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Updated: Aug 17, 2026
Intralymphatic Immunotherapy and Vaccination in Mice
Published on: February 2, 2014
Mucosal immunization with Salmonella typhimurium expressing Lassa virus nucleocapsid protein cross-protects mice from
M Djavani1, C Yin, I S Lukashevich
1Institute of Human Virology, University of Maryland Biotechnology Center, Baltimore 21201, USA.
Objectives:
Lassa fever virus (LAS) is transmitted to man by rodent carriers and is fatal in a third of untreated cases. Our goal is to provide immune protection from Lassa fever by mucosal vaccination.
Study Design/Methods:
Mice were vaccinated intragastrically with control vectors or with vectors (vaccinia or Salmonella) expressing LAS nucleocapsid protein (NP). Mice were challenged intracranially with a lethal dose of the related arenavirus, lymphocytic choriomeningitis virus (LCMV), as a measure of the vaccine's ability to elicit cross-protection.
Results:
Salmonella and vaccinia vectors expressing LAS NP each protected a third of the mice from lethal challenge with LCMV. All mice vaccinated with a vector expressing LCMV NP were protected as expected.
Conclusions:
The LAS recombinant Salmonella vector is comparable to the LAS recombinant vaccinia vector in its ability to cross-protect mice from lethal challenge. Nucleocapsid protein is an inadequate immunogen on its own, but provides sufficient cross-protection to make it a useful component of a broadly reactive arenavirus vaccine.
Insights
Mucosal vaccination using Lassa fever virus (LAS) nucleocapsid protein (NP) shows potential for cross-protection against related arenaviruses. LAS NP provides partial protection, suggesting its utility in a broad-spectrum arenavirus vaccine.
Area of Science:
- Virology
- Immunology
- Vaccinology
Background:
- Lassa fever virus (LAS) poses a significant public health threat, transmitted by rodents and causing fatal illness in a substantial portion of untreated individuals.
- Developing effective vaccination strategies is crucial for controlling LAS and related arenavirus infections.
Purpose of the Study:
- To evaluate the potential of mucosal vaccination with LAS nucleocapsid protein (NP) for inducing immune protection against Lassa fever.
- To assess the cross-protective capabilities of LAS NP-expressing vectors against a related arenavirus.
Main Methods:
- Mice were administered LAS NP via intragastric vaccination using vaccinia or Salmonella vectors.
- Vaccinated mice were subsequently challenged with a lethal dose of lymphocytic choriomeningitis virus (LCMV) to evaluate cross-protection.
Main Results:
- Both LAS NP-expressing Salmonella and vaccinia vectors conferred protection in approximately one-third of the mice against lethal LCMV challenge.
- Mice vaccinated with a vector expressing LCMV NP demonstrated complete protection, as anticipated.
Conclusions:
- LAS recombinant Salmonella and vaccinia vectors exhibit comparable efficacy in inducing cross-protection against lethal arenavirus challenge in mice.
- While LAS nucleocapsid protein alone is insufficient as a standalone immunogen, it offers adequate cross-protection, positioning it as a valuable component for a broadly reactive arenavirus vaccine.
