A new intra-NALT route elicits mucosal and systemic immunity against Moraxella catarrhalis in a mouse challenge model.
Mucosally administered antigens are often poorly immunogenic due to the difficulty of transporting antigens through the mucosal epithelium. We investigated a new route of intranasal-associated lymphoid tissue (intra-NALT) administration of antigens to circumvent the antigen transportation barrier. A comparative study was carried out on mice administered with killed whole cells of Moraxella catarrhalis strain 25238 plus cholera toxin (CT) by intra-NALT injection and nasal inoculation. Both routes induced significant elevations of several isotype antibodies against strain 25238 in saliva, lung lavage, and serum as measured by an enzyme-linked immunosorbent assay (ELISA). Most of these antibodies were paralleled by the numbers of their corresponding antibody forming cells in mucosal or systemic lymphoid tissues. However, intra-NALT injection elicited higher levels of immunoglobulin (Ig) A and IgG in saliva, IgA and IgG in lung lavage, and IgG and IgM in sera than nasal inoculation (P<or=0.05). In addition, both routes generated significant reductions of bacteria in lungs following an aerosol challenge with strain 25238 in a mouse model of pulmonary clearance. Once again, intra-NALT route showed better bacterial clearance in mouse lungs than nasal inoculation (P<0.01). These results demonstrate that intra-NALT administration of antigens is a convenient and effective route for mucosal immunization that elicits improved mucosal and systemic immunity. This new route can be used as a model to study mucosal antigens or vaccine candidates for antigen activation and interaction with the NALT that is one of major inductive sites for common mucosal immune system.
Hou
Yingchun
Y
National Institute for Deafness and Other Communication Disorders, National Institute of Health, Rockville, MD 20850, USA.
Hu
Wei Gang
WG
Hirano
Takashi
T
Gu
Xin Xing
XX
D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000097:blood / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D018928:Immunity, Mucosal; D007272:Injections, Intralymphatic; D008168:Lung / Q000276:immunology / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D001936:Moraxella catarrhalis / Q000276:immunology*; D014611:Vaccination / Q000379:methods*
D000907:Antibodies, Bacterial