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Gordon, A.

Publications and source records attributed to Gordon, A..

At least 19 recordsLinked to original sources

Antibody evasion and receptor binding of SARS-CoV-2 RW.1.1

The continued evolution of SARS-CoV-2 is shaped by changes in antibody evasion and receptor engagement that influence viral fitness. RW.1.1, an emerging descendant of XFJ carrying five additional spike substitutions, has recently increased in frequency in North America. Here, we characterized the serum antibody evasion, monoclonal antibody sensitivity, and ACE2 receptor engagement of RW.1.1. Pseudovirus neutralization assays using sera from adults showed that RW.1.1 was not more resistant to serum neutralization than currently circulating variants, with neutralizing titers comparable to XFG, BA.3.2.2, and NB.1.8.1 in the tested cohort. Neutralization of RW.1.1 also did not differ significantly among adults, children, and infants and toddlers. Despite the absence of increased overall serum antibody resistance, monoclonal antibody neutralization assays revealed substantial resistance to several RBD class 1 antibodies and increased resistance to a subset of class 1/4 antibodies. Moreover, RW.1.1 exhibited reduced ACE2 receptor engagement compared with XFG, which itself has reduced receptor engagement relative to earlier JN.1 subvariants. Thus, RW.1.1 has continued to expand despite a further reduction in receptor engagement and without a substantial increase in overall serum antibody evasion. These findings suggest that the fitness of emerging SARS-CoV-2 variants may depend not only on the magnitude of antibody evasion but also on the specific components of the polyclonal antibody response that are evaded, highlighting the increasingly complex interplay between population immunity and receptor engagement in shaping SARS-CoV-2 evolution.

microbiology↗

Multidimensional control of ingestive behavior by lateral hypothalamic neurotensin neurons

Consumption of food and water is regulated by interactions between neural circuits that govern motivational drive states, arousal, motor activity, and reward signaling, among other factors. Neurons in the lateral hypothalamus that express the neuropeptide neurotensin (LH-Nts neurons) are known to influence many of these elements, but their precise role in regulating specific aspects of ingestive behavior remains unclear. Utilizing a tightly controlled head-fixed task, we find that LH-Nts neurons strongly encode the rate of licking for water and sweet solutions, with weaker modulation of activity by solution identity and restriction state. Silencing LH-Nts neurons reduces water intake but has little direct effect on hunger or satiety. Instead, we find that these neurons impact multiple underlying behavioral components necessary for food consumption, including arousal and engagement with a novel food source, and also influence thermoregulation and metabolism. Together, these data establish tonic activity of LH-Nts neurons as a critical signal supporting exploration and volitional movement, while also delineating a role for these neurons in driving active consumption, particularly of water. Furthermore, quantitative projection mapping revealed widespread innervation of structures linked to thirst, arousal, reward, metabolism, and facial motor control, suggesting that these neurons play an important role coordinating neural circuits governing multiple different aspects of ingestion.

neuroscience↗

SARS-CoV-2 BA.3.2.2 is more evasive of neutralization by sera from young children

Dominant SARS-CoV-2 variants have most prominently displayed greater evasion of serum neutralizing antibodies than predecessor strains. BA.3.2, a descendant of Omicron BA.3, carrying 43 additional spike mutations, emerged in 2024, and over the last several months its subvariant BA.3.2.2 has slowly increased in prevalence globally. BA.3.2.2 continues to circulate at lower frequency than the genetically and antigenically distant dominant JN.1 subvariants NB.1.8.1 and XFG. However, concerningly, epidemiologic analyses have suggested that a larger proportion of COVID-19 cases in children are caused by BA.3.2.2 compared to adults, raising the possibility that susceptibility to BA.3.2.2 differs across age groups. Since immune imprinting shapes variant-specific anti-SARS-CoV-2 antibody profiles and children born after 2021 primarily were first exposed to Omicron subvariants, we hypothesized that young children may have lower circulating neutralizing antibody titers against BA.3.2.2 than adults. Using pseudovirus neutralization assays, we measured titers against BA.3.2.2 and other SARS-CoV-2 variants in serum or plasma samples from a total of 36 adults ([≥]18 years old), school-age children (3-10 years old), and infants/toddlers (6-28 months old) in the US. We found that both cohorts of children had lower geometric mean titers against BA.3.2.2 than adults, even though all tested age groups had similar titers against dominant strains NB.1.8.1 and XFG. Together, these findings suggest that susceptibility to emerging SARS-CoV-2 variants may diverge across age groups, perhaps as a result of their different exposure histories. Furthermore, these results highlight the importance of SARS-CoV-2 surveillance and the monitoring of immunity against viral variants across age ranges.

microbiology↗

LP.8.1-directed COVID-19 mRNA vaccines boost neutralizing antibodies and mitigate ancestral immune imprinting

As SARS-CoV-2 evolves, it evades existing immunity elicited by exposure to earlier strains of the virus. In response, vaccine manufacturers have updated COVID-19 vaccines annually since 2022, though immune imprinting to the ancestral strain has blunted antibody responses to modern viral variants. In early 2025, the JN.1 subvariant LP.8.1 was dominant and manufacturers updated mRNA vaccine formulations to target LP.8.1 (LP.8.1 MV). However, by late 2025, other subvariants were dominant (XFG and NB.1.8.1) or emerging (e.g., PE.1.4, BA.3.2, PY.1.1.1) around the world. It is critical to understand the extent to which updated vaccine boosters elicit titers against both their target strain and recent variants. Further, it is important to quantify the extent to which immune imprinting continues to shape antiviral immune responses. Using pseudoviruses, we measured neutralizing antibody titers against a panel of 11 SARS-CoV-2 variants in serum samples from 36 adult participants in the United States before and approximately 1 month after LP.8.1 MV booster. We found that neutralizing antibody titers were substantially increased by the boost, with the greatest increases elicited against LP.8.1 and XFG. For the first time since 2022, post-boost titers were higher against the homologous vaccine target (LP.8.1) than against D614G (representing the ancestral strain). Combined, these results indicate that ancestral immune imprinting is mitigated to the greatest extent observed to date by LP.8.1 MV. Lastly, for a subset of participants, we measured neutralizing titers at approximately 4 months post-booster and found that LP.8.1-directed antibody titers were durable, with an estimated average half-life of approximately 66 days.

microbiology↗

Structural Basis for Childhood Antibody Recognition of The Human Metapneumovirus Fusion Protein

Human metapneumovirus (hMPV) is a significant cause of acute respiratory illness in children and adults, with the majority of children being seropositive for hMPV by five years of age. Infants, older adults, and immunocompromised individuals are more susceptible to severe hMPV infections that can lead to hospitalization and death. The hMPV fusion (F) protein is the sole target of neutralizing antibodies, and while the most common neutralizing epitopes on the hMPV F protein targeted by B cells in hMPV-infected adults have been previously determined, the antibody response in hMPV-infected children remains undefined. We isolated a panel of human monoclonal antibodies (mAbs) from children previously infected with hMPV (MPV498, MPV499, MPV510, MPV511, and MPV513), and the mAbs were assessed for binding avidity, neutralization potency, epitope specificity, and in vivo efficacy. All mAbs were neutralizing, and epitope binning revealed the presence of four different epitopes targeted by the mAbs. We determined the cryo-EM structures of four mAbs in complex with the hMPV F protein, which revealed epitopes located on the hMPV F trimer surface as well as an intratrimer epitope located completely within the hMPV F trimer interface. Furthermore, we determined the prophylactic efficacy of the mAbs in protection against hMPV challenge in mice. Overall, our data reveal new insights into the immunodominant antigenic epitopes on the hMPV F protein in children and identify new mAb therapies for hMPV F disease prevention.

immunology↗

Antibody evasion and receptor binding of SARS-CoV-2 LP.8.1.1, NB.1.8.1, XFG, and related subvariants

SARS-CoV-2 continues to evolve, causing repeated waves of infections around the world. It is critical to understand the features of the virus that explain its growth advantages. Recently, the SARS-CoV-2 Omicron JN.1 subvariants KP.3.1.1 and XEC were outcompeted by later JN.1 progenies, most prominently LP.8.1 and LP.8.1.1. Other recent JN.1 subvariants, such as LF.7.2.1, which became prevalent in Asia, and MC.10.1, have also been under monitoring. Subsequently, NB.1.8.1 and XFG subvariants began increasing in prevalence, as well. We found that serum neutralizing antibody titers against LP.8.1, LP.8.1.1, LF.7, LF.7.2.1, MC.10.1 were similar to XEC in a cohort of 20 KP.2-based monovalent mRNA vaccine (KP.2 MV) recipients and in a cohort 20 adults who did not receive KP.2 MV. NB.1.8.1 and XFG were more evasive of serum neutralization than LP.8.1.1. We then characterized subvariant susceptibility to monoclonal antibody (mAb) neutralization using a panel of 12 mAbs spanning several epitopes on the SARS-CoV-2 spike, and found that LP.8.1 and XFG, MC.10.1 and NB.1.8.1, and LF.7.2.1 evade different classes of mAbs relative to earlier JN.1 subvariants, even if the tested polyclonal serum neutralizing antibody titers were not different overall. Next, we found that the receptor-binding affinity of LP.8.1 to ACE2 was the highest among the tested viruses, while that of LF.7.2.1 was lowest. Therefore, unlike most prior SARS-CoV-2 sublineage evolutionary trajectories, receptor-binding affinity, possibly reflecting enhanced transmissibility-and not increased antibody evasion-better explained the rise of LP.8.1, while the expansion of NB.1.8.1 and XFG again appear correlated with their enhanced antibody evasion.

microbiology↗

Do Existing COVID-19 Vaccines Need to Be Updated in 2025?

COVID-19 vaccines have been updated each year since 2022 to improve protection against evolving SARS-CoV-2 variants. However, it is unclear whether a reformulation will be necessary for 2025. KP.2-based monovalent COVID-19 mRNA vaccines (KP.2 MV) were authorized for use in 2024, and they conferred substantial protection against hospitalizations caused by viral variants that emerged and dominated later, such as KP.3.1.1 and XEC. Today, LP.8.1 and its subvariant LP.8.1.1 have become dominant worldwide, particularly so in North America. Other variants, such as the LF.7 subvariant LF.7.2.1, have emerged with a growth advantage in Asia. To characterize the antigenicity of LP.8.1, LP.8.1.1, LF.7, LF.7.2.1, and another variant under monitoring, MC.10.1, we tested serum samples from 20 individuals who recently received KP.2 MV in neutralization assays against JN.1, KP.2, KP.3, KP.3.1.1, XEC, LP.8.1, LP.8.1.1, LF.7, LF.7.2.1, or MC.10.1 pseudoviruses. Serum neutralizing antibody titers against LP.8.1, LP.8.1.1, LF.7, LF.7.2.1, and MC.10.1 were comparable to those against KP.3.1.1 and XEC, indicating that LP.8.1.1 and other recently dominant subvariants are antigenically similar to their predecessors. Therefore, the currently authorized KP.2 MV may not need to be updated for 2025, if the vaccine manufacturers could demonstrate comparable immunogenicity for KP.2 MV and LP.8.1-based mRNA vaccines and, of course, in the absence of an antigenically divergent SARS-CoV-2 variant emerging.

microbiology↗

Functional profiling of KCNE1 variants informs population carrier frequency of Jervell and Lange-Nielsen syndrome type 2

Congenital long-QT syndrome (LQTS) is most often associated with pathogenic variants in KCNQ1 encoding the pore-forming voltage-gated potassium channel subunit of the slow delayed rectifier current (IKs). Generation of IKs requires assembly of KCNQ1 with an auxiliary subunit encoded by KCNE1, which is also associated with LQTS but causality of autosomal dominant disease is disputed. By contrast, KCNE1 is an accepted cause of recessive type 2 Jervell and Lange-Nielson syndrome (JLN2). The functional consequences of most KCNE1 variants have not been determined and the population prevalence of JLN2 is unknown. Methods: We determined the functional properties of 95 KCNE1 variants co-expressed with KCNQ1 in heterologous cells using high-throughput voltage-clamp recording. Experiments were conducted with each KCNE1 variant expressed in the homozygous state and then a subset was studied in the heterozygous state. The carrier frequency of JLN2 was estimated by considering the population prevalence of dysfunctional variants. Results: There is substantial overlap between disease-associated and population KCNE1 variants. When examined in the homozygous state, 68 KCNE1 variants exhibited significant differences in at least one functional property compared to WT KCNE1, whereas 27 variants did not significantly affect function. Most dysfunctional variants exhibited loss-of-function properties. We observed no evidence of dominant-negative effects. Most variants were scored as variants of uncertain significance (VUS) and inclusion of functional data resulted in revised classifications for only 14 variants. The population carrier frequency of JLN2 was calculated as 1 in 1034. Peak current density and activation voltage-dependence but no other biophysical properties were correlated with findings from a mutational scan of KCNE1. Conclusions: Among 95 disease-associated or population KCNE1 variants, many exhibit abnormal functional properties but there was no evidence of dominant-negative behaviors. Using functional data, we inferred a population carrier frequency for recessive JLN2. This work helps clarify the pathogenicity of KCNE1 variants.

genetics↗

KP.2-based monovalent mRNA vaccines robustly boost antibody responses to SARS-CoV-2

In response to the ongoing evolution of SARS-CoV-2, COVID-19 mRNA vaccines were recently updated to encode the spike protein of the KP.2 subvariant of the JN.1 sublineage. However, the immunogenicity of KP.2-based monovalent mRNA vaccines (KP.2 MV) has yet to be fully evaluated and reported, particularly against dominant and growing viral variants KP.3.1.1 and XEC, which bear some distinct mutations from KP.2. Here we report that KP.2 MV boosters elicit robust neutralizing antibody titers in a cohort of 16 healthy adult participants against all tested variants in pseudovirus neutralization assays. The highest post-boost geometric mean titers were against older variants D614G (17,293) and BA.5 (14,358), suggestive of immune imprinting, but the post-boost titers against currently dominant or growing viruses KP.3.1.1 (1,698) and XEC (1,721) were still robust. Fold-changes in titers were highest against recent JN.1 subvariants, including JN.1, KP.2, KP.3, KP.3.1.1, and XEC, (5.8-to-7.8-fold), compared to older variants D614G and BA.5 (1.6- and 2.5-fold), which suggests that KP.2 MV boosters have at least partially mitigated immune imprinting. Overall, these results show that KP.2 MV boosters elicit robust neutralizing antibodies against dominant SARS-CoV-2 viruses.

microbiology↗

Antibody evasiveness of SARS-CoV-2 subvariants KP.3.1.1 and XEC

SARS-CoV-2 continues to evolve and spread around the world, and it remains critical to understand the functional consequences of mutations that lead to dominant viral variants. KP.3.1.1 is currently the most prevalent subvariant worldwide, while the recombinant subvariant XEC is exhibiting the fastest growth rate. Here we measured the in vitro neutralization of KP.3.1.1 and XEC by human sera, monoclonal antibodies, and soluble hACE2 receptor relative to their parental subvariants KP.3 and JN.1. KP.3.1.1 and XEC were slightly more resistant (1.3-1.6-fold) than KP.3 to serum neutralization, and the resultant antigenic map showed that the new subvariants are antigenically similar. Both also demonstrated greater resistance to neutralization by select monoclonal antibodies and soluble hACE2, all of which target the top of the viral spike. Our findings suggested that upward motion of the receptor-binding domain in spike is partially hindered by the N-terminal-domain mutations found KP.3.1.1 and XEC, thereby allowing these subvariants to better evade serum antibodies that target the viral spike when it is in the up position and thus having a growth advantage in the population.

microbiology↗

Tracking the genetic diversity of SARS-CoV-2 variants in Nicaragua throughout the COVID-19 Pandemic

The global circulation of SARS-CoV-2 has been extensively documented, yet the dynamics within Central America, particularly Nicaragua, remain underexplored. This study characterizes the genomic diversity of SARS-CoV-2 in Nicaragua from March 2020 through December 2022, utilizing 1064 genomes obtained via next-generation sequencing. These sequences were selected nationwide and analyzed for variant classification, lineage predominance, and phylogenetic diversity. We employed both Illumina and Oxford Nanopore Technologies for all sequencing procedures. Results indicated a temporal and spatial shift in dominant lineages, initially from B.1 and A.2 in early 2020 to various Omicron subvariants towards the studys end. Significant lineage shifts correlated with changes in COVID-19 positivity rates, underscoring the epidemiological impact of variant dissemination. The comparative analysis with regional data underscored the low diversity of circulating lineages in Nicaragua and their delayed introduction compared to other countries in the Central American region. The study also linked specific viral mutations with hospitalization rates, emphasizing the clinical relevance of genomic surveillance. This research advances the understanding of SARS-CoV-2 evolution in Nicaragua and provide valuable information regarding its genetic diversity for public health officials in Central America. We highlight the critical role of ongoing genomic surveillance in identifying emergent lineages and informing public health strategies.

genomics↗

Recurrent SARS-CoV-2 spike mutations confer growth advantages to select JN.1 sublineages

The recently dominant SARS-CoV-2 Omicron JN.1 has evolved into multiple sublineages, with recurrent spike mutations R346T, F456L, and T572I, some of which exhibit growth advantages, such as KP.2. We investigated these mutations in JN.1, examining their individual and combined effects on immune evasion, ACE2 receptor affinity, and in vitro infectivity. F456L increased resistance to neutralization by human sera, including those after JN.1 breakthrough infections, and by RBD class-1 monoclonal antibodies, significantly altering JN.1 antigenicity. R346T enhanced ACE2-binding affinity, without a discernible effect on serum neutralization. Individually, R346T and T572I modestly enhanced infectivity of each pseudovirus. Importantly, expanding sublineages such as KP.2 containing R346T, F456L, and V1104L, showed similar neutralization resistance as JN.1 with R346T and F456L, suggesting V1104L does not appreciably affect antibody evasion. Our findings illustrate how certain JN.1 mutations confer growth advantages in the population and could inform the design of the next COVID-19 vaccine booster.

microbiology↗

Developmental convergence and divergence in human stem cell models of autism spectrum disorder

Two decades of genetic studies in autism spectrum disorder (ASD) have identified over a hundred genes harboring rare risk mutations. Despite this substantial heterogeneity, transcriptomic and epigenetic analyses have identified convergent patterns of dysregulation across ASD post-mortem brain tissue. To identify shared and distinct mutational mechanisms, we assembled the largest hiPS cell patient cohort to date, consisting of 70 hiPS cell lines after stringent quality control representing 8 ASD-associated mutations, idiopathic ASD, and 20 lines from non-affected controls. We used these hiPS lines to generate human cortical organoids (hCO), profiling by RNAseq at four distinct timepoints up to 100 days of in vitro differentiation. Early timepoints harbored the largest mutation-specific changes, but different genetic forms converged on shared transcriptional changes as development progressed. We identified a shared RNA and protein interaction network, which was enriched in ASD risk genes and predicted to drive the observed down-stream changes in gene expression. CRISPR-Cas9 screening of these candidate transcriptional regulators in induced human neural progenitors validated their downstream molecular convergent effects. These data illustrate how genetic risk can propagate via transcriptional regulation to impact convergently dysregulated pathways, providing new insight into the convergent impact of ASD genetic risk on human neurodevelopment.

neuroscience↗

Antibiotics damage the colonic mucus barrier in a microbiota-independent manner

Antibiotic use is a risk factor for development of inflammatory bowel diseases (IBDs). IBDs are characterized by a damaged mucus layer, which does not properly separate the host intestinal epithelium from the microbiota. Here, we hypothesized that antibiotics might affect the integrity of the mucus barrier. By systematically determining the effects of different antibiotics on mucus layer penetrability we found that oral antibiotic treatment led to breakdown of the mucus barrier and penetration of bacteria into the mucus layer. Using fecal microbiota transplant, RNA sequencing followed by machine learning and ex vivo mucus secretion measurements, we determined that antibiotic treatment induces ER stress in the colonic tissue which inhibits colonic mucus secretion in a microbiota-independent manner. This mucus secretion flaw led to penetration of bacteria into the colonic mucus layer, translocation of microbial antigens into circulation and exacerbation of ulcerations in a mouse model of IBD. Thus, antibiotic use might predispose to development of intestinal inflammation by impeding mucus production.

immunology↗

SARS-CoV-2 Omicron BA.2.87.1 Exhibits Higher Susceptibility to Serum Neutralization Than EG.5.1 and JN.1

As SARS-CoV-2 continues to spread and mutate, tracking the viral evolutionary trajectory and understanding the functional consequences of its mutations remain crucial. Here, we characterized the antibody evasion, ACE2 receptor engagement, and viral infectivity of the highly mutated SARS-CoV-2 Omicron subvariant BA.2.87.1. Compared with other Omicron subvariants, including EG.5.1 and the current predominant JN.1, BA.2.87.1 exhibits less immune evasion, reduced viral receptor engagement, and comparable infectivity in Calu-3 lung cells. Intriguingly, two large deletions ({Delta}15-26 and {Delta}136-146) in the N-terminal domain (NTD) of the spike protein facilitate subtly increased antibody evasion but significantly diminish viral infectivity. Collectively, our data support the announcement by the USA CDC that the public health risk posed by BA.2.87.1 appears to be low.

microbiology↗

Robust SARS-CoV-2 Neutralizing Antibodies Sustained through Three Months Post XBB.1.5 mRNA Vaccine Booster

SARS-CoV-2-neutralizing antibodies were substantially expanded one month after a shot of XBB.1.5 monovalent mRNA vaccine (XBB.1.5 MV) booster, but the durability of this response remained unknown. Here, we addressed this question by performing neutralization assays on four viral variants (D614G, BA.5, XBB.1.5, and JN.1) using sera from 39 adult participants obtained at [~]1 month and [~]3 months post an XBB.1.5 MV booster. Our findings indicate that the resultant neutralizing antibody titers were robust and generally maintained at stable levels for the study period, similar to those following XBB infection. Importantly, this durability of neutralizing antibody titers contrasts with the decline observed after a booster of the original monovalent or BA.5 bivalent mRNA vaccine. Our results are in line with the recent national data from the Centers for Disease Control and Prevention, showing the efficacy against symptomatic SARS-CoV-2 infection is sustained for up to 4 months after an XBB.1.5 MV booster.

immunology↗

XBB.1.5 monovalent mRNA vaccine booster elicits robust neutralizing antibodies against emerging SARS-CoV-2 variants

COVID-19 vaccines have recently been updated with the spike protein of SARS-CoV-2 XBB.1.5 subvariant alone, but their immunogenicity in humans has yet to be fully evaluated and reported, particularly against emergent viruses that are rapidly expanding. We now report that administration of an updated monovalent mRNA vaccine (XBB.1.5 MV) to uninfected individuals boosted serum virus-neutralization antibodies significantly against not only XBB.1.5 (27.0-fold) and the currently dominant EG.5.1 (27.6-fold) but also key emergent viruses like HV.1, HK.3, JD.1.1, and JN.1 (13.3-to-27.4-fold). In individuals previously infected by an Omicron subvariant, serum neutralizing titers were boosted to highest levels (1,504-to-22,978) against all viral variants tested. While immunological imprinting was still evident with the updated vaccines, it was not nearly as severe as the previously authorized bivalent BA.5 vaccine. Our findings strongly support the official recommendation to widely apply the updated COVID-19 vaccines to further protect the public.

immunology↗

Antigenicity and receptor affinity of SARS-CoV-2 BA.2.86 spike

Although the COVID-19 pandemic has officially ended1, SARS-CoV-2 continues to spread and evolve. Recent infections have been dominated by XBB.1.5 and EG.5.1 subvariants2. A new subvariant designated BA.2.86 has just emerged, spreading to 21 countries in 5 continents3. This virus contains 34 spike mutations compared to its BA.2 predecessor, thereby raising concerns about its propensity to evade existing antibodies. We examined its antigenicity using human sera and monoclonal antibodies (mAbs). Reassuringly, BA.2.86 was not more resistant to human sera than XBB.1.5 and EG.5.1, indicating that the new subvariant would not have a growth advantage in this regard. Importantly, sera from patients who had XBB breakthrough infection exhibited robust neutralizing activity against all viruses tested, suggesting that upcoming XBB.1.5 monovalent vaccines could confer added protection. The finding that the longer genetic distance of BA.2.86 did not yield a larger antigenic distance was partially explained by the mAb data. While BA.2.86 showed greater resistance to mAbs to subdomain 1 (SD1) and receptor-binding domain (RBD) class 2 and 3 epitopes, it was more sensitive to mAbs to class 1 and 4/1 epitopes in the "inner face" of RBD that is exposed only when this domain is in the "up" position. We also identified six new spike mutations that mediate antibody resistance, including E554K that threatens SD1 mAbs in clinical development. The BA.2.86 spike also had a remarkably high receptor affinity. The ultimate trajectory of this new SARS-CoV-2 variant will soon be revealed by continuing surveillance, but its worldwide spread is worrisome.

microbiology↗