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T-helper-cell determinants in protein antigens are preferentially located in cysteine-rich antigen segments resistant to proteolytic cleavage by cathepsin B , L , and D .
 protein: cysteine-rich antigen segments; protein: T-helper-cell determinants; protein: protein antigens
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 protein: cysteine-rich antigen segments; protein: T-helper-cell determinants; protein: protein antigens