1590
Activation of individual CD4+ T cells results in differential lymphokine expression : interleukin 2 ( IL-2 ) is preferentially produced by T helper type 1 (TH1) cells , which are involved in cell-mediated immune responses, whereas IL-4 is synthesized by TH2 cells , which are essential for humoral immunity .
 protein: IL-4; protein: interleukin 2; cell line: T helper type 1 (TH1) cells; cell line: TH2 cells; protein: lymphokine; protein: IL-2; cell line: CD4+ T cells
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: IL-4; protein: interleukin 2; cell line: T helper type 1 (TH1) cells; cell line: TH2 cells; protein: lymphokine; protein: IL-2; cell line: CD4+ T cells