DR*W201/P65 tetramer visualization of epitope-specific CD4 T-cell during M. tuberculosis infection and its resting memory pool after BCG vaccination.
BACKGROUND
In vivo kinetics and frequencies of epitope-specific CD4 T cells in lymphoid compartments during M. tuberculosis infection and their resting memory pool after BCG vaccination remain unknown.


RESULTS
Macaque DR*W201 tetramer loaded with Ag85B peptide 65 was developed to directly measure epitope-specific CD4 T cells in blood and tissues form macaques after M. tuberculosis infection or BCG vaccination via direct staining and tetramer-enriched approach. The tetramer-based enrichment approach showed that P65 epitope-specific CD4 T cells emerged at mean frequencies of approximately 500 and approximately 4500 per 10(7) PBL at days 28 and 42, respectively, and at day 63 increased further to approximately 22,000/10(7) PBL after M. tuberculosis infection. Direct tetramer staining showed that the tetramer-bound P65-specific T cells constituted about 0.2-0.3% of CD4 T cells in PBL, lymph nodes, spleens, and lungs at day 63 post-infection. 10-fold expansion of these tetramer-bound epitope-specific CD4 T cells was seen after the P65 peptide stimulation of PBL and tissue lymphocytes. The tetramer-based enrichment approach detected BCG-elicited resting memory P65-specific CD4 T cells at a mean frequency of 2,700 per 10(7) PBL.


CONCLUSIONS
Our work represents the first elucidation of in vivo kinetics and frequencies for tetramer-bound epitope-specific CD4 T cells in the blood, lymphoid tissues and lungs over times after M. tuberculosis infection, and BCG immunization.
Wei
Huiyong
H
Department of Immunology & Microbiology, Center for Primate Biomedical Research, University of Illinois College of Medicine at Chicago (UIC), Chicago, Illinois, United States of America.
Wang
Richard
R
Yuan
Zhuqing
Z
Chen
Crystal Y
CY
Huang
Dan
D
Halliday
Lisa
L
Zhong
Weihua
W
Zeng
Gucheng
G
Shen
Yun
Y
Shen
Ling
L
Wang
Yunqi
Y
Chen
Zheng W
ZW
D000483:Alleles; D000818:Animals; D001500:BCG Vaccine / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D049109:Cell Proliferation; D000939:Epitopes / Q000737:chemistry*; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry; D006684:HLA-DR Antigens / Q000737:chemistry*; D007156:Immunologic Memory / Q000276:immunology*; D007700:Kinetics; D008253:Macaca mulatta; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry; D014376:Tuberculosis / Q000276:immunology*; D014397:Tuberculosis, Pulmonary / Q000276:immunology*
D001500:BCG Vaccine; D000939:Epitopes; D018984:Epitopes, T-Lymphocyte; D006684:HLA-DR Antigens; D010455:Peptides