| First Author | Eisenbraun MD | Year | 1999 |
| Journal | J Immunol | Volume | 163 |
| Issue | 5 | Pages | 2621-7 |
| PubMed ID | 10453001 | Mgi Jnum | J:57091 |
| Mgi Id | MGI:1343670 | Doi | 10.4049/jimmunol.163.5.2621 |
| Citation | Eisenbraun MD, et al. (1999) mdr1a-encoded P-glycoprotein is not required for peripheral T cell proliferation, cytokine release, or cytotoxic effector function in mice. J Immunol 163(5):2621-7 |
| abstractText | The plasma membrane transport protein P-glycoprotein (P-gp) is expressed by subsets of both CD4+ and CD8+ T cells in mice. The proportion of T cells that express P-gp goes up with age, and the P-gp-expressing subset of the CD4 memory population is hyporesponsive in many in vitro assays. The significance of P-gp expression for T cell function has not been well established, although several reports have suggested that it may promote cytokine export and/or cytotoxic T cell function. To elucidate which T cell functions may require P-gp, we have compared a variety of responses using T cells from wt and P-gp knockout mice. Protein expression and rhodamine-123 efflux studies revealed that peripheral T cells exclusively utilize the mdr1a-encoded isoform rather than the homologous mdr1b or mdr2 isoforms. Comparisons of T cells from mdr1a+/+ and mdr1a-/- mice showed no differences in proliferation or in secretion of IL-2, IL-4, IL-5, IL-10, or IFN-gamma in response to polyclonal stimulation. Moreover, mdr1a-/- T cells produced strong allospecific cytotoxic responses comparable to those of wt T cells. Our results show that P-gp is not a necessary component of peripheral T cell functional responses. Further investigation will be needed to determine the significance of P-gp expression in T lymphocytes. |
