Mycobacterium tuberculosis epitope-specific interferon-g production in healthy Brazilians reactive and non-reactive to tuberculin skin test
Mem. Inst. Oswaldo Cruz
; 109(8): 999-1004, 12/2014. tab, graf
Article
in En
| LILACS
| ID: lil-732606
Responsible library:
BR1.1
ABSTRACT
The interferon (IFN)-γ response to peptides can be a useful diagnostic marker of Mycobacterium tuberculosis (MTB) latent infection. We identified promiscuous and potentially protective CD4+ T-cell epitopes from the most conserved regions of MTB antigenic proteins by scanning the MTB antigenic proteins GroEL2, phosphate-binding protein 1 precursor and 19 kDa antigen with the TEPITOPE algorithm. Seven peptide sequences predicted to bind to multiple human leukocyte antigen (HLA)-DR molecules were synthesised and tested with IFN-γ enzyme-linked immunospot (ELISPOT) assays using peripheral blood mononuclear cells (PBMCs) from 16 Mantoux tuberculin skin test (TST)-positive and 16 TST-negative healthy donors. Eighty-eight percent of TST-positive donors responded to at least one of the peptides, compared to 25% of TST-negative donors. Each individual peptide induced IFN-γ production by PBMCs from at least 31% of the TST-positive donors. The magnitude of the response against all peptides was 182 ± 230 x 106 IFN-γ spot forming cells (SFC) among TST-positive donors and 36 ± 62 x 106 SFC among TST-negative donors (p = 0.007). The response to GroEL2 (463-477) was only observed in the TST-positive group. This combination of novel MTB CD4 T-cell epitopes should be tested in a larger cohort of individuals with latent tuberculosis (TB) to evaluate its potential to diagnose latent TB and it may be included in ELISPOT-based IFN-γ assays to identify individuals with this condition.
Key words
Full text:
1
Index:
LILACS
Main subject:
Tuberculin Test
/
Interferon-gamma
/
Latent Tuberculosis
/
Mycobacterium tuberculosis
/
Epitopes
Type of study:
Prognostic_studies
Limits:
Adult
/
Humans
Country/Region as subject:
America do sul
/
Brasil
Language:
En
Journal:
Mem. Inst. Oswaldo Cruz
Journal subject:
MEDICINA TROPICAL
/
PARASITOLOGIA
Year:
2014
Type:
Article