Thein vitro-Inductionof Type II Collagen-Specific Immune Tolerance in BALB/C Mice

Abstract

Type II collagen (CII) protein is the main component of hyaline cartilage. The clinical importance of CII in arthritis, aging, and osteoarthritis is significant, but its ability to induce specific immune tolerance has not been extensively studied previously. We have recently proven that CII is capable of inducing Anterior Chamber Associated Immune Deviation (ACAID) when injected into the eye. Here, we hypothesized that ACAID-mediated tolerance could be induced in Balb/c mice that receive an intravenous administration of CII-induced in vitro-generated ocular-like antigen-presenting cells (APCs) or T regulatory cells (Tregs), Delayed hypersensitivity (DTH) assays were used to examine this hypothesis. In mice injected with CII-specific ACAID APCs, the specific regulatory activities resided in the spleen cells, splenic T cells, and ACAID CD8+ T cells, as proven by local adoptive transfer (LAT) assays. Conversely, there was a lack of regulatory activity in the CD4+ CD25+ T cell compartment of the recipient mice. Thus, ACAID CD8+ Tregs generated in vitro could be directly responsible for the expression of CII-driven ACAID-mediated tolerance and could be used as potential therapeutic tools in the treatment of CII-associated autoimmune diseases.The eye is vulnerable to severe inflammatory immune responses that could cause serious damage. Thus, regulatory mechanisms are in place to protect against intra-ocular inflammation. Anterior chamber-associated immune deviation (ACAID) is one such mechanism whereby the antigenic entry into the AC induces potent antigen-specific immune tolerance that is not only localized in the eye but also extends to the periphery. In order to obtain this potent antigen-specific peripheral immune tolerance, ACAID involves intricate multicellular communications between the eye-derived F4/80+ antigen presenting cells (APCs), splenic T cells, marginal zone B cells, NKT cells, and yo T cells (l). ACAID is characterized by the negative regulation of systemic Th 1 responses and of delayed type hypersensitivity (DTH) responses (2). This is achieved through professional APCs that induce the generation of afferent and efferent T regulatory cells (Tregs) (3), which could potentially be used to curb T-helper cell responses in autoimmune diseases. Professional APCs can be immunogenic or tolerogenic depending on the involvement of unique cytokines that impact their maturation and activation, such as the immunosuppressive cytokines IL-I 0 and TGF-~that push towards the tolerogenic type (4, 5). The in vitro culture of F4/80+ macrophages with antigens in the presence ofTGF-~2 could lead to the

Eye‐mediated immune tolerance to Type II collagen in arthritis‐prone strains of mice

“…We have previously shown the induction of specific immune tolerance in Balb/c mice through injection of CII into the AC of the eye or the intravenous injection of in vitro ‐generated ACAID APCs specific to CII . In the present study, we extended our observations to C57BL/6 and DBA/1 mice, in which arthritis could be potentially induced.…”

“…We have recently shown that CII could induce peripheral tolerance in Balb/c mice via the AC injection of CII or the intravenous injection of in vitro ‐generated CII‐specific ACAID APCs . Whether CII could induce ACAID in the arthritis‐prone DBA/1 or C57BL/6 mice remains to be elucidated.…”

“…Studies reported that arthritis could be induced in C57BL/6 mice when immunized with CII . CII‐mediated ACAID induction resulting from the injection of CII into the AC of the eye or the adoptive transfer of in vitro ‐generated CII‐specific ACAID antigen‐presenting cells (APCs) in Balb/c mice has been recently shown by our group . In this study, we aimed to test for CII‐induced ACAID in arthritis‐prone strains of mice (C57BL/6 and DBA/1).…”