[Analysis of ESAT-6-specific multifunctional CD4+; T cells in pleural fluid from patients with tuberculous pleurisy].

AIM: To evaluate cytokine production by CD4(+); T cells and frequency of multifunctional CD4(+); T cells after stimulation with ESAT-6 peptide pool. To understand the role of ESAT-6 specific CD4(+); T cells in the control of local TB infection.

METHODS

PFCs were isolated from patients with tuberculous pleurisy, and assessed by flow cytometry for cytokine production, subpopulation, frequency and function of multifunctional CD4(+);T cells after stimulation with ESAT-6 peptide pool.

RESULTS

Following stimulation with BCG, ESAT-6 peptide pool and recombinant ESAT-6 protein, CD4(+); but not CD8(+); T cells expressed IFN-γ, IL-2 and TNF-α. Distinct from BCG, ESAT-6 peptide pool and recombinant ESAT-6 protein induced similar frequencies of IFN-γ, IL-2 and TNF-α. High frequency of multifunctional CD4(+);T cells was observed. Analysis of mean fluorescence intensity (MFI) indicated that triple positive cells produced most amounts of cytokines on single cell level compared with double positive and single positive cells.

CONCLUSION

ESAT-6 peptide pool predominantly induced Th1 cytokine production by CD4(+);T cells in PFCs. Multifunctional CD4(+); T cells were observed and secreted most amounts of cytokines on single cell level, suggesting that these cells probably played essential role in local TB infection.