CD3+ cells transfer the hypersensitive granulomatous response to mycobacterial glycolipid trehalose 6,6′-dimycolate in mice

Abstract

The granulomatous response is the characteristic histological feature of Mycobacterium tuberculosis infection that is essential for organism containment. Trehalose 6,6-dimycolate (TDM), a cell-wall glycolipid present on most mycobacterial species, has been implicated in the pathogenesis of M. tuberculosis infection. TDM has potent immunoregulatory and inflammatory properties, and can be used to model granulomatous reactions that mimic, in part, pathology caused during active infection. This study examined the hypersensitive granulomatous response, focusing on cellular responses specific to TDM. Lungs from mice immunized with TDM emulsion demonstrated exacerbated histological damage, inflammation, and lymphocytic infiltration upon subsequent challenge with TDM. Splenocytes recovered from these mice demonstrated significant interferon (IFN)-γ production during recall response to TDM, as well as increased production of proinflammatory mediators (tumour necrosis factor-α, interleukin-6 and macrophage inflammatory protein-1α). The exacerbated response could be adoptively transferred to naïve mice. Administration of non-adherent lymphocytes or purified CD3+ cells from TDM-immunized mice led to increased inflammation, lymphocytic infiltration, and vascular endothelial cell damage upon challenge with TDM. Recipient mice that received immunized CD3+ lymphocytes demonstrated significant increases in Th1-type cytokines and proinflammatory mediators in lung tissue following TDM challenge. When CD1d−/− mice were immunized with TDM, they failed to generate a specific IFN-γ response, suggesting a role for this molecule in the generation of hypersensitivity. These experiments provide further evidence for the involvement of TDM-specific CD3+ T cells in pathological damage elicited during M. tuberculosis infection.

Mycobacterial glycolipid trehalose 6,6′-dimycolate-induced hypersensitive granulomas: contribution of CD4+ lymphocytes

“…More recently, the contribution of CD3 + T cells to the generation of this hypersensitive pathology was confirmed (Guidry et al, 2006). The current study identifies the importance of CD4 + cells to this response.…”

“…These cells produced inflammatory and Th1-type cytokines in a TDM-specific manner. Adoptive transfer of CD3 + TDM-immunized cells was sufficient in transferring the hypersensitive granulomatous response, while transfer of T cells immunized with an alternative antigen did not transfer the hypersensitive pathology, indicating that this response was TDM specific (Guidry et al, 2006).…”

“…Mice were sacrificed and lungs were perfused with 1 ml PBS with 1 mM EDTA via the right ventricle. Lungs were grossly monitored for inflammation and pathological damage, evaluating tissue according to lung weight index (LWI), as detailed previously (Guidry et al, 2004(Guidry et al, , 2006. The right lung was separated from the left by severing the bronchus distal to the ligature; the right lower lobe was snap-frozen in RNAzol B (TelTest) and stored at 270 uC for RNA extraction and qRT-PCR.…”

“…Mice were immunized according to previously published methods (Guidry et al, 2004(Guidry et al, , 2006Yamagami et al, 2001). Briefly, mice received 100 ml of a water/oil emulsion containing 100 mg TDM (Sigma) emulsified in complete Freund's adjuvant (Sigma) and 100 mg methylated BSA (Promega) administered by subcutaneous injection at the base of the tail.…”

Influence of bovine lactoferrin on expression of presentation molecules on BCG-infected bone marrow derived macrophages

“…Splenocytes from naïve and BCG (1 × 10 7 CFU/mouse) immunized mice were isolated as previously described [40]. CD3 + T-cells were purified by passing ACK treated splenocytes through a CD3 + enrichment column (R&D Systems, Minneapolis, MN), yielding a minimum of 90% CD3 + cells as determined by FACS analysis.…”