Autoimmunity to Uroplakin II Causes Cystitis in Mice: A Novel Model of Interstitial Cystitis

Abstract

Background The pathophysiology of interstitial cystitis (IC) is unknown. Deficits in urothelial cell layers and autoimmune mechanisms may play a role. Objective To examine whether immunization of mice with recombinant mouse uroplakin II (rmUPK2), a bladder-specific protein, would provoke an autoimmune response sufficient to create an IC phenotype. Design, setting, and participants RmUPK2 complementary DNA was generated, transferred into a bacterial expression vector, and the generated protein was purified. Eight-week-old SWXJ female mice were immunized with rmUPK2 protein via subcutaneous injection of 200 µg of rmUPK2 protein in 200 µl of an emulsion. Measurements Mice were euthanized 5 wk after immunization. Axillary and inguinal lymph node cells were tested for antigen-specific responsiveness and cytokine production, serum isotype antibody titers against rmUPK2 were determined, and gene expression of inflammatory mediators was measured in the bladder and other organs. For functional analysis, mice were placed in urodynamic chambers for 24-h micturition frequency and total voided urine measurements. Results and limitations Immunization with rmUPK2 resulted in T-cell infiltration of the bladder urothelium and increased rmUPK2-specific serum antibody responses in the experimental autoimmune cystitis (EAC) mice models compared with controls. The ratio of bladder to body weight was increased in EAC mice. Quantitative reverse transcriptase polymerase chain reaction analysis showed elevated gene expression of tumor necrosis factor α, interferon γ, interleukin (IL)-17A, and IL-1β in bladder urothelium but not in other organs. Evaluation of 24-h micturition habits of EAC mice showed significantly increased urinary frequency (p < 0.02) and significantly decreased urine output per void (p < 0.021) when compared with control mice. Conclusions Our study showed that a bladder-specific autoimmune response sufficient to induce inflammation and EAC occurs in mice following immunization with rmUPK2. EAC mice displayed significant evidence of urinary frequency and decreased urine output per void. Further phenotype characterization of EAC mice should include evidence for pain and/or afferent hypersensitivity, and evidence of urothelial cell layer damage.

Chronic pelvic allodynia is mediated by CCL2 through mast cells in an experimental autoimmune cystitis model

“…UPK3A 65-84 immunization yielded significantly less suprapubic (A) and hindpaw (B) allodynia (higher 50% thresholds) in Ccr2 Ϫ/Ϫ mice than in WT mice at all time points (*P Ͻ 0.0001 by two-way ANOVA of log-transformed 50% response thresholds with Bonferroni multiple comparisons test). In addition, CFAinjected WT mice had significantly lower 50% response thresholds than CFA-injected Ccr2 uroplakin 2 protein induced a proinflammatory type 1 cytokine response in the bladder and increased urinary frequency but without detectable tactile allodynia (4). In the present study, we focused on the allodynia phenotype in the UPK3A 65-84 model, because it is considered the most distressing symptom of IC/PBS (55).…”

A novel murine model of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) induced by immunization with a spermine binding protein (p25) peptide

“…In particular, peptides containing a tetrapeptide sequence motif, in which arginine or lysine is separated from serine, threonine, or cysteine by two irrelevant amino acids (-K/R-X-X-S/T/C-) are often immunogenic and capable of inducing several CD4ϩ T-cell-mediated autoimmune diseases in SWXJ(H-2 q,s ) mice (41). Using this strategy, we have successfully developed multiple autoimmune models of disease (2,4,18).…”

“…In particular, peptides containing a tetrapeptide sequence motif, in which arginine or lysine is separated from serine, threonine, or cysteine by two irrelevant amino acids (-K/R-X-X-S/T/C-) are often immunogenic and capable of inducing several CD4ϩ T-cell-mediated autoimmune diseases in SWXJ(H-2 q,s ) mice (41). Using this strategy, we have successfully developed multiple autoimmune models of disease (2,4,18).In this study, we sought to isolate and use peptides derived from prostate-specific proteins: spermine binding protein (p25), six transmembrane epithelial antigen of the prostate (STEAP), and probasin (PB) (11,16,30). The prostate specificity and tissue expression levels of p25, STEAP, and PB render them potentially good markers of prostate-specific disease, as well as good targets for prostate-specific autoimmu-* Firouz Daneshgari and Vincent K. Tuohy contributed equally to this work.…”

“…Further, immunization with homogenate may induce a systemic inflammation beyond prostatitis due to inclusion of both prostate-specific and nonspecific antigens. Thus, there is a need for a CP/CPPS model that combines all the phenotypical features, including frequency, urgency, and pelvic pain with prostate specificity and high incidence rate.Our strategy involves mobilizing a sensitized T-cell response capable of proliferating and differentiating in response to organ-specific proteins (2,4,19,20). In particular, peptides containing a tetrapeptide sequence motif, in which arginine or lysine is separated from serine, threonine, or cysteine by two irrelevant amino acids (-K/R-X-X-S/T/C-) are often immunogenic and capable of inducing several CD4ϩ T-cell-mediated autoimmune diseases in SWXJ(H-2 q,s ) mice (41).…”

Reviewing Interstitial Cystitis Models and Treatments: A Focus on the Urothelium

“…Recent studies suggest the involvement of T helper cells as key players in bladder homogenate-induced IC models (34). Another EIC model was generated by immunizing SWXJ mice with a recombinant uroplakin II, which is abundantly expressed in urothelial cell membranes (35). The symptoms exhibited by those mice were an increased urination frequency, decreased volume per void, thus, and an increased infiltration of T cells in the bladder.…”