Characteristics of cell-mediated, anti-listerial immunity induced by a naturally avirulent Listeria monocytogenes serotype 4a strain HCC23.
The characteristics of cell-mediated, anti-listerial immune response initiated by an avirulent Listeria monocytogenes serotype 4a strain HCC23 was assessed. Similar to virulent strain EGD, avirulent strain HCC23 grew readily within macrophage-like J774 cells, but nonhemolytic strain ATCC 15313 did not. Compared with EGD, HCC23 induced a relatively low level of gamma interferon (IFN-gamma) in mice, and ATCC 15313 stimulated no detectable IFN-gamma. The percentages of gated CD4 T cells from mice immunized with EGD and HCC23 showed a notable drop (to 30%) at 21 days post exposure in comparison with that (about 50%) from ATCC 15313-injected or untreated mice; and the percentage of gated NK cells from EGD-immunized group was markedly higher than those from other treatment groups. Mice immunized with HCC23 and EGD developed an equally strong protective immunity against listeriosis that was effective in both short and long terms, but those injected with ATCC 15313 or saline succumbed to listeriosis within 6 days of challenge.
Liu
Dongyou
D
College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA. liu@cvm.msstate.edu
Lawrence
Mark L
ML
Pinchuk
Lesya M
LM
Ainsworth
A Jerald
AJ
Austin
Frank W
FW
D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology* / Q000494:pharmacology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D007111:Immunity, Cellular / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D008089:Listeria monocytogenes / Q000276:immunology* / Q000472:pathogenicity; D008088:Listeriosis / Q000276:immunology* / Q000517:prevention & control*; D051379:Mice; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D014774:Virulence
D001428:Bacterial Vaccines; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma