Screening for immune biomarkers associated with infection or protection against Ehrlichia ruminantium by RNA-sequencing analysis.

Heartwater is one of the most economically important tick-borne fatal diseases of livestock. The disease is caused by the bacteria Ehrlichia ruminantium transmitted by Amblyomma ticks. Although there is evidence that interferon-gamma controls E.

Protection of Cattle Elicited Using a Bivalent Lumpy Skin Disease Virus-Vectored Recombinant Rift Valley Fever Vaccine.

Lumpy skin disease and Rift Valley fever are two high-priority livestock diseases which have the potential to spread into previously free regions through animal movement and/or vectors, as well as intentional release by bioterrorists. Since the distribution range of both diseases is similar in Africa, it makes sense to use a bivalent vaccine to control them. This may lead to the more consistent and sustainable use of vaccination against Rift Valley fever through a more cost-effective vaccine.

A multi-epitope DNA vaccine co-administered with monophosphoryl lipid A adjuvant provides protection against tick transmitted Ehrlichia ruminantium in sheep.

Previously, a heartwater experimental DNA vaccine provided 100% protection following laboratory challenge with Ehrlichia ruminantium administered by needle but not against an E. ruminantium tick challenge in the field. A multi-epitope DNA vaccine incorporating both CD4 and CD8 cytotoxic T lymphocytes epitopes could provide a better alternative.

Identification and characterisation of conserved epitopes of E. ruminantium that activate Th1 CD4 T cells: Towards the development of a multi-epitope vaccine.

Several studies have shown that cytotoxic T lymphocytes (CTL) require CD4 + Th1 epitopes to generate strong immune responses to intracellular pathogens. However, not much is known about Ehrlichia ruminantium epitopes, particularly those that can be considered potential candidates for inclusion in a multi-epitope vaccine. In order to identify CD4 Th1 epitopes that induce IFNγ, a number of proteins previously identified as immunogenic were first screened to determine if they induce cellular immunity in tick infected immune sheep PBMC.

Ehrlichia ruminantium antigens and peptides induce cytotoxic T cell responses in vitro.

Since CD8 T cells play an important role in resistance to infection with heartwater, effective vaccines against this disease will likely require identification of antigens that contain CD8 T cell epitopes responsible for cytotoxic T lymphocyte (CTL) responses. With the use of the fluorescent antigen-transfected target cell (FATT)-CTL assay, IFN-γ ELISPOT and flow cytometry, peptides that induce CTL, proliferation of CD8 + T cells and IFN-γ production were identified as possible target antigens for vaccine development. Of particular relevance was the finding that different peptides from different antigens were able to elicit varied cytotoxic activities by immune peripheral blood mononuclear cells (PBMC) from heartwater immune tick-infected sheep.