You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["RNA", "CellLine", "Protein", "DNA", "CellType"].

Please return the output as a JSON object of the format: {"DNA" : ["TAL1", ...], "RNA": ["mRNAs", ...], "CellLine": ["T cells", ...], "CellType": ["monocytes", ...], "Protein": ["IL-2", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

One base pair change abolishes the T cell-restricted activity of a kB-like proto-enhancer element from the interleukin 2 promoter. The inducible, T cell-specific enhancers of murine and human Interleukin 2 (Il-2) genes contain the kB-like sequence GGGATTTCACC as an essential cis-acting enhancer motif. When cloned in multiple copies this so-called TCEd (distal T cell element) acts as an inducible proto-enhancer element in E14 T lymphoma cells, but not in HeLa cells. In extracts of induced, Il-2 secreting El4 cells three individual protein factors bind to TCEd DNA. The binding of the most prominent factor, named TCF-1 (T cell factor 1), is correlated with the proto-enhancer activity of TCEd. TCF-1 consists of two polypeptides of about 50 kD and 105 kD; the former seems to be related to the 50 kD polypeptide of NF-kB. Purified NF-kB is also able to bind to the TCEd, but TCF-1 binds stronger than NF-kB to TCEd DNA. The conversion of the TCEd to a 'perfect' NF-kB binding site leads to a tighter binding of NF-kB to TCEd DNA and, as a functional consequence, to the activity of the 'converted' TCEd motifs in HeLa cells. Thus, the substitution of the underlined A residue to a C within the GGGATTTCACC motif abolishes its T cell-restricted activity and leads to its functioning in both El4 cells and HeLa cells. These results indicate that lymphocyte-specific factors binding to the TCEd are involved in the control of T cell specific-transcription of the Il-2 gene.
{"CellLine": ["El4 cells", "E14 T lymphoma cells", "Il - 2 secreting El4 cells", "HeLa cells"], "CellType": [], "DNA": ["\u0027converted\u0027 TCEd motifs", "NF - kB", "TCEd DNA", "GGGATTTCACC motif", "essential cis - acting enhancer motif", "distal T cell element", "T cell - specific enhancers", "the Il - 2 gene", "TCEd", "kB - like proto - enhancer element", "interleukin 2 promoter", "proto - enhancer element", "\u0027perfect\u0027 NF - kB binding site", "murine and human Interleukin 2 (Il - 2) genes", "Il - 2 gene", "kB - like sequence", "Il - 2"], "Protein": ["NF - kB", "50 kD polypeptide", "protein factors", "TCF - 1", "Purified NF - kB", "Il - 2", "T cell factor 1"], "RNA": []}