Syntrophin binds to a variety of signaling molecules including sodium channels, neuronal nitric oxide synthase, aquaporin-4 and serine/threonine kinases. Mice lacking a1-syntrophin display aberrations in neuromuscular synapses with undetectable levels of postsynaptic utrophin and reduced levels of acetylcholine receptor and acetylcholinesterase. MAP1B deficiency did not appear to alter syntrophin expression or localization in Schwann cells, nor did it alter the characteristic organization of DRP2 in clusters at the abaxonal Schwann cell membrane, nor the internodal distance or the organization of the nodes of Ranvier as analyzed by staining for ezrin and Caspr1/paranodin. Thus, the previously observed reduction in nerve conductance velocity and the reduced myelination in MAP1B deficient sciatic nerves do not appear to be reflected by changes in syntrophin expression or intracellular organization. Originally, MAPs were thought to regulate neuronal microtubule dynamics, CPI-613 95809-78-2 stability, and spacing between individual microtubules in a microtubule bundle as well as modulating access and activity of microtubule-dependent motor proteins and thus axonal and dendritic transport through their direct interaction with microtubules. In a more recent development, classical MAPs have been found to bind to a wide variety of proteins with diverse functions. For example, proteins of the MAP1 family bind to receptors and ion channels, postsynaptic density proteins PSD-93 and PSD-95, signaling molecules and proteins involved in intracellular traffic. Thus, our findings presented here add to a growing body of evidence that classical MAPs can play a role in signal transduction not only by directly modulating microtubule function, but also through their interaction with a variety of signal transduction proteins. Exosomes are secreted membrane vesicles of nanometer size formed by inward budding of late endosomes resulting in the formation of multivesicular bodies in the cell and subsequent release into the cytosol by exocytosis. These mechanisms were first described in the 1980s by the groups of Stahl and Johnstone when studying the maturation of erythrocytes. Since then exosomes have been shown to be released by several cell types including epithelial cells, dendritic cells, B cells, T cells, mast cells and tumor cells among others. The presence of exosomes has also been shown in human body fluids such as plasma, urine, breast milk, bronchoalveolar lavage and malignant effusions. They have also been suggested to play a role in tumor immunity both as tumor growth promoters and as inhibitors of tumor growth. Exosome secretion from different T cell types has been demonstrated by several groups e.g. from activated CD3+ cells, CD4+ T cells and CD8+ T cells. The exosomes from CD4+ T cells have been suggested to deliver antigen specific signals, atherogenic signals and co-stimulatory signals whereas exosomes from CD8+ T cells have been associated with non-cytotoxic suppression of HIV1 transcription. While many studies have demonstrated the impact of immune signaling from exosomes derived from antigen presenting cells on T cells, not many, to our knowledge, have demonstrated the role of T cell exosome communication with other T cells. However, it has been shown that activated human T cells can release microvesicles containing Fas and APO2 ligand. The cytokine IL-2 is a potent lymphokine which regulates immune responses. It stimulates the proliferation and differentiation of activated immune cell e.g. T cells, B cells, monocytes and natural killer cells. T cells, activated by T cell receptor engagement with an antigen together with costimulation, are the main IL-2 secreting cells which stimulate proliferation of themselves in an autocrine manner as well as other neighboring antigen activated T cells.