Chlamydia trachomatis is the most common cause of infectious blindness and sexually transmitted bacterial infection globally. C. trachomatis contains a conserved chlamydial plasmid with eight coding sequences. Plasmid-cured Chlamydia strains are attenuated and display reduced infectivity in cell culture and in vivo genital infection of female mice.

Chlamydia trachomatis (Ct) is the most prevalent sexually transmitted bacterial infection in the world. In ~50% of cisgender women, Ct ascends from the cervix to infect the upper genital tract and increased ascension is linked to hormonal therapies. Oviduct infection induces inflammation which can lead to tubal scarring and sequelae of infertility and ectopic pregnancy. Fortunately, these complications occur in a minority of infected women, suggesting that intrinsic factors may protect the fallopian tubes from infection or tissue damage. In vitro inoculation of primary fallopian tube epithelial (FTE) cells with Ct serovar E resulted in a 10-fold reduction in infected cells compared to transformed endocervical HeLa cells. Indoleamine 2,3-dioxygenase (IDO) in the cytoplasm of epithelial cells acts as a key mediator of chlamydial host defense by metabolizing tryptophan, an essential Ct nutrient. We determined that uninfected primary FTE cells expressed on average 9 times higher levels of ido1 transcripts by qPCR compared to HeLa cells, and that in vitro infectivity of FTE cells was rescued by addition of an IDO-inhibitor (9-fold), tryptophan (21-fold), or indole (a metabolite that bypasses tryptophan starvation; 16-fold). Induction of IDO has mostly been attributed to IFNγ, but it can also be induced by Type I IFNs. Detection of high constitutive ido1 transcription in primary FTE cells indicates their ability to produce IDO independently of IFNγ. Ongoing studies are examining the role of Type I IFNs, including IFNɛ, which is constitutively expressed by reproductive tract epithelium and regulated by hormones. This work has implications for defining factors that contribute to protection of women from Ct-induced disease. The study was funded through a Translational Team Science Award (UNC School of Medicine and NC TRaCS) and also funded by NIAID NIH R01 AI067678 to U.M.N., NIAID NIH R01 AI119164 to T.D., and NIH grant DK065988 and Cystic Fibrosis Foundation grant BOUCHE15R0 to S.H.R.

Identification of the association between Early Childhood Caries (ECC) and Iron Deficiency Anaemia (IDA) will aid paediatricians and paediatric dentists to enhance health promotion measures to reduce the related morbidity in children. This systematic review aims to determine an evidence-based association between ECC and IDA. A systematic search was carried out from MEDLINE via PubMed, EMBASE, LILACS, Cochrane Oral Health Group's Specialized Register, CINAHL via EBSCO, Web of Science, and Scopus up to May 2020. Hand searching and grey literature screening were also conducted. Cross-sectional, case-control, and cohort studies in English language which assessed the association was included. Two reviewers independently assessed the study quality and extracted the outcome data. A total of 1,434 studies were identified. Fourteen studies qualified for qualitative review and 7 of them for a meta-analysis. In comparison with children not affected by ECC, those affected had an increased likelihood of IDA (OR = 6.07 [3.61, 10.21]). The meta-analysis showed no statistical difference when comparing blood parameters (Hb, MCV, and serum ferritin) in children with and without ECC. This systematic review demonstrates an association between ECC and increased odds of IDA rather than it being the cause for IDA. Further longitudinal studies with robust methodology are required to determine an evidence-based association.

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.

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.

Chlamydia trachomatis (Ct) causes the most prevalent bacterial sexually transmitted disease leading to ectopic pregnancy and infertility. Swine not only have many similarities to humans, but they are also susceptible to Ct. Despite these benefits and the ease of access to primary tissue from this food animal, in vitro research in swine has been underutilized. This study will provide basic understanding of the Ct host–pathogen interactions in porcine oviduct epithelial cells (pOECs)—the counterparts of human Fallopian tube epithelial cells. Using NanoString technology, flow cytometry, and confocal and transmission-electron microscopy, we studied the Ct developmental cycle in pOECs, the cellular immune response, and the expression and location of the tight junction protein claudin-4. We show that Ct productively completes its developmental cycle in pOECs and induces an immune response to Ct similar to human cells: Ct mainly induced the upregulation of interferon regulated genes and T-cell attracting chemokines. Furthermore, Ct infection induced an accumulation of claudin-4 in the Ct inclusion with a coinciding reduction of membrane-bound claudin-4. Downstream effects of the reduced membrane-bound claudin-4 expression could potentially include a reduction in tight-junction expression, impaired epithelial barrier function as well as increased susceptibility to co-infections. Thereby, this study justifies the investigation of the effect of Ct on tight junctions and the mucosal epithelial barrier function. Taken together, this study demonstrates that primary pOECs represent an excellent in vitro model for research into Ct pathogenesis, cell biology and immunity.

Chlamydia trachomatis infection of the human fallopian tubes can lead to damaging inflammation and scarring, ultimately resulting in infertility. To study the human cellular responses to chlamydial infection, researchers have frequently used transformed cell lines that can have limited translational relevance. We developed a primary human fallopian tube epithelial cell model based on a method previously established for culture of primary human bronchial epithelial cells. After protease digestion and physical dissociation of excised fallopian tubes, epithelial cell precursors were expanded in growth factor-containing medium. Expanded cells were cryopreserved to generate a biobank of cells from multiple donors and cultured at an air-liquid interface. Culture conditions stimulated cellular differentiation into polarized mucin-secreting and multiciliated cells, recapitulating the architecture of human fallopian tube epithelium. The polarized and differentiated cells were infected with a clinical isolate of C. trachomatis, and inclusions containing chlamydial developmental forms were visualized by fluorescence and electron microscopy. Apical secretions from infected cells contained increased amounts of proteins associated with chlamydial growth and replication, including transferrin receptor protein 1, the amino acid transporters SLC3A2 and SLC1A5, and the T-cell chemoattractants CXCL10, CXCL11, and RANTES. Flow cytometry revealed that chlamydial infection induced cell surface expression of T-cell homing and activation proteins, including ICAM-1, VCAM-1, HLA class I and II, and interferon gamma receptor. This human fallopian tube epithelial cell culture model is an important tool with translational potential for studying cellular responses to Chlamydia and other sexually transmitted pathogens.

Chlamydia trachomatis infection of the female genital tract can lead to irreversible fallopian tube scarring. In the mouse model of genital infection using Chlamydia muridarum, IL-1R signaling plays a critical role in oviduct tissue damage. In this study, we investigated the pathologic role of IL-1 alpha, one of the two proinflammatory cytokines that bind to IL-1R. Il1a(-/-) mice infected with C. muridarum cleared infection at their cervix at the same rate as wild-type (WT) mice, but were significantly protected from end point oviduct damage and fibrosis. The contribution of IL-1 alpha to oviduct pathology was more dramatic than observed in mice deficient for IL-1 beta. Although chlamydial burden was similar in WT and Il1a(-/-) oviduct during peak days of infection, levels of IL-1p, IL-6, CSF3, and CXCL2 were reduced in Il1a(-/-) oviduct lysates. During infection, Il1a(-/-) oviducts and uterine horns exhibited reduced neutrophil infiltration, and this reduction persisted after the infection resolved. The absence of IL-1 alpha did not compromise CD4 T cell recruitment or function during primary or secondary chlamydial infection. IL-1 alpha is expressed predominantly by luminal cells of the genital tract in response to infection, and low levels of expression persisted after the infection cleared. Ab-mediated depletion of IL-1 alpha in WT mice prevented infection-induced oviduct damage, further supporting a key role for IL-1 alpha in oviduct pathology.

It has been shown that caspase-1, but not its upstream activator, ASC, contributes to oviduct pathology during mouse genital Chlamydia muridarum infection. We hypothesized that this dichotomy is due to the inadvertent absence of caspase-11 in previously used caspase-1-deficient mice. To address this, we studied the independent contributions of caspase-1 and -11 during genital Chlamydia infection. Our results show that caspase-11 deficiency was sufficient to recapitulate the effect of the combined absence of both caspase-1 and caspase-11 on oviduct pathology. Further, mice that were deficient for both caspase-1 and -11 but that expressed caspase-11 as a transgene (essentially, caspase-1-deficient mice) had no significant difference in oviduct pathology from control mice. Caspase-11-deficient mice showed reduced dilation in both the oviducts and uterus. To determine the mechanism by which caspase-11-deficient mice developed reduced pathology, the chlamydial burden and immune cell infiltration were determined in the oviducts. In the caspase-11-deficient mice, we observed increased chlamydial burdens in the upper genital tract, which correlated with increased CD4 T cell recruitment, suggesting a contribution of caspase-11 in infection control. Additionally, there were significantly fewer neutrophils in the oviducts of caspase-11-deficient mice, supporting the observed decrease in the incidence of oviduct pathology. Therefore, caspase-11 activation contributes to pathogen control and oviduct disease independently of caspase-1 activation.

Background and aims: Atherosclerosis is a chronic inflammatory disease, and recent studies have shown that infection at remote sites can contribute to the progression of atherosclerosis in hyperlipidemic mouse models. In this report, we tested the hypothesis that genital Chlamydia infection could accelerate the onset and progression of atherosclerosis. Methods: Apolipoprotein E (Apoe(-/-)) and LDL receptor knockout (Ldlr(-/-)) mice on a high-fat diet were infected intra-vaginally with Chlamydia muridarum. Atherosclerotic lesions on the aortic sinuses and in the descending aorta were assessed at 8-weeks post-infection. Systemic, macrophage, and vascular site inflammatory responses were assessed and quantified. Results: Compared to the uninfected groups, infected Apoe(-/-) and Ldlr(-/-) mice developed significantly more atherosclerotic lesions in the aortic sinus and in the descending aorta. Increased lesions were associated with higher circulating levels of serum amyloid A-1, IL-1 beta, TNF-alpha, and increased VCAM-1 expression in the aortic sinus, suggesting an association with inflammatory responses observed during C. muridarum infection. Genital infection courses were similar in Apoe(-/-), Ldlr(-/-), and wild type mice. Further, Apoe(-/-) mice developed severe uterine pathology with increased dilatations. Apoe-deficiency also augmented cytokine/chemokine response in C. muridarum infected macrophages, suggesting that the difference in macrophage response could have contributed to the genital pathology in Apoe(-/-) mice. Conclusions: Overall, these studies demonstrate that genital Chlamydia infection exacerbates atherosclerotic lesions in hyperlipidemic mouse and suggest a novel role for Apoe in full recovery of uterine anatomy after chlamydial infection.

Sexually transmitted infections with Chlamydia trachomatis and/or Neisseria gonorrhoeae and rates of pelvic inflammatory disease (PID) in women continue to rise, with reinfection being common because of poor adaptive immunity. Diagnosis remains imprecise, and pathogenesis data are derived primarily from monoinfection of mice with C. trachomatis or N. gonorrhoeae By comparing blood mRNA responses of women with C. trachomatis- and/or N. gonorrhoeae-induced PID and histologic endometritis with those from women with C. trachomatis and/or N. gonorrhoeae infection limited to their cervix and asymptomatic uninfected women determined via microarray, we discovered important pathogenic mechanisms in PID and response differences that provide a pathway to biomarker discovery. Women with N. gonorrhoeae- and/or C. trachomatis-induced PID exhibit overexpression of myeloid cell genes and suppression of protein synthesis, mitochondrial oxidative phosphorylation, and T cell-specific genes. Coinfected women exhibited the greatest activation of cell death pathways and suppression of responses essential for adaptive immunity. Women solely infected with C. trachomatis expressed elevated levels of type I and type II IFN genes, and enhanced type I IFN-induced chemokines in cervical secretions were associated with ascension of C. trachomatis to the endometrium. Blood microarrays reveal discrete pathobiological endotypes in women with PID that are driven by pathogen invasion of the upper genital tract.

Chlamydia muridarum and Chlamydia caviae have equivalent growth rates in mouse epithelial cells but only C. muridarum replicates inside mouse macrophages, while C. caviae does not. Macrophages infected with C. muridarum or C. caviae were used to address the hypothesis that the early signaling pathways initiated during infection depend on the fate of chlamydiae in the host cell. Transmission electron microscopy of C. muridarum‐infected macrophages showed intact chlamydial elementary bodies and reticulate bodies 2 h postinfection in compact vacuoles. Conversely, in macrophages infected with C. caviae, chlamydiae were observed in large phagocytic vacuoles. Furthermore, C. caviae infections failed to develop into inclusions or produce viable bacteria. Expression of proinflammatory cytokines TNFα, IL‐1β and MMP13 was similar in C. caviae‐ or C. muridarum‐infected macrophages at 3 h postinfection, indicating that chlamydial survival is not required for initiation of these responses. IL‐1β secretion, dependent on inflammasome activation, occurred in C. caviae‐infected macrophages despite no chlamydial growth. Conversely, IFNβ mRNA was observed only in C. muridarum‐ but not in C. caviae‐infected macrophages. These data demonstrate that differential signaling events are initiated during a productive versus nonproductive chlamydial infection in a macrophage.

Abstract BACKGROUND Independent type I/III IFN regulation, interferon-regulatory factor 3 (IRF3) can mediate cell death and suppress proliferation during stress. Novel ‘suicide necrosis’ centers around IRF3 and is one protective mechanism against intracellular pathogens. Uterine epithelial cells infected with obligate intracellular Chlamydia trachomatis are typically shed 3–5 days post-infection (dpi) by unknown mechanism(s) and exhibit new growth. We have previously shown IRF3-deficient mice exhibit decreased epithelial shedding and 10-fold greater bacterial burdens during early infection. We hypothesize that IRF3-mediated cell death restricts chlamydial infection in the genital mucosa, providing a potentially novel mechanism to reduce pathogen load. METHODS Progesterone-treated C57BL/6J and IRF3 KO mice were infected vaginally with 3e5 IFUs of C. muridarum strain “Nigg” and histologically assessed 3 and 4 dpi for chlamydia inclusions, cell death and proliferation using proliferation marker PCNA. Cell death was assessed in vivo with PI delivery by NSET device 10 minutes before sacrifice 4 dpi. RESULTS/CONCL 3 dpi, uterine epithelia in WT and IRF3 KO mice remain intact with no epithelial shedding. WT show a single layer of infected epithelial cells, while IRF3 KO have several layers of infected cells, suggesting the next layer(s) of epithelial cells are generated before the first is shed. 4 dpi we see dramatic increases in epithelial shedding in WT mice when stained in vivo with PI. In contrast, IRF3 KO epithelia show relatively few PI-stained cells. We conclude that IRF3 is playing a significant and protective role during C. muridarum infection by facilitating cell death and limiting cellular proliferation of epithelial cells.

Chlamydia muridarum and Chlamydia caviae have equivalent growth rates in mouse epithelial cells but only C. muridarum replicates inside mouse macrophages, while C. caviae does not. Macrophages infected with C. muridarum or C. caviae were used to address the hypothesis that the early signaling pathways initiated during infection depend on the fate of chlamydiae in the host cell. Transmission electron microscopy of C. muridarum -infected macrophages showed intact chlamydial elementary bodies and reticulate bodies 2 h postinfection in compact vacuoles. Conversely, in macrophages infected with C. caviae , chlamydiae were observed in large phagocytic vacuoles. Furthermore, C. caviae infections failed to develop into inclusions or produce viable bacteria. Expression of proinflammatory cytokines TNFα, IL-1β and MMP13 was similar in C. caviae- or C. muridarum -infected macrophages at 3 h postinfection, indicating that chlamydial survival is not required for initiation of these responses. IL-1β secretion, dependent on inflammasome activation, occurred in C. caviae -infected macrophages despite no chlamydial growth. Conversely, IFNβ mRNA was observed only in C. muridarum - but not in C. caviae -infected macrophages. These data demonstrate that differential signaling events are initiated during a productive versus nonproductive chlamydial infection in a macrophage.

During intracellular Chlamydia infection, cytosolic DNA is sensed by cyclic GMP-AMP synthase (cGAS) that catalyzes the synthesis of cGAMP from ATP and GTP. cGAMP is a key mediator of IFN beta expression during DNA sensing and can also transfer to adjacent uninfected cells through intercellular connexin gap-junctions to induce intrinsic immunity. In this study, we investigated the role of gap junction protein connexin 43 (CX43) during Chlamydia infection. Using RNA-in situ hybridization, we discovered a distinct intracellular contribution of CX43 in IFN beta expression in the infected cells and cells transfected with DNA, a function distinct from its intercellular gap-junction role affecting IFN beta expression in adjacent uninfected cell. CX43 is essential for IFN beta expression during DNA-sensing upstream of STING activation, but not required during RNA-sensing. CX43 co-localized with transfected DNA and on the chlamydial inclusion membrane with cGAS. CX43-depleted cells showed significantly reduced cGAMP production during DNA-sensing. CX43 forms hemichannels on intracellular membrane, which open and close to allow nucleotide transfer. Blocking this transport across CX43 hemichannel reduced IFN beta expression during infection and DNA-sensing, without altering CX43 localization. These results uncover a novel role of CX43 in cGAMP synthesis by cGAS during cytosolic DNA-sensing.

ABSTRACTCD4 T cells and antibody are required for optimal acquired immunity toChlamydia muridarumgenital tract infection, and T cell-mediated gamma interferon (IFN-γ) production is necessary to clear infection in the absence of humoral immunity. However, the role of T cell-independent immune responses during primary infection remains unclear. We investigated this question by inoculating wild-type and immune-deficient mice withC. muridarumCM001, a clonal isolate capable of enhanced extragenital replication. Genital inoculation of wild-type mice resulted in transient dissemination to the lungs and spleen that then was rapidly cleared from these organs. However, CM001 genital infection proved lethal forSTAT1−/−andIFNG−/−mice, in which IFN-γ signaling was absent, and forRag1−/−mice, which lacked T and B cells and in which innate IFN-γ signaling was retained. In contrast, B cell-deficient muMT mice, which can generate a Th1 response, and T cell-deficient mice with intact B cell and innate IFN-γ signaling survived. These data collectively indicate that IFN-γ prevents lethal CM001 dissemination in the absence of T cells and suggests a B cell corequirement. Adoptive transfer of convalescent-phase immune serum but not naive IgM toRag1−/−mice infected with CM001 significantly increased the survival time, while transfer of naive B cells completely rescuedRag1−/−mice from CM001 lethality. Protection was associated with a significant reduction in the lung chlamydial burden of genitally infected mice. These data reveal an important cooperation between T cell-independent B cell responses and innate IFN-γ in chlamydial host defense and suggest that interactions between T cell-independent antibody and IFN-γ are essential for limiting extragenital dissemination.

Pulmonary tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is a leading cause of global morbidity and mortality. The only licensed TB vaccine, Mycobacterium bovis bacillus Calmette-Guerin (BCG), has variable efficacy in protecting against pulmonary TB. Thus, the development of more effective TB vaccines is critical to control the TB epidemic. Specifically, vaccines delivered through the mucosal route are known to induce Th17 responses and provide superior protection against Mtb infection. However, already tested Th17-inducing mucosal adjuvants, such as heat-labile enterotoxins and cholera toxins, are not considered safe for use in humans. In the current study, we rationally screened adjuvants for their ability to induce Th17-polarizing cytokines in dendritic cells (DCs) and determined whether they could be used in a protective mucosal TB vaccine. Our new studies show that monophosphoryl lipid A (MPL), when used in combination with chitosan, potently induces Th17-polarizing cytokines in DCs and downstream Th17/Th1 mucosal responses and confers significant protection in mice challenged with a clinical Mtb strain. Additionally, we show that both TLRs and the inflammasome pathways are activated in DCs by MPL-chitosan to mediate induction of Th17-polarizing cytokines. Together, our studies put forward the potential of a new, protective mucosal TB vaccine candidate, which incorporates safe adjuvants already approved for use in humans.

Chlamydia is responsible for millions of new infections annually, and current efforts focus on understanding cellular immunity for targeted vaccine development. The Chlamydia-specific CD4 T cell response is characterized by the production of IFN-γ, and polyfunctional Th1 responses are associated with enhanced protection. A major limitation in studying these responses is the paucity of tools available for detection, quantification, and characterization of polyfunctional Ag-specific T cells. We addressed this problem by developing a TCR-transgenic (Tg) mouse with CD4 T cells that respond to a common Ag in Chlamydia muridarum and Chlamydia trachomatis Using an adoptive-transfer approach, we show that naive Tg CD4 T cells become activated, proliferate, migrate to the infected tissue, and acquire a polyfunctional Th1 phenotype in infected mice. Polyfunctional Tg Th1 effectors demonstrated enhanced IFN-γ production compared with polyclonal cells, protected immune-deficient mice against lethality, mediated bacterial clearance, and orchestrated an anamnestic response. Adoptive transfer of Chlamydia-specific CD4 TCR-Tg T cells with polyfunctional capacity offers a powerful approach for analysis of protective effector and memory responses against chlamydial infection and demonstrates that an effective monoclonal CD4 T cell response may successfully guide subunit vaccination strategies.

Abstract Background The DNA sensor cGAS is essential for IFNβ expression in cells infected with Chlamydia. cGAMP generated during DNA sensing can also transfer via intercellular gap-junction proteins, connexins CX43/45 leading to IFNβ expression in adjacent uninfected cells. Present study highlights a novel role for CX43 in IFNβ expression during DNA-sensing and during Chlamydia infection, independent of its gap junction function. Methods Total IFNβ transcripts were measured by qRT-PCR following CX43 or CX45 siRNA mediated knockdown (KD). Single cell RNA-ISH method view RNA™ was used to visualize IFNβ mRNA in infected HeLa cells. CX43 localization was studied using IF and confocal microscopy. Results CX43-KD in HeLa cells reduced IFNβ expression by >90% (p<0.001) compared to control or CX45 KD, as measured by qRT-PCR. CX43-KD also reduced IFNβ mRNA in dsDNA transfected cells (p<0.001) but not with poly IC RNA. RNA-ISH showed IFNβ mRNA transcripts in infected cells (>90%) and in adjacent uninfected (~10%) cells, but not in distal uninfected cells, suggesting cell contact is required for adjacent-cell effect. Surprisingly, RNA-ISH of CX43-KD cells showed >85% reduction in IFNβ transcripts (p<0.0001) in infected cells, in addition to the loss of transcripts in cells adjacent to infected cells. CX43 localized proximal to the chlamydial inclusion membrane. Co-localization of CX43 was also observed with transfected dsDNA, but not dsRNA. Conclusion CX43 depletion has been shown to increase autophagy in cells. Here we show that CX43 depletion decreases IFNβ induction during DNA sensing. Our results suggest that like STING, CX43 could be a key player in both DNA sensing and autophagy, but with opposing roles. (Funded by NIAID R01-AI067678 to UN).