Description

Human CD3 Pan T Cells

Human CD3 Pan T cells consist of both CD4 and CD8 T cells, and make up approximately 45-75% of PBMCs in a typical adult. All T cells carry the CD3 protein marker and the T cell receptor (TCR), which recognizes foreign antigens presented by major histocompatibility complex molecules on antigen presenting cells to activate them.

T cells develop in the thymus to become mature CD4 or CD8 T cells and exit the thymus to reside and encounter foreign pathogens in lymphoid tissues.

When activated, CD4 T cells will become T helper subsets to secrete cytokines to boost either the humoral or cell-mediated immune response. In contrast, CD8 T cells, when stimulated, will become cytotoxic T cells that can lyse infected or transformed cells.  Together, these two main subsets work to clear infections or diseased cells.

Pan T Cell Application Summary

Purified human blood T cells are a good source of cells to study the biology of T cells and their role in the immune system. T cells are responsible for producing cytokines and performing cytotoxicity. Thus, pan T cells can be used for a variety of stimulation-dependent functional experiments to assess cytokine production, proliferation, and cytotoxicity.

With the current trend toward development of immuno-modulatory drugs, purified pan T cells are an ideal source of cells to test T cell response in the presence of therapeutic molecules.

The negative isolation of pan T cells leaves them untouched without any antibody binding to cell surface markers that may influence function. This method leaves all cell surface proteins eligible to be bound to antibodies or other molecules for functional or population characterization studies.

In contrast, positive isolation of pan T cells may lead to internalization of the marker that was used to isolate the cells.  In most cases, these markers are only used for identification purposes and may not have any effect on function, but it will depend on the organism and function.  Therefore, cells isolated using this method may also be employed for functional or population characterization studies with the knowledge that the isolation marker may be internalized and not present.

Pan T Cell Enrichment

Collection of samples

Leukapheresis was performed on verified healthy donors at a world-renowned blood center to obtain PBMCs. PBMCs were carefully washed to remove excess buffers according to iQ Biosciences’ standard operating procedures to obtain clean and healthy PBMCs.

Isolation of Human Pan T cells

To enrich for pan T cells by the negative isolation method, PBMCs were incubated with antibodies against B cells, NK cells, dendritic cells, monocytes, granulocytes, and erythrocytes in a test tube, and subsequently subjected to a magnet. Cells labeled with the antibodies bound to the magnet through the test tube wall, while unlabeled cells, the pan T cells, were decanted into a fresh tube to obtain the enriched population.

For the positive selection method, PBMCs were incubated in a test tube with antibodies against a pan T cell-specific marker and subsequently subjected to a magnet, similar to negative isolation.  However, the cells that were decanted into the fresh test tube were the non-pan T cells, which can be used for other purposes, while the labeled pan T cells were left bound to the magnet through the test tube wall.  The test tube was then removed from the magnet to release the purified pan T cells directly into the test tube.

Contact us for more information about purchasing our magnetically isolated pan T cells.

Purity

A small aliquot of cells was tested for post-sort purity by flow cytometry analysis. Purity of pan T cells, as defined by CD3 expression, was > 99% (Figure 1).

Figure 1. Purity of pan T cells after negative magnetic isolation from PBMCs.  In this representation, human PBMCs were incubated with antibodies against B cells, NK cells, dendritic cells, monocytes, granulocytes, and erythrocytes and subjected to negative magnetic isolation to obtain untouched pan T cells.  A small aliquot was taken after selection to evaluate post-sort purity (right).  Percent of CD3+ cells in PBMCs is also shown (left).

Cryopreservation and storage

Purified human CD3 pan T cells were cryopreserved carefully using iQ Biosciences’ cryopreservation protocol that ensures high viability (> 90%) after thawing.

Cells should be stored at < -120°C once they are received, such as within a liquid nitrogen tank (vapor phase).