Comprehensive gene expression profiling in lungs of mice infected with Mycobacterium tuberculosis following DNAhsp65 immunotherapy.
BACKGROUND
The continued increase in tuberculosis (TB) rates and the appearance of extremely resistant Mycobacterium tuberculosis strains (XDR-TB) worldwide are some of the great problems of public health. In this context, DNA immunotherapy has been proposed as an effective alternative that could circumvent the limitations of conventional drugs. Nonetheless, the molecular events underlying these therapeutic effects are poorly understood.


METHODS
We characterized the transcriptional signature of lungs from mice infected with M. tuberculosis and treated with heat shock protein 65 as a genetic vaccine (DNAhsp65) combining microarray and real-time polymerase chain reaction analysis. The gene expression data were correlated with the histopathological analysis of lungs.


RESULTS
The differential modulation of a high number of genes allowed us to distinguish DNAhsp65-treated from nontreated animals (saline and vector-injected mice). Functional analysis of this group of genes suggests that DNAhsp65 therapy could not only boost the T helper (Th)1 immune response, but also could inhibit Th2 cytokines and regulate the intensity of inflammation through fine tuning of gene expression of various genes, including those of interleukin-17, lymphotoxin A, tumour necrosis factor-alpha, interleukin-6, transforming growth factor-beta, inducible nitric oxide synthase and Foxp3. In addition, a large number of genes and expressed sequence tags previously unrelated to DNA-therapy were identified. All these findings were well correlated with the histopathological lesions presented in the lungs.


CONCLUSIONS
The effects of DNA therapy are reflected in gene expression modulation; therefore, the genes identified as differentially expressed could be considered as transcriptional biomarkers of DNAhsp65 immunotherapy against TB. The data have important implications for achieving a better understanding of gene-based therapies.
Zárate-Bladés
Carlos Rodrigo
CR
Núcleo de Pesquisas em Tuberculose, Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
Bonato
Vânia Luiza Deperon
VL
da Silveira
Eduardo Lani Volpe
EL
Oliveira e Paula
Marina
M
Junta
Cristina Moraes
CM
Sandrin-Garcia
Paula
P
Fachin
Ana Lúcia
AL
Mello
Stephano Spanó
SS
Cardoso
Renato Sousa
RS
Galetti
Fábio Cícero de Sá
FC
Coelho-Castelo
Arlete Aparecida Martins
AA
Ramos
Simone Gusmão
SG
Donadi
Eduardo Antonio
EA
Sakamoto-Hojo
Elza Tiemi
ET
Passos
Geraldo Aleixo da Silva
GA
Silva
Celio Lopes
CL
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D018834:Chaperonin 60; D018833:Chaperonins / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics / Q000627:therapeutic use; D005260:Female; D020869:Gene Expression Profiling; D007167:Immunotherapy; D008168:Lung / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000378:metabolism; D014397:Tuberculosis, Pulmonary / Q000235:genetics* / Q000517:prevention & control / Q000628:therapy*; D019444:Vaccines, DNA / Q000235:genetics / Q000627:therapeutic use*
D001426:Bacterial Proteins; D018834:Chaperonin 60; D004269:DNA, Bacterial; D019444:Vaccines, DNA; C074119:heat-shock protein 65, Mycobacterium; D018833:Chaperonins