Abstract: The invention relates to an antibody or antigen-binding fragment thereof which binds to the CXC chemokine receptor Bonzo (also referred to as STRL33, TYMSTR and HBMBU14) and blocks the binding of a ligand (e.g., SExCkine (also referred to as chemokine alpha-5) to the receptor. The invention also relates to a method of identifying agents (molecules, compounds) which can bind to Bonzo and inhibit the binding of a ligand (e.g., SExCkine) and/or modulate a function of Bonzo. The invention relates to an antibody or antigen-binding fragment thereof which binds to the CXC chemokine SExCkine (also referred to as chemokine alpha-5) and inhibit binding of SExCkine to receptor (e.g., Bonzo). The invention also relates to targeting molecules which contain a first binding moiety which binds to mammalian Bonzo and a second binding moiety which binds to a molecule expressed on the surface of a target cell.

Abstract: Methods are provided to specifically modulate the trafficking of systemic memory T cells, particularly CD4+ T cells, without affecting naive T cells or intestinal memory T cells. It is shown that systemic memory T cells, which are characterized as CD45Ra31 , and integrin &agr;4&bgr;731 , express high levels of CCR4. Ligands of CCR4, such as TARC or MDC, act as an adhesion trigger, wherein upon CCR4 binding, these cells undergo integrin-dependent arrest to the appropriate vascular receptor(s). This arrest acts to localize the cells at the target site. The methods of the invention manipulate this triggering, and CCR4 mediated chemotaxis, to affect the localization of T cells in targeted tissues. In one embodiment of the invention, the active agent is a CCR4 agonist, that acts to enhance T cell localization. In an alternative embodiment, the agent is an antagonist that blocks CCR4 biological activity.

Abstract: The invention relates to a method of detecting and/or identifying agents (molecules, compounds) which can bind to Bonzo and inhibit the binding of a ligand and/or modulate a function of Bonzo.

Abstract: Methods are provided to specifically modulate the trafficking of systemic memory T cells, particularly CD4+ T cells, without affecting naive T cells or intestinal memory T cells. It is shown that systemic memory T cells, which are characterized as CD45Ra−, and integrin &agr;4&bgr;7−, express high levels of CCR4. Ligands of CCR4, such as TARC or MDC, act as an adhesion trigger, wherein upon CCR4 binding, these cells undergo integrin-dependent arrest to the appropriate vascular receptor(s). This arrest acts to localize the cells at the target site. The methods of the invention manipulate this triggering, and CCR4 mediated chemotaxis, to affect the localization of T cells in targeted tissues. In one embodiment of the invention, the active agent is a CCR4 agonist, that acts to enhance T cell localization. In an alternative embodiment, the agent is an antagonist that blocks CCR4 biological activity.