Antibodies and CD4(+) T-cells mediate cross-protection against H5N1 influenza virus infection in mice after vaccination with a low pathogenic H5N2 strain.
A H5N2 low pathogenic avian influenza virus (LPAIV) was isolated from a natural reservoir in Bavaria during a routine screen and was used as a vaccine strain to scrutinize the immune response involved in cross-protection after challenge infection with a H5N1 highly pathogenic avian influenza virus (HPAIV). The challenge virus was also isolated from a natural reservoir in Bavaria. Wild type, antibody deficient (muMT), CD4(-/-) and CD8(-/-) mice were infected with the apathogenic H5N2 vaccine strain and challenge infection with a 100-fold MLD(50) of the H5N1 strain was performed 80 days later. While 100% of the wild type and 100% of the CD8(-/-) mice stayed healthy, only 50% of the CD4(-/-) and none of the antibody deficient mice were protected. These results support the view that the humoral immune response and to certain extends the CD4(+) T helper cells are a prerequisite for cross-protective immunity against H5 influenza virus.
Friedrich-Loeffler-Institut, Institute of Immunology, Paul-Ehrlich Str. 28, D-72076 Tübingen, Germany.
Karoline
K
Droebner
Emanuel
E
Haasbach
Cordula
C
Fuchs
Andreas O
AO
Weinzierl
Stefan
S
Stevanovic
Mathias
M
Büttner
Oliver
O
Planz
D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D000917:Antibody Formation / Q000276:immunology; D000918:Antibody Specificity; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D003429:Cross Reactions; D005260:Female; D005434:Flow Cytometry; D006385:Hemagglutination Inhibition Tests; D007111:Immunity, Cellular / Q000276:immunology; D007121:Immunocompetence; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D053125:Influenza A Virus, H5N2 Subtype / Q000276:immunology* / Q000472:pathogenicity; D007252:Influenza Vaccines / Q000276:immunology*; D018655:Lymphocyte Count; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009500:Neutralization Tests; D009976:Orthomyxoviridae Infections / Q000276:immunology* / Q000517:prevention & control*; D012137:Respiratory System / Q000473:pathology; D014611:Vaccination; D010948:Viral Plaque Assay
D000914:Antibodies, Viral; D007252:Influenza Vaccines