Binding of monosodium urate crystals with idiotype protein efficiently promote dendritic cells to induce cytotoxic T cells

Abstract

Monosodium urate (MSU) crystals have been reported to evoke specific cell immunity and to work as an adjuvant in a mouse model. The crystals also have another unique characteristic to bind with positively charged proteins, which could help to deliver some antigens into human dendritic cells (DC). We focused on the application of MSU crystals as not only an adjuvant but also as a carrier of positively charged antigenic protein to induce human cytotoxic T cells (CTL) efficiently in vitro. We selected human leukocyte antigen (HLA)-A2 expressing the multiple myeloma IM-9 cell line and its product idiotype (Id) protein as one of the best pairs of target cells and positively charged tumor-specific antigen, respectively. Following the sensitization of DC derived from HLA-A2-positive volunteers pulsed with tumor-specific monoclonal immunoglobulin G-Fab fragments (IM-9 Fab) attached to MSU crystals, the DC-stimulated CD8 + T cells killed significantly more target cells (40.1 ± 1.7%) than those stimulated by DC pulsed with MSU crystals alone (6.2 ± 8.6%, P < 0.01) or IM-9 Fab alone (4.7 ± 8.1%, P < 0.01). These cytotoxic effects of the DC-stimulated CD8 + cells were reduced when MSU crystals were precoated with fetal bovine serum. In addition, we confirmed that MSU crystals facilitated human DC to express the maturation marker, CD83 and deliver ( T umor-specific immunotherapy can open the way for an alternative approach for patients with hematological malignancies. Studies have shown that cell therapy using sensitized dendritic cells (DC) resulted in good responses in follicular lymphoma, in which tumor-producing idiotype protein (Id) was used as the specific antigen.(1,2) Multiple myeloma seems to be another promising candidate for cell immunotherapy using idiotype proteins, because the monoclonal immunoglobulin secreted into serum by myeloma cells is easily obtained for use as a tumor-specific antigen. Administration of DC pulsed with Id proteins has been clinically performed in a few studies, however, the results were disappointing because the response cases were very limited. (3)(4)(5) The reason why the ideal T-cellmediated immune responses could not be achieved is the functional deficiency of circulating DC (6,7) or lower immunogenicity of autologous Id proteins. For successful tumor-specific immunotherapy, it is necessary to develop an efficient method for DC to recognize tumor-specific Id proteins and then become mature and activated.Although monosodium urate monohydrate (MSU) is famous as the causative crystals that induce gouty arthritis, its action as a key substance in local immunoreactions has only been studied in recent years. MSU released from locally damaged cells works as an endogenous danger signal to antigen-presenting cells. (8) Depending on uric acid concentration, s.c. administered MSU crystals exhibit adjuvant activities to reduce tumor burden in vivo.(9) In addition, MSU crystals have shown another unique characteristic as they bind a lot of serum (10) or cell-surface proteins due to their negative...

Safety of Intradermal Injection of Monosodium Urate Crystals as a Vaccine Carrier in Volunteers

“…In addition, MSU crystals evoke specific cell immunity and work as an adjuvant by delivering several kinds of binding proteins into dendritic cells, suggesting that MSU crystals have the potential to function as an antigen carrier and an adjuvant. [11] MSU crystals would thus be expected to represent an ideal peptide vaccine carrier for cancer immunotherapy. However, the safety of in vivo injection of MSU crystals has not yet been established.…”

“…[11] Flow cytometric analysis was thus performed to determine whether the administration of MSU crystals could increase the number of dendritic cells or promote the terminal differentiation of immature dendritic cells in vivo. Unfortunately, the intensity of dendritic cell markers, CD83 and CD86, in peripheral blood mononuclear cells was not ascertained during this trial (data not shown).…”

“…[10] We have also reported the potential of MSU crystals to bind with an idiotypic protein produced by a human myeloma cell line. [11] Using the resulting complex, we succeeded in inducing cytotoxic T lymphocytes targeting the myeloma cells.…”

Monosodium Urate Crystals Induce Upregulation of NK1.1-Dependent Killing by Macrophages and Support Tumor-Resident NK1.1+ Monocyte/Macrophage Populations in Antitumor Therapy

“…T he formation of monosodium urate (MSU) crystals is a wellrecognized autoinflammatory danger signal that exhibits potent endogenous adjuvant activities to alter local immune cell phenotypes and boost adaptive immune responses (1)(2)(3)(4).…”

Identification of potential mediators of oxidative damage and targets for novel treatments for chronic kidney disease

“…A 20.6 % prevalence of hyperuricaemia was found in a cross-sectional study of 18,020 CKD patients , and a positive correlation was found between serum uric acid and serum creatinine with impaired renal function . Retention of uremic toxins promotes inflammation, and oxidative stress, by priming polymorphonuclear lymphocytes, activating IL-1β and IL-8 (Martinon et al, 2006) and stimulating the innate immune response through CD8+ cells (Sakamaki et al, 2008). Additionally, uric acid synthesis can promote oxidative stress directly through the activities of xanthine oxidase, which produce NO…”