Prognostic impact of inter-metastatic heterogeneity of viable tumour cells in colorectal liver metastases.

BACKGROUND: Heterogenous response to neoadjuvant chemotherapy in patients with multiple colorectal liver metastases (CRLM) has been associated with an acquired resistance to systemic therapy. This study evaluated the occurrence of a heterogenous inter-metastatic tumour response with regards to the proportion of viable tumour cells, and its prognostic impact. METHODS: A retrospective cohort study was conducted, including all patients with CRLM surgically treated at Karolinska University Hospital, Stockholm, Sweden, from 2013 to 2018. Factors associated with the proportion of viable tumour cells and inter-metastatic heterogeneity were analysed with regression and survival analyses. RESULTS: Out of 640 surgically treated patients, 405 patients (1357 CRLM), received neoadjuvant chemotherapy. Multiple CRLM were present in 314 patients (78%), out of whom 72 patients (23%) presented with a heterogenous tumour response. The median overall survival (OS) for patients with a heterogenous inter-metastatic tumour response was 36 months, compared to 57 months for patients with a homogenous inter-metastatic tumour response (p < .001). Poor OS in patients receiving preoperative chemotherapy was significantly associated with a heterogenous inter-metastatic tumour response (hazard ratio (HR) 1.68 (1.02-2.78)), right-sided primary tumour (HR 2.01 (1.29-3.43)) and CRLM diameter >5 cm (HR 1.83 (1.06-3.17)). CONCLUSION: Outcome in patients with a heterogenous inter-metastatic tumour response, illustrated by the proportion of viable tumour cells, is inferior to that of patients with a homogenous response. These results suggest that heterogeneity in treatment response is an important marker of aggressive disease and could be of clinical value for decisions on post-operative therapy.

[Impact of an educational program for parents of children with cancer on the increased knowledge of their children's disease and the decrease in anxiety]. / Impacto de un programa educativo a los padres de niños con cáncer en el aumento del conocimiento de la enfermedad de sus hijos y la disminución de la ansiedad.

PURPOSE: To determine the impact of an educational program provided by a nurse to parents of children with cancer to improve the level of knowledge of the disease and to decrease the levels of anxiety. PATIENTS AND METHODS: A prospective randomized study was conducted on parents of children recently diagnosed with cancer and treated in the Hospital Luis Calvo Mackenna. After informed consent, parents were randomized in two groups: one receiving the educational program and another without intervention. Both groups completed a questionnaire on social risk, and three tests to assess the levels of knowledge and anxiety. RESULTS: A total of 96 parents were enrolled (July 2010-November 2011). When comparing the number of correct responses on day 10, and day 90 after the intervention, a significant increase was observed in the level of parental knowledge in the group that received the educational program (P<.0001). No significant differences were observed in the levels of anxiety (P=.06) between both groups. CONCLUSIONS: An educational program provided by nurses to parents of children recently diagnosed with cancer, increased the knowledge of their children's disease. However there was no effect on the levels of anxiety. A feasible educational intervention is proposed that could be implemented at other cancer centers for children.

Impacto de un programa educativo a los padres de niños con cáncer en el aumento del conocimiento de la enfermedad de sus hijos y la disminución de la ansiedad / Impact of an educational program for parents of children with cancer on the increased knowledge of their children's disease and the decrease in anxiety

Propósito: Determinar el impacto de un programa de educación entregado por la enfermera a los padres de niños con cáncer en el aumento del conocimiento de la enfermedad de sus hijos y disminución de la ansiedad. Pacientes y métodos: Estudio prospectivo y aleatorio. Incluyó a los padres de niños con diagnóstico reciente de cáncer, atendidos en el Hospital Dr. Luis Calvo Mackenna. Tras la firma de consentimiento informado se aleatorizó a los padres en 2 grupos, uno que recibió el programa educativo y otro sin intervención. Ambos grupos contestaron una encuesta de riesgo social y 3 evaluaciones de conocimiento y de ansiedad. Resultados: Un total de 96 padres fueron incluidos (julio 2010-noviembre 2011). Al comparar el número de respuestas correctas al día 10 y 90 posterior a la intervención entre ambos grupos, se encontró un aumento significativo en el nivel de conocimiento de los padres del grupo que recibió el programa educativo (p < 0,0001). Al comparar los resultados obtenidos en las evaluaciones de ansiedad entre ambos grupos, no se obtuvo una diferencia significativa (p = 0,06). Conclusiones: El estudio mostró que la realización de un programa educativo, entregado a los padres de niños con diagnóstico reciente de cáncer, aumentó el conocimiento de estos en mayor grado que aquellos que no la recibieron. Sin embargo, no hubo efectos en los grados de ansiedad de dichos padres en el período evaluado. Esta es una intervención factible que se podría implementar en los centros oncológicos infantiles del país.

Purpose: To determine the impact of an educational program provided by a nurse to parents of children with cancer to improve the level of knowledge of the disease and to decrease the levels of anxiety. Patients and methods: A prospective randomized study was conducted on parents of children recently diagnosed with cancer and treated in the Hospital Luis Calvo Mackenna. After informed consent, parents were randomized in two groups: one receiving the educational program and another without intervention. Both groups completed a questionnaire on social risk, and three tests to assess the levels of knowledge and anxiety. Results: A total of 96 parents were enrolled (July 2010-November 2011). When comparing the number of correct responses on day 10, and day 90 after the intervention, a significant increase was observed in the level of parental knowledge in the group that received the educational program (P < .0001). No significant differences were observed in the levels of anxiety (P = .06) between both groups. Conclusions: An educational program provided by nurses to parents of children recently diagnosed with cancer, increased the knowledge of their children's disease. However there was no effect on the levels of anxiety. A feasible educational intervention is proposed that could be implemented at other cancer centers for children.

Amphipols from A to Z.

Amphipols (APols) are short amphipathic polymers that can substitute for detergents to keep integral membrane proteins (MPs) water soluble. In this review, we discuss their structure and solution behavior; the way they associate with MPs; and the structure, dynamics, and solution properties of the resulting complexes. All MPs tested to date form water-soluble complexes with APols, and their biochemical stability is in general greatly improved compared with MPs in detergent solutions. The functionality and ligand-binding properties of APol-trapped MPs are reviewed, and the mechanisms by which APols stabilize MPs are discussed. Applications of APols include MP folding and cell-free synthesis, structural studies by NMR, electron microscopy and X-ray diffraction, APol-mediated immobilization of MPs onto solid supports, proteomics, delivery of MPs to preexisting membranes, and vaccine formulation.

Susceptibility of human and murine Chlamydia trachomatis serovars to granulocyte- and epithelium-derived antimicrobial peptides.

Four antimicrobial peptides, protegrin-1, RTD-1, cryptdin-4, and indolicidin, were tested for their ability to inhibit the in vitro growth of Chlamydia trachomatis serovars E, L2, and mouse pneumonitis (MoPn). In general, protegrin-1 was found to have the strongest anti-chlamydial activity. Overall, of the three serovars tested, L2 was the most susceptible while MoPn was the most resistant to these peptides.

Immunization with the Chlamydia trachomatis mouse pneumonitis major outer membrane protein can elicit a protective immune response against a genital challenge.

Infertility, ectopic pregnancy, and chronic abdominal pain are frequent complications of genital infections with Chlamydia trachomatis. In an attempt to produce a vaccine to protect against this pathogen we purified and refolded the C. trachomatis mouse pneumonitis (MoPn) major outer membrane protein (MOMP). This preparation, mixed with Freund's adjuvant using vortexing or sonication, was used to immunize BALB/c mice that were subsequently challenged in the upper genital tract. Vaginal cultures were taken on a weekly basis, and mice were mated 6 weeks after the challenge. Gels of the vortexed MOMP showed a predominant band with a molecular size of 62 kDa and weaker bands at 42 and 132 kDa, while the sonicated MOMP had a single band with a molecular size of 42 kDa. Following immunization with these two preparations, strong humoral and cell-mediated immune responses were detected in the mice inoculated with the vortexed MOMP. On the other hand, mice immunized with the sonicated MOMP had a strong humoral immune response but a relatively weak cell-mediated immune response, as determined by a T-cell lymphoproliferative assay and level of cytokine production by splenocytes. Vaginal cultures showed that the mice immunized with the vortexed MOMP were significantly protected, as determined by a decrease in the number of animals with positive cultures, the length of time the mice shed viable organisms, and the number of inclusion-forming units recovered per mouse. Animals immunized with the sonicated MOMP, on the other hand, showed a weaker level of protection based on the same three parameters. After mating, the number of fertile animals and number of embryos per mouse were significantly higher for the mice immunized with vortexed MOMP, but not for the mice immunized with sonicated MOMP, compared to those of the control groups. In conclusion, immunization with a purified and refolded preparation of the C. trachomatis MoPn MOMP confers a significant level of protection in mice against a genital challenge.

Susceptibility of mice to vaginal infection with Chlamydia trachomatis mouse pneumonitis is dependent on the age of the animal.

Mice from three strains, BALB/c (H-2(d)), C3H (H-2(k)), and C57BL/6 (H-2(b)), ranging from 5 to 14 weeks of age, were inoculated intravaginally with different doses of the Chlamydia trachomatis mouse pneumonitis serovar. Vaginal swabs taken at weekly intervals showed that the percentage of animals with positive cultures and the number of inclusion-forming units recovered per mouse were higher in the younger animals. Furthermore, vaginal shedding lasted longer in the young mice than in the older mice. In addition, following mating higher rates of infertility and a decrease in the number of embryos were observed in the infected young mice. In conclusion, susceptibility to a chlamydial vaginal infection is dependent on the age of the mice, with the older animals being more resistant.

Role of Nramp1 deletion in Chlamydia infection in mice.

Elicited macrophages from 129sv mice with a functional deletion of the natural-resistance-associated macrophage protein 1 gene (Nramp1) were shown to be as susceptible as wild-type mice to infection with the Chlamydia trachomatis mouse pneumonitis and L3 serovars and to Chlamydia pneumoniae. Furthermore, the two groups of mice were shown to be similarly susceptible to an intranasal infection with these microorganisms. In conclusion, the Nramp1 gene does not appear to play a major role in the regulation of the susceptibility of mice to a chlamydial infection.

Immunogenic and protective ability of the two developmental forms of Chlamydiae in a mouse model of infertility.

To compare the ability of elementary bodies (EB) and reticulate bodies (RB) of the Chlamydia trachomatis mouse pneumonitis (MoPn) biovar to induce a protective immune response, two groups of BALB/c mice were inoculated and boosted twice, with UV-inactivated EB or RB in Freund's adjuvant. Two weeks after the last immunization mice were challenged with C. trachomatis in the ovarian bursa. Vaginal cultures collected for 6 weeks after the intrabursal challenge showed that mice inoculated with EB were significantly protected, while mice inoculated with RB were not. Six weeks after the genital challenge mice were mated. Mice immunized with EB showed significant protection as demonstrated by the number of animals which were fertile and the number of embryos present in the uterine horns. In contrast, no significant protection against infertility was observed in the mice immunized with RB.

Comparison of direct and concentrated acid-fast smears to identify specimens culture positive for Mycobacterium spp.

Microscopic examination of respiratory specimens for acid-fast bacilli (AFB) plays a key role in the initial diagnosis of tuberculosis, monitoring of treatment, and determination of eligibility for release from isolation. The objective of this study was to compare the sensitivity obtained with smears for detection of AFB (AFB smears) made directly from respiratory specimens (direct AFB smears) to that obtained with parallel smears made from concentrates of the specimens (concentrated AFB smears). A total of 2,693 specimens were evaluated; 1,806 were from the University of California Irvine Medical Center Medical Microbiology Laboratory (UCIMC), which serves a tertiary-care hospital with outpatient clinics, and 887 were from the Microbial Disease Laboratory at the California Department of Public Health (MDL), which receives specimens from outpatient facilities and clinics on Pacific islands. Of the 353 AFB culture-positive specimens at UCIMC, there was a statistically significant difference in the sensitivity of the direct AFB smear (34%) and that of the smear made from the concentrated specimen (58%) (P < 0.05). This was also true for the 208 specimens positive for Mycobacterium tuberculosis, for which the sensitivity of the direct smear was 42% (87 of 208) and that for the smear made from the concentrated specimen was 74% (154 of 208). At MDL, where all but 1 of the 45 culture-positive specimens grew M. tuberculosis, the sensitivity of the smear made from the concentrated specimen was 93% (42 of 45) and was not significantly higher than the sensitivity of the direct smear, which was 82% (37 of 45). By combining the results from both laboratories, 42 patients from whom at least three specimens were received were culture positive for M. tuberculosis. The cumulative results for the initial three specimens from these patients showed that the direct smear detected M. tuberculosis in 81% of these patients, whereas the smear made from the concentrate detected M. tuberculosis in 91% of these patients. In summary, when all culture-positive specimens are considered, the sensitivity of the direct smear compared to that of a smear made from the concentrated specimen was significantly different overall in the two different laboratory settings. However, this difference was reduced only if the cumulative results for the initial three specimens received from patients who were culture positive for M. tuberculosis were evaluated.

Intranasal immunization with Chlamydia trachomatis, serovar E, protects from a subsequent vaginal challenge with the homologous serovar.

To vaccinate against a vaginal challenge with Chlamydia trachomatis, C3H/HeJ (H-2k) mice were immunized intranasally (i.n.) or intraperitoneally (i.p.) with 1 x 10(6) inclusion forming units (IFU) of C. trachomatis, serovar E and i.n. with 1 x 10(6) UV inactivated IFU of serovar E. Animals inoculated i.n. with mock infected HeLa 229 cells were used as controls. Upon a vaginal challenge with 5 x 10(3) IFU of serovar E, mice immunized i.n. with viable serovar E exhibited significant protection as judged by the number of mice infected compared to controls (p < 0.05). In contrast, mice immunized i.n. with serovar E that had been UV-inactivated, were not protected from a subsequent vaginal challenge with serovar E. Mice immunized i.p. with serovar E showed attenuation of the infection by 4 weeks after challenge compared to control mice as to the number of animals with positive vaginal cultures (p < 0.05). Of the immune parameters examined, the best correlation with protection was seen with Chlamydia specific IgG and IgA vaginal titers and lymphoproliferative responses to serovar E. In summary, mucosal immunization with viable serovar E partially protected mice against a subsequent vaginal challenge, thereby showing that it is possible to elicit a protective response to a human strain of C. trachomatis at a distant mucosal site in this animal model.

Cerebral phaeohyphomycosis caused by Ramichloridium obovoideum (Ramichloridium mackenziei): case report.

OBJECTIVE AND IMPORTANCE: Only a few cerebral infections with the dark-walled mold Ramichloridium obovoideum (Ramichloridium mackenziei) have been reported in the literature. Central nervous system infections caused by this fungus have poor prognoses; the optimal medical and surgical treatments have not yet been established. We report a case of cerebral R. obovoideum infection for which a combination of medical and surgical treatments failed. CLINICAL PRESENTATION: A 58-year-old Kuwaiti woman, with a history of chronic renal failure requiring hemodialysis, presented with a 3-day history of left frontal headache, blurry vision, dizziness, and right-sided clumsiness. Computed tomography demonstrated multiple, ring-enhancing, cerebral lesions (the largest of which measured 2-3 cm) in the deep left parieto-occipital region. INTERVENTION: A computed tomography-guided needle biopsy of the parieto-occipital lesion yielded 10 ml of dark caseous fluid. Stains demonstrated long, branching, septate hyphae. Fungal cultures grew R. obovoideum. The patient was treated with a combination of amphotericin B and itraconazole. The condition of the patient continued to deteriorate, and stereotactic aspiration of the largest lesion was performed. Despite this approach, the lesion progressed and the patient died. CONCLUSION: R. obovoideum is being increasingly recognized as a cause of cerebral abscesses in patients residing in the Middle East. Prognoses are poor, and responses to antifungal therapy are generally short-lived. Until more effective therapies are found, the greatest chance for adequate treatment involves early recognition, prompt treatment with antifungal agents, and attempts at complete resection.

Immunization with a peptide corresponding to chlamydial heat shock protein 60 increases the humoral immune response in C3H mice to a peptide representing variable domain 4 of the major outer membrane protein of Chlamydia trachomatis.

C3H (H-2(k)) mice are susceptible to a vaginal challenge with human strains of Chlamydia trachomatis and thus are a useful strain for testing potential Chlamydia vaccine candidates. However, C3H mice are fairly poor responders in terms of the level of antibody resulting from immunization with potential protective peptides representing variable domains (VDs) of the major outer membrane protein (MOMP). C57BL/6 (H-2(b)) mice, on the other hand, are moderately resistant to a vaginal challenge but are good responders to the chlamydial MOMP VDs. Peptides representing universal T-cell helper epitopes were employed to determine whether the antibody response to a peptide representing VD4 of the MOMP, which has been shown to contain neutralizing epitopes, could be enhanced in C3H and C57 mice. Universal T-cell helper peptides from tetanus toxin, the pre-S2 region of hepatitis B virus, and the mouse heat shock protein 60, as well as the corresponding segment of the Chlamydia heat shock protein 60 (hspct), were coadministered with the VD4 peptide. Peptides were coencapsulated in liposomes containing the adjuvant monophosphoryl lipid A and administered by using a combination of mucosal and intramuscular injection. The only T-cell helper peptide that improved the immune response as judged by antibody level, in vitro neutralization assays, and T-cell proliferation was hspct. The response in the C57BL/6 strain was not significantly enhanced with hspct over levels achieved with VD4 alone; however, in C3H mice the levels of serum antibody to C. trachomatis increased to that seen in C57 mice. However, the molecular specificity and immunoglobulin subclass distribution differed from those of the C57 response, and the neutralizing titers and T-cell proliferation responses were lower. In both strains of mice, titers of vaginal antibody to C. trachomatis were low. In summary, of the T-helper peptides used, only hspct significantly enhanced the immune response of C3H mice to the VD4 peptide, but it had only a modest effect on the immune response of C57 mice.

A murine model for the study of Chlamydia trachomatis genital infections during pregnancy.

Pregnant BALB/c mice were inoculated intravaginally on day 5 of gestation with the Chlamydia trachomatis mouse pneumonitis biovar. Animals that received 10(5), 10(6), or 10(7) inclusion-forming units (IFU) of C. trachomatis delivered prematurely on days 15 to 16 of gestation. A focal inflammatory infiltrate was observed in the wall of the uterus on the day 14 of gestation in animals inoculated with 10(5) IFU. In this group of mice, immunohistochemical analysis showed chlamydial inclusions in the endometrium and fetal membranes.

Vaccination of mice with DNA plasmids coding for the Chlamydia trachomatis major outer membrane protein elicits an immune response but fails to protect against a genital challenge.

A DNA plasmid encoding the gene of the major outer membrane protein (MOMP) of the Chlamydia trachomatis mouse pneumonitis (MoPn) serovar and three plasmids containing the variable domains (VD) of the MOMP were constructed. Female mice were inoculated with the plasmids and 60 days later were challenged in the genital tract with C. trachomatis. Six weeks after challenge female mice were caged with male mice and the course of the mating followed. Mice immunized with the MOMP plasmids mounted weak humoral and cell mediated immune responses. However, following the genital challenge no significant differences in vaginal shedding were observed between the groups immunized with the MOMP and control plasmids. In addition, the fertility rates were similar in the experimental and negative control groups. In conclusion, vaccination with DNA plasmids encoding the MOMP elicited a modest immune response but did not protect against infection or disease.

Chlamydia infections and heart disease linked through antigenic mimicry.

Chlamydia infections are epidemiologically linked to human heart disease. A peptide from the murine heart muscle-specific alpha myosin heavy chain that has sequence homology to the 60-kilodalton cysteine-rich outer membrane proteins of Chlamydia pneumoniae, C. psittaci, and C. trachomatis was shown to induce autoimmune inflammatory heart disease in mice. Injection of the homologous Chlamydia peptides into mice also induced perivascular inflammation, fibrotic changes, and blood vessel occlusion in the heart, as well as triggering T and B cell reactivity to the homologous endogenous heart muscle-specific peptide. Chlamydia DNA functioned as an adjuvant in the triggering of peptide-induced inflammatory heart disease. Infection with C. trachomatis led to the production of autoantibodies to heart muscle-specific epitopes. Thus, Chlamydia-mediated heart disease is induced by antigenic mimicry of a heart muscle-specific protein.

Factors influencing the induction of infertility in a mouse model of Chlamydia trachomatis ascending genital tract infection.

In women, infections due to Chlamydia trachomatis frequently result in long-term sequelae including chronic abdominal pain, ectopic pregnancy and infertility. In an attempt to characterise the pathogenesis of the infection, female C3H (H-2k) mice were inoculated intravaginally with different doses of C. trachomatis and then mated with proven male breeder mice. The inoculated mice developed a broad spectrum of clinical manifestations ranging from infertility to asymptomatic shedding. The dose inducing infertility in 50% of the mice was c. 10(5) inclusion-forming units of C. trachomatis. In another group of mice sampled at intervals after intravaginal inoculation, C. trachomatis was recovered from the upper genital tract starting at 24 h after infection. A higher percentage of animals infected during the luteal phase of the oestrous cycle had positive cultures from the middle and upper genital tract than when mice were inoculated during the follicular phase. These results indicate that rapid therapeutic intervention is required to avoid the sequelae resulting from C. trachomatis genital infection, and suggest that hormonal factors play a role in the pathogenesis of the disease.

Role of nitric oxide in the inhibition of cytochrome P450 in the liver of mice infected with Chlamydia trachomatis.

In this study, we attempted to determine the effect of a systemic infection with Chlamydia trachomatis on cytochrome P450(CYP)-dependent metabolism in mice. Furthermore, we wanted to assess if these effects were mediated through NO. BALB/c(H-2d) female mice were inoculated intraperitoneally with the C. trachomatis mouse pneumonitis (MoPn) biovar, and induction of NO synthase (NOS) was detected by measuring [NOx] levels and inducible NOS protein content in peritoneal macrophages by Western blotting. Recovery of C. trachomatis from liver, lung, and spleen peaked at 4 days postinfection. Following cotreatment with N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase, there was a significant increase in the intensity and the length of the infection. Six days after inoculation with C. trachomatis, CYP1A- and CYP2B-mediated metabolism in the liver of the mice was diminished up to 49% of control levels. However, when animals were treated with N(G)-nitro-L-arginine methyl ester at days 4 and 6 postinfection, the decrease in the metabolism of CYP1A and CYP2B was largely blocked. These results suggest that C. trachomatis infection can depress cytochrome P450 in a manner similar to other types of infections and that NO is likely to be a mediator of this depression. This finding may be of significance to patients taking drugs that are metabolized by phase I enzymes during infections with some bacteria such as C. trachomatis.

Characterization of a neutralizing monoclonal antibody directed at the lipopolysaccharide of Chlamydia pneumoniae.

Identification of protective epitopes is one of the first steps in the development of a subunit vaccine. One approach to accomplishing this is to identify structures or epitopes by using monoclonal antibodies (MAb) that can attenuate infectivity in vitro and in vivo. To date attempts to use this approach with Chlamydia pneumoniae have failed. This report is the first description of a MAb directed to the lipopolysaccharide (LPS) of Chlamydia that neutralizes both in vitro and in vivo the infectivity of C. pneumoniae. MAb CP-33, an immunoglobulin G2b (IgG2b), was identified from a fusion using splenocytes from mice immunized with C. pneumoniae TW-183. By Western blot analysis, MAb CP-33 exhibited genus-specific reactivity in that it recognized the LPSs of C. pneumoniae, Chlamydia trachomatis, and Chlamydia psittaci. MAb CP-33 did not react with 15 genera of gram-negative and gram-positive bacteria and Candida albicans. By using isolated LPS of Re mutants of Escherichia coli, Salmonella enterica serovar Minnesota, and recombinants expressing the 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo) transferase gene kdtA of C. trachomatis, MAb CP-33 was shown to require for binding the presence of the genus-specific trisaccharide epitope alphaKdo(2-->8)alphaKdo(2-->4)alphaKdo. By employing synthetic oligosaccharides and neoglycoconjugates in an enzyme immunoassay (EIA) and EIA inhibition, it was further shown that MAb CP-33 differed from the extensively investigated prototype chlamydial LPS MAb S25-23. Most likely, MAb CP-33 recognizes a conformational epitope in which the alphaKdo(2-->8)alphaKdo(2-->4)alphaKdo trisaccharide is an essential structural component. When tested in an in vitro neutralization assay, MAb CP-33 gave a 50% neutralization titer of 8 ng/ml against C. pneumoniae TW-183. However, this MAb did not neutralize other C. pneumoniae strains, C. trachomatis, or C. psittaci. C. pneumoniae TW-183 was treated with either MAb CP-33 or a control IgG and then used to inoculate mice by the respiratory route. Five days after inoculation, there was a difference between the mice inoculated with the control IgG-treated inoculum and those inoculated with the MAb CP-33-treated organisms as to the number of mice infected as well as the number of inclusion-forming units recovered from lung cultures (P < 0.05). In summary, a Chlamydia-specific LPS MAb was able to neutralize in vitro the infectivity of C. pneumoniae TW-183.

Immunization with an acellular vaccine consisting of the outer membrane complex of Chlamydia trachomatis induces protection against a genital challenge.

The ability to induce protection against a genital challenge was studied in BALB/c female mice with three Chlamydia trachomatis mouse pneumonitis (MoPn) major outer membrane protein (MOMP) preparations as well as an acellular vaccine consisting of the chlamydial outer membrane complex (COMC). The MOMP preparations were extracted with three different types of detergents, sodium dodecyl sulfate (SDS), n-octyl-beta-D-glucopyranoside (OGP), and Zwittergent 3-14 (Z3-14). A positive immunization control consisted of mice inoculated intranasally with 10(4) C. trachomatis MoPn inclusion-forming units (IFU). Mice inoculated with ovalbumin served as a negative control. Furthermore, a sham-immunized, nonchallenged group was included as a fertility control. Two weeks after the last immunization, the mice were challenged in the left ovarian bursa with 10(5) C. trachomatis MoPn IFU. Vaginal swabs were collected for culture, vaginal and serum samples were assayed for chlamydial-specific antibodies, and splenocytes were collected to determine the lymphoproliferative response. At 42 days after the challenge, the mice were mated with proven male breeder mice. Animals that were considered to be pregnant (as determined by weight) were killed, and the embryos were counted. A significant humoral and cell-mediated immune response was observed in all the groups of mice inoculated with chlamydial antigens. Antibodies to variable domain (VD)1 of the MOMP were detected in serum samples from all the immunized groups. However, antibodies to VD3 and VD4 were detected only in the groups immunized with the Z3-14-MOMP and the COMC. Mice immunized with COMC developed significant immunoglobulin A chlamydia-specific antibodies in the vagina, while mice immunized with the detergent-extracted MOMPs had low antibody titers. Following the intrabursal challenge, a significant decrease in the intensity and duration of vaginal shedding was noted in the mice immunized with COMC and a moderate decrease was noted in the group immunized with OGP-MOMP. No protection against the infection was noted in the groups of animals immunized with SDS- and Z3-14-MOMP. Furthermore, of the mice immunized with the COMC preparation, only 25% (4 of 20) shed C. trachomatis, as determined by vaginal culture, while 83% (40 of 48) of the control mice inoculated with ovalbumin were culture positive (P < 0.05). In addition, after mating, the mice inoculated with COMC were found to have fertility rates comparable to those of the control sham-immunized, nonchallenged animals (70% [14 of 20] versus 81% [17 of 21], respectively [P > 0.05]), and there were no significant differences between the average number of embryos per mouse in the two groups (5.1 versus 5.9, respectively [P > 0.05]). In contrast, mice immunized with the purified MOMP preparations were not protected against infertility. In summary, a preparation of the COMC protected mice against infection and infertility, supporting the feasibility of the development of an acellular vaccine against C. trachomatis infections.