Article

The two different receptors for tumor necrosis factor mediate distinct cellular responses.

Department of Molecular Biology, Genentech, Inc., South San Francisco, CA 94080.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 11/1991; 88(20):9292-6. DOI: 10.1073/pnas.88.20.9292
Source: PubMed

ABSTRACT The individual roles of the murine type 1 and type 2 tumor necrosis factor (TNF) receptors (TNF-R1 and TNF-R2) were investigated utilizing (i) the strong species specificity of TNF-R2 for murine TNF compared to human TNF and (ii) agonistic rabbit polyclonal antibodies directed against the individual TNF receptors. Proliferation of mouse thymocytes and the murine cytotoxic T-cell line CT-6 is stimulated by murine TNF but not by human TNF. Consistent with this observation, polyclonal antibodies directed against TNF-R2 induced proliferation in both of these cell types, whereas polyclonal antibodies directed against TNF-R1 had no effect. In contrast, cytotoxicity in murine LM cells (which are sensitive to murine and human TNF) was induced by antibodies against TNF-R1 but not by antibodies against TNF-R2. Also, the steady-state level of manganous superoxide dismutase mRNA in the murine NIH 3T3 cell line was induced by murine TNF, human TNF, and anti-TNF-R1 but not by anti-TNF-R2. These results suggest that TNF-R2 initiates signals for the proliferation of thymocytes and cytotoxic T cells, whereas TNF-R1 initiates signals for cytotoxicity and the induction of the protective activity, manganous superoxide dismutase. The nonredundant signaling observed for the two TNF receptors cannot be explained simply by the differential expression of the two TNF receptors in the various cell types, because LM cells express on their surface higher levels of TNF-R2 than TNF-R1, and LM cells, NIH 3T3 cells, and thymus cells all express mRNA corresponding to both receptor types. It is therefore likely that the two receptors initiate distinct signaling pathways that result in the induction of different cellular responses.

1 Follower
 · 
75 Views
  • Journal of Experimental Medicine 05/1993; 177(5):1277-1286. DOI:10.1084/jem.177.5.1277 · 13.91 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this study, a complete molecular characterization of tumor necrosis factor receptor 1 (TNFR1) which was identified from the constructed cDNA library of striped murrel Channa striatus (Cs) is reported. The CsTNFR1 encoded a type I membrane receptor protein that contains 399 amino acids including three cysteine-rich domains (CRDs) at CRD1(41-46), CRD2(79-118) and CRD3(120-159) in the extracellular region and a putative TNF receptor-associated factor (TRAF) site at 245-253 and a death domain between 297 and 388 in the cytoplasmic region which is essential for induction of apoptosis. The predicted molecular mass of CsTNFR1 is 45kDa and its corresponding theoretical isoelectric point (pI) is 6.3. CsTNFR1 shared maximum identity with TNFR1 from olive flounder Paralichthys olivaceus (82%). Real-time PCR showed that CsTNFR1 gene was expressed most abundantly (P<0.05) in the head kidney. Further, CsTNFR1 mRNA transcription was studied after challenge with fungus Apanomyces invadans and bacteria Aeromonas hydrophila. The fungus injected murrels showed a highest expression at 48h, whereas bacteria injected murrels showed at 24h. The gene expression studies revealed that CsTNFR1 may be involved in innate immune process of murrels against pathogenic infections. The over-expressed and purified recombinant CsTNFR1 protein (rCsTNFR1) was subjected to TNF-α inhibition assay to confirm their specificity and activity against TNF-α which confirmed that the rCsTNFR1 inhibits the activity of TNF-α in a dose dependent manner where maximum inhibition (97%) was observed at 10,000 fold concentration of rCsTNFR1. In addition, the direct cytotoxic effect of rCsTNFR1 was analyzed against head kidney phagocyte. The results showed that the recombinant CsTNFR1 protein does not exhibit any significant cytotoxicity against head kidney phagocyte cells even at higher concentration (8μg/ml). Moreover, the recombinant protein was analyzed for respiratory burst activity in the presence of two different ROS inducers, opsonized zymosan (fungal cell wall component) and phorbol 12-myristate 13-acetate (PMA). The findings showed that the C. striatus head kidney phagocyte exposed to purified recombinant CsTNFR1 protein alone do not produced any ROS. However, opsonized zymosan induced recombinant CsTNFR1 protein significantly (P<0.05) enhanced the ROS production on concentration basis which is revealed that the ROS production depends on the concentration of the recombinant CsTNFR1 protein. Overall, the study showed that the CsTNFR1 plays an important role in the pathogen-induced inflammatory process of striped murrel. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Molecular Immunology 04/2015; 66(2):240-252. DOI:10.1016/j.molimm.2015.03.015 · 3.00 Impact Factor
  • Journal of Experimental Medicine 06/1995; 181(6):2029-2036. DOI:10.1084/jem.181.6.2029 · 13.91 Impact Factor

Full-text (2 Sources)

Download
29 Downloads
Available from
May 19, 2014