RESUMEN
To begin to optimize the immunization routes for our reported PLGA-rMOMP nanovaccine [PLGA-encapsulated Chlamydia muridarum (Cm) recombinant major outer membrane protein (rMOMP)], we compared two prime-boost immunization strategies [subcutaneous (SC) and intramuscular (IM-p) prime routes followed by two SC-boosts)] to evaluate the nanovaccine-induced protective efficacy and immunogenicity in female BALB/c mice. Our results showed that mice immunized via the SC and IM-p routes were protected against a Cm genital challenge by a reduction in bacterial burden and with fewer bacteria in the SC mice. Protection of mice correlated with rMOMP-specific Th1 (IL-2 and IFN-γ) and not Th2 (IL-4, IL-9, and IL-13) cytokines, and CD4+ memory (CD44highCD62Lhigh) T-cells, especially in the SC mice. We also observed higher levels of IL-1α, IL-6, IL-17, CCL-2, and G-CSF in SC-immunized mice. Notably, an increase of cytokines/chemokines was seen after the challenge in the SC, IM-p, and control mice (rMOMP and PBS), suggesting a Cm stimulation. In parallel, rMOMP-specific Th1 (IgG2a and IgG2b) and Th2 (IgG1) serum, mucosal, serum avidity, and neutralizing antibodies were more elevated in SC than in IM-p mice. Overall, the homologous SC prime-boost immunization of mice induced enhanced cellular and antibody responses with better protection against a genital challenge compared to the heterologous IM-p.
Asunto(s)
Anticuerpos Antibacterianos , Vacunas Bacterianas , Infecciones por Chlamydia , Chlamydia muridarum , Citocinas , Ratones Endogámicos BALB C , Animales , Femenino , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/administración & dosificación , Chlamydia muridarum/inmunología , Citocinas/metabolismo , Infecciones por Chlamydia/prevención & control , Infecciones por Chlamydia/inmunología , Ratones , Anticuerpos Antibacterianos/sangre , Inyecciones Intramusculares , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Proteínas de la Membrana Bacteriana Externa/inmunología , Proteínas de la Membrana Bacteriana Externa/genética , Vacunas Sintéticas/inmunología , Vacunas Sintéticas/administración & dosificación , Inmunización Secundaria , Modelos Animales de Enfermedad , Inmunogenicidad Vacunal , Inyecciones Subcutáneas , Nanopartículas/administración & dosificación , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/administración & dosificación , Eficacia de las Vacunas , Células TH1/inmunología , NanovacunasRESUMEN
We have demonstrated previously that TNF-α-producing CD8+ T cells mediate chlamydial pathogenesis, likely in an antigen (Ag)-specific fashion. Here we hypothesize that inhibition of Ag-specific CD8+ T cell response after immunization and/or challenge would correlate with protection against oviduct pathology induced by a protective vaccine regimen. Intranasal (i.n.) live chlamydial elementary body (EB), intramuscular (i.m.) live EB, or i.n. irrelevant antigen, bovine serum albumin (BSA), immunized animals induced near-total protection, 50% protection, or no protection, respectively against oviduct pathology following i.vag. C. muridarum challenge. In these models, we evaluated Ag-specific CD8+ T cell cytokine response at various time-periods after immunization or challenge. The results show protective efficacy of vaccine regimens correlated with reduction of Ag-specific CD8+ T cell TNF-α responses following i.vag. chlamydial challenge, not after immunization. Depletion of CD4+ T cells abrogated, whereas adoptive transfer of Ag-specific CD4+ T cells induced the significant reduction of Ag-specific CD8+ T cell TNF-α response after chlamydial challenge. In conclusion, protective anti-chlamydial vaccine regimens induce Ag-specific CD4+ T cell response that mediate early inhibition of pathogenic CD8+ T cell response following challenge and may serve as a predictive biomarker of protection against Chlamydia -induced chronic pathologies.
Asunto(s)
Vacunas Bacterianas , Linfocitos T CD4-Positivos , Linfocitos T CD8-positivos , Infecciones por Chlamydia , Animales , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD4-Positivos/inmunología , Infecciones por Chlamydia/inmunología , Infecciones por Chlamydia/prevención & control , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/administración & dosificación , Femenino , Ratones , Modelos Animales de Enfermedad , Factor de Necrosis Tumoral alfa/metabolismo , Chlamydia muridarum/inmunologíaRESUMEN
Chlamydia trachomatis is a leading infectious cause of infertility in women due to its induction of lasting pathology such as hydrosalpinx. Chlamydia muridarum induces mouse hydrosalpinx because C. muridarum can both invade tubal epithelia directly (as a first hit) and induce lymphocytes to promote hydrosalpinx indirectly (as a second hit). In the current study, a critical role of CD8+ T cells in chlamydial induction of hydrosalpinx was validated in both wild type C57BL/6J mice and OT1 transgenic mice. OT1 mice failed to develop hydrosalpinx partially due to the failure of their lymphocytes to recognize chlamydial antigens. CD8+ T cells from naive C57BL/6J mice rescued the ability of recipient OT1 mice to develop hydrosalpinx when naive CD8+ T cells were transferred at the time of infection with Chlamydia. However, when the transfer was delayed for 2 weeks or longer after the Chlamydia infection, naive CD8+ T cells no longer promoted hydrosalpinx. Nevertheless, CD8+ T cells from mice immunized against Chlamydia still promoted significant hydrosalpinx in the recipient OT1 mice even when the transfer was delayed for 3 weeks. Thus, CD8+ T cells must be primed within 2 weeks after Chlamydia infection to be pathogenic, but, once primed, they can promote hydrosalpinx for >3 weeks. However, Chlamydia-primed CD4+ T cells failed to promote chlamydial induction of pathology in OT1 mice. This study optimized an OT1 mouse-based model for revealing the pathogenic mechanisms of Chlamydia-specific CD8+ T cells.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Infecciones por Chlamydia/inmunología , Infecciones por Chlamydia/metabolismo , Infecciones por Chlamydia/microbiología , Chlamydia muridarum/inmunología , Animales , Antígenos Bacterianos/inmunología , Biopsia , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Femenino , Interacciones Huésped-Patógeno/inmunología , Ratones , Salpingitis/etiología , Salpingitis/metabolismo , Salpingitis/patología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Subgrupos de Linfocitos T/patologíaRESUMEN
Chlamydia trachomatis-genital infection in women can be modeled in mice using Chlamydia muridarum. Using this model, it has been shown that the cytokines tumor necrosis factor (TNF)α and interleukin (IL)-1α lead to irreversible tissue damage in the oviducts. In this study, we investigated the contribution of TNFα on IL-1α synthesis in infected epithelial cells. We show that C muridarum infection enhanced TNFα-induced IL-1α expression and release in a mouse epithelial cell line. In addition to IL-1α, several TNFα-induced inflammatory genes were also highly induced, and infection enhanced TNF-induced cell death. In the mouse model of genital infection, oviducts from mice lacking the TNFα receptor displayed minimal staining for IL-1α compared with wild-type oviducts. Our results suggest TNFα and IL-1α enhance each other's downstream effects resulting in a hyperinflammatory response to chlamydial infection. We propose that biologics targeting TNF-induced IL-1α synthesis could be used to mitigate tissue damage during chlamydial infection.
Asunto(s)
Muerte Celular , Infecciones por Chlamydia , Chlamydia muridarum/inmunología , Interleucina-1alfa , Factor de Necrosis Tumoral alfa , Animales , Infecciones por Chlamydia/inmunología , Infecciones por Chlamydia/metabolismo , Células Epiteliales , Femenino , Interleucina-1alfa/inmunología , Interleucina-1alfa/metabolismo , Ratones , Ratones Endogámicos C57BL , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Genital infections with Chlamydia trachomatis can lead to uterine and oviduct tissue damage in the female reproductive tract. Neutrophils are strongly associated with tissue damage during chlamydial infection, while an adaptive CD4 T cell response is necessary to combat infection. Activation of triggering receptor expressed on myeloid cells-1 (TREM-1) on neutrophils has previously been shown to induce and/or enhance degranulation synergistically with Toll-like receptor (TLR) signaling. Additionally, TREM-1 can promote neutrophil transepithelial migration. In this study, we sought to determine the contribution of TREM-1,3 to immunopathology in the female mouse genital tract during Chlamydia muridarum infection. Relative to control mice, trem1,3-/- mice had no difference in chlamydial burden or duration of lower-genital-tract infection. We also observed a similar incidence of hydrosalpinx 45 days postinfection in trem1,3-/- compared to wild-type (WT) mice. However, compared to WT mice, trem1,3-/- mice developed significantly fewer hydrometra in uterine horns. Early in infection, trem1,3-/- mice displayed a notable decrease in the number of uterine glands containing polymorphonuclear cells and uterine horn lumens had fewer neutrophils, with increased granulocyte colony-stimulating factor (G-CSF). trem1,3-/- mice also had reduced erosion of the luminal epithelium. These data indicate that TREM-1,3 contributes to transepithelial neutrophil migration in the uterus and uterine glands, promoting the occurrence of hydrometra in infected mice.
Asunto(s)
Infecciones por Chlamydia/inmunología , Chlamydia muridarum/inmunología , Receptores Inmunológicos/inmunología , Receptor Activador Expresado en Células Mieloides 1/inmunología , Útero/inmunología , Inmunidad Adaptativa/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/microbiología , Movimiento Celular/inmunología , Infecciones por Chlamydia/metabolismo , Infecciones por Chlamydia/microbiología , Chlamydia trachomatis/inmunología , Modelos Animales de Enfermedad , Epitelio/inmunología , Epitelio/metabolismo , Epitelio/microbiología , Femenino , Genitales Femeninos/inmunología , Genitales Femeninos/metabolismo , Genitales Femeninos/microbiología , Ratones , Ratones Endogámicos C57BL , Neutrófilos/inmunología , Neutrófilos/metabolismo , Neutrófilos/microbiología , Oviductos/inmunología , Oviductos/metabolismo , Oviductos/microbiología , Receptores Inmunológicos/metabolismo , Infecciones del Sistema Genital/inmunología , Infecciones del Sistema Genital/metabolismo , Infecciones del Sistema Genital/microbiología , Receptor Activador Expresado en Células Mieloides 1/metabolismo , Útero/metabolismo , Útero/microbiologíaRESUMEN
Anatomical positioning of memory lymphocytes within barrier tissues accelerates secondary immune responses and is thought to be essential for protection at mucosal surfaces. However, it remains unclear whether resident memory in the female reproductive tract (FRT) is required for Chlamydial immunity. Here, we describe efficient generation of tissue-resident memory CD4 T cells and memory lymphocyte clusters within the FRT after vaginal infection with Chlamydia Despite robust establishment of localized memory lymphocytes within the FRT, naïve mice surgically joined to immune mice, or mice with only circulating immunity following intranasal immunization, were fully capable of resisting Chlamydia infection via the vaginal route. Blocking the rapid mobilization of circulating memory CD4 T cells to the FRT inhibited this protective response. These data demonstrate that secondary protection in the FRT can occur in the complete absence of tissue-resident immune cells. The ability to confer robust protection to barrier tissues via circulating immune memory provides an unexpected opportunity for vaccine development against infections of the FRT.
Asunto(s)
Anticuerpos Antibacterianos/biosíntesis , Linfocitos T CD4-Positivos/inmunología , Infecciones por Chlamydia/prevención & control , Chlamydia muridarum/inmunología , Genitales Femeninos/inmunología , Inmunización/métodos , Administración Intranasal , Administración Intravaginal , Animales , Antígenos Bacterianos/administración & dosificación , Vacunas Bacterianas/administración & dosificación , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/microbiología , Movimiento Celular/efectos de los fármacos , Movimiento Celular/inmunología , Infecciones por Chlamydia/inmunología , Infecciones por Chlamydia/microbiología , Chlamydia muridarum/efectos de los fármacos , Chlamydia muridarum/crecimiento & desarrollo , Chlamydia muridarum/patogenicidad , Femenino , Genitales Femeninos/efectos de los fármacos , Genitales Femeninos/microbiología , Inmunidad Mucosa/efectos de los fármacos , Memoria Inmunológica/efectos de los fármacos , Ratones , Parabiosis/métodosRESUMEN
IL-27, a heterodimeric cytokine of the IL-12 family, has diverse influences on the development of multiple inflammatory diseases. In this study, we identified the protective role of IL-27/IL-27R in host defense against Chlamydia muridarum respiratory infection and further investigated the immunological mechanism. Our results showed that IL-27 was involved in C. muridarum infection and that IL-27R knockout mice (WSX-1-/- mice) suffered more severe disease, with greater body weight loss, higher chlamydial loads, and more severe inflammatory reactions in the lungs than C57BL/6 wild-type mice. There were excessive IL-17-producing CD4+ T cells and many more neutrophils, neutrophil-related proteins, cytokines, and chemokines in the lungs of WSX-1-/- mice than in wild-type mice following C. muridarum infection. In addition, IL-17/IL-17A-blocking Ab treatment improved disease after C. muridarum infection in WSX-1-/- mice. Overall, we conclude that IL-27/IL-27R mediates protective immunity during chlamydial respiratory infection in mice by suppressing excessive Th17 responses and reducing neutrophil inflammation.
Asunto(s)
Inflamación/inmunología , Interleucinas/inmunología , Neutrófilos/inmunología , Receptores de Interleucina/inmunología , Animales , Chlamydia muridarum/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Interleucina/deficiencia , Células Th17/inmunologíaRESUMEN
Vaccine-induced immune responses following immunization with promising Chlamydia vaccines protected experimental animals from Chlamydia-induced upper genital tract pathologies and infertility. In contrast, primary genital infection with live Chlamydia does not protect against these pathologies. We hypothesized that differential miRNA profiles induced in the upper genital tracts (UGT) of mice correlate with the disparate immunity vs. pathologic outcomes associated with vaccine immunization and chlamydial infection. Thus, miRNA expression profiles in the UGT of mice after Chlamydia infection (Live EB) and immunization with dendritic cell (DC)-based vaccine (DC vaccine) or VCG-based vaccine (VCG vaccine) were compared using the NanoString nCounter Mouse miRNA assay. Of the 602 miRNAs differentially expressed (DE) in the UGT of immunized and infected mice, we selected 58 with counts >100 and p-values < 0.05 for further analysis. Interestingly, vaccine immunization and Chlamydia infection induced the expression of distinct miRNA profiles with a higher proportion in vaccine-immunized compared to Chlamydia infected mice; DC vaccine (41), VCG vaccine (23), and Live EB (15). Hierarchical clustering analysis showed notable differences in the uniquely DE miRNAs for each experimental group, with DC vaccine showing the highest number (21 up-regulated, five down-regulated), VCG vaccine (two up-regulated, five down-regulated), and live EB (two up-regulated, four down-regulated). The DC vaccine-immunized group showed the highest number (21 up-regulated and five down-regulated compared to two up-regulated and four down-regulated in the live Chlamydia infected group). Pathway analysis showed that the DE miRNAs target genes that regulate several biological processes and functions associated with immune response and inflammation. These results suggest that the induction of differential miRNA expression plays a significant role in the disparate immunity outcomes associated with Chlamydia infection and vaccination.
Asunto(s)
Vacunas Bacterianas/administración & dosificación , Infecciones por Chlamydia/prevención & control , Chlamydia muridarum/inmunología , Células Dendríticas/inmunología , Inmunogenicidad Vacunal , MicroARNs/genética , Transcriptoma , Traslado Adoptivo , Animales , Vacunas Bacterianas/inmunología , Infecciones por Chlamydia/genética , Infecciones por Chlamydia/inmunología , Infecciones por Chlamydia/microbiología , Chlamydia muridarum/patogenicidad , Células Dendríticas/microbiología , Células Dendríticas/trasplante , Modelos Animales de Enfermedad , Femenino , Perfilación de la Expresión Génica , Interacciones Huésped-Patógeno , Ratones Endogámicos C57BL , MicroARNs/inmunología , MicroARNs/metabolismo , Vacunación , Vibrio cholerae/genética , Vibrio cholerae/inmunologíaRESUMEN
Chlamydia trachomatis is the most commonly reported sexually transmitted infection in the United States. The high prevalence of infection and lack of a vaccine indicate a critical knowledge gap surrounding the host's response to infection and how to effectively generate protective immunity. The immune response to C. trachomatis is complex, with cells of the adaptive immune system playing a crucial role in bacterial clearance. Here, we discuss the CD4+ and CD8+ T cell response to Chlamydia, the importance of antigen specificity and the role of memory T cells during the recall response. Ultimately, a deeper understanding of protective immune responses is necessary to develop a vaccine that prevents the inflammatory diseases associated with Chlamydia infection.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones por Chlamydia/inmunología , Chlamydia trachomatis/patogenicidad , Evasión Inmune , Inmunidad Adaptativa , Animales , Carga Bacteriana , Linfocitos T CD4-Positivos/microbiología , Linfocitos T CD8-positivos/microbiología , Infecciones por Chlamydia/complicaciones , Infecciones por Chlamydia/microbiología , Infecciones por Chlamydia/patología , Chlamydia muridarum/crecimiento & desarrollo , Chlamydia muridarum/inmunología , Chlamydia muridarum/patogenicidad , Chlamydia trachomatis/crecimiento & desarrollo , Chlamydia trachomatis/inmunología , Genitales/inmunología , Genitales/microbiología , Genitales/patología , Humanos , Inmunidad Innata , Memoria Inmunológica , Interferón gamma/biosíntesis , Interferón gamma/inmunología , Interleucinas/biosíntesis , Interleucinas/inmunología , RatonesRESUMEN
The IL-21/IL-21R interaction plays an important role in a variety of immune diseases; however, the roles and mechanisms in intracellular bacterial infection are not fully understood. In this study, we explored the effect of IL-21/IL-21R on chlamydial respiratory tract infection using a chlamydial respiratory infection model. The results showed that the mRNA expression of IL-21 and IL-21R was increased in Chlamydia muridarum-infected mice, which suggested that IL-21 and IL-21R were involved in host defense against C. muridarum lung infection. IL-21R-/- mice exhibited less body weight loss, a lower bacterial burden, and milder pathological changes in the lungs than wild-type (WT) mice during C. muridarum lung infection. The absolute number and activity of CD4+ T cells and the strength of Th1/Th17 responses in IL-21R-/- mice were significantly higher than those in WT mice after C. muridarum lung infection, but the Th2 response was weaker. Consistently, IL-21R-/- mice showed higher mRNA expression of Th1 transcription factors (T-bet/STAT4), IL-12p40, a Th17 transcription factor (STAT3), and IL-23. The mRNA expression of Th2 transcription factors (GATA3/STAT6), IL-4, IL-10, and TGF-ß in IL-21R-/- mice was significantly lower than that in WT mice. Furthermore, the administration of recombinant mouse IL-21 aggravated chlamydial lung infection in C57BL/6 mice and reduced Th1 and Th17 responses following C. muridarum lung infection. These findings demonstrate that IL-21/IL-21R may aggravate chlamydial lung infection by inhibiting Th1 and Th17 responses.
Asunto(s)
Infecciones por Chlamydia/inmunología , Chlamydia muridarum/inmunología , Interleucinas/metabolismo , Pulmón/inmunología , Receptores de Interleucina-21/metabolismo , Subgrupos de Linfocitos T/inmunología , Células TH1/inmunología , Células Th17/inmunología , Animales , Femenino , Inflamación , Espacio Intracelular , Ratones , Receptores de Interleucina-21/genética , Factor de Transcripción STAT3/genética , Transducción de Señal , Proteínas de Dominio T Box/genéticaRESUMEN
To date, no reports have linked the multifunctional protein, staphylococcal nuclease domain-containing protein 1 (SND1), to host defense against intracellular infections. In this study, we investigated the role and mechanisms of SND1, by using SND1 knockout (SND1-/-) mice, in host defense against the lung infection of Chlamydia muridarum, an obligate intracellular bacterium. Our data showed that SND1-/- mice exhibited significantly greater body weight loss, higher organism growth, and more severe pathological changes compared with wild-type mice following the infection. Further analysis showed significantly reduced Chlamydia-specific Th1/17 immune responses in SND1-/- mice after infection. Interestingly, the dendritic cells (DCs) isolated from SND1-/- mice showed lower costimulatory molecules expression and IL-12 production, but higher IL-10 production compared with those from wild-type control mice. In the DC-T cell co-culture system, DCs isolated from SND1-/- infected mice showed significantly reduced ability to promote Chlamydia-specific IFN-γ producing Th1 cells but enhanced capacity to induce CD4+T cells into Foxp3+ Treg cells. Adoptive transfer of DCs isolated from SND1-/- mice, unlike those from wild-type control mice, failed to protect the recipients against challenge infection. These findings provide in vivo evidence that SND1 plays an important role in host defense against intracellular bacterial infection, and suggest that SND1 can promote Th1/17 immunity and inhibit the expansion of Treg cells through modulation of the function of DCs.
Asunto(s)
Infecciones por Chlamydia/inmunología , Chlamydia muridarum/inmunología , Células Dendríticas/inmunología , Endonucleasas/fisiología , Pulmón/inmunología , Células TH1/inmunología , Células Th17/inmunología , Animales , Infecciones por Chlamydia/metabolismo , Infecciones por Chlamydia/microbiología , Infecciones por Chlamydia/patología , Células Dendríticas/metabolismo , Células Dendríticas/microbiología , Femenino , Inmunidad Celular/inmunología , Pulmón/metabolismo , Pulmón/microbiología , Ratones , Ratones Endogámicos C57BL , Ratones NoqueadosRESUMEN
Chlamydiae are pathogenic intracellular bacteria that cause a wide variety of diseases throughout the globe, affecting the eye, lung, coronary arteries and female genital tract. Rather than by direct cellular toxicity, Chlamydia infection generally causes pathology by inducing fibrosis and scarring that is largely mediated by host inflammation. While a robust immune response is required for clearance of the infection, certain elements of that immune response may also damage infected tissue, leading to, in the case of female genital infection, disease sequelae such as pelvic inflammatory disease, infertility and ectopic pregnancy. It has become increasingly clear that the components of the immune system that destroy bacteria and those that cause pathology only partially overlap. In the ongoing quest for a vaccine that prevents Chlamydia-induced disease, it is important to target mechanisms that can achieve protective immunity while preventing mechanisms that damage tissue. This review focuses on mouse models of genital Chlamydia infection and synthesizes recent studies to generate a comprehensive model for immunity in the murine female genital tract, clarifying the respective contributions of various branches of innate and adaptive immunity to both host protection and pathogenic genital scarring.
Asunto(s)
Infecciones por Chlamydia/inmunología , Chlamydia trachomatis/patogenicidad , Cicatriz/inmunología , Interacciones Huésped-Patógeno/inmunología , Interferón gamma/inmunología , Interleucinas/inmunología , Inmunidad Adaptativa , Animales , Carga Bacteriana , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/microbiología , Infecciones por Chlamydia/complicaciones , Infecciones por Chlamydia/microbiología , Infecciones por Chlamydia/patología , Chlamydia muridarum/crecimiento & desarrollo , Chlamydia muridarum/inmunología , Chlamydia muridarum/patogenicidad , Chlamydia trachomatis/crecimiento & desarrollo , Chlamydia trachomatis/inmunología , Cicatriz/complicaciones , Cicatriz/microbiología , Cicatriz/patología , Modelos Animales de Enfermedad , Femenino , Genitales/inmunología , Genitales/microbiología , Genitales/patología , Humanos , Inmunidad Innata , Interferón gamma/biosíntesis , Interleucinas/biosíntesis , Ratones , EmbarazoRESUMEN
Recent studies have identified semaphorin 3E (Sema3E) as a novel mediator of immune responses. However, its function in immunity to infection has yet to be investigated. Using a mouse model of chlamydial lung infection, we show that Sema3E plays a significant role in the host immune response to the infection. We found that Sema3E is induced in the lung after chlamydial infection, and Sema3E deficiency has a detrimental impact on disease course, dendritic cell (DC) function, and T cell responses. Specifically, we found that Sema3E knockout (KO) mice exhibited higher bacterial burden, severe body weight loss, and pathological changes after Chlamydia muridarum lung infection compared with wild-type (WT) mice. The severity of disease in Sema3E KO mice was correlated with reduced Th1/Th17 cytokine responses, increased Th2 response, altered Ab response, and a higher number of regulatory CD4 T cells. Moreover, DCs isolated from Sema3E KO mice showed lower surface expression of costimulatory molecules and production of IL-12, but higher expression of PD-L1, PD-L2, and IL-10 production. Functional DC-T cell coculture studies revealed that DCs from infected Sema3E KO mice failed to induce Th1 and Th17 cell responses compared with DCs from infected WT mice. Upon adoptive transfer, mice receiving DCs from Sema3E KO mice, unlike those receiving DCs from WT mice, were not protected against challenge infection. In conclusion, our data evidenced that Sema3E acts as a critical factor for protective immunity against intracellular bacterial infection by modulating DC functions and T cell subsets.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Infecciones por Chlamydia/inmunología , Células Dendríticas/inmunología , Semaforinas/metabolismo , Subgrupos de Linfocitos T/inmunología , Traslado Adoptivo , Animales , Linfocitos T CD4-Positivos/metabolismo , Infecciones por Chlamydia/microbiología , Infecciones por Chlamydia/patología , Chlamydia muridarum/inmunología , Técnicas de Cocultivo , Células Dendríticas/trasplante , Modelos Animales de Enfermedad , Humanos , Pulmón/inmunología , Pulmón/microbiología , Pulmón/patología , Ratones , Ratones Noqueados , Semaforinas/genética , Índice de Severidad de la Enfermedad , Subgrupos de Linfocitos T/metabolismoRESUMEN
The obligate intracellular bacterium Chlamydia muridarum can colonize the mouse colon for a long period, but a gamma interferon (IFN-γ)-susceptible mutant clone fails to do so. Nevertheless, the mutant's colonization is rescued in mice deficient in interleukin-7 receptor (IL-7R) (lacking both lymphocytes and innate lymphoid cells [ILCs]) or IFN-γ but not in mice lacking recombination-activated gene 1 (Rag1-/- mice) (lacking adaptive immunity lymphocytes), indicating a critical role of ILC-derived IFN-γ in regulating chlamydial colonization. In the current study, we have used an adoptive transfer approach for further characterizing the responsible ILCs. First, intestinal ILCs isolated from Rag1-/- mice were able to rescue IL-7R-deficient mice to restrict the colonization of the IFN-γ-susceptible Chlamydia muridarum mutant. Second, the responsible ILCs were localized to the intestinal lamina propria since ILCs from the lamina propria but not the intraepithelial compartment conferred the restriction. Third, lamina propria ILCs enriched for RORγt expression but not those negative for RORγt rescued the IL-7R-deficient mice to restrict mutant colonization, indicating a critical role of group 3-like ILCs (ILC3s) since RORγt is a signature transcriptional factor of ILC3s. Fourth, a portion of the ILC3s expressed IFN-γ, thus defined as ex-ILC3s, and the transfer of the ex-ILC3s conferred colon resistance to mutant Chlamydia muridarum colonization in IFN-γ-deficient mice. Finally, genetically labeled RORγt-positive (RORγt+) ILCs were able to inhibit mutant colonization. Thus, we have demonstrated that ILC3s are sufficient for regulating chlamydial colonization, laying a foundation for further revealing the mechanisms by which an obligate intracellular bacterium activates colonic ILC3s.
Asunto(s)
Infecciones por Chlamydia/terapia , Chlamydia muridarum/genética , Chlamydia muridarum/inmunología , Chlamydia muridarum/patogenicidad , Resistencia a la Enfermedad/inmunología , Inmunidad Innata/genética , Linfocitos/inmunología , Traslado Adoptivo , Animales , Colon/microbiología , Modelos Animales de Enfermedad , Resistencia a la Enfermedad/genética , Variación Genética , Genotipo , Humanos , Interferón gamma/inmunología , Transfusión de Linfocitos , Ratones , Mutación , Virulencia/genética , Virulencia/inmunologíaRESUMEN
Chlamydia spp. productively infect mucosal epithelial cells of multiple anatomical sites, including the conjunctiva, lungs, gastrointestinal (GI) tract, and urogenital tract. We, and others, previously established that chlamydial GI tropism is mediated by distinct chromosomal and plasmid factors. In this study, we describe a genital infection-attenuated Chlamydia muridarum mutant (GIAM-1) that is profoundly and specifically attenuated in the murine genital tract. GIAM-1 infected the murine GI tract similarly to wild-type (WT) Chlamydia muridarum but did not productively infect the lower genital tract of female mice, ascend to infect the upper genital tract, or cause hydrosalpinx. However, GI infection of mice with GIAM-1 elicited a transmucosal immune response that protected against subsequent genital challenge with WT Chlamydia muridarum Collectively, our results demonstrate that chlamydia mutants that are profoundly attenuated for specific organ tissues can be derived and demonstrate that live-attenuated vaccine strains that infect the GI tract, but do not elicit genital tract disease, could be used to protect against chlamydia genital tract infection and disease.IMPORTANCE Chlamydia is the most common sexually transmitted bacterial infection in the United States. Most chlamydia genital infections resolve without serious consequences; however, untreated infection in women can cause pelvic inflammatory disease and infertility. Antibiotics are very effective in treating chlamydia, but most genital infections in both men and women are asymptomatic and go undiagnosed. Therefore, there is a critical need for an effective vaccine. In this work, we show that a mutant chlamydia strain, having substantially reduced virulence for genital infection, colonizes the gastrointestinal tract and produces robust immunity to genital challenge with fully virulent wild-type chlamydia. These results are an important advance in understanding chlamydial virulence and provide compelling evidence that safe and effective live-attenuated chlamydia vaccines may be feasible.
Asunto(s)
Infecciones por Chlamydia/inmunología , Chlamydia muridarum/inmunología , Protección Cruzada/inmunología , Gastroenteritis/inmunología , Infecciones del Sistema Genital/inmunología , Animales , Anticuerpos Antibacterianos/inmunología , Infecciones por Chlamydia/microbiología , Chlamydia muridarum/genética , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Femenino , Gastroenteritis/microbiología , Tracto Gastrointestinal/microbiología , Genitales/microbiología , Genoma Bacteriano , Interacciones Huésped-Patógeno/inmunología , Ratones , Mutación , Polimorfismo de Nucleótido Simple , Infecciones del Sistema Genital/microbiología , VirulenciaRESUMEN
Chlamydia trachomatis, a leading infectious cause of tubal infertility, induces upper genital tract pathology, such as hydrosalpinx, which can be modeled with Chlamydia muridarum infection in mice. Following C. muridarum inoculation, wild-type mice develop robust hydrosalpinx, but OT1 mice fail to do so because their T cell receptors are engineered to recognize a single ovalbumin epitope (OVA457-462). These observations have demonstrated a critical role of Chlamydia-specific T cells in chlamydial pathogenicity. In the current study, we have also found that OT1 mice can actively inhibit chlamydial pathogenicity. First, depletion of CD8+ T cells from OT1 mice led to the induction of significant hydrosalpinx by Chlamydia, indicating that CD8+ T cells are necessary to inhibit chlamydial pathogenicity. Second, adoptive transfer of CD8+ T cells from OT1 mice to CD8 knockout mice significantly reduced chlamydial induction of hydrosalpinx, demonstrating that OT1 CD8+ T cells are sufficient for attenuating chlamydial pathogenicity in CD8 knockout mice. Finally, CD8+ T cells from OT1 mice also significantly inhibited hydrosalpinx development in wild-type mice following an intravaginal inoculation with Chlamydia Since T cells in OT1 mice are engineered to recognize only the OVA457-462 epitope, the above observations have demonstrated a chlamydial antigen-independent immune mechanism for regulating chlamydial pathogenicity. Further characterization of this mechanism may provide information for developing strategies to reduce infertility-causing pathology induced by infections.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Infecciones por Chlamydia/inmunología , Chlamydia muridarum/patogenicidad , Salpingitis/inmunología , Traslado Adoptivo , Animales , Derrame de Bacterias/inmunología , Linfocitos T CD8-positivos/trasplante , Infecciones por Chlamydia/microbiología , Infecciones por Chlamydia/patología , Infecciones por Chlamydia/terapia , Chlamydia muridarum/inmunología , Modelos Animales de Enfermedad , Femenino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Ovalbúmina/química , Ovalbúmina/inmunología , Fragmentos de Péptidos/inmunología , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/inmunología , Salpingitis/microbiología , Salpingitis/patología , Salpingitis/terapiaRESUMEN
BACKGROUND: The T-cell response to chlamydia genital tract infections in humans and mice is unusual because the majority of antigen-specific CD8 T cells are not class I restricted (referred to here as "unrestricted" or "atypical"). We previously reported that a subset of unrestricted murine chlamydia-specific CD8 T cells had a cytokine polarization pattern that included interferon (IFN)-γ and interleukin (IL)-13. METHODS: In this study, we investigated the transcriptome of CD8γ13 T cells, comparing them to Tc1 clones using microarray analysis. That study revealed that CD8γ13 polarization included IL-5 in addition to IFN-γ and IL-13. Adoptive transfer studies were performed with Tc1 clones and a CD8γ13 T-cell clone to determine whether either influenced bacterial clearance or immunopathology during Chlamydia muridarum genital tract infections. RESULTS: To our surprise, an adoptively transferred CD8γ13 T-cell clone was remarkably proficient at preventing chlamydia immunopathology, whereas the multifunctional Tc1 clone did not enhance clearance or significantly alter immunopathology. Mapping studies with major histocompatibility complex (MHC) class I- and class II-deficient splenocytes showed our previously published chlamydia-specific CD8 T-cell clones are MHC class II restricted. CONCLUSIONS: The MHC class II-restricted CD8 T cells may play an important role in protection from intracellular pathogens that limit class I antigen presentation or diminish CD4 T-cell numbers or impair their function.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Infecciones por Chlamydia/inmunología , Chlamydia muridarum/inmunología , Animales , Infecciones por Chlamydia/microbiología , Células Clonales/virología , Femenino , Antígenos de Histocompatibilidad Clase I/inmunología , Humanos , Ratones , Ratones Endogámicos C57BLRESUMEN
Revealing the mechanisms by which bacteria establish long-lasting colonization in the gastrointestinal tract is an area of intensive investigation. The obligate intracellular bacterium Chlamydia is known to colonize mouse colon for long periods. A colonization-deficient mutant strain of this intracellular bacterium is able to regain long-lasting colonization in gamma interferon (IFN-γ) knockout mice following intracolon inoculation. We now report that mice deficient in conventional T lymphocytes or recombination-activating gene (Rag) failed to show rescue of mutant colonization. Nevertheless, antibody depletion of IFN-γ or genetic deletion of interleukin 2 (IL-2) receptor common gamma chain in Rag-deficient mice did rescue mutant colonization. These observations suggest that colonic IFN-γ, responsible for inhibiting the intracellular bacterial mutant, is produced by innate lymphoid cells (ILCs). Consistently, depletion of NK1.1+ cells in Rag-deficient mice both prevented IFN-γ production and rescued mutant colonization. Furthermore, mice deficient in transcriptional factor RORγt, but not chemokine receptor CCR6, showed full rescue of the long-lasting colonization of the mutant, indicating a role for group 3-like ILCs. However, the inhibitory function of the responsible group 3-like ILCs was not dependent on the natural killer cell receptor (NCR1), since NCR1-deficient mice still inhibited mutant colonization. Consistently, mice deficient in the transcriptional factor T-bet only delayed the clearance of the bacterial mutant without fully rescuing the long-lasting colonization of the mutant. Thus, we have demonstrated that the obligate intracellular bacterium Chlamydia maintains its long-lasting colonization in the colon by evading IFN-γ from group 3-like ILCs.
Asunto(s)
Infecciones por Chlamydia/microbiología , Chlamydia muridarum/inmunología , Colon/microbiología , Inmunidad Innata , Interferón gamma/inmunología , Linfocitos/inmunología , Animales , Chlamydia muridarum/patogenicidad , Ratones , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: Chlamydia trachomatis and Chlamydia muridarum are intracellular bacterial pathogens of mucosal epithelial cells. CD4 T cells and major histocompatibility complex (MHC) class II molecules are essential for protective immunity against them. Antigens presented by dendritic cells (DCs) expand naive pathogen-specific T cells (inductive phase), whereas antigens presented by epithelial cells identify infected epithelial cells as targets during the effector phase. We previously showed that DCs infected by C trachomatis or C muridarum present epitopes from a limited spectrum of chlamydial proteins recognized by Chlamydia-specific CD4 T cells from immune mice. METHODS: We hypothesized that Chlamydia-infected DCs and epithelial cells present overlapping sets of Chlamydia-MHC class II epitopes to link inductive and effector phases to generate protective immunity. We tested that hypothesis by infecting an oviductal epithelial cell line with C muridarum, followed by immunoaffinity isolation and sequencing of MHC class I- and II-bound peptides. RESULTS: We identified 26 class I-bound and 4 class II-bound Chlamydia-derived peptides from infected epithelial cells. We were surprised to find that none of the epithelial cell class I- and class II-bound chlamydial peptides overlapped with peptides presented by DCs. CONCLUSIONS: We suggest the discordance between the DC and epithelial cell immunoproteomes has implications for delayed clearance of Chlamydia and design of a Chlamydia vaccine.
Asunto(s)
Infecciones por Chlamydia/inmunología , Chlamydia muridarum/inmunología , Chlamydia trachomatis/inmunología , Células Dendríticas/inmunología , Células Epiteliales/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Interacciones Huésped-Patógeno/inmunología , Animales , Antígenos Bacterianos/inmunología , Vacunas Bacterianas/inmunología , Linfocitos T CD4-Positivos/inmunología , Línea Celular , Infecciones por Chlamydia/microbiología , Epítopos de Linfocito T/inmunología , Femenino , Células HeLa , Antígenos de Histocompatibilidad Clase I/inmunología , Humanos , Ratones , Ratones Endogámicos C57BL , Péptidos/inmunologíaRESUMEN
Chlamydia trachomatis is the most commonly reported bacterial sexually transmitted infection in the United States. Modeling infection in animals can be challenging, as mice naturally clear C. trachomatis when it is deposited in the lower genital tract. However, C. trachomatis can productively infect mice when the lower genital tract is bypassed and bacteria are deposited directly into the upper genital tract via transcervical inoculation. Interestingly, the mouse-adapted Chlamydia species C. muridarum can infect mice both by transcervical inoculation and by natural ascension if introduced into the vaginal vault. In this study, we investigated whether the route of infection plays a role in the downstream immune responses to C. muridarum infection. We found that transcervical infection with C. muridarum results in higher bacterial burdens in the upper genital tract at earlier time points, correlating with levels of innate immune cells. When bacterial burdens were equivalent in intravaginally and transcervically infected mice at later time points, we observed substantially higher levels of adaptive immune cells in transcervically infected mice. Our data suggest that different routes of infection with the same organism can elicit different immune responses in the same tissue.