Direct Ex Vivo Detection of HLA-DR3–Restricted Cytomegalovirus- and Mycobacterium tuberculosis–Specific CD4+ T Cells

DR*W201/P65 Tetramer Visualization of Epitope-Specific CD4 T-Cell during M. tuberculosis Infection and Its Resting Memory Pool after BCG Vaccination

“…The development of defined epitope-specific CD4 T cells in the blood and lymphoid tissues during primary M. tuberculosis infection remains poorly characterized [14], [28], [29]. At least two open questions appear to remain for direct measurement of class II MHC tetramer-bound CD4 T cells in M. tuberculosis infection [14], [28]: (i) given low-frequency antigen-specific CD4 T cells, how can standard tetramer staining readily distinguish the tetramer-bound CD4 T cells from background staining?…”

“…At least two open questions appear to remain for direct measurement of class II MHC tetramer-bound CD4 T cells in M. tuberculosis infection [14], [28]: (i) given low-frequency antigen-specific CD4 T cells, how can standard tetramer staining readily distinguish the tetramer-bound CD4 T cells from background staining? (ii) how high are the frequencies of tetramer-bound epitope-specific CD4 T cells in lymphoid tissues compared to blood?…”

“…Class I MHC/peptide tetramers have revolutionized the identification, enumeration, and phenotyping of antigen-specific CD8 + T cells [8], [11], [12], [13], but the potential of class II MHC/peptide tetramers has not been adequately appreciated due to technical problems for generating useful class II MHC/peptide tetramer and for measuring low-frequency Ag-specific CD4 + T helper cells. Despite the fact that class II MHC tetramers loaded with autoantigen peptides have been well-documented [see review in reference [10]], only limited numbers of class II MHC/microbial peptide tetramers were developed to measure microbial epitope-specific CD4 T cells [9], [14], [15], [16], [17]. Although class II MHC tetramer-based analysis may open a new avenue to further understand differentiation and evolution of antigen-specific CD4 T-cell subpopulations in the context of vaccinations or infections, fundamental aspects of the tetramer application remain to be characterized.…”

Use of HLA-DR*08032/E7 and HLA-DR*0818/E7 tetramers in tracking of epitope-specific CD4+ T cells in active and convalescent tuberculosis patients compared with control donors

“…Thus, visualization and quantification of MTB antigenspecific CD4 + T cell populations would provide critical information on immune responses against MTB infections. There have been a number of applications using MHC class II tetramers, including three TB-related studies (Bronke et al 2005;Höhn et al 2007;Wei et al 2009), but tracking of tetramer-positive, epitope-specific CD4 + T cells in blood and other tissues of TB patients during the course of TB development and treatment in comparison with control donor samples is not well characterized.…”

“…To date, there have been a number of applications using MHC class II tetramers including three tuberculosis (TB)-related studies. These involved the detection of tetramer-positive CD4 + T cells in samples from human TB or an MTB infection macaque model by using the HLA-DR3/hsp65 peptide tetramer, HLA-DR4/ESAT-6 or Ag85B peptide tetramers, and the Mamu-DR*W201/hsp65 peptide tetramer, respectively (Bronke et al 2005;Höhn et al 2007;Wei et al 2009). However, tracking of tetramer-positive and epitope-specific CD4 + T cells in blood and other tissues of TB patients during the course of TB development and treatment in comparison with control donor samples is not well characterized.…”