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Introduction: The neonatal sequential organ failure assessment (nSOFA) score is a tool for calculating mortality risk of infants in the neonatal intensive care unit. The utility of the nSOFA in determining the risk of mortality or the association with surgical intervention among infants with necrotizing enterocolitis (NEC) has not been investigated. Methods: We performed a retrospective, cohort study of preterm (Results: Of the 259 infants, nSOFA scores for infants who died (n = 39) or had the composite outcome of surgery or death (n = 114) were significantly higher (p < 0.05) early in the NEC course compared to nSOFA scores for infants who survived medical NEC. Twelve hours after evaluation, the area under the receiver operating characteristic curve was 0.87 (95% confidence interval [CI], 0.80–0.93) to discriminate for mortality and 0.84 (95% CI, 0.79–0.90) for surgery or death (p < 0.001). A maximum nSOFA score of ≥4 at −6, 0, 6, or 12 h following evaluation was associated with a 20-fold increase in mortality and 19-fold increase in surgery or death compared with a score of p < 0.001). Conclusion: In this multicenter cohort, the nSOFA score was able to discriminate well for death as well as surgery or death among infants with NEC. The nSOFA is a clinical research tool that may be used in infants with NEC to improve classification by objective quantification of organ dysfunction.

Parenteral lipid emulsions are a necessary component of nutrition for extremely low gestational age newborns until adequate levels of enteral intake are established. Historically, Intralipid, a 100% soybean oil emulsion, has filled this role. Newer multicomponent lipid emulsions containing a mixture of other oils, including olive oil and fish oil, are now available as options, although the regulatory approval for use in neonates varies worldwide. When dosed at currently published recommendations, each of these lipid emulsions meets total fat and energy requirements without a risk of essential fatty acid deficiency. Thus, when choosing which lipid emulsion to provide, the answer must be based on the metabolic differences induced as a result of these fatty acid-rich emulsions and whether the emulsions provide a health advantage or pose a health risk. The questions of induced fatty acid profiles, health benefit and health risk are discussed sequentially for multicomponent lipid emulsions. Despite the growing acceptance of multicomponent lipid emulsions, there is concern regarding changes in blood fatty acid levels and potential health risk without strong evidence of benefit. There remains no ideal parenteral lipid emulsion option for the preterm infant. Standardising future animal and human studies in lipid delivery with the inclusion of lipid metabolism data will iteratively provide answers to inform the optimal lipid emulsion for the preterm infant.

The coronavirus disease 2019 (COVID-19) pandemic, resulting from infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused severe and widespread illness in adults, including pregnant women, while rarely infecting neonates. An incomplete understanding of disease pathogenesis and viral spread has resulted in evolving guidelines to reduce transmission from infected mothers to neonates. Fortunately, the risk of neonatal infection via perinatal/postnatal transmission is low when recommended precautions are followed. However, the psychosocial implications of these practices and racial/ethnic disparities highlighted by this pandemic must also be addressed when caring for mothers and their newborns. This review provides a comprehensive overview of neonatal-perinatal perspectives of COVID-19, ranging from the basic science of infection and recommendations for care of pregnant women and neonates to important psychosocial, ethical, and racial/ethnic topics emerging as a result of both the pandemic and the response of the healthcare community to the care of infected individuals.

Prematurity presents a diagnostic challenge in interpreting primary immunodeficiency (PID) testing.We retrospectively reviewed the charts of all infants in our level IV referral neonatal intensive care unit (NICU) in Massachusetts, with immunologic testing performed from 2006 to 2018.The overall rate of PID testing was enriched in our population, with 1% of admitted patients having extended immunologic testing. The addition of TREC (T cell receptor excision circle) newborn screening in Massachusetts in 2009 increased the proportion of infants tested for PID in our NICU by 3-fold (1.21% post-newborn screening (NBS) vs. 0.46% pre-NBS). A majority of the term and late preterm (≥34 weeks) infants (31 of 41, 76%), as well as very premature (29-33 weeks) infants (12 of 17, 71%), who had immune testing, had a genetic diagnosis associated with secondary immunodeficiency or a PID. Most infants who were born extremely premature (EP,29 weeks) (25 of 29, 86%) had no identifiable cause of immunodeficiency besides prematurity, despite a mean postmenstrual age of 40.1 weeks at the time of testing.Persistent immune derangements were present within a subgroup of the EP population through term postmenstrual age. EP infants with significant infectious history and abnormal immune testing at term-corrected age should be considered for genetic testing.The role of immunologic testing in the premature population is unclear, we therefore reviewed the records of all infants in our NICU who had immunologic testing, to rule out immunodeficiency, done from 2006 to 2018. The addition of newborn screening for SCID in 2009 doubled the number of infants who had immune investigations. The extremely premature cohort included many infants with persistent immune derangements through term-corrected gestational age, suggesting a persistent effect of prematurity on immune development and potential function. We propose that former premature infants with clinical evidence of immunodeficiency and sustained immune abnormalities by term-corrected age undergo genetic testing for immunodeficiency.

Although the coronavirus disease 2019 pandemic has served as a flashlight, illuminating and unmasking deep socio-economic and health care divides in our country, the terrible events surrounding the horrific murder of Mr. George Floyd in Minneapolis has spawned even greater outrage. As we all know, Mr. Floyd’s death is not an isolated incident, as there have been a tragic string of such deaths in recent years that further reflect deep issues regarding racism and systemic underlying causes of injustice. Unfortunately, the country’s inability to fully address these systemic foundations of injustice persists.

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.

We would like to thank Bernhard and colleagues for their thoughtful letter, ‘Parenteral nutrition for preterm infants: correcting for arachidonic and docosahexaenoic acid may not suffice’ written in response to our review. The authors of the letter raised important issues regarding the lack of data surrounding the optimal balance of arachidonic …

Rhesus macaques were studied to directly address the potential for plasmid-deficient Chlamydia trachomatis to serve as a live attenuated vaccine in the genital tract. Five repeated cervical inoculations of rhesus macaques with wild-type serovar D strain D/UW-3/Cx or a plasmid-deficient derivative of this strain, CTD153, resulted in infections with similar kinetics and induced comparable levels of protective immunity. After all animals received five challenges with D/UW-3/Cx, levels of inflammation observed grossly and histologically were similar between the groups. Animals in both groups developed evidence of oviduct dilatation; however, reduced oviduct dilatation was observed for “controllers,” i.e., animals without detectable chlamydial DNA in the fimbriae at weeks 5 and 12. Grouping animals into “ascenders” and “controllers” revealed that elevated early T cell responses were associated with protection, whereas higher antibody responses were associated with ascension. Protected animals shared common major histocompatibility complex (MHC) alleles. Overall, genetic differences of individual animals, rather than the presence or absence of the chlamydial plasmid in the primary infecting strain, appeared to play a role in determining the outcome of infection.

Resolution of Chlamydia genital tract infection is delayed in the absence of MyD88. In these studies, we first used bone marrow chimeras to demonstrate a requirement for MyD88 expression by hematopoietic cells in the presence of a wild-type epithelium. Using mixed bone marrow chimeras we then determined that MyD88 expression was specifically required in the adaptive immune compartment. Furthermore, adoptive transfer experiments revealed that CD4+ T cell expression of MyD88 was necessary for normal resolution of genital tract infection. This requirement was associated with a reduced ability of MyD88−/−CD4+ T cells to accumulate in the draining lymph nodes and genital tract when exposed to the same inflammatory milieu as wild-type CD4+ T cells. We also demonstrated that the impaired infection control we observed in the absence of MyD88 could not be recapitulated by deficiencies in TLR or IL-1R signaling. In vitro, we detected an increased frequency of apoptotic MyD88−/−CD4+ T cells upon activation in the absence of exogenous ligands for receptors upstream of MyD88. These data reveal an intrinsic requirement for MyD88 in CD4+ T cells during Chlamydia infection and indicate that the importance of MyD88 extends beyond innate immune responses by directly influencing adaptive immunity.

BACKGROUND Natural infection induces partial immunity to Chlamydia trachomatis Identification of chlamydial antigens that induce interferon γ (IFN-) secretion by T cells from immune women could advance vaccine development. METHODS IFN-γ production by CD4+ and CD8+ peripheral blood T cells from 58 high-risk women was measured after coculture with antigen-presenting cells preincubated with recombinant Escherichia coli expressing a panel of 275 chlamydial antigens. Quantile median regression analysis was used to compare frequencies of IFN-γ responses in women with only cervical infection to those in women with endometrial infection and frequencies in women who remained uninfected for over 1 year to those in women who developed incident infection. Statistical methods were then used to identify proteins associated with protection. RESULTS A higher median frequency of CD8+ T-cell responses was detected in women with lower genital tract chlamydial infection, compared with those with upper genital tract chlamydial infection (13.8% vs 9.5%; P =04), but the CD4+ T-cell response frequencies were not different. Women who remained uninfected displayed a greater frequency of positive CD4+ T-cell responses (29% vs 18%; P < .0001), compared with women who had incident infection, while the frequencies of CD8+ T-cell responses did not differ. A subset of proteins involved in central metabolism, type III secretion, and protein synthesis were associated with protection. CONCLUSIONS Investigations in naturally exposed women reveal protective responses and identify chlamydial vaccine candidate antigens.

Our previous studies revealed that intravaginal infection of mice with a plasmid-deficient strain of Chlamydia muridarum , CM3.1, does not induce the development of oviduct pathology. In this study, we determined that infection with CM3.1 resulted in a significantly reduced frequency and absolute number of neutrophils in the oviducts during acute infection. This reduction in neutrophils was associated with significantly lower levels of neutrophil chemokines in the oviducts and decreased production of neutrophil chemokines by oviduct epithelial cells infected with CM3.1 in vitro . Infection with CM3.1 also resulted in an increased frequency of late apoptotic/dead neutrophils in the oviduct. Examination of the ability of Chlamydia trachomatis to prevent neutrophil apoptosis in vitro revealed that C. trachomatis strain D/UW-3/Cx exhibited an enhanced ability to prevent neutrophil apoptosis compared to plasmid-deficient CTD153, and this effect was dependent on the presence of CD14 high monocytes. The presence of monocytes also resulted in enhanced neutrophil cytokine production and increased production of tissue-damaging molecules in response to D/UW-3/Cx relative to results with CTD153. Attempts to use antibody-mediated depletion to discern the specific role of neutrophils in infection control and pathology in vivo revealed that although Ly6G high neutrophils were eliminated from the blood and oviducts with this treatment, immature neutrophils and high levels of tissue-damaging molecules were still detectable in the upper genital tract. These data support the role of neutrophils in chlamydia-induced pathology and reveal that novel methods of depletion must be developed before their role can be specifically determined in vivo .

We have previously shown that MyD88 knockout (KO) mice exhibit delayed clearance of Chlamydia muridarum genital infection compared to wild-type (WT) mice. A blunted Th1 response and ineffective suppression of the Th2 response were also observed in MyD88 KO mice. The goal of the present study was to investigate specific mechanisms whereby absence of MyD88 leads to these effects and address the compensatory mechanisms in the genital tract that ultimately clear infection in the absence of MyD88. It was observed that NK cells recruited to the genital tract in MyD88 KO mice failed to produce gamma interferon (IFN-γ) mRNA and protein. This defect was associated with decreased local production of interleukin-17 (IL-17), IL-18, and tumor necrosis factor alpha (TNF-α) but normal levels of IL-12p70. Additionally, recruitment of CD4 T cells to the genital tract was reduced in MyD88 KO mice compared to that in WT mice. Although chronic infection in MyD88 KO mice resulted in oviduct pathology comparable to that of WT mice, increased histiocytic inflammation was observed in the uterine horns. This was associated with increased CCL2 levels and recruitment of macrophages as a potential compensatory mechanism. Further deletion of TLR4-TRIF signaling in MyD88 KO mice, using TLR4/MyD88 double-KO mice, did not further compromise host defense against chlamydiae, suggesting that compensatory mechanisms are Toll-like receptor (TLR) independent. Despite some polarization toward a Th2 response, a Th1 response remained predominant in the absence of MyD88, and it provided equivalent protection against a secondary infection as observed in WT mice.

In women, Chlamydia trachomatis can ascend from the cervix to the fallopian tubes, where an overly aggressive host inflammatory response can cause scarring that leads to chronic pelvic pain, infertility, or ectopic pregnancy. Although screening and treatment programs for women have resulted in decreased rates of sequelae, morbidities associated with oviduct scarring continue to occur. Since corticosteroids have anti-inflammatory and antifibrotic effects, we tested the ability of dexamethasone to inhibit inflammation and prevent oviduct scarring in mice genitally infected with Chlamydia muridarum . The administration of 1 or 2.5 mg/kg of body weight of dexamethasone on days 7 to 21 of infection resulted in reduced accumulation of inflammatory cells in the oviducts compared to that in controls. However, a concomitant increase in bacterial burden was observed, and chronic oviduct disease was not reduced. Adjunctive administration of a prolonged (21-day) or short (3-day) course of dexamethasone in combination with the antibiotic doxycycline also failed to reduce chronic oviduct pathology compared to antibiotic treatment alone. Steroids administered alone or adjunctively with antibiotics failed to prevent oviduct damage in this murine model of C. trachomatis infection.

An evaluation of CD4 T cell responses to candidate Chlamydia trachomatis vaccine antigens was conducted in an adolescent female cohort exposed through natural infection to explore antigen immunogenicity and correlation with protection from reinfection. The frequency of peripheral blood CD4 T cell IFN-γ and IL-17 responses to three candidate vaccine antigens, polymorphic membrane protein G (PmpG), F (PmpF), and major outer membrane protein (MOMP), were determined by ELISPOT; responses to chlamydial heat shock protein 60 (HSP60) and to elementary bodies (EB) were included for comparison. Responses of Infected ( n =8), Seropositive/Uninfected ( n =13), and Seronegative/Uninfected ( n =18) participants were compared. The median CD4 IFN-γ response to EB was significantly increased in Infected ( P =0.003) and Seropositive/Uninfected ( P =0.002) versus Seronegative/Uninfected female subjects. Higher rates of positive IFN-γ responders to EB, PmpF, and MOMP were detected in Seropositive/Uninfected versus Seronegative/Uninfected participants ( P =0.021). IL-17 responses were generally low. A positive IFN-γ response to any of the antigens tested was associated with a trend toward a reduced risk of reinfection, although not statistically significant. Among this adolescent cohort, chlamydial-specific CD4 IFN-γ but not IL-17 responses were detected in acutely and previously infected participants and a positive CD4 IFN-γ response was associated with a non-significant reduced risk of reinfection.

Objective Chlamydia trachomatis infections are a significant cause of reproductive tract pathology. Protective and pathological immune mediators must be differentiated to design a safe and effective vaccine. Methods Wild-type mice and mice deficient in IL-22 and IL-23 were infected intravaginally with Chlamydia muridarum, and their course of infection and oviduct pathology were compared. Local genital tract and draining lymph node immune responses were also examined in IL-23-deficient mice. Results IL-22- and IL-23-deficient mice exhibited normal susceptibility to infection and oviduct pathology. IL-23 was required for the development of a Chlamydia-specific Th17 response in the lymph nodes and for production of IL-22 and IL-17 in the genital tract. However, influx of Th1 and innate immune cells was not compromised in the absence of IL-23. Conclusion IL-22 and IL-23 play either redundant or minimal roles in the pathogenesis of Chlamydia infection in the mouse model. Induction of Th17-associated cytokines by a Chlamydia vaccine should be avoided as these responses are not central to resolution of infection and have pathologic potential.

The D1 dopamine receptor (D1R) is widely expressed in the kidney and plays a crucial role in blood pressure regulation. Although much is known about D1R desensitization, especially through G-protein-coupled receptor kinase 4 (GRK4), comparatively little is known about other aspects of D1R trafficking and the proteins involved in the process. We now report the discovery of a dynamic interaction between sorting nexin 5 (SNX5), a component of the mammalian retromer, and D1R in human renal epithelial cells. We show that internalization of agonist-activated D1R is regulated by both SNX5 and GRK4, and that SNX5 is critical to the recycling of the receptor to the plasma membrane. SNX5 depletion increases agonist-activated D1R phosphorylation (>50% at basal condition), prevents D1R internalization and cAMP response, and delays receptor recycling compared to mock siRNA-transfected controls. Moreover, renal restricted subcapsular infusion of Snx5-specific siRNA (vs. mock siRNA) decreases sodium excretion (Δ=−0.2±0.005 mEq/mg creatinine) and further elevates the systolic blood pressure (Δ=48±5 mm Hg) in spontaneously hypertensive rats, indicating that SNX5 depletion impairs renal D1R function. These studies demonstrate an essential role for SNX5 in regulating D1R function, which may have important diagnostic, prognostic, and therapeutic implications in the management of essential hypertension.—Villar, V. A. M., Armando, I., Sanada, H., Frazer, L. C., Russo, C. M., Notario, P. M., Lee, H., Comisky, L., Russell, H. A., Yang, Y., Jurgens, J. A., Jose, P. A., Jones, J. E. Novel role of sorting nexin 5 in renal D1 dopamine receptor trafficking and function: implications for hypertension.

The significant morbidities of ectopic pregnancy and infertility observed in women after Chlamydia trachomatis genital infection result from ascension of the bacteria from the endocervix to the oviduct, where an overly aggressive inflammatory response leads to chronic scarring and Fallopian tube obstruction. A vaccine to prevent chlamydia-induced disease is urgently needed. An important question for vaccine development is whether sterilizing immunity at the level of the oviduct is essential for protection because of the possibility that a chlamydial component drives a deleterious anamnestic T cell response upon oviduct reinfection. We show that mice inoculated with attenuated plasmid-cured strains of Chlamydia muridarum are protected from oviduct pathology upon challenge with wild-type C. muridarum Nigg despite induction of a response that did not prevent reinfection of the oviduct. Interestingly, repeated abbreviated infections with Nigg also elicited recall responses that protected the oviduct from pathology despite low-level reinfection of this vulnerable tissue site. Challenged mice displayed significant decreases in tissue infiltration of inflammatory leukocytes with marked reductions in frequencies of neutrophils but significant increases in frequencies of CD4 Th1 and CD8 T cells. An anamnestic antibody response was also detected. These data indicate that exposure to a live attenuated chlamydial vaccine or repeated abbreviated genital infection with virulent chlamydiae promotes anamnestic antibody and T cell responses that protect the oviduct from pathology despite a lack of sterilizing immunity at the site.

Interleukin 17 (IL-17) contributes to development of Th1 immunity and neutrophil influx during Chlamydia muridarum pulmonary infection, but its role during C. muridarum genital tract infection has not been described. We detected similar numbers of Chlamydia -specific Th17 and Th1 cells in iliac nodes of wild-type mice early during genital C. muridarum infection, while Th1 cells predominated later. il17ra − / − mice exhibited a reduced chlamydia-specific Th1 response in draining iliac nodes and decreased local IFN-γ production. Neutrophil influx into the genital tract was also decreased. However, il17ra − / − mice resolved infection normally, and no difference in pathology was observed compared to the wild type. Macrophage influx and tumor necrosis factor alpha (TNF-α) production were increased in il17ra − / − mice, providing a compensatory mechanism to effectively control chlamydial genital tract infection despite a reduced Th1 response. In ifn γ − / − mice, a marked increase in cellular infiltrates and chronic pathology was associated with an increased Th17 response. Although neutralization of IL-17 in ifn γ − / − mice decreased neutrophil influx, macrophage infiltration remained intact and the bacterial burden was not increased. Collectively, these results indicate that IL-17 contributes to the generation of Th1 immunity and neutrophil recruitment but is not required for macrophage influx or normal resolution of C. muridarum genital infection. These data highlight the redundant immune mechanisms operative at this mucosal site and the importance of examining site-specific responses to mucosal pathogens.

Loss of the conserved “cryptic” plasmid from C. trachomatis and C. muridarum is pleiotropic, resulting in reduced innate inflammatory activation via TLR2, glycogen accumulation and infectivity. The more genetically distant C. caviae GPIC is a natural pathogen of guinea pigs and induces upper genital tract pathology when inoculated intravaginally, modeling human disease. To examine the contribution of pCpGP1 to C. caviae pathogenesis, a cured derivative of GPIC, strain CC13, was derived and evaluated in vitro and in vivo. Transcriptional profiling of CC13 revealed only partial conservation of previously identified plasmid-responsive chromosomal loci (PRCL) in C. caviae. However, 2-deoxyglucose (2DG) treatment of GPIC and CC13 resulted in reduced transcription of all identified PRCL, including glgA, indicating the presence of a plasmid-independent glucose response in this species. In contrast to plasmid-cured C. muridarum and C. trachomatis, plasmid-cured C. caviae strain CC13 signaled via TLR2 in vitro and elicited cytokine production in vivo similar to wild-type C. caviae. Furthermore, inflammatory pathology induced by infection of guinea pigs with CC13 was similar to that induced by GPIC, although we observed more rapid resolution of CC13 infection in estrogen-treated guinea pigs. These data indicate that either the plasmid is not involved in expression or regulation of virulence in C. caviae or that redundant effectors prevent these phenotypic changes from being observed in C. caviae plasmid-cured strains.