethodsPBMC from healthy donors were cultured in the presence or absence of keyhole limpet haemocyanin (KLH), an antigen to which people have not been previously exposed. IL-2 was added from the beginning or on the fifth day of culture. Proliferation was determined by incorporation of tritiated thymidine at eight days. The recall antigen, tuberculin PPD, provided a positive control.ResultsIL-2 added at the beginning of culture can induce extremely high levels of proliferation even in the absence of antigen. However, when added on the fifth day it allowed the clear observation of a proliferative response to KLH that was barely detectable in its absence. Added late it was similarly able to boost low responses to PPD and to the mitogens lipopolysaccharide and poly(I:C), but it had no such effect with pokeweed mitogen.ConclusionsIL-2 added late in culture is highly effective in increasing the sensitivity of T lymphocyte proliferative assays.
Highlights
It can be difficult to register a weak proliferative response of T lymphocytes to an antigen, in a simple culture system of peripheral blood mononuclear cells (PBMC)
We have studied the effect of added IL-2 on the response to keyhole limpet haemocyanin (KLH), an antigen with which people will have had no previous contact
With the objective of increasing the sensitivity of the lymphocyte proliferation assay, we began by testing the effect of adding IL-2 to cultures in the absence of antigen
Summary
It can be difficult to register a weak proliferative response of T lymphocytes to an antigen, in a simple culture system of peripheral blood mononuclear cells (PBMC). We assess the usefulness of the cytokine IL-2 in amplifying such a response. It can sometimes be difficult to identify the presence of antigen-reactive T lymphocytes by assaying for antigeninduced proliferation of the cells. The number of reactive cells may be too small. They may be in an anergic state or under the influence of regulatory T cells. There may be 'noise', that is the proliferation in culture of cells other than those being assayed. The problem may be one of inappropriate antigen presentation or that the culture conditions are sub-optimal
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have