Abstract
Background:
Listeria monocytogenes (LM) is a life-threatening bacterium affecting many individuals worldwide, including elderly people, pregnant women, and immune-deficient patients.
Aim:
Whole-Cell Killed-Formalin of Listeria monocytogenes Antigens (WKLMAgs) and Listeria Culture Filtrated Proteins (LCFPs) against challenge-attenuated Listeria monocytogenes after two booster doses (0, and 14 days) of immunization act as an antigen activating a high level of IgG3, IgM, CXCL2, and IL-1 beta.
Methods:
Forty male rats were randomly assigned to four groups. The first group served as a control negative, while the second positive (+) control was inoculation orally 1 ml with virulent (1×107 colony forming unit CFU/ml) of Listeria monocytogenes on day 28. Whereas, the other two groups were injected with 1 ml Whole Killed Listeria Monocytogenes Antigen (WKLMAgs) and 1 ml Listeria culture filtrate proteins (LCFPs) in two subcutaneously (S/C) doses with day 14 intervals, with at day 28 a challenged effective dose (1×107 CFU/ml) of virulent Listeria monocytogenes. Serum blood parameters. During the 35 days, the euthanized animal histopathology studies were performed on the (spleen, liver, small intestine, and brain).
Results:
The current study indicated a significant difference between WKLMAgs and LCFPs for serological tests Immunoglobulin M, chemokine (C-X-C motif) ligand 2, Immunoglobulin G3 and Interleukin 1beta compared to both negative and positive control at P <0.001. Additionally, the WKLMAgs and LCFPs led to a decrease in the histopathological changes of organs such as (brain, spleen, liver, and intestine) compared to the positive control, which affected the organs with microgranuloma, with a pathological difference between the WKLMAgs and LCFPs compared to the negative control group.
Conclusion:
Both WKLMAgs and LCFPs are capable to be as a vaccine candidate antigen for the induction of protective immunity against Listeria monocytogenes.
Key words: Listeria monocytogenes, IgM, CXCL2, Vaccine design, PCR
