Distinct regulation of integrin-dependent T cell conjugate formation and NF-kappa B activation by the adapter protein ADAP.

Abstract

Following TCR stimulation, T cells utilize the hematopoietic specific adhesion and degranulation-promoting adapter protein (ADAP) to control both integrin adhesive function and NF-kappaB transcription factor activation. We have investigated the molecular basis by which ADAP controls these events in primary murine ADAP(-/-) T cells. Naive DO11.10/ADAP(-/-) T cells show impaired adhesion to OVAp (OVA aa 323-339)-bearing APCs that is restored following reconstitution with wild-type ADAP. Mutational analysis demonstrates that the central proline-rich domain and the C-terminal domain of ADAP are required for rescue of T:APC conjugate formation. The ADAP proline-rich domain is sufficient to bind and stabilize the expression of SKAP55 (Src kinase-associated phosphoprotein of 55 kDa), which is otherwise absent from ADAP(-/-) T cells. Interestingly, forced expression of SKAP55 in the absence of ADAP is insufficient to drive T:APC conjugate formation, demonstrating that both ADAP and SKAP55 are required for optimal LFA-1 function. Additionally, the ADAP proline-rich domain is required for optimal Ag-induced activation of CD69, CD25, and Bcl-x(L), but is not required for assembly of the CARMA1/Bcl10/Malt1 (caspase-recruitment domain (CARD) membrane-associated guanylate kinase (MAGUK) protein 1/B-cell CLL-lymphoma 10/mucosa-associated lymphoid tissue lymphoma translocation protein 1) signaling complex and subsequent TCR-dependent NF-kappaB activity. Our results indicate that ADAP is used downstream of TCR engagement to delineate two distinct molecular programs in which the ADAP/SKAP55 module is required for control of T:APC conjugate formation and functions independently of ADAP/CARMA1-mediated NF-kappaB activation.

• Authors: Brandon J Burbach, Rupa Srivastava, Ricardo B Medeiros, William E O'Gorman, Erik J Peterson, Yoji Shimizu
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 181 Issue 7 Pg. 4840-51 (Oct 01 2008) ISSN: 1550-6606 [Electronic] United States
• PMID: 18802088 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Adaptor Proteins, Signal Transducing
• Fyb protein, mouse
• Integrins
• Membrane Proteins
• NF-kappa B
• OVA 323-339
• Peptide Fragments
• Phosphoproteins
• Receptors, Virus
• SKAP55 protein, mouse
• adenovirus receptor
• Ovalbumin

Topics

• Adaptor Proteins, Signal Transducing (biosynthesis, deficiency, genetics, physiology)
• Adenoviridae (genetics, immunology)
• Animals
• Antigen Presentation (genetics)
• Antigen-Presenting Cells (immunology, metabolism)
• Cell Adhesion (genetics, immunology)
• Cells, Cultured
• Humans
• Integrins (physiology)
• Jurkat Cells
• Lymphocyte Activation (genetics, immunology)
• Membrane Proteins (biosynthesis, genetics, metabolism)
• Mice
• Mice, Inbred BALB C
• Mice, Knockout
• Mice, Transgenic
• NF-kappa B (genetics, metabolism)
• Ovalbumin (immunology, metabolism)
• Peptide Fragments (immunology, metabolism)
• Phosphoproteins (biosynthesis, genetics, metabolism)
• Proline-Rich Protein Domains (physiology)
• Receptors, Virus (biosynthesis, genetics)
• T-Lymphocyte Subsets (immunology, metabolism)