Role of CD8+ and WC-1+ γ/δ T cells in resistance to Mycobacterium bovis infection in the SCID-bo mouse

Abstract

The role of various effector T cell populations in the bovine immune response toMycobacterium bovis infection is poorly understood. This is largely due to the difficulties associated with performing in vivo challenge studies in the natural host species. In this report, we utilized a fetal bovine-severe combined immunodeficient (SCID-bo) xenochimeric mouse model to study the protective role of two putative effector cell types, CD8 ؉ T cells and a subpopulation of ␥/␦ T cells that express WC-1, a member of the cysteine-rich scavenger receptor superfamily (CRSR). We demonstrate that CD8 ؉ T cells play a key role in protection and contribute substantially to bovine IFN-␥ mRNA levels at 30 days post-infection. The role of WC-1 bearing cells to protection was less definitive but our results suggest that this population may play a pivotal role early in infection. Granuloma architecture was altered in anti-WC-1 (ILA29) but not anti-CD8 (ILA51) -treated animals, suggesting that this population may be involved in recruitment of various cell types to sites of infection. J. Leukoc. Biol. 65: 28-34; 1999.

In Vitro Responsiveness of γδ T Cells fromMycobacterium bovis-Infected Cattle to Mycobacterial Antigens: Predominant Involvement of WC1+Cells

“…Doherty et al (21) (55). However, the exact mechanism by which bovine ␥␦ cells become activated is the subject of ongoing studies.…”

Modulation of Immune Responses toMycobacterium bovisin Cattle Depleted of WC1+γδ T Cells

“…A novel, severe combined immunodeficient mouse, reconstituted with a bovine immune system (SCID-bo), has been used to investigate the role of WC1 ϩ ␥␦ T cells (56). The results obtained from M. bovis infection in this model suggest a role for WC1 ϩ ␥␦ T cells in cattle similar to that already postulated for ␥␦ T cells in mice (17).…”

Circulating γδ T Cells in Response toSalmonellaentericaSerovar Enteritidis Exposure in Chickens

“…Meanwhile, a number of interesting distinctions between ␥␦ and ␣␤ T cells have been found, such as tissue distribution, repertoire restrictions, and nonclassical major histocompatibility complex (MHC) restriction (1,22). In addition, ␥␦ T cells were shown to possess antimicrobial activity in bacterial, parasitic, and viral infections (15,19,45) as well as to perform a wide range of functions, such as cytokine production, cytotoxic activity, immunomodulation, granuloma organization, and regulation of inflammation (10,12,26,35,41). Based on the expression of different V␥ or V␦ elements, tissue localization, TCR diversity, and the expression of some surface antigens, ␥␦ T cells could be divided into various functionally different subpopulations in mice and humans (14), cattle (25,46), and rats (42).…”