Evidence of a cross-protective immune response to influenza A in the cotton rat model.
Epidemiologic evidence suggests that cross-protective immune responses to influenza A viruses that have different hemagglutinin and neuraminidase subtypes occur in humans. This study characterized this heterosubtypic immunity in cotton rats (Sigmodon hispidus). Animals were infected with influenza A/PR/8/34 (H1N1) or A/Wuhan/359/95 (H3N2), and then challenged with A/Wuhan/359/95(H3N2) virus 4 weeks later. Viral titers, respiratory rates, and pathology of the respiratory tract following primary and secondary infection were compared. Cross-protection from heterosubtypic influenza A challenge in cotton rats was characterized by enhanced viral clearance, protection from tachypnea, a vigorous early cellular recall response, and a reduction in bronchiolar epithelial cell damage. Cross-protection was retained in steroid treated animals, in which the inflammatory recall response was minimal. Identification of the mechanisms that contribute to cross-protection in cotton rats may lead to the development of influenza vaccine strategies that are broadly protective.
Straight
Timothy M
TM
Department of Clinical Investigation, Brooke Army Medical Center, 3400 Rawley E. Chambers Avenue, Fort Sam Houston, TX 78234, USA. timothy.m.straight@us.army.mil <timothy.m.straight@us.army.mil>
Ottolini
Martin G
MG
Prince
Gregory A
GA
Eichelberger
Maryna C
MC
D000818:Animals; D005260:Female; D007114:Immunization; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology* / Q000302:isolation & purification; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology* / Q000302:isolation & purification; D007252:Influenza Vaccines / Q000276:immunology*; D008171:Lung Diseases / Q000276:immunology / Q000517:prevention & control / Q000821:virology; D008297:Male; D009976:Orthomyxoviridae Infections / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control / Q000821:virology; D051381:Rats; D016205:Sigmodontinae; D014779:Virus Replication
D007252:Influenza Vaccines