Neonatal immunization with Listeria monocytogenes induces T cells with an adult-like avidity, sensitivity, and TCR-Vbeta repertoire, and does not adversely impact the response to boosting.
Listeria monocytogenes (Lm) holds promise as a neonatal vaccine vehicle. Here we show that Lm immunized neonatal mice reached maximal Ag-specific CD8(+) T cell expansion after only a single immunization, while adults required two doses. Ag-specific CD4(+) T cell expansion in both age groups required a boost to reach its peak. Neither functional avidity, sensitivity, nor the TCR-Vbeta repertoire of the Ag-specific T cells differed between mice immunized as neonates or adults. Lastly, neonatal immunization did not decrease protection or preclude a booster response. Overall, our data provide further evidence in support of immunization at birth as a feasible public health strategy to combat early life infections.
Department of Experimental Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
Kinga K
KK
Smolen
Daniela I M
DI
Loeffler
Brian A
BA
Reikie
Laura
L
Aplin
Bing
B
Cai
Edgardo S
ES
Fortuno
Tobias R
TR
Kollmann
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D000942:Antigens, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D007117:Immunization, Secondary; D007371:Interferon-gamma / Q000276:immunology; D008088:Listeriosis / Q000276:immunology / Q000517:prevention & control*; D051379:Mice; D008810:Mice, Inbred C57BL; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D013154:Spleen / Q000276:immunology
D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D016693:Receptors, Antigen, T-Cell, alpha-beta; D007371:Interferon-gamma