TLR2, TLR4 and TLR9 genotypes and haplotypes in the susceptibility to and clinical course of Chlamydia trachomatis infections in Dutch women.

Chlamydia trachomatis infections demonstrate remarkable differences in clinical course that are approximately 40% based on host genetic variation. Here, we study the single nucleotide polymorphisms (SNPs) and their haplotypes in TLR2, TLR4 and TLR9 (TLR2 +2477G>A; TLR2 -16934T>A; TLR4+896A>G; TLR9 -1237T>C and TLR9 +2848G>A) in relation to the susceptibility to, and severity of C. trachomatis infections. We analysed the five SNPs in a cohort of 770 Dutch Caucasian women either attending a sexually transmitted diseases outpatient clinic (n = 731) or having complaints of subfertility (n = 39). Haplotype analyses showed a trend for TLR2 haplotype I (-16934T/+2477G) to protect against the development of symptoms and tubal pathology (Ptrend = 0.03) after Chlamydia infection. In the susceptibility cohort, TLR9 haplotype III (-1237C/+2848A) showed a significant decreasing trend in the development of symptoms after C. trachomatis infection (P = 0.02, OR: 0.55, 95%CI: 0.33-0.91). Logistic regression of the TLR2 haplotypes, TLR4+896A>G, and TLR9 haplotypes showed that the TLR2 haplotype combinations AG-TA and AG-TG confer risk (OR 3.4 (P = 0.01) and 1.6 (P = 0.03)), while the TLR9 haplotype combination TG-TA protects against C. trachomatis infections (OR: 0.4, P = 0.004). Our study shows that both TLR2 and TLR9 genes and SNP combinations do influence the clinical course of Chlamydia infections.

Vaccine progress.

Despite the recent development of new anti-mould agents, there remains a significant incidence of invasive aspergillosis in the most immunocompromised hosts and the response to these agents is still dismal. There is a need for a different approach: prevention by vaccination. We have demonstrated that a hyphal sonicate of Aspergillus fumigatus was capable of conferring protection against subsequent invasive pulmonary aspergillosis in corticosteroid immunosuppressed mice. Subcutaneous vaccination was superior to nasal vaccination. Mice exposed intranasally to viable conidia were noted to respond serologically to a 19 kDa protein. This protein was identified as the allergen Asp f 3 by mass spectrometry. Vaccination with recombinant Asp f 3 was protective. Truncated forms of Asp f 3 that lacked either one of the two known IgE binding sites were cloned and also demonstrated protection against aspergillosis. Although all of these recombinant proteins required an adjuvant (TiterMax) for efficacy, a particulate preparation of rAsp f 3 was also found to be protective without requiring adjuvant. At least two T-cell epitopes (11-mer and 13-mer) have been identified in Asp f 3. There are homologues of Asp f 3 in other Aspergillus species as well as in other moulds (Coccidioides posadasii, Penicillium citrinum) and yeasts (Candida albicans, C. boidinii, Saccharomyces cerevisiae). Asp f 3, truncated non-allergenic versions of Asp f 3, and T-cells epitopes of Asp f 3 are potential candidates for vaccines potentially capable of protecting immunocompromised hosts against invasive aspergillosis.

Efficacy of an immune modulator in experimental Chlamydia trachomatis infection of the female genital tract.

OBJECTIVE: The aim of this study was to determine if vaginal application of the immune response modifier imiquimod (Aldara cream, 3M Pharmaceuticals, St Paul, Minn) would alter the course and/or outcome of female genital tract infection with a human isolate of Chlamydia trachomatis in a murine model. METHODS: Groups of CF-1 mice were treated with Aldara on three different schedules: (1) ongoing beginning 5 days prior to and continuing through day 5 of infection; (2) a single prophylactic dose 2 hours prior to infection; and (3) therapeutic from day 4 to day 14 of infection. Mice were infected vaginally with a serovar D strain of C trachomatis, and monitored by culture to determine the level of shedding and duration of infection. RESULTS: We observed a significant reduction in both duration of infection and the level of shedding during the acute phase in mice treated on an ongoing basis commencing 5 days prior to infection. There was no effect with respect to the other regimens. CONCLUSION: These results demonstrate that ongoing Aldara treatment has efficacy and may enhance local innate immunity which reduces the duration of subsequent infection with human isolates of C trachomatis in a murine model of female genital tract infection.

Vaccinations with recombinant variants of Aspergillus fumigatus allergen Asp f 3 protect mice against invasive aspergillosis.

A vaccine that effectively protects immunocompromised patients against invasive aspergillosis is a novel approach to a universally fatal disease. Here we present a rationale for selection and in vivo testing of potential protein vaccine candidates, based on the modification of an immunodominant fungal allergen for which we demonstrate immunoprotective properties. Pulmonary exposure to viable Aspergillus fumigatus conidia as well as vaccination with crude hyphal extracts protects corticosteroid-immunosuppressed mice against invasive aspergillosis (J. I. Ito and J. M. Lyons, J. Infect. Dis. 186:869-871, 2002). Sera from the latter animals contain antibodies with numerous and diverse antigen specificities, whereas sera from conidium-exposed mice contain antibodies predominantly against allergen Asp f 3 (and some against Asp f 1), as identified by mass spectrometry. Subcutaneous immunization with recombinant Asp f 3 (rAsp f 3) but not with Asp f 1 was protective. The lungs of Asp f 3-vaccinated survivors were free of hyphae and showed only a patchy low-density infiltrate of mononuclear cells. In contrast, the nonimmunized animals died with invasive hyphal elements and a compact peribronchial infiltrate of predominantly polymorphonuclear leukocytes. Three truncated versions of rAsp f 3, spanning amino acid residues 15 to 168 [rAsp f 3(15-168)], 1 to 142, and 15 to 142 and lacking the known bipartite sequence required for IgE binding, were also shown to be protective. Remarkably, vaccination with either rAsp f 3(1-142) or rAsp f 3(15-168) drastically diminished the production of antigen-specific antibodies compared to vaccination with the full-length rAsp f 3(1-168) or the double-truncated rAsp f 3(15-142) version. Our findings point to a possible mechanism in which Asp f 3 vaccination induces a cellular immune response that upon infection results in the activation of lymphocytes that in turn enhances and/or restores the function of corticosteroid-suppressed macrophages to clear fungal elements in the lungs.

Do host genetic traits in the bacterial sensing system play a role in the development of Chlamydia trachomatis-associated tubal pathology in subfertile women?

BACKGROUND: In women, Chlamydia (C.) trachomatis upper genital tract infection can cause distal tubal damage and occlusion, increasing the risk of tubal factor subfertility and ectopic pregnancy. Variations, like single nucleotide polymorphisms (SNPs), in immunologically important host genes are assumed to play a role in the course and outcome of a C. trachomatis infection. We studied whether genetic traits (carrying multiple SNPs in different genes) in the bacterial sensing system are associated with an aberrant immune response and subsequently with tubal pathology following a C. trachomatis infection. The genes studied all encode for pattern recognition receptors (PRRs) involved in sensing bacterial components. METHODS: Of 227 subfertile women, serum was available for C. trachomatis IgG antibody testing and genotyping (common versus rare allele) of the PRR genes TLR9, TLR4, CD14 and CARD15/NOD2. In all women, a laparoscopy was performed to assess the grade of tubal pathology. Tubal pathology was defined as extensive peri-adnexal adhesions and/or distal occlusion of at least one tube. RESULTS: Following a C. trachomatis infection (i.e. C. trachomatis IgG positive), subfertile women carrying two or more SNPs in C. trachomatis PRR genes were at increased risk of tubal pathology compared to women carrying less than two SNPs (73% vs 33% risk). The differences were not statistically significant (P = 0.15), but a trend was observed. CONCLUSION: Carrying multiple SNPs in C. trachomatis PRR genes tends to result in an aberrant immune response and a higher risk of tubal pathology following a C. trachomatis infection. Larger studies are needed to confirm our preliminary findings.

Comparison of multiple genital tract infections with Chlamydia trachomatis in different strains of female mice.

We have previously shown that female outbred CF-1 mice are susceptible to prolonged genital tract infection with the oculogenital serovars (D-K) of Chlamydia trachomatis, and that partial homotypic and heterotypic protection against reinfection is induced. To understand the possible role of inherent T-helper 1 (Th1)/Th2 polarity bias on both the course of infection and the level of acquired immunity induced by infection, 2 immunologically different and well-characterized inbred strains of mice, BALB/c and C57BL/6, were studied in this model. Groups of mice were inoculated intravaginally with C. trachomatis serovar D (Ct D) and monitored by culture to determine the duration of initial infection. Two months later, mice were reinfected, and monitored along with age- and condition-matched control groups. Plasma and vaginal secretions were collected for serologic analysis and specific delayed-type hypersensitivity was assessed by footpad swelling. Initial infection in C57BL/6 mice was comparable in duration to outbred CF-1 mice (median duration 42 versus 43.5 days), while BALB/c mice had a shorter median duration of initial infection (12 days). All strains had significantly shorter durations of infection following reinfection. BALB/c mice shed 4-10 times more inclusion-forming units (IFU) than both C57BL/6 and CF-1 mice on sample days during the first week of infection and all strains shed less IFU during reinfection. C57BL/6 and BALB/c mice had significantly lower anti-Ct D immunoglobulin G titers in both plasma and vaginal secretions than CF-1 mice following resolution of infection; the frequency of immunoglobulin A seropositive vaginal secretions was less in both inbred strains, being significantly less in the case of C57BL/6 mice. Qualitative analysis of the antigen specificity and isotype composition revealed differences among the mouse strains. All 3 strains had detectable levels of specific footpad swelling on day 14 of infection, whereas only BALB/c mice showed a significant response at 70 days post-infection. Significant differences between 2 strains of mice that differ in Th1/Th2 polarity bias were observed in: 1) the duration of infection; 2) the level of bacterial shedding during infection; and 3) the quantitative and qualitative cellular and humoral responses made in response to female genital tract infection with a human oculogenital isolate of C. trachomatis. In addition, a similar and significant level of partial acquired immunity to reinfection was observed in both strains, suggesting that inherent Th1/Th2 polarity bias present upon initial infection does not prevent the development of a protective immune response within the genital tract during infection with an oculogenital isolate of C. trachomatis.

Acquired homotypic and heterotypic immunity against oculogenital Chlamydia trachomatis serovars following female genital tract infection in mice.

BACKGROUND: Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen causing female genital tract infection throughout the world. Reinfection with the same serovar, as well as multiple infections with different serovars, occurs in humans. Using a murine model of female C. trachomatis genital tract infection, we determined if homotypic and/or heterotypic protection against reinfection was induced following infection with human oculogenital strains of C. trachomatis belonging to two serovars (D and H) that have been shown to vary significantly in the course of infection in the murine model. METHODS: Groups of outbred CF-1 mice were reinfected intravaginally with a strain of either serovar D or H, two months after initial infection with these strains. Cellular immune and serologic status, both quantitative and qualitative, was assessed following initial infection, and the course of infection was monitored by culturing vaginal samples collected every 2-7 days following reinfection. RESULTS: Serovar D was both more virulent (longer duration of infection) and immunogenic (higher level of circulating and vaginal IgG and higher incidence of IgA in vaginal secretions) in the mouse genital tract. Although both serovars induced cross-reacting antibodies during the course of primary infection, prior infection with serovar H resulted in only a slight reduction in the median duration of infection against homotypic reinfection (p approximately 0.10), while prior infection with serovar D resulted in significant reduction in the median duration of infection against both homotypic (p < 0.01) and heterotypic reinfection (p < 0.01) when compared to primary infection in age and conditions matched controls. CONCLUSION: Serovar D infection resulted in significant homotypic and heterotypic protection against reinfection, while primary infection with serovar H resulted in only slight homotypic protection. In addition to being the first demonstration of acquired heterotypic immunity between human oculogenital serovars, the differences in the level and extent of this immunity could in part explain the stable difference in serovar prevalence among human isolates.

Vaccination of corticosteroid immunosuppressed mice against invasive pulmonary aspergillosis.

Invasive pulmonary aspergillosis is an emerging devastating infection in the immunocompromised host that is treated with corticosteroids for neoplastic disease or for organ transplantation. By use of a model of invasive pulmonary aspergillosis in corticosteroid-treated CF-1 mice, prior infection and 2 Aspergillus fumigatus vaccine preparations (sonicate and filtrate) administered intranasally and subcutaneously were tested for efficacy in protecting against subsequent lethal A. fumigatus infection. The mortality rates were as follows: control subjects, 100%; prior infection, 12.5%; sonicate administered intranasally, 29%; sonicate given subcutaneously, 0%; filtrate given intranasally, 75%; and filtrate given subcutaneously, 50%. Prior infection and A. fumigatus sonicate vaccine administered by 2 routes protected corticosteroid-treated animals against subsequent lethal invasive pulmonary aspergillosis. The sonicate vaccine was more protective, but the subcutaneous route was more effective.