Oral administration of recombinant Neisseria meningitidis PorA genetically fused to H. pylori HpaA antigen increases antibody levels in mouse serum, suggesting that PorA behaves as a putative adjuvant.
The Neisseria meningitidis outer membrane protein PorA from a Chilean strain was purified as a recombinant protein. PorA mixed with AbISCO induced bactericidal antibodies against N. meningitidis in mice. When PorA was fused to the Helicobacter pylori HpaA antigen gene, the specific response against H. pylori protein increased. Splenocytes from PorA-immunized mice were stimulated with PorA, and an increase in the secretion of IL-4 was observed compared with that of IFN-γ. Moreover, in an immunoglobulin sub-typing analysis, a substantially higher IgG1 level was found compared with IgG2a levels, suggesting a Th2-type immune response. This study revealed a peculiar behavior of the purified recombinant PorA protein per se in the absence of AbISCO as an adjuvant. Therefore, the resistance of PorA to proteolytic enzymes, such as those in the gastrointestinal tract, was analyzed, because this is an important feature for an oral protein adjuvant. Finally, we found that PorA fused to the H. pylori HpaA antigen, when expressed in Lactococcus lactis and administered orally, could enhance the antibody response against the HpaA antigen approximately 3 fold. These observations strongly suggest that PorA behaves as an effective oral adjuvant.
a Department of Biotechnology ; Instituto de Salud Pública de Chile ; Ñuñoa , Santiago , Chile.
Abel E
AE
Vasquez
Ricardo A
RA
Manzo
Daniel A
DA
Soto
Magaly J
MJ
Barrientos
Aurora E
AE
Maldonado
Macarena
M
Mosqueira
Anastasia
A
Avila
Jorge
J
Touma
Elsa
E
Bruce
Paul R
PR
Harris
Alejandro
A
Venegas
D018829:Adhesins, Bacterial / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000235:genetics; D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D005260:Female; D016480:Helicobacter pylori / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D013294:Lactococcus lactis / Q000235:genetics / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008807:Mice, Inbred BALB C; D018272:Porins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D044967:Serum / Q000737:chemistry; D013154:Spleen / Q000276:immunology
D018829:Adhesins, Bacterial; D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D018272:Porins; D011993:Recombinant Fusion Proteins; C057699:porin protein, Neisseria; C095977:adhesin A, Helicobacter; D015847:Interleukin-4; D007371:Interferon-gamma
AbISCO TM-100® adjuvant; AbISCO TM-100®, adjuvant based on saponin; Helicobacter pylori antigen; LAL, limulus amebocyte lysate; hybrid PorA antigens; immunostimulant complex matrix; meningococcal B porin antigen; oral immunization; recombinant PorA