Association of human leucocyte antigen phenotype with vaccine efficacy in patients receiving vaginal mucosal immunization for recurrent urinary tract infection.

Immune responses to specific antigens can be influenced by an individual's genetic make-up. We examined whether the efficacy of a vaginal mucosal vaccine for urinary tract infections (UTI) was affected by a patient's human leucocyte antigen (HLA) phenotype. Urinary tract infection data and the HLA phenotypes of 47 women participating in a phase II clinical trial of immunization for recurrent UTI were statistically analysed for associations between HLA-A, -B, -DR, or -DQ phenotype and postimmunization infection course. Women who received the vaccine and had HLA-DR phenotypes other than DR2 had significantly delayed times to re-infection compared with women receiving placebo. Vaccine-treated patients with the HLA-DR2 phenotype had re-infection courses that were not different than women receiving placebo. These results indicate that the efficacy of a vaginal mucosal UTI vaccine may be influenced by an individual's HLA-DR phenotype.

The urinary tract response to entry of pathogens.

The urinary tract response to the entry of pathogens is complex and involves multiple aspects of the immune system. Herein we have divided them into cytokine, immunoglobulin, and cellular responses. Our current understanding suggests that interleukin 6 (IL-6) and IL-8 are the major contributors to the cytokine response. Both IL-6 and IL-8 are produced locally and systemically as part of the initiation of an inflammatory reaction. The cellular response becomes clinically apparent by the appearance of polymorphonuclear neutrophils (PMNs) in the urine. The contribution of gamma delta T-lymphocytes is beginning to be appreciated due to the use of gene-knockout mice in studies of urinary tract infection (UTI). B-lymphocytes are important because antibody response to UTI is important. In addition to the classic systemic antibody response, a local antibody response dominated by secretory immunoglobulin A (sIgA) has been shown to play a major role in the host response to UTI. Efforts to create a vaccine against UTI have focused on stimulation and intensification of this local sIgA production. Investigation continues to define the role of these responses, explain how they interact, and elucidate other aspects of the immune response to UTI that are yet unknown. Ultimately, this work aims to provide more effective treatment and prevention of UTI in those susceptible to invasions of the urinary tract by pathogens. Comprehension of how these responses interact may lead to a better understanding of UTI susceptibility and promote new and innovative types of treatment.

Treatment of mice with staphylococcal enterotoxin B enhances resolution of an induced Escherichia coli urinary tract infection and stimulates production of proinflammatory cytokines.

Staphylococcal enterotoxin B (SEB) is a superantigen that causes mass proliferation of murine Vbeta8+ T cells via major histocompatibility complex (MHC) class II molecules and leads to their apoptosis or anergy. SEB also stimulates other MHC class II-bearing cells to proliferate and secrete cytokines, some of which might enhance early host defenses against urinary tract infections (UTIs). We investigated the effect of SEB administration on the course of an induced Escherichia coli UTI in mice. Treatment with SEB 3 or 7 days before the infection had no effect on UTI resolution. However, when SEB was administered at the time of infection, bacterial colonization in the bladders was reduced at time points between 6 h and 3 days. This reduction was not due to a physiological effect, such as increased urinary glycosaminoglycans, or altered pH, nor was SEB bactericidal for the inoculum. Cytokine production in the spleens and bladders of SEB-treated and/or infected mice was evaluated by reverse transcription-PCR. SEB treatment resulted in increased levels of interleukin-2 (IL-2), IL-4, IL-6, and IL-10 mRNAs in the spleen and IL-1alpha, IL-6, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor alpha transcripts in the bladder. Also, liver cells from SEB-treated mice expressed IL-6 mRNA, which induces the production of acute-phase proteins. These data indicate that SEB treatment in vivo leads to enhanced UTI resolution through a mechanism that may include direct stimulation of effector cells in the bladder, the action of cytokines induced in the spleen, or cytokine-mediated induction of acute-phase proteins.

A comparative study of major histocompatibility complex and red blood cell antigen phenotypes as risk factors for recurrent urinary tract infections in women.

Recurrent urinary tract infections (RUTI) are a significant health problem for many women, and host characteristics that increase susceptibility are not completely defined. This study evaluated data from 99 patients to examine further the question of a possible association between major histocompatibility complex (MHC) or red blood cell (RBC) antigen phenotype and predisposition to RUTIs. MHC class I and II, ABO, and Lewis RBC phenotypes were determined serologically. The MHC class II phenotypes of 55 subjects were also determined by DNA polymerase chain reaction techniques. There were no significant differences in the proportions of HLA-A or -B antigen types between patients and controls, nor in the frequencies of serologically or DNA-defined HLA-DR or -DQ phenotypes. Patient ABO and Lewis RBC phenotypes were not statistically different than those for controls. Thus, the overall risk for women to develop RUTIs does not appear to be associated with any single HLA, ABO, or Lewis phenotype.

Time course and host responses to Escherichia coli urinary tract infection in genetically distinct mouse strains.

Recurrent urinary tract infections (UTIs) are a significant clinical problem for many women; however, host susceptibility factors have not been completely defined. The mouse model of induced UTI provides an experimental environment in which to identify specific host characteristics that are important in initial bacterial colonization of the urinary tract and in resolution of an infection. This study examined initial susceptibility, bacterial clearance, and host defense mechanisms during induction and resolution of Escherichia coli UTIs in genetically distinct strains of mice. Of the ten inbred strains tested, six (BALB/c, C3H/HeN, C57BL/6, DBA.1, DBA.2, and AKR) showed progressive resolution of bladder infections over a 14-day period. A constant, low-level bladder infection was observed in SWR and SJL mice. High bladder infection levels persisted over the 14-day study period in C3H/HeJ and C3H/OuJ mice. Kidney infection levels generally correlated with bladder infection levels, especially in C3H/HeJ and C3H/OuJ mice, the two most susceptible strains, in which infections became more severe with time after challenge. The degree of inflammation in bladder and kidneys, as well as antibody-forming cell responses, positively correlated with infection intensity in all strains except C3H/HeJ, which had minimal inflammation despite high infection levels. These results demonstrate two important aspects of host defense against UTI. First, the innate immune response to an infection in the bladder or kidneys consists primarily of local inflammation, which is followed by an adaptive response characterized in part by an antibody response to the infecting bacteria. Second, a UTI will be spontaneously resolved in most cases; however, in mice with specific genetic backgrounds, a UTI can persist for an extended length of time. The latter result strongly suggests that the presence or absence of specific host genes will determine how effectively an E. coli UTI will be resolved.

Vaginal mucosal immunization for recurrent urinary tract infection: phase II clinical trial.

PURPOSE: Decreased local immunity to uropathogenic bacteria may be a factor predisposing women to recurrent urinary tract infections. Our phase I study demonstrated the safety of a multi-strain vaccine administered as a vaginal suppository. A phase II study was conducted to determine vaccine efficacy. MATERIALS AND METHODS: A total of 91 women susceptible to recurrent urinary tract infections was entered into the study and the courses were analyzed in a randomized, double-blind, placebo controlled trial of vaginal mucosal immunization. Subjects received 3 vaginal suppositories at weekly intervals. Depending on the treatment group each suppository contained 1 of 2 vaccine doses or suppository material only. Each patient was followed for 5 months to record infection episodes, and obtain urine, vaginal irrigates and serum to measure immunological responses. RESULTS: Immunogen treated women who were off antibiotic prophylaxis throughout the study had a significant delay in interval to reinfection during the first 8 weeks compared to women receiving placebo. Mean interval until reinfection was delayed from 8.7 weeks for placebo treated to 13 weeks for vaccine treated women. Immunological responses in serum, urine and vaginal fluid were variable. No serious adverse effects were observed. CONCLUSIONS: These data demonstrate that vaginal mucosal immunization can enhance resistance to urinary tract infections in susceptible patients.

Prospective serial technetium diphosphonate and indium-111 white blood cell labeled imaging in primary uncemented total hip arthroplasty.

Although technetium diphosphonate (TcMP) and Indium-111 white blood cell labeled (Ind-WBC) imaging are reported useful in identifying aseptic and septic loosening in cemented hip arthroplasty, their usefulness has not been identified in uncemented porous coated hip arthroplasty. We attempted to define the natural history of TcMP and Ind-WBC imaging in primary P.C.A. uncemented total hip arthroplasty. Twenty-five hips in 21 patients were scanned immediately postoperatively, at 3 months, 6 months, 12 months, 18 months, and 24 months after surgery with both TcMP and Ind-WBC tracers. Clinical and radiographic follow-up were also obtained at each interval. Intensity and distribution of tracer activity were recorded as well as the time when stabilization occurred around the acetabulum, femoral porous surface areas, and femoral stem tip. Acetabular cup and femoral porous surface areas stabilized in the first year on both TcMP and Ind-WBC imaging. Focal femoral hip activity continued at 24 months in 72% of TcMP and 24% of Ind-WBC images. TcMP and Ind-WBC images used to assess uncemented total hip arthroplasty should not be over interpreted. Although persistent intense activity after one year around the acetabulum and porous surface femoral areas should be considered abnormal for both TcMP and Ind-WBC scans, femoral tip activity is present in the majority of patients, with or without thigh pain, at 24 months on TcMP scans. Tip activity can also persist at 24 months on Ind-WBC images and should be interpreted in conjunction with TcMP images.

Western blot analysis of anti-Escherichia coli serum immunoglobulins in women susceptible to recurrent urinary tract infections.

The basis for increased susceptibility of some women to recurrent urinary tract infections (UTIs) is not clear; increased susceptibility may be due to host factors that promote increased colonization of the vaginal and bladder mucosa with uropathogens or to decreased immune responses to uropathogens. Anti-Escherichia coli antibody specificities in sera from UTI patients and controls were comprehensively assessed to determine whether UTI-susceptible and -nonsusceptible women differed in their capacities to make antibodies to individual E. coli antigens. Sera were analyzed by one-dimensional Western blots using antigens prepared from uropathogenic E. coli. The results showed that sera from subjects without a history of recurrent UTIs contained IgG antibodies to specific E. coli antigens more often than did sera from UTI-susceptible patients. These data suggest that hyporesponsiveness to specific E. coli antigens may be linked to increased UTI susceptibility in some women.

Induction of urinary tract infection by intraurethral inoculation with Escherichia coli: refining the murine model.

Murine models are important for studying the induction and pathophysiology of ascending urinary tract infections (UTI). However, when vesicoureteral reflux occurs during intravesical inoculation of mice with bacterial suspensions, it is difficult to distinguish between naturally ascending infections and those resulting from the inoculation procedure. The current study investigated whether introducing a bacterial suspension into the urethra rather than into the bladder could minimize or eliminate this complication. There were no differences in the intensity or time course of bladder infections induced by intraurethral or intravesical inoculation. In contrast, the prevalence of kidney infections was < 7% in mice given 10 microliters of intraurethral inoculations versus nearly 60% in animals inoculated intravesically with 100 microliters. There were equivalent numbers of bacteria in the kidneys after inoculation by either route. Thus, intraurethral inoculation of female mice with a small volume of bacteria appears to simulate most closely the pathophysiology of ascending UTIs in humans.

Resolution time of Escherichia coli cystitis is correlated with levels of preinfection antibody to the infecting Escherichia coli strain.

OBJECTIVES: A number of studies in animals have demonstrated that immunization against uropathogenic bacteria can lessen the severity or duration of induced urinary tract infections (UTI). This study examined whether preinfection levels of serum or urinary anti-Escherichia coli antibodies were correlated with length of time needed to resolve an induced E coli cystitis. METHODS: Serum and urine anti-E coli antibody levels in 36 control and 42 vaginally immunized cynomolgus monkeys were measured by enzyme-linked immunosorbent assay. Regression analyses were used to determine correlations between resolution time and preinfection antibody level, and to estimate antibody levels that might be associated with effective resolution of an E coli UTI. RESULTS: Linear regression analysis showed significant correlations between short resolution time and high levels of serum immunoglobulin M (IgM), urinary secretory IgA, and urinary IgG specific for the infecting E coli strain. Serum IgM and urinary IgG anti-E coli levels in monkeys that cleared infections early were significantly higher than in animals with protracted infections. Logistic regression estimated the serum IgM and urinary IgG anti-E coli levels associated with a 50% probability of accelerated clearance to be 3.3 micrograms/mL and 2.7 micrograms/24 hours, respectively. CONCLUSIONS: For this primate model, the observed correlations between short resolution time and pre-existing serum and urinary antibody suggest that antibody-mediated immunity is an important component of host defense against UTI.

Phase I clinical trial of vaginal mucosal immunization for recurrent urinary tract infection.

In a phase I clinical trial to test safety and patient acceptance 25 women with a history of recurrent urinary tract infections but no identifiable anatomic abnormality received a multivalent vaccine instilled into the vagina. The vaccine contained 6 heat-killed Escherichia coli strains and 4 nonE. coli uropathogens. Only minimal adverse reactions were observed in the 5-month period following immunization. Total vaginal and urinary IgG and IgA increased significantly (p < 0.01 by repeated measures analysis of variance). Serum antibodies to some of the nonE. coli strains but not to the E. coli strains increased after vaginal immunization. While efficacy is yet to be shown, this study indicates that this vaginally applied urinary tract infection vaccine is well tolerated, and capable of increasing vaginal and urinary antibody.

Vaginal immunization of monkeys against urinary tract infection with a multi-strain vaccine.

Cynomolgus monkeys were treated with a vaccine containing 10 heat-killed uropathogenic bacteria including 6 Escherichia coli strains. The multi-strain vaccine was administered either as a vaginal surface immunogen or intramuscularly. Following an induced E. coli cystitis, bladder infections were significantly reduced compared with controls at 1 and 2 weeks (intramuscular route) or 1 week (vaginal route) after UTI. This vaccine has been shown to be efficacious against cystitis in humans when given parenterally and has now proved efficacious in nonhuman primates by the vaginal mucosal route.

Congenital immunodeficiencies in mice increase susceptibility to urinary tract infection.

Severe combined immunodeficient (SCID), T cell deficient, and immunocompetent mice were challenged intravesically with viable uropathogenic Escherichia coli. In comparison to immunocompetent controls, SCID mice had significantly greater numbers of viable E. coli in their bladders and kidneys 7 days after inoculation. Splenic anti-E. coli antibody-forming cells (AFC) were virtually absent in SCID mice at 7.0 days after infection. Adoptive transfer of spleen cells from E. coli-immunized immunocompetent mice to SCID mice enhanced their resistance to urinary tract infection (UTI), as evidenced by lower bacterial counts in bladder and kidneys following an induced infection. Congenitally T cell deficient nude mice and immunocompetent heterozygous controls had equivalent bladder and kidney infection levels at 2 and 7 days after UTI. Immunocompetency thus appears to play a significant role in resistance to E. coli UTI in this animal model. Since mice deficient only in T cells did not show increased UTI susceptibility, T cell-independent antibody responses may be an important immunologic defense mechanism.

Immunization against urinary tract infection with a multi-valent vaginal vaccine.

Systemic and local immune responses are thought to play an important role in susceptibility to urinary tract infection. In an attempt to boost local immunity, a vaccine was administered parenterally or vaginally to two mouse strains. Both routes of immunization increased the number of splenic antibody-forming cells against the bacterial strains in the vaccine. Following vaginal or parenteral immunization and subsequent induction of cystitis with live E. coli, immunized animals had fewer viable bladder E. coli than non-immunized animals.

Decreased immunologic responsiveness following intensified vaginal immunization against urinary tract infection.

In an attempt to further increase the protective effect of vaginal immunization against urinary tract infections in Cynomolgus monkeys, the immunogen of killed E. coli was given more times, in larger amounts, and with the adjuvant MDP. Instead of increasing the protective effect, no protective effect on induced cystitis was observed. In addition, rises in urinary and serum immunoglobulins previously observed after vaginal immunization and induced cystitis were lessened. These observations appear to correspond with the classical concepts of immunologic unresponsiveness.

Adherence of uropathogenic E. coli to differentiated human uroepithelial cells grown in vitro.

A quantitative in vitro model to measure E. coli adherence to differentiated human uroepithelial cells has been developed. Primary cultures of uroepithelial cells were initiated from normal ureteral epithelium. Adherence of uropathogenic 3H-labelled Escherichia coli to postconfluent human uroepithelial cells was directly related to the bacteria:epithelial cell ratio during incubation. Bacterial attachment was inhibited either by mannose or by urine containing anti-E. coli antibodies. Transmission electron microscopy showed that epithelial cells differentiated in vitro to resemble normal uroepithelium in vivo. Furthermore, electron microscopy showed specific adherence of bacteria to the glycocalyx of microvilli of the superficial uroepithelial cells in vitro in a manner which closely mimics the in vivo interaction. This model of bacterial adherence permits in vitro analysis of adhesin-receptor interactions between uropathogenic E. coli and a layer of viable uroepithelial cells similar to those lining the bladder.

Urinary glycosaminoglycan levels following induced cystitis in monkeys.

Urinary glycosaminoglycan (GAG) levels were measured by the Whiteman assay in five monkeys following induction of an E. coli urinary tract infection. Urinary GAG levels rose as the infection developed and returned to baseline levels as the infection resolved. Elevated urinary GAG levels may be a marker for the tissue injury incurred by such infections and may offer insight into their pathophysiology.