Increased Frequency of Antigen-Specific Polyfunctional T Cells in Tuberculosis Patients

Abstract

This study assessed the polyfunctional T cells in healthy household contacts (HHCs) and TB patients. This study also assessed the memory subsets responsible for the secretion of IFN-γ during the short-term culture with Mycobacterium tuberculosis antigens. Frequencies of CD4+IFN-γ+TNF-α+ T cells and CD8+IFN-γ+TNF-α+ T cells specific to M. tuberculosis antigens were significantly higher in TB patients compared to HHC. IFN-γ-secreting T cells, during overnight stimulation with M. tuberculosis antigens, belonged to effector memory subset with a CD45RA−CD27− phenotype. However, the number of IFN-γ-secreting effector memory cells did not differ between HHC and TB patients.

High dose aerosol challenge with Mycobacterium tuberculosis fails to overcome BCG vaccination-induced protection in cynomolgus macaques of Chinese origin: implications of natural resistance for TB vaccine evaluation.

“…Until a true correlate of protection is available, functional markers such as IFN-g expression are measured to assess vaccine immunogenicity. There is evidence that the quality of the T-cell response is important to the induction of T-cell memory 17,18 and multifunctional CD4 T-cells expressing combinations of the cytokines IFN-g, TNF-α and IL-2 are involved in the active phase of disease [19][20][21] and provide potential correlates of vaccine-induced protection [22][23][24][25] although not all reports support this latter role 26,27 . This study aimed to establish a high dose aerosol challenge model of TB in cynomolgus macaques of Chinese origin (CCM), in order to evaluate the e cacy afforded by BCG and to elucidate correlates of protective immunity.…”

High-dose Mycobacterium tuberculosis aerosol challenge cannot overcome BCG-induced protection in Chinese origin cynomolgus macaques; implications of natural resistance for vaccine evaluation

“…Until a true correlate of protection is available, functional markers such as IFN-γ expression are measured to assess vaccine immunogenicity. There is evidence that the quality of the T-cell response is important to the induction of T-cell memory 20 , 21 and multifunctional CD4 T-cells expressing combinations of the cytokines IFN-γ, TNF-α and IL-2 are involved in the active phase of disease 22 – 24 and provide potential correlates of vaccine-induced protection 25 – 28 although not all reports support this latter role 29 , 30 .…”