Basset, AlanThompson, Claudette M.Hollingshead, Susan K.Briles, David E.Ades, Edwin W.Lipsitch, MarcMalley, Richard2019-09-302007Basset, A., C. M. Thompson, S. K. Hollingshead, D. E. Briles, E. W. Ades, M. Lipsitch, and R. Malley. 2007. “Antibody-Independent, CD4+ T-Cell-Dependent Protection against Pneumococcal Colonization Elicited by Intranasal Immunization with Purified Pneumococcal Proteins.” Infection and Immunity 75 (11): 5460–64. https://doi.org/10.1128/iai.00773-07.0019-95671070-63131098-5522http://nrs.harvard.edu/urn-3:HUL.InstRepos:41426793Immunity to pneumococcal colonization in mice by exposure to live or killed pneumococci has been shown to be antibody independent but dependent on CD4(+) T cells. Here we show that intranasal immunization with pneumococcal proteins (pneumococcal surface protein C, adhesin A, and a pneumolysoid) can elicit a similar mechanism of protection. Colonization could be significantly reduced in mice congenitally deficient in immunoglobulins after intranasal immunization with this mixture of proteins; conversely, the depletion of CD4(+) T cells in immunized wild-type mice at the time of challenge eliminated the protection afforded by immunization. Overall, our results show that intranasal immunization with a mixture of pneumococcal proteins protects against colonization in an antibody-independent, CD4(+) T-cell-dependent manner.en-USJournal Article2019-09-3010.1128/IAI.00773-07