Human Recombinant Interleukin 2 Binds to Mouse Red Blood Cells via the Erythropoietin Receptor
Murine red blood cells (RBC) incubated with recombinant human interleukin 2 (rIL2) bound 10–20% of the added cytokine with 41.28 ± 4.64% of the population positive for bound cytokine as determined by fluorescence activated cell scanning (FACS) analysis. It has been well documented that a high degree of homology exists between the erythropoietin receptor (EPOR) and the IL2βR chain (based both on amino acid sequence and hydrophobicity alignment), we hypothesized that the rIL2 was binding to residual EPOR on murine RBC. Upon bioassay, it was found that reticulocytes (RET), which express a higher percentage of EPOR than normal RBC, bound 400% more rIL2 as compared to normal RBC. FACS analysis using fluorescently labeled rIL2 revealed a log higher fluorescence intensity on RET compared to RBC. Therefore, the population of immature or young RBC in circulation which are expressing residual EPOR are binding rIL2 due to cross-reactivity between the EPOR and IL2βR.
KeywordsErythropoietin Receptor CTLL Cell Residual EPOR Fluorescence Activate Cell Scanning Natural Killer Enhance Factor
Unable to display preview. Download preview PDF.
- Anstee, N. J., Gardner, B. K., Spring, F. A., Holmes, C. H., Simpson, K. L., Parsons, S. F., Mallinson, G., Yousaf, S. M., Judson, P. A. New monoclonal antibodies in CD44 and CD58:their use to quantify CD44 and CD58 on normal human erythrocytes and to compare the distribution of CD44 and CD58 in human tissues. Immunol. 74, 197–205, 1991.Google Scholar
- DeLoach, J.R., Andrews, K., Kruse, C. Encapsulation of human recombinant interleukin-2 into carrier erythrocytes by hypoosmotic dialysis and its subsequent biological activity. Adv. Biosciences 81, 59–65, 1991.Google Scholar
- DeLoach, J.R., Andrews, K., Sheffield, C.L. Encapsulation of Interleukin-2 in murine erythrocytes and subsequent deposition in mice receiving a subcutaneous injection. Biotech. Appl. Biochem. 10, 183–190, 1988.Google Scholar
- Kniep, E.M., Strelow, I., Lohman-Matthes, M.-L. The monocyte interleukin-2 receptor light chain: production of cell-associated and soluble interleukin-2 receptor by monocytes. Immunol. 75, 299–304, 1992.Google Scholar
- Moyes, R.B., Kirch, H.J., DeLoach, J.R. Immunotherapeutic evaluation of human recombinant interleukin 2 (rIL2) coated erythrocytes using the murine model. Adv Biosciences 92, 151–162, 1993.Google Scholar
- Youssofian, H., Longmore, G., Neumann, D., Yoshimura, A., Lodish, H. Structure, function, and activation of the erythropoietin receptor. Blood 81 (9), 2223–2236, 1993.Google Scholar