A recombinant BCG vaccine generates a Th1-like response and inhibits IgE synthesis in BALB/c mice.
The tubercle vaccine, bacille Calmette-Guérin (BCG), is a strong inducer of T-helper type 1 (Th1) responsiveness, and it has been suggested that recombinant BCG (rBCG), which produces and secretes antigens, may be used to prevent allergic diseases. The effects of rBCG vaccination on allergic responses in a murine model were examined in this study. A BCG-Escherichia coli shuttle vector was developed with the promoter and signal sequence of the alpha-antigen of Mycobacterium bovis, and the vector was tested using E. coli beta-galactosidase as the model antigen and allergen. This vector enabled the expression of the E. coli beta-galactosidase gene in BCG, which was detected in its protein extract by immunoblotting analysis. Vaccination of mice with a single dose of 106 recombinant BCG generated a beta-galactosidase-specific antibody response. The splenocytes of vaccinated mice compared with controls produced significantly higher amounts of interferon-gamma (IFN-gamma) (P<0. 01) and interleukin-2 (IL-2) (P<0.05) and lower amounts of IL-5 (P<0. 01). Mice vaccinated with rBCG had significantly less (P<0.01) serum IgE compared with controls. These results together demonstrate that rBCG secreting antigens or allergens may be utilized for the induction of a Th1-like response and the down-regulation of IgE antibody response.
Kumar
M
M
Joy McCann Culverhouse, Airway Disease Research Center, Division of Allergy and Immunology, Department of Internal Medicine, VA Hospital, Tampa, FL 33612, USA.
Behera
A K
AK
Matsuse
H
H
Lockey
R F
RF
Mohapatra
S S
SS
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001500:BCG Vaccine / Q000276:immunology*; D018929:Cell Culture Techniques; D005260:Female; D015870:Gene Expression; D007114:Immunization; D007073:Immunoglobulin E / Q000096:biosynthesis*; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D015848:Interleukin-5 / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology*; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D000907:Antibodies, Bacterial; D001500:BCG Vaccine; D007376:Interleukin-2; D015848:Interleukin-5; D014614:Vaccines, Synthetic; D007073:Immunoglobulin E; D007371:Interferon-gamma; D001616:beta-Galactosidase