Mycobacterium tuberculosis Rv1419 encodes a secreted 13 kDa lectin with immunological reactivity during human tuberculosis.
In this study, we have identified a secreted 13 kDa lectin from Mtb (Mtb, Mycobacterium tuberculosis; sMTL-13) by homology search of a non-redundant lectin database. Bioinformatic analysis revealed that sMTL-13 belongs to the ricin-type beta-trefoil family of proteins containing a Sec-type signal peptide present in Mtb complex species, but not in non-tuberculous mycobacteria. Following heterologous expression of sMTL-13 and generation of an mAb (clone 276.B7/IgG1kappa), we confirmed that this lectin is present in culture filtrate proteins from Mtb H37Rv, but not in non-tuberculous mycobacteria-derived culture filtrate proteins. In addition, sMTL-13 leads to an increased IFN-gamma production by PBMC from active tuberculosis (ATB) patients. Furthermore, sera from ATB patients displayed high titers of IgG Ab against sMTL-13, a response found to be decreased following successful anti-tuberculosis therapy. Together, our findings reveal a secreted 13 kDa ricin-like lectin from Mtb, which is immunologically recognized during ATB and could serve as a biomarker of disease treatment.
Nogueira
Lucas
L
Laboratório de Imunologia e Doenças Infecciosas, Departamento de Microbiologia e Parasitologia, Universidade Federal de Santa Catarina-SC, Brazil.
Cardoso
Fernanda C
FC
Mattos
Ana M
AM
Bordignon
Juliano
J
Figueiredo
Cláudia P
CP
Dahlstrom
Pedro
P
Frota
Cristiane C
CC
Duarte Dos Santos
Cláudia N
CN
Chalhoub
Marcelo
M
Cavada
Benildo S
BS
Teixeira
Henrique C
HC
Oliveira
Sérgio C
SC
Barral-Netto
Manoel
M
Báfica
André
A
D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000235:genetics / Q000276:immunology; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001483:Base Sequence; D015153:Blotting, Western; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007150:Immunohistochemistry; D037102:Lectins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D014397:Tuberculosis, Pulmonary / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; D037102:Lectins