ANTI-MOUSE CD25 (IL-2 Receptor alpha chain),
CLONE PC61

SPECIFICITY

The PC61 antibody reacts with the low-affinity (alpha chain, p55) IL-2R expressed on activated T and B lymphocytes from all mouse strains tested.(1,2) Resting T and B lymphocytes and resting and activated NK cells do not express IL-2Ralpha. CD25 is transiently expressed at a low level during normal B-cell development in the bone marrow on the CD45R/B220low TdT- sIg- Pre-B/Pre-B-II and CD45R/B220low TdT- sIgM+ sIgD- immature B stages, but not on the CD45R/B220low TdT+ sIg- Pro-B/Pre-B-I stage nor on CD45R/B220high TdT- sIgM+ sIgD+ mature B cells.(4,5) It is expressed at a higher level during a very early stage of T-cell development in fetal and adult thymus.(3,6) The PC61 antibody recognizes an epitope of CD25 which is distinct from the IL-2 binding site and from those recognized by mAbs 3C7 (Cat. no. 01101D) and 7D4 (Cat. no. 01091D).(7) It blocks binding of IL-2 to CD25, presumably by inducing a conformational change in CD25.(1,7)

USAGE

The antibody has been tested by immunofluorescent staining (< 1 µg/million cells) with flow cytometric analysis and immunohistochemical staining of acetone-fixed frozen sections (0.3 - 2.5 µg/ml) to assure specificity and reactivity. Other reported applications include immunoprecipitation (2,3) and in vitro blocking of IL-2 binding to low- and high-affinity receptors.(1,2,3,7) For detection of the low-density CD25 on developing B cells in the bone marrow, we recommend use of the PE conjugate of PC61 antibody (Cat. no. 09985B) or the biotin conjugate of the 7D4 antibody (Cat. no. 01092D) with a "bright" second-step reagent, such as Streptavidin-PE (Cat. no. 13025D). Since applications vary, each investigator must determine dilutions appropriate for individual use.

Cat. No. Description Clone Isotype Size
09980D Purified anti-mouse CD25 (NA/LE) PC61 Rat IgG1 0.5mg
09981D Purified anti-mouse CD25 PC61 Rat IgG1 0.5mg
09985B PE labeled anti-mouse CD25 PC61 Rat IgG1 0.2mg

For Research Use Only. Not For Diagnostic or Therapeutic Use.

REFERENCES

  1. Lowenthal, J.W., P. Corthésy, C. Tougne, R. Lees, H.R. MacDonald, and M. Nabholz. 1985. High and low affinity IL-2 receptors: Analysis by IL-2 dissociation rate and reactivity with monoclonal anti-receptor antibody PC61. J. Immunol. 135: 3988 - 3994.
  2. Lowenthal, J.W., R.H. Zubler, M. Nabholz, and H.R. MacDonald. 1985. Similarities between interleukin-2 receptor number and affinity on activated B and T lymphocytes. Nature 315: 669 - 672.
  3. Ceredig, R., J.W. Lowenthal, M. Nabholz, and H.R. MacDonald. 1985. Expression of interleukin-2 receptors as a differentiation marker on intrathymic stem cells. Nature 314: 98 - 100.
  4. Rolink, A., U. Grawunder, T.H. Winkler, H. Karasuyama, and F. Melchers. 1994. IL-2 receptor a chain (CD25, TAC) expression defines a crucial stage in pre-B cell development. Int. Immunol. 6: 1257 - 1264.
  5. Chen, J., A. Ma, F. Young, and F.W. Alt. 1994. IL-2 receptor a chain expression during early B lymphocyte differentiation. Int. Immunol. 6: 1265 - 1268.
  6. Godfrey, D.I., and A. Zlotnik. 1993. Control points in early T-cell development. Immunol. Today 14: 547 - 553.
  7. Moreau, J.-L., M. Nabholz, T. Diamantstein, T. Malek, E. Shevach, and J. Thèze. 1987. Monoclonal antibodies identify three epitope clusters on the mouse p55 subunit of the interleukin 2 receptor: relationship to the interleukin 2-binding site. Eur. J. Immunol. 17: 929 - 935.

PharMingen offers a complete line of antibodies to mouse cell surface antigens, including:

[Homepage] [New Products Page] [Catalog of Products] [Ordering Information] [Technical Service]