Helicobacter pylori-pulsed dendritic cells induce H. pylori-specific immunity in mice.
BACKGROUND
The growing concern over the emergence of antibiotic-resistant Helicobacter pylori infection is propelling the development of an efficacious vaccine to control this highly adaptive organism.


OBJECTIVE
We studied the use of a dendritic cell (DC)-based vaccine against H. pylori infection in mice.


METHODS
The cellular immune responses to murine bone marrow-derived DCs pulsed with phosphate-buffered saline (PBS-DC) or live H. pylori SS1 (HP-DC) were assessed in vitro and in vivo. The protective immunity against H. pylori SS1 oral challenge was compared between HP-DC or PBS-DC immunized mice. The effect of regulatory T-cell (Treg) depletion by anti-CD25 antibody on HP-DC vaccine efficacy was also evaluated.


RESULTS
HP-DC induced a Th1-dominant response in vitro. In vivo, HP-DC immunized mice were characterized by a mixed Th1/Th2 peripheral immune response. However, in the stomach, HP-DC immunized mice expressed a higher level of IFN-gamma compared to PBS-DC immunized mice; no difference was found for interleukin-5 expressions in the stomach. A lower bacterial colonization post-H. pylori challenge was observed in HP-DC immunized mice compared to PBS-DC immunized mice with no significant difference in gastritis severity. H. pylori-specific Th1 response and protective immunity were further enhanced in vivo by depletion of Treg with anti-CD25 antibody.


CONCLUSIONS
DC-based anti-H. pylori vaccine induced H. pylori-specific helper T-cell responses capable of limiting bacterial colonization. Our data support the critical role of effector cellular immune response in the development of H. pylori vaccine.
Zhang
Min
M
Department of Internal Medicine (Gastroenterology Division), University of Michigan, Ann Arbor, Michigan 48109, USA.
Berndt
Bradford E
BE
Eaton
Kathryn A
KA
Rathinavelu
Sivaprakash
S
Pierzchala
Anna
A
Kao
John Y
JY
D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D016481:Helicobacter Infections / Q000276:immunology* / Q000517:prevention & control*; D016480:Helicobacter pylori / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
D000942:Antigens, Bacterial