Tat-based immunomodulatory compositions and methods for their discovery and use

Abstract

A method for identifying new immunomodulatory chemical entities (NICE) comprising reacting a candidate NICE with a Tat SH3 binding domain, identifying the bound candidate NICE and determining whether the candidate NICE induces monocytes to differentiate into dendritic cells (DC) or regulatory macrophages (AReg). In particular, the present invention relates to identifying NICE that are either immunostimulatory or immunosuppressive.

1 . A method for identifying new immunomodulatory chemical entities (NICE) comprising:
 a. reacting a candidate NICE with a Tat SH3 binding domain wherein said Tat SH3 binding domain is bound to a solid phase to identify candidate NICE that bind to said Tat SH3;   b. identifying said candidate NICE bound to said Tat SH3;   c. adding said identified candidate NICE to a culture of purified peripheral blood monocytes;   d. adding Tat having an SH3 binding domain to said peripheral blood monocytes and candidate NICE to form a test culture;   e. incubating said test culture to allow said monocytes to differentiate into dendritic cells (DC) or regulatory macrophages (AReg);   f. removing said differentiated cells from said test culture and determining the presence or absence of DCs or AReg.   
     
     
         2 . The method according to  claim 1  wherein said Tat SH3 binding domain in step (a) is selected from the group consisting of native immunosuppressive human immunodeficiency virus (HIV) Tat, simian lentivirus Tat, long-term non-responder Tat, randomly mutated HIV Tat and site-specific mutated HIV Tat. 
     
     
         3 . The method according to  claim 1  further comprising the step of injecting confirmed immunostimulatory NICE from step (f) of  claim 1  into an immunosuppressed mouse wherein said immunosuppression results from the presence of an endogenous SH3 binding domain. 
     
     
         4 . The method according to  claim 2  wherein the said immunosuppressive mouse is a hairless (hr) mouse. 
     
     
         5 . A method according to  claim 1  further comprising the step of injecting a tolerogenic NICE from step (f) of  claim 1  into a mouse and further challenging said mouse with an antigen wherein said tolerance results from the pre-treatment with tolerogenic NICE.