Lattice-like structures known as perineuronal nets (PNNs) are key components of the extracellular matrix (ECM). Once fully crystallized by adulthood, they are largely stable throughout life. Contrary ...to previous reports that PNNs inhibit processes involving plasticity, here we report that the dynamic regulation of PNN expression in the adult auditory cortex is vital for fear learning and consolidation in response to pure tones. Specifically, after first confirming the necessity of auditory cortical activity for fear learning and consolidation, we observed that mRNA levels of key proteoglycan components of PNNs were enhanced 4 hr after fear conditioning but were no longer different from the control groups 24 hr later. A similar pattern of regulation was observed in numbers of cells surrounded by PNNs and area occupied by them in the auditory cortex. Finally, the removal of auditory cortex PNNs resulted in a deficit in fear learning and consolidation.
•Auditory cortex activity after auditory fear conditioning is necessary for learning•Removal of PNNs from the auditory cortex of adult mice decreases fear learning•Regrowth of PNNs restores the ability to learn new memories•Temporal regulation of PNNs occurs in response to fear learning
Banerjee et al., 2017 show that key components of the extracellular matrix, perineuronal nets (PNNs) in the auditory cortex of adult mice, are necessary for consolidation of fear learning in response to Pavlovian fear conditioning.
The newly emerged human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a pandemic of respiratory illness. Current evidence suggests that severe cases of ...SARS-CoV-2 are associated with a dysregulated immune response. However, little is known about how the innate immune system responds to SARS-CoV-2. In this study, we modeled SARS-CoV-2 infection using primary human airway epithelial (pHAE) cultures, which are maintained in an air-liquid interface. We found that SARS-CoV-2 infects and replicates in pHAE cultures and is directionally released on the apical, but not basolateral, surface. Transcriptional profiling studies found that infected pHAE cultures had a molecular signature dominated by proinflammatory cytokines and chemokine induction, including interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and CXCL8, and identified NF-κB and ATF-4 as key drivers of this proinflammatory cytokine response. Surprisingly, we observed a complete lack of a type I or III interferon (IFN) response to SARS-CoV-2 infection. However, pretreatment and posttreatment with type I and III IFNs significantly reduced virus replication in pHAE cultures that correlated with upregulation of antiviral effector genes. Combined, our findings demonstrate that SARS-CoV-2 does not trigger an IFN response but is sensitive to the effects of type I and III IFNs. Our studies demonstrate the utility of pHAE cultures to model SARS-CoV-2 infection and that both type I and III IFNs can serve as therapeutic options to treat COVID-19 patients.
The current pandemic of respiratory illness, COVID-19, is caused by a recently emerged coronavirus named SARS-CoV-2. This virus infects airway and lung cells causing fever, dry cough, and shortness of breath. Severe cases of COVID-19 can result in lung damage, low blood oxygen levels, and even death. As there are currently no vaccines approved for use in humans, studies of the mechanisms of SARS-CoV-2 infection are urgently needed. Our research identifies an excellent system to model SARS-CoV-2 infection of the human airways that can be used to test various treatments. Analysis of infection in this model system found that human airway epithelial cell cultures induce a strong proinflammatory cytokine response yet block the production of type I and III IFNs to SARS-CoV-2. However, treatment of airway cultures with the immune molecules type I or type III interferon (IFN) was able to inhibit SARS-CoV-2 infection. Thus, our model system identified type I or type III IFN as potential antiviral treatments for COVID-19 patients.
Stressors affect populations exposed to them as well as offspring. Strategies preventing the intergenerational propagation of effects of stress would benefit public health. Olfactory cue-based fear ...conditioning provides a framework to address this issue.
We 1) exposed adult male mice to an odor, acetophenone (Ace) or Lyral (parental generation F0-Exposed), 2) trained mice to associate these odors with mild foot shocks (F0-Trained), and 3) trained mice to associate these odors with mild foot shocks and then extinguished their fear toward these odors with odor-only presentations (F0-Extinguished). We then examined sensitivity of future generation (F1) offspring to these odors, expression of M71 odorant (Ace-responsive) and MOR23 odorant (Lyral-responsive) receptor-expressing cell populations in F1 offspring, and DNA methylation at genes encoding the Ace- (Olfr151, Olfr160) and Lyral- (Olfr16) responsive receptors in F0 sperm.
Extinguishing fear toward Ace or Lyral of F0 male mice (F0-Extinguished) that had been fear conditioned with Ace or Lyral, respectively, results in F1-Extinguished offspring that do not demonstrate behavioral sensitivity to Ace or Lyral, respectively, and do not have enhanced representation for M71 or MOR23 odorant receptors in the olfactory system, as is observed in F1-Trained-Ace or F1-Trained-Lyral cohorts, respectively. The promoters of genes encoding Olfr151 and Olfr160 receptors are less methylated in F0-Trained-Ace sperm compared with F0-Exposed-Ace sperm. The Olfr16 promoter is less methylated in F0-Trained-Lyral sperm compared with F0-Exposed-Lyral sperm, and F0-Extinguished-Lyral sperm have methylation levels comparable to F0-Exposed-Lyral sperm.
Our study demonstrates the potential of using extinction-based behavioral strategies to reverse influences of parental stress in offspring and in the parental germline.
Salient sensory environments experienced by a parental generation can exert intergenerational influences on offspring. While these data provide an exciting new perspective on biological inheritance, ...questions remain about causes and consequences of intergenerational influences of salient sensory experience. We previously showed that exposing male mice to a salient olfactory experience, like olfactory fear conditioning, resulted in offspring demonstrating a sensitivity to the odor used to condition the paternal generation and possessing enhanced neuroanatomical representation for that odor. In this study, we first injected RNA extracted from sperm of male mice that underwent olfactory fear conditioning into naïve single‐cell zygotes and found that adults that developed from these embryos had increased sensitivity and enhanced neuroanatomical representation for the odor (Odor A) with which the paternal male had been conditioned. Next, we found that female, but not male offspring sired by males conditioned with Odor A show enhanced consolidation of a weak single‐trial Odor A + shock fear conditioning protocol. Our data provide evidence that RNA found in the paternal germline after exposure to salient sensory experiences can contribute to intergenerational influences of such experiences, and that such intergenerational influences confer an element of adaptation to the offspring. In so doing, our study of intergenerational influences of parental sensory experience adds to existing literature on intergenerational influences of parental exposures to stress and dietary manipulations and suggests that some causes (sperm RNA) and consequences (behavioral flexibility) of intergenerational influences of parental experiences may be conserved across a variety of parental experiences.
Intergenerational influences of salient sensory experiences are mediated by sperm RNA and have positive consequences for offspring.
The emergency use authorization of two mRNA vaccines in less than a year from the emergence of SARS-CoV-2 represents a landmark in vaccinology
. Yet, how mRNA vaccines stimulate the immune system to ...elicit protective immune responses is unknown. Here we used a systems vaccinology approach to comprehensively profile the innate and adaptive immune responses of 56 healthy volunteers who were vaccinated with the Pfizer-BioNTech mRNA vaccine (BNT162b2). Vaccination resulted in the robust production of neutralizing antibodies against the wild-type SARS-CoV-2 (derived from 2019-nCOV/USA_WA1/2020) and, to a lesser extent, the B.1.351 strain, as well as significant increases in antigen-specific polyfunctional CD4 and CD8 T cells after the second dose. Booster vaccination stimulated a notably enhanced innate immune response as compared to primary vaccination, evidenced by (1) a greater frequency of CD14
CD16
inflammatory monocytes; (2) a higher concentration of plasma IFNγ; and (3) a transcriptional signature of innate antiviral immunity. Consistent with these observations, our single-cell transcriptomics analysis demonstrated an approximately 100-fold increase in the frequency of a myeloid cell cluster enriched in interferon-response transcription factors and reduced in AP-1 transcription factors, after secondary immunization. Finally, we identified distinct innate pathways associated with CD8 T cell and neutralizing antibody responses, and show that a monocyte-related signature correlates with the neutralizing antibody response against the B.1.351 variant. Collectively, these data provide insights into the immune responses induced by mRNA vaccination and demonstrate its capacity to prime the innate immune system to mount a more potent response after booster immunization.
The immunopathological mechanisms driving the development of severe COVID-19 remain poorly defined. Here, we utilize a rhesus macaque model of acute SARS-CoV-2 infection to delineate perturbations in ...the innate immune system. SARS-CoV-2 initiates a rapid infiltration of plasmacytoid dendritic cells into the lower airway, commensurate with IFNA production, natural killer cell activation, and a significant increase of blood CD14
CD16
monocytes. To dissect the contribution of lung myeloid subsets to airway inflammation, we generate a longitudinal scRNA-Seq dataset of airway cells, and map these subsets to corresponding populations in the human lung. SARS-CoV-2 infection elicits a rapid recruitment of two macrophage subsets: CD163
MRC1
, and TREM2
populations that are the predominant source of inflammatory cytokines. Treatment with baricitinib (Olumiant®), a JAK1/2 inhibitor is effective in eliminating the influx of non-alveolar macrophages, with a reduction of inflammatory cytokines. This study delineates the major lung macrophage subsets driving airway inflammation during SARS-CoV-2 infection.
...there was a cross-contamination of the day-1 samples obtained from participants 2049 (male) and 2051 (female), which resulted in the erroneous appearance of cell clusters containing cells of both ...male and female origin in the CITE-seq data. The major conclusions from the analysis of bulk transcriptional data, including the dynamics and nature of the transcriptional response, and the transcriptional correlates of T cell and antibody response remain unaffected. ...the reassignment ofsamples to the appropriate time points resulted in more negatively enri1ched gene sets on day 7 and later, and a diminution of the correlation between the monocyte-associated transcriptional signature and the cross-neutralization potential against the B.1.351 strain (Extended Data Fig. 12).
Exposure to stress is a risk factor for perturbed mental health, including impoverished regulation of emotional and physiological responses that accompany anxiety and mood disorders, substance abuse ...and behavioral disorders. Such disruptions to well‐being could be triggered by discrete environmental events or pervasive early life stress (ELS) resulting for example from adverse caregiving. Recent data mostly collected from rodents exposed to anthropogenic stressors suggest that one way via which the detrimental effects of such stress extend beyond the exposed population to future offspring is via stress‐induced alterations of RNA found in the paternal germline. In contrast, less attention has been paid to how naturally occurring stress in males might influence offspring biology and behavior. In this study, we used a translational nonhuman primate model of ELS caused by naturally occurring adverse caregiving of infant macaques to (1) profile total RNA in the adolescent male germline, and (2) identify how those RNA profiles are affected by exposure to ELS. Our findings that the top 100 transcripts identified correspond to transcripts related to germline biology and reproduction demonstrate the validity and feasibility of profiling RNA in the germline of rhesus macaques. While our small sample sizes precluded definitive assessment of stress‐induced alterations of RNA in the male germline of rhesus macaques that experienced ELS, our study sets the foundation for future investigations of how early adversity might alter the male germline, across species and in experimental protocols that involve anthropogenic vs natural stressors.
This study utilized a translational nonhuman primate model of early life stress (ELS) to profile total RNA in the adolescent male germline and to identify how those RNA profiles are affected by exposure to ELS. The top 100 highly expressed transcripts corresponded to transcripts related to germline biology and reproduction. No significant differences were found in gene expression between Control and Maltreated groups.
Photo credit: monkey portrait (Marie Collantes/Yerkes National Primate Research Center, Emory University); sperm (Hadj Aoued)
Research Highlights
The top 100 genes in the male germline for which RNA sequences aligned to the sense strand were relevant to male germline‐related biology and reproduction.
Sequences aligned to the antisense strand that may play an important role in regulation of gene expression in the zygote after fertilization were also found.
PDF
