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Spinophilin participates in information transfer at immunological synapses.

Bloom O, Unternaehrer JJ, Jiang A, Shin JS, Delamarre L, Allen P, Mellman I - J. Cell Biol. (2008)

Bottom Line: In DCs interacting with T cells, spinophilin is polarized dynamically to contact sites in an antigen-dependent manner.It is also required for optimal T cell activation because DCs derived from mice lacking spinophilin exhibit defects in antigen presentation both in vitro and in vivo.Thus, spinophilin may play analogous roles in information transfer at both neuronal and immunological synapses.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Ludwig Institute for Cancer Research, New Haven, CT 06520, USA.

ABSTRACT
The adaptive immune response is initiated by the presentation of peptides bound to major histocompatibility complex molecules on dendritic cells (DCs) to antigen-specific T lymphocytes at a junction termed the immunological synapse. Although much attention has been paid to cytoplasmic events on the T cell side of the synapse, little is known concerning events on the DC side. We have sought signal transduction components of the neuronal synapse that were also expressed by DCs. One such protein is spinophilin, a scaffolding protein of neuronal dendritic spines that regulates synaptic transmission. In inactive, immature DCs, spinophilin is located throughout the cytoplasm but redistributes to the plasma membrane upon stimulus-induced maturation. In DCs interacting with T cells, spinophilin is polarized dynamically to contact sites in an antigen-dependent manner. It is also required for optimal T cell activation because DCs derived from mice lacking spinophilin exhibit defects in antigen presentation both in vitro and in vivo. Thus, spinophilin may play analogous roles in information transfer at both neuronal and immunological synapses.

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Spinophilin is expressed in the immune cells and its localization in DCs is dynamic. (a) Detection of spinophilin by Western blot in serial dilutions of cell lysates from brain, spleen, or DCs. Numbers below indicate the ratio of adjusted mean density of spinophilin to actin on the Western blot. (b) Localization of spinophilin was detected by immunofluorescence in immature (top) and mature BMDCs (bottom) as indicated. DCs were stained with anti-spinophilin (RU466; Allen et al., 1997) and anti-MHCII (14.4.4 anti–IE-k FITC) antibodies and, to detect lysosomes, anti-Lamp (Lamp2) antibodies. (c) Localization of spinophilin, actin, and MHCII was detected by immunofluorescence in immature (top) and mature BMDCs (bottom) as indicated. DCs were stained with anti-spinophilin (RU466; Allen et al., 1997), TRITC-phalloidin, and anti-MHCII (14.4.4 anti–IE-k FITC) antibodies. Images in section c were pseudo-colored for illustrative purposes. Bars, 5 μM.
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fig1: Spinophilin is expressed in the immune cells and its localization in DCs is dynamic. (a) Detection of spinophilin by Western blot in serial dilutions of cell lysates from brain, spleen, or DCs. Numbers below indicate the ratio of adjusted mean density of spinophilin to actin on the Western blot. (b) Localization of spinophilin was detected by immunofluorescence in immature (top) and mature BMDCs (bottom) as indicated. DCs were stained with anti-spinophilin (RU466; Allen et al., 1997) and anti-MHCII (14.4.4 anti–IE-k FITC) antibodies and, to detect lysosomes, anti-Lamp (Lamp2) antibodies. (c) Localization of spinophilin, actin, and MHCII was detected by immunofluorescence in immature (top) and mature BMDCs (bottom) as indicated. DCs were stained with anti-spinophilin (RU466; Allen et al., 1997), TRITC-phalloidin, and anti-MHCII (14.4.4 anti–IE-k FITC) antibodies. Images in section c were pseudo-colored for illustrative purposes. Bars, 5 μM.

Mentions: We found that spinophilin mRNA is expressed by a variety of immune cells in mice, including DCs, macrophages, B cells, and T cells, by RT-PCR (unpublished data). At the protein level, we could detect the same 135-kD band in lysates of brain-, spleen-, and bone marrow–derived DCs by Western blotting (Fig. 1 a). Although most abundant (relative to actin) in brain, significant amounts of spinophilin were detected in DCs (∼10–20% that of brain, normalized to actin). Purified B and T cell populations also expressed spinophilin, as equivalent 135-kD proteins were detected in Western blots of lysates (unpublished data). As expected, the neuron-specific isoform of spinophilin, neurabin I (Allen et al., 1997; Nakanishi et al., 1997), was found only in brain lysates (unpublished data).


Spinophilin participates in information transfer at immunological synapses.

Bloom O, Unternaehrer JJ, Jiang A, Shin JS, Delamarre L, Allen P, Mellman I - J. Cell Biol. (2008)

Spinophilin is expressed in the immune cells and its localization in DCs is dynamic. (a) Detection of spinophilin by Western blot in serial dilutions of cell lysates from brain, spleen, or DCs. Numbers below indicate the ratio of adjusted mean density of spinophilin to actin on the Western blot. (b) Localization of spinophilin was detected by immunofluorescence in immature (top) and mature BMDCs (bottom) as indicated. DCs were stained with anti-spinophilin (RU466; Allen et al., 1997) and anti-MHCII (14.4.4 anti–IE-k FITC) antibodies and, to detect lysosomes, anti-Lamp (Lamp2) antibodies. (c) Localization of spinophilin, actin, and MHCII was detected by immunofluorescence in immature (top) and mature BMDCs (bottom) as indicated. DCs were stained with anti-spinophilin (RU466; Allen et al., 1997), TRITC-phalloidin, and anti-MHCII (14.4.4 anti–IE-k FITC) antibodies. Images in section c were pseudo-colored for illustrative purposes. Bars, 5 μM.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2315669&req=5

fig1: Spinophilin is expressed in the immune cells and its localization in DCs is dynamic. (a) Detection of spinophilin by Western blot in serial dilutions of cell lysates from brain, spleen, or DCs. Numbers below indicate the ratio of adjusted mean density of spinophilin to actin on the Western blot. (b) Localization of spinophilin was detected by immunofluorescence in immature (top) and mature BMDCs (bottom) as indicated. DCs were stained with anti-spinophilin (RU466; Allen et al., 1997) and anti-MHCII (14.4.4 anti–IE-k FITC) antibodies and, to detect lysosomes, anti-Lamp (Lamp2) antibodies. (c) Localization of spinophilin, actin, and MHCII was detected by immunofluorescence in immature (top) and mature BMDCs (bottom) as indicated. DCs were stained with anti-spinophilin (RU466; Allen et al., 1997), TRITC-phalloidin, and anti-MHCII (14.4.4 anti–IE-k FITC) antibodies. Images in section c were pseudo-colored for illustrative purposes. Bars, 5 μM.
Mentions: We found that spinophilin mRNA is expressed by a variety of immune cells in mice, including DCs, macrophages, B cells, and T cells, by RT-PCR (unpublished data). At the protein level, we could detect the same 135-kD band in lysates of brain-, spleen-, and bone marrow–derived DCs by Western blotting (Fig. 1 a). Although most abundant (relative to actin) in brain, significant amounts of spinophilin were detected in DCs (∼10–20% that of brain, normalized to actin). Purified B and T cell populations also expressed spinophilin, as equivalent 135-kD proteins were detected in Western blots of lysates (unpublished data). As expected, the neuron-specific isoform of spinophilin, neurabin I (Allen et al., 1997; Nakanishi et al., 1997), was found only in brain lysates (unpublished data).

Bottom Line: In DCs interacting with T cells, spinophilin is polarized dynamically to contact sites in an antigen-dependent manner.It is also required for optimal T cell activation because DCs derived from mice lacking spinophilin exhibit defects in antigen presentation both in vitro and in vivo.Thus, spinophilin may play analogous roles in information transfer at both neuronal and immunological synapses.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Ludwig Institute for Cancer Research, New Haven, CT 06520, USA.

ABSTRACT
The adaptive immune response is initiated by the presentation of peptides bound to major histocompatibility complex molecules on dendritic cells (DCs) to antigen-specific T lymphocytes at a junction termed the immunological synapse. Although much attention has been paid to cytoplasmic events on the T cell side of the synapse, little is known concerning events on the DC side. We have sought signal transduction components of the neuronal synapse that were also expressed by DCs. One such protein is spinophilin, a scaffolding protein of neuronal dendritic spines that regulates synaptic transmission. In inactive, immature DCs, spinophilin is located throughout the cytoplasm but redistributes to the plasma membrane upon stimulus-induced maturation. In DCs interacting with T cells, spinophilin is polarized dynamically to contact sites in an antigen-dependent manner. It is also required for optimal T cell activation because DCs derived from mice lacking spinophilin exhibit defects in antigen presentation both in vitro and in vivo. Thus, spinophilin may play analogous roles in information transfer at both neuronal and immunological synapses.

Show MeSH
Related in: MedlinePlus