The antibody-induced clustering and endocytosis of HLA antigens on cultured human fibroblasts

Huet, Christian; Ash, J. F.; Singer, S. J.

doi:10.1016/0092-8674(80)90479-1

Cited by 133 publications

(88 citation statements)

References 19 publications

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“…This mechanism may occur through a protein guanine exchange factor, P-Rex1, which associates with mTORC2 to activate Rac, leading to increases in cell migration (41). Cross-linking of MHC class I molecules has also been shown to lead to the activation of Rho GTPases, assembly of focal adhesions, and stress fiber formation (11,12,42,43). We have recently shown that transfection with FAK siRNA decreased class I-mediated phosphorylation of Src at Tyr 418 and paxillin at Tyr 118 and blocked paxillin redistribution to focal adhesions in EC (14).…”

Section: Discussionmentioning

confidence: 99%

HLA Class I Antibody-Mediated Endothelial Cell Proliferation via the mTOR Pathway

Jindra¹,

Jin²,

Rozengurt

et al. 2008

The Journal of Immunology

145

144

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Anti-HLA Abs have been shown to contribute to the process of transplant vasculopathy by binding to HLA class I molecules expressed by the endothelial and smooth muscle cells of the graft and transducing intracellular signals that elicit cell proliferation. The aim of this study was to determine the role of mammalian target of rapamycin (mTOR) in HLA class I-induced endothelial cell proliferation and to explore in depth the relationship between mTOR complexes and their downstream targets following ligation of HLA class I molecules by anti-HLA Abs. We used small interfering RNA technology to abrogate mTOR, rapamycin-insensitive companion of mTOR (rictor), or regulatory associated protein of mTOR (raptor) to study the function of these gene products to activate proteins involved in MHC class I-induced cell proliferation and survival. Knockdown of mTOR inhibited class I-mediated phosphorylation of proteins downstream of mTOR complex 1 and mTOR complex 2. Furthermore, knockdown of mTOR, rictor, or raptor blocked HLA class I-induced endothelial cell proliferation. Long-term pretreatment with the mTOR inhibitor rapamycin significantly blocked both mTOR-raptor and mTOR-rictor complex formation. Interestingly, rapamycin also blocked class I-induced Akt phosphorylation at Ser473 and Bcl-2 expression. These results support the role of anti-HLA Abs in the process of transplant vasculopathy and suggest that exposure of the graft endothelium to anti-HLA Abs may promote proliferation through the mTOR pathway.

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Section: Discussionmentioning

confidence: 99%

HLA Class I Antibody-Mediated Endothelial Cell Proliferation via the mTOR Pathway

Jindra¹,

Jin²,

Rozengurt

et al. 2008

The Journal of Immunology

145

144

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“…This is apparent from our own experiments as well as from previous work by Hutteroth et al (21) where it was shown that antibodies directed against/32 microglobulin were unable to determine the modulation of their target in human B lymphoblastoid cells; similar observations with murine B cells were made by Grey et al (22). There is, on the other hand, some evidence that cross-linking by antibodies may determine internalization of Class I MHC antigens in nonlymphoid cells (23).…”

Section: The Internalization Process Is Blocked By Monensin and Is Afmentioning

confidence: 99%

Spontaneous internalization of Class I major histocompatibility complex molecules in T lymphoid cells.

Tse¹,

Pernis²

1984

The Journal of Experimental Medicine

111

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A vast portion of the immunological literature has been dedicated, in the last 15 years, to the role of the major histocompatibility complex (MHC) ~ in the immune response. There is now agreement (1, 2) that the molecules coded by the genes of the MHC are essential for cellular interactions and ultimately for self, not-self distinction, at least for what concerns the response of the T system and for the production of antibodies to T-dependent antigens.In spite of the extensive efforts and of the considerable advances in the immunogenetics and biochemistry of the MHC system, several important aspects of the immune function of this system are still unknown.We have chosen to re-examine the cytology of histocompatibility antigens, with a view to some more recently investigated aspects of cell receptor dynamics, as a contribution to the knowledge of the cellular basis of MHC function. This paper is dedicated to Class I MHC molecules and T cells. It shows that Class I MHC molecules are spontaneously internalized at a rapid rate by activated T lymphoid cells in a manner that has many similarities with the recently elucidated internalization and recycling of different receptors in nonimmunocytes (3). Materials and MethodsMice. Female BALB/c, A/J, and C3H/HeJ mice were obtained from The Jackson Laboratory, Bar Harbor, ME. C3H.OL mice were obtained from Dr. A. Augustin, Columbia University, New York and bred in our animal facilities.Cell Culture. Single cell suspensions were obtained from spleens of unprimed mice 4-8 wk of age. Erythrocytes were removed by lysis with NH4CI buffer and unfractionated splenocytes were cultured at 108 cells/ml in RPMI-1640 supplemented with 10% fetal calf serum (FCS), 100 U/ml penicillin, 100 ug/ml Fungizone, 20 mM glutamine, and 5 × 10 -s M 2-mercaptoethanol in the absence or presence of either 2 t~g/ml concanavalin A (Con A), or 20 #g/ml lipopolysaccharide (LPS), or as a 1 : 1 two-way mixed-lymphocyte reaction (MLR). All tissue culture reagents were purchased from Grand Island Biological Co.,

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“…This paper describes the direct selection of variant cells that overproduce a different integral membrane protein, the sodium, potassium activated adenosinetriphosphatase (Na+,K+-ATPase) L The selection was attempted to establish a line bearing an increased amount of an integral membrane protein that is not a hormone receptor. Such cells would facilitate the study of ligandinduced clustering and endocytosis of nonreceptor integral proteins (7) in the same way that the A-431 cells are currently used in the study of the epidermal growth factor receptor. The selection scheme is based on previous work that employed a specific enzyme inhibitor to select for the overpro-Ouabain Binding: Cells were plated at 5-10 x 104 cells/well in 24-well dishes and cultured for 48 media hours in ouabain free medium.…”

mentioning

confidence: 99%

Amplification of sodium- and potassium-activated adenosinetriphosphatase in HeLa cells by ouabain step selection.

Ash¹,

Fineman²,

Kalka³

et al. 1984

The Journal of Cell Biology

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A multistep selection for ouabain resistance was used to isolate a clone of HeLa S3 cells that overproduces the plasma membrane sodium, potassium activated adenosinetriphosphatase (Na+,K+-ATPase). Measurements of specific [3H]ouabain-binding to the resistant clone, C+, and parental HeLa cells indicated that C+ cells contain 8-10 X 10(6) ouabain binding sites per cell compared with 8 X 10(5) per HeLa cell. Plasma membranes isolated from C+ cells by a vesiculation procedure and analyzed for ouabain-dependent incorporation of [32P]phosphate into a 100,000-mol-wt peptide demonstrated a ten- to twelvefold increase in Na+,K+-ATPase catalytic subunit. The affinity of the enzyme for ouabain on the C+ cells was reduced and the time for half maximal ouabain binding was increased compared with the values for the parental cells. The population doubling time for cultures of C+ cells grown in dishes was increased and C+ cells were unable to grow in suspension. Growth of C+ cells in ouabain-free medium resulted in revertant cells, C-, with biochemical and growth properties identical with HeLa. Karyotype analysis revealed that the ouabain-resistant phenotype of the C+ cells was associated with the presence of minute chromosomes which are absent in HeLa and C- cells. This suggests that a gene amplification event is responsible for the Na+,K+-ATPase increase in C+ cells.

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The antibody-induced clustering and endocytosis of HLA antigens on cultured human fibroblasts

Cited by 133 publications

References 19 publications

HLA Class I Antibody-Mediated Endothelial Cell Proliferation via the mTOR Pathway

HLA Class I Antibody-Mediated Endothelial Cell Proliferation via the mTOR Pathway

Spontaneous internalization of Class I major histocompatibility complex molecules in T lymphoid cells.

Amplification of sodium- and potassium-activated adenosinetriphosphatase in HeLa cells by ouabain step selection.

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