Method for detecting IL-16 activity and modulation of IL-16 activity based on rantes proxy protein levels

1. A method of detecting IL-16 biological activity in a sample comprising the steps of:

a) providing a first population of eukaryotic cells surrounded by media and responsive to IL-16 biological activity with a first test sample;

b) providing a second population, of the same type of eukaryotic cells as in a) and surrounded by media and responsive to IL-16 biological activity, with a negative control sample;

c) measuring the amount of a RANTES proxy protein produced by the first and second populations of eukaryotic cells; and

d) comparing the amount of a RANTES proxy protein produced by the first and second populations of eukaryotic cells, wherein a smaller amount of a RANTES proxy protein produced by the first population of eukaryotic cells relative to the RANTES proxy protein level produced by the second population of eukaryotic cells indicates the detection of IL-16 biological activity in the test sample.

2. The method of claim 1 wherein the eukaryotic cells express a CD4 peptide chain or CD9 peptide chain.

3. The method of claim 2 wherein the eukaryotic cells are selected from the group consisting of peripheral blood mononuclear cells, HuT-78 cells, and THP-1 cells.

4. The method of claim 1 wherein providing the first test sample produces a final IL-16 concentration in the media surrounding the first population of eukaryotic cells that is 100 ng/ml to 1000 ng/ml.

5. The method of claim 1 wherein the RANTES proxy protein is secreted into the media.

6. The method of claim 1 , wherein the smaller amount of RANTES proxy protein produced by the first population relative to the second population is at least about a 1.5 fold decrease.

7. A method of detecting a molecule that increases IL-16 biological activity in a sample comprising the steps of:

a) providing a first population of eukaryotic cells surrounded by media and responsive to IL-16 biological activity with a first test sample;

b) providing a second population, of the same type of eukaryotic cells as in a) and surrounded by media and responsive to IL-16 biological activity, with a positive control sample containing biologically active IL-16;

c) measuring the amount of a RANTES proxy protein produced by the first and second populations of eukaryotic cells; and

d) comparing the amount of a RANTES proxy protein produced by the first and second populations of eukaryotic cells, wherein a smaller amount of a RANTES proxy protein produced by the first population of eukaryotic cells relative to the RANTES proxy protein level produced by the second population of eukaryotic cells indicates the presence of a molecule that increases IL-16 biological activity in the test sample.

8. The method of claim 7 wherein the eukaryotic cells express a CD4 peptide chain or CD9 peptide chain.

9. The method of claim 8 wherein the eukaryotic cells are selected from the group consisting of peripheral blood mononuclear cells, HuT-78 cells, and THP-1 cells.

10. The method of claim 7 wherein the first test sample comprises an antibody molecule.

11. The method of claim 7 wherein the RANTES proxy protein is secreted into the media.

12. The method of claim 7 , wherein the smaller amount of RANTES proxy protein produced by the first population relative to the second population is at least about a 1.5 fold decrease.

13. A method of detecting a molecule that decreases IL-16 biological activity in a sample comprising the steps of:

a) providing a first population of eukaryotic cells surrounded by media and responsive to IL-16 biological activity with a first test sample;

b) providing a second population, of the same type of eukaryotic cells as in a) and surrounded by media and responsive to IL-16 biological activity, with a positive control sample containing biologically active IL-16;

c) measuring the amount of a RANTES proxy protein produced by the first and second populations of eukaryotic cells; and

d) comparing the amount of a RANTES proxy protein produced by the first and second populations of eukaryotic cells, wherein a larger amount of a RANTES proxy protein produced by the first population of eukaryotic cells relative to the RANTES proxy protein level produced by the second population of eukaryotic cells indicates the presence of a molecule that decreases IL-16 biological activity in the test sample.

14. The method of claim 13 wherein the eukaryotic cells express a CD4 peptide chain or CD9 peptide chain.

15. The method of claim 14 wherein the eukaryotic cells are selected from the group consisting of peripheral blood mononuclear cells, HuT-78 cells, and THP-1 cells.

16. The method of claim 13 wherein the first test sample comprises an antibody molecule.

17. The method of claim 13 wherein the RANTES proxy protein is secreted into the media.

18. The method of claim 13 , wherein the larger amount of RANTES proxy protein produced by the first population relative to the second population is at least about a 1.5 fold increase.