Binding constants of isolated NGF-receptors from different species

In the rat, nerve growth factor (NGF) has been shown to affect immune reactivity by binding to cell surface receptors on a subpopulation of splenic mononuclear cells. This binding occurs in a specific and saturable fashion to what appear to be low-affinity (type II) NGF receptors (NGFR). Immunofluorescence studies here showed that NGFR are also present on a proportion of human peripheral blood mononuclear cells (PBMC). Equilibrium binding studies demonstrated that the binding of NGF to its receptors on PBMC occurs with a single equilibrium binding constant (mean) of 2.11 X 10(-9) M. The number of receptors per cell was determined to be approximately 6.94 X 10(3) receptors/cell. These results would suggest a role for NGF in the regulation of immune function in man, as well as in animals.

Section: Receptor Assaymentioning

confidence: 66%

“…NGF was isolated, characterized, and iodinated as described elsewhere (Mobley et al, 1976;Lyons et al, 1983). Radioiodinated NGF was always used within a 2 week period.…”

Section: Soluble Ngf Receptor Assaymentioning

confidence: 99%

Expression of nerve growth factor receptors by human peripheral blood mononuclear cells

Morgan

Thorpe

Marchetti

et al. 1989

“…These receptors have been shown to have dissociation constants of approximately lo-" and 10-9M with 10 to 20 times as many lower-affinity receptors per cell as high-affinity receptors [Olender et al, 1981;Olender and Stach, 1980;Massague et al, 1982;Costrini and Bradshaw, 1979;Puma et al, 1983;Stach and Rusenko, 19841. In several of these studies, it has been demonstrated that NGF receptors can be solubilized in NP4O-PBS [Lyons et al, 1983;Costrini and Bradshaw, 19791. Recovery of binding capacity is better than 94 % for all cells studied [Lyons et al, 19831.…”

Section: Iodination Of 0-ngf and Cell Surface Membrane Proteinsmentioning

confidence: 99%

Receptors for nerve growth factor on rat spleen mononuclear cells

Thorpe

Stach

Hashim

et al. 1987

Considerable evidence is mounting to support the concept of a modulatory role for the brain and neuroendocrine system on the immune response. This neuroimmunomodulation occurs in part through the interaction of specific neurosubstances with receptors on lymphocytes and monocytes. Nerve growth factor (NGF) is a neuronotrophic factor necessary for the development and maintenance of sympathetic and embryonic sensory neurons. This trophic effect is initiated through binding of NGF at specific cell surface receptor sites on NGF-responsive cells. Several recent studies suggest that NGF may interact with cells of the immune system and may play a role in the regulation of some immunologic reactions. In this study we report on the presence of specific receptors for NGF on the surface of mononuclear cells from rat spleens. The NGF-binding sites are of the low-affinity type with Kd's in the 10(-9) M range. These receptors migrate on SDS-PAGE as two molecular species of approximately 190 and 125 kilodaltons. Our findings of receptors for NGF on lymphocytes and accessory cells support other evidence that NGF may influence immunoreactivity in vivo.

“…However, it has been reported that approximately 40% of the binding capacity of NGFR can be lost during lectin chromatography (Lyons et al, 1983). The recovery of radioactivity in the glycoprotein pool was estimated to be 0.8% of the total radioactivity associated with the solubilized proteins present.…”

Section: Resultsmentioning

confidence: 99%

Reverse‐phase high‐performance liquid chromatography of nerve growth factor receptor‐like proteins identified with monoclonal antibodies

Shan

Beck

Werrbach‐Perez

et al. 1990

Human neuroblastoma SK-N-SH-SY5Y (SY5Y) and rat pheochromocytoma PC12 cells are model cell lines used in the study of nerve growth factor (NGF) effect. The effects of NGF are initiated by binding to cell surface receptors (NGFR). The amino acid sequence for NGFR has been deduced based on the identification of a single gene for NGFR. However, there are two kinds of NGF binding activities and several reported molecular weights of NGFR. We report here on the demonstration of NGFR-like proteins from PC12 and SY5Y cells by sequential lectin chromatography, reverse-phase HPLC, and SDS-PAGE analysis of immunoprecipitates obtained with NGFR-specific monoclonal antibodies. For both human and rodent NGFR, there was a tendency for the higher molecular-weight species of NGFR-like proteins to be eluted in more hydrophobic fractions. Also, the expression of different species of NGFR could be modified by treatment with retinoic acid (RA). These results are consistent with the hypothesis that the different molecular species of NGFR may result from the generation of a truncated form of NGFR, the presence of sugar residues on the NGFR protein, dimer formation between NGFR, or the association of NGFR with a receptor-associated protein.