Seroprevalence of IgG1 and IgG4 class antibodies against Mycobacterium avium subsp. paratuberculosis in Japanese population.
Mycobacterium avium subsp. paratuberculosis (MAP) is the established causative agent of Johne's disease in cattle and other ruminants, and it has also been speculated to be a putative etiological agent of several human autoimmune diseases. It is acknowledged that dairy products deriving from infected animals play a role (could be vehicles) in exposing humans to MAP. MAP could stimulate the human immune system by means of their complex antigen (in the case of lipids, multivalent antigens) and may modulate it, acting as adjuvant molecules such as Freund's complete adjuvant. The immune system might be abnormally stimulated by the constant presence of MAP antigens (for example, in the dairy products), and this might be particularly relevant in genetically predisposed individuals. However, there is limited understanding about the current human exposure to MAP. The present study analyzed the antibody recognition profile of MAP lipophilic antigens in a cohort of 126 healthy Japanese. We measured the serum levels of total immunoglobulin G (IgG) and subclasses targeting MAP surface antigens through ethanol vortex indirect enzyme-linked immunosorbent assay (EVELISA) by using serum absorbed with Mycobacterium phlei. Elevated IgG (especially IgG1 and IgG4) responses were observed in 14% of the sera. To assess the specificity of EVELISA, the same samples were analyzed by means of a commercially available Johnelisa II kit. It was noteworthy that a high degree of correlation was observed when comparing the two methodologies (rs=0.7, p<0.0001). Moreover, in order to investigate the specificity of the binding, inhibition assay experiments were carried out also searching for antibodies against Bacillus Calmette-Guérin antigens, but no cross-reaction was observed. The result obtained represents the first evidence implying that the Japanese population is exposed to MAP, and additionally the existence of a foodborne chain of exposure that transmits MAP antigens to humans.
1 Sangenjaya Hospital , Tokyo, Japan .
Shigeru
S
Otsubo
2 Department of Biomedical Sciences, Division of Microbiology and Virology, University of Sassari , Viale San Pietro, Italy .|3 Department of Human-Care, Tohto College of Health Sciences (TCHS) , Saitama, Japan .
Davide
D
Cossu
4 Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, University of Tennessee , Knoxville, Tennessee.
Shigetoshi
S
Eda
1 Sangenjaya Hospital , Tokyo, Japan .
Yuriko
Y
Otsubo
2 Department of Biomedical Sciences, Division of Microbiology and Virology, University of Sassari , Viale San Pietro, Italy .
Leonardo Antonio
LA
Sechi
3 Department of Human-Care, Tohto College of Health Sciences (TCHS) , Saitama, Japan .
Tsuyoshi
T
Suzuki
3 Department of Human-Care, Tohto College of Health Sciences (TCHS) , Saitama, Japan .
Yumiko
Y
Iwao
5 Laboratories of Immunology, School of Life and Environmental Science, Azabu University , Kanagawa, Japan .
Shizuo
S
Yamamoto
5 Laboratories of Immunology, School of Life and Environmental Science, Azabu University , Kanagawa, Japan .
Takashi
T
Kuribayashi
3 Department of Human-Care, Tohto College of Health Sciences (TCHS) , Saitama, Japan .
Eiichi
E
Momotani
D000818:Animals; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology; D064368:Healthy Volunteers; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007564:Japan / Q000453:epidemiology; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology*; D010283:Paratuberculosis / Q000453:epidemiology* / Q000276:immunology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies
D007074:Immunoglobulin G