METHODS OF TREATMENT USING AN ANTI IL B50 ANTIBODY

1 .- 3 . (canceled)

4 . A method of modulating physiology or development of an IL-7Rα or Rδ2 expressing cell comprising contacting said cell to an exogenous agonist or antagonist of a mammalian IL-B50.

5 . The method of claim 4 , wherein:

A) said antagonist is:

1) an antibody which neutralizes said mammalian IL-B50;

2) a mutein of said IL-B50; or

3) an antibody which binds to IL-7Rα or Rδ2 or a complex comprising both;

B) said physiology is selected from:

1) proliferation;

2) lymphoid or dendritic lineage cell development;

3) antigen presentation; or

4) production of inflammatory mediators, including cytokines, chemokines, or adhesion molecules; or

C) said cell is a hematopoietic cell.

6 . The method of claim 4 , wherein:

a) said antagonist is an antibody and said physiology is hematopoietic cell proliferation;

b) said agonist is IL-B50 and said physiology is hematopoietic cell differentiation; or

c) said physiology is antigen presentation.

7 . The method of claim 4 , wherein said modulating is blocking, and said physiology is lymphoid lineage cell proliferation.

8 . A method of modulating a signal to a cell mediated by IL-B50 comprising contacting said cell to an administered agonist or antagonist of IL-B50.

9 . The method of claim 8 , wherein said modulating is inhibiting, and said signal is a proliferation signal.

10 . The method of claim 9 , wherein:

a) said antagonist is a neutralizing antibody to IL-7Rα or the Rδ2 subunit or a complex comprising said subunits;

b) said agonist or antagonist is administered in combination with another antagonist or agonist of IL-B50; or

c) said agonist or antagonist is administered in combination with a growth factor, cytokine, chemokine, or immune adjuvant.

11 . The method of claim 9 , wherein said contacting is with another anti-proliferative agent or treatment.

12 .- 21 . (canceled)