CD8+ Type 1 CD44hi CD45 RBlo T lymphocytes control intracellular Brucella abortus infection as demonstrated in major histocompatibility complex class I- and class II-deficient mice
✍ Scribed by Sergio C. Oliveira; Gary A. Splitter
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 831 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0014-2980
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Genetically engineered mice with a targeted disruption in the β2‐microglobulin (β2‐m) gene or the H2‐I‐Aβ chain (αβ) which lack functional CD8^+^ or CD4^+^ T cells, respectively, were used to assess the role of T cell subsets in Brucella abortus infection. Murine brucellosis was markedly exacerbated in β2‐m‐deficient mice (β2‐m^−/−^) compared to Aβ mutant (Aβ^−/−^) or C57BL/6 mice, strongly indicating that optimal resistance to B. abortus requires CD8^+^ T cells. Splenocytes from Brucella‐primed β2‐m^−/−^, αβ^−/−^ and C57BL/6 mice exhibited a type 1 cytokine profile marked by elevated IFN‐γ mRNA expression and protein production, and basal levels of IL‐2 and IL‐4 transcripts. B. abortus did not induce secretion of TGF‐β1, but substantial IL‐10 activity was detected in spleen cell supernatants from all mouse strains studied. CD8^+^ T cells from Aβ^−/−^ and C57BL/6 mice displayed a CD44^hi^ CD45RB^lo^ phenotype and a type 1 cytokine transcription profile featuring high levels of IFN‐γ mRNA. Additionally, we have shown the ability of C57BL/6 CD8^+^ CTL to kill Brucella‐infected macrophages. This study illustrates the predominant role of MHC class I‐restricted T cells in controlling B. abortus infection.