Peripheral blood lymphocyte proliferative responses in cattle infected with or vaccinated against Anaplasma marginale

Abstract

An assay was developed for measurement of the peripheral blood lymphocyte proliferative response (PBLPR) in cattle infected with or immunised against Anaplasma marginale. PBLPR was not evident in all cattle that had recovered from A. marginale infection. However, A. marginale-sensitised lymphocytes were detected in the spleens of all immune cattle tested in the absence of detectable PBLPR. During the course of initial infection, cattle exhibited detectable PBLPR for a period corresponding with and up to 2 weeks after patent parasitaemia, followed by a second, usually larger peak in PBLPR corresponding to the time of sub-clinical relapse of cattle. Analysis of the PBLPR of A. marginale chronically infected cattle demonstrated highly variable PBLPR between individuals and over time. A positive PBLPR was induced in cattle by vaccination using a crude A. marginale antigen preparation. The PBLPR of vaccinated cattle subsequently infected with A. marginale was markedly different from that of naive cattle, with reduced PBLPR being associated with the onset of parasitaemia. The antigen used in the PBLPR assay was inactivated by proteolysis. Proteolysis also abolished immunity that had been induced in cattle vaccinated using the antigen preparation. A marginale-sensitised PBL did not proliferate in response to antigen from the heterologous species A. centrale. A. centrale-sensitised PBL, however, responded to A. marginale antigen. Interferon-gamma (IFN-gamma) was detected in PBLPR-assay supernatants and was associated with a strong PBLPR.

Adaptive immunity to Anaplasma pathogens and immune dysregulation: Implications for bacterial persistence

“…Gale et al [55] measured T-lymphocyte proliferation in blood and spleens of cattle during infection. Responses were not detected in PBMC of all cattle that had recovered from infection, whereas responses by splenic lymphocytes were detected, although the responses were inconsistent between time points for individual animals.…”

Mapping the T cell epitopes of the Babesia bovis antigen 12D3: implications for vaccine design

“…In addition, the two 'nonresponders' carried circulating antibodies to 12D3 (Results not shown) and therefore must have produced 12D3 specific T cells which may have been sequestered away from the circulation at the time of sampling. Gale et al (1996) demonstrated that the spleens of cattle immunized against Anaplasma marginale contained T cells capable of antigen stimulated proliferation even when such cells were absent from the peripheral circulation. The seven experimentally determined epitopes were restricted to the amino terminal (peptides 4 & 7) and carboxy terminal (peptides 22, 27,28, 29 & 31) regions of the protein.…”

Anaplasma marginale: effect of the treatment of cattle with an interferon γ‐neutralizing monoclonal antibody or the nitric oxide synthetase inhibitor aminoguanidine on the course of infection

“…T. buffeli, Stewart et al 1990, Gale et al 1997). In addition, the spleen plays a central role in immunity against anaplasmosis (Roby et al 1961) and lymphoproliferative responses have been demonstrated in the spleens of A. marginale-immune cattle (Gale et al 1996).…”