This space represents the ideas, views, opinions, projects and data of researchers within the Aptamer Stream of the Freshman Research Initiative, a program developed at the University of Texas at Austin. These are projects we currently have in the pipeline.
- We're not exclusive...we are SELECTIVE!
Nucleic acid selection against PDL1 as a means of inhibiting immunosuppression by cancerous cells
Orlando Adrian Lara
December 3, 2013
RNA N56H pool
Protein A bead
based selection against PD-L1
Aptamer selection against PD-L1 as a means of
inhibiting immunosuppressive properties of cancerous cells
Recent studies in the field of cancer
immunotherapy have shown that the Programmed death 1 receptor/Programed death
ligand1 (PD-1/PD-L1) pathway contributes to the ability of cancer cells to
evade the immune system. Programmed death ligand 1 (PD-L1) interacts with the
surface receptor site of cytotoxic T lymphocytes PD1, causing T cell inhibition
and apoptosis (Haile, S. et al. 2013).
Studies using flow cytometry show increased
up regulation of PD-L1 in the tissues of patients with lymphoma, suggesting
PDL1 can help promote carcinogenesis (Li, Y. et al. 2013). Iwai Y et al. (2004)
demonstrated that blocking the PD-1/PD-L1 pathway—by genetic manipulations or
antibody treatment— inhibited the metastasis of melanoma cells to the liver and
the metastasis of colon cancer cells to the lung by enhancing the recruitment
of T cells.
The use of aptamers as a means of blocking
the PD-1/PD-L1 pathway is introduced as a way of promoting inhibition of
immunosuppressive properties characterized by cancerous cells. Aptamers are
short oligonucleotide sequences that have the ability to bind to a wide range
of target molecules, including drugs, proteins, and other organic or inorganic
molecules with high affinity and specificity (Ellington, A. D., 1990).
Specific Aim – Find an aptamer that will
bind to PDL1. Binding an aptamer to PD-L1 has the potential to inhibit the
immunosuppression of cytotoxic T cells and promote the recruitment of cytotoxic
T cells for the destruction of cancer cells.
aptamer against PDL1 can be used to block the PD1/PDL1 pathway inhibiting
immunosuppression of T cells and promoting tumor-immunity.
PD-L1 was obtained from R&D systems
(www.rndsystems.com) and is listed under the catalog number 1019-B7-100. The
protein was order as 100ug lyophilized for $329, and was reconstituted in
twenty microliters of 1X PBS plus 5mM MgCl2 for a final
concentration of 100μM. The stock solution was then made into
200pmol aliquots. The cost of per round was calculated to be $32.9 for a total
of 10 rounds and was received functionalized with F/C chimera.
Haile, S., Dalal,
S., Clements, V., Tamada, K., & Ostrand-Rosenberg, S. (2013, August 5). Soluble
CD80 Restores T Cell Activation and Overcomes Tumor Cell Programmed Death
Ligand 1-Mediated Immune Suppression." J Immunol 191.5 (2013): 2829-836.
Li, Y., Wang, J.,
& Ke, X. (2013, April 21). [Expression of PD-L1 in l... [Zhongguo Shi Yan
Xue Ye Xue Za Zhi. 2013] - PubMed - NCBI. National Center for Biotechnology
Information. Retrieved September 16, 2013, from http://www.ncbi.nlm.nih.gov/pubmed/?term=Expression+of+PD-
Iwai, Y., Terawaki,
S., & Honjo, T. (2004, December 20). PD-1 blockade inhibits hematogenous
spread of poorly immunogenic tumor cells by enhanced recruitment of effector T
cells . Oxford Journals | Life Sciences & Medicine | International
Ellington, A. D.,
& Szostak, J. W. (1990). In Vitro Selection Of RNA Molecules That Bind
Specific Ligands. Nature, 346(6287), 818-822.