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T cells from renal cell carcinoma patients exhibit an abnormal pattern of kappa B-specific DNA-binding activity: a
Abstract:
Recent data suggest that the poor induction of a T-cell response to human renal cell carcinoma (RCC) may be related to alterations in signal transduction pathways. We report that T cells from RCC patients have two alterations in kappa B motif-specific DNA-binding activity. The first alteration involves the constitutive expression of substantial kappa B-binding activity in nuclear extracts, which was observed in the electrophoretic mobility shift assay. The magnitude of kappa B activity in unstimulated patient T cells was similar to that observed in T cells from normal individuals that had been activated in vitro. On the basis of Western blotting experiments using antibodies to kappa B/Rel family proteins, the kappa B-binding activity constitutively expressed in T cells from RCC patients is composed mostly of the NF-kappa B1 (p50) subunit. The second abnormality in kappa B-binding activity in T cells from these patients is that RelA, a member of the Rel homology family which is part of the normal NF-kappa B complex, was not induced in the nucleus following activation. Western blotting analysis did not detect any RelA in nuclear extracts either before or after stimulation of T cells. The altered kappa B-binding activity in T cells from RCC patients may impair their capacity to respond normally to various stimuli.
Insights
T cells from renal cell carcinoma (RCC) patients show abnormal NF-kappa B activity, with constitutive binding and lack of RelA induction. These changes may impair T-cell responses in cancer patients.
Area of Science:
- Immunology
- Molecular Biology
- Oncology
Background:
- T-cell response is crucial for controlling human renal cell carcinoma (RCC).
- Impaired T-cell responses in RCC patients may stem from signal transduction pathway alterations.
- Nuclear factor-kappa B (NF-kappa B) is a key regulator of immune cell activation and signaling.
Purpose of the Study:
- To investigate alterations in kappa B motif-specific DNA-binding activity in T cells from RCC patients.
- To identify the specific components of the NF-kappa B complex affected in these T cells.
- To understand how these molecular changes might impact T-cell function in RCC.
Main Methods:
- Electrophoretic mobility shift assay (EMSA) to assess DNA-binding activity.
- Western blotting using antibodies against NF-kappa B/Rel family proteins.
- Analysis of T cells from both RCC patients and healthy individuals.
Main Results:
- T cells from RCC patients exhibited constitutive kappa B-binding activity, even without stimulation.
- This constitutive activity was primarily composed of the NF-kappa B1 (p50) subunit.
- RelA, a critical component of the normal NF-kappa B complex, was not induced in the nucleus of RCC patient T cells upon activation.
Conclusions:
- RCC patient T cells display two key abnormalities in NF-kappa B signaling: constitutive p50 activity and absent RelA induction.
- These alterations in NF-kappa B binding activity may significantly impair the ability of T cells to respond effectively to stimuli.
- Understanding these molecular defects could inform strategies to enhance anti-tumor immunity in RCC.