FoxA1 and FoxA2 control growth and cellular identity in NKX2-1-positive lung adenocarcinoma

Changes in cellular identity (also known as histologic transformation or lineage plasticity) can drive malignant progression and resistance to therapy in many cancers, including lung adenocarcinoma (LUAD). The lineage-specifying transcription factors FoxA1 and FoxA2 (FoxA1/2) control identity in NKX2-1/TTF1-negative LUAD. However, their role in NKX2-1-positive LUAD has not been systematically investigated. We find that Foxa1/2 knockout severely impairs tumorigenesis in KRAS-driven genetically engineered mouse models and human cell lines. Loss of FoxA1/2 leads to the collapse of a dual-identity state, marked by co-expression of pulmonary and gastrointestinal transcriptional programs, which has been implicated in LUAD progression. Mechanistically, FoxA1/2 loss leads to aberrant NKX2-1 activity and genomic localization, which in turn actively inhibits tumorigenesis and drives alternative cellular identity programs that are associated with non-proliferative states. This work demonstrates that FoxA1/2 expression is a lineage-specific vulnerability in NKX2-1-positive LUAD and identifies mechanisms of response and resistance to targeting FoxA1/2 in this disease.

scRNA-Seq profiling of stickleback fish splenocytes: Expansion of myeloid and B cells on immunization

Threespine stickleback is characterized by wide phenotypic variations attributed to repeated evolutions that took place when colonizing new environments. This fish species is hence deemed a powerful model candidate for comparative immunology to gain new insights into the function and evolution of vertebrate immune system, given also fish small size, wide distribution, and easiness of husbandry. Harnessing single-cell RNA sequencing potential to dissect tissue cellular heterogeneity at high resolution, here we employed that technique to profile naïve, and immunized stickleback spleens identifying the different immune cell types present, and reveal the transcriptional changes driven by immunization. Analysis of the compiled splenic data revealed 18 cell clusters, including major leukocyte types (e.g., B cells, macrophages, and neutrophils), and erythrocytes. Surprisingly, none of the clusters could be recognized or presumed as a T cell population based on the genes expressed in each cluster. Fish immunization led to total cell expansion and interestingly to the emergence of distinct myeloid and B cell populations. The myeloid population lacks the expression of MHCII genes, but was found enriched in the expression of GRN2, S100A10, NCCRP, BPIFC, and PRDX1 genes, suggesting that additional cytotoxic roles are possibly played by that population. Despite the B cell population being enriched in the expression of proteolysis associated genes, i.e., TRY and PRSS59, it also, unlike other B cell populations, lacks the expression of MHCII genes. This study creates a comprehensive atlas of threespine stickleback spleen at single-cell resolution and raises new questions about the immune response evolving in such vertebrate species.

Supported by a grants from NIH (Grant number: NIH R01 AI146168)

Contribution of PU.1 and STAT6 to fibrosis-mediated growth suppression of the Diphyllobothriidae family cestode, Schistocephalus solidus

Threespine stickleback (Gasterosteus aculeatus) fish are naturally infected with the Diphyllobothriidae family tapeworm, Schistocephalus solidus. The anti-parasite response to this body cavity infection varies greatly among wild stickleback populations. Some populations generate extensive peritoneal fibrosis which suppresses cestode grown, thereby preventing the parasite from reaching sexual maturity and blocking its ability to infect its terminal host. In extreme cases this response can encapsulate the cestode. On the other hand, other fish populations tolerate S. solidus, carry heavy parasite burdens, grow parasites 34-fold larger than resistant fish, and do not produce fibrosis. Combined genetic mapping and population genomics identified regions of the genome associated with this resistance-tolerance axis. Quantitative trait loci (QTL) mapping of the fibrosis phenotype led us to a 78bp deletion in SPI1b which encodes the transcription factor PU.1 which is associated with the initiation of tissue fibrosis. This deletion was fixed in tolerant fish, but not resistant fish. SPI1b expression increases with infection and is higher in fibrotic fish compared to non-fibrotic controls. QTL mapping of cestode mass detected STAT6 on Ch 12, which is associated with alternatively activated macrophages and fibrosis. In tolerant fish, but not resistant, a deletion in stat6 exon 5 is nearly fixed. Several additional QTL were also found containing genes associated with fibrosis initiation or regulation, evidence for strong selection on this anti-parasite mechanism and identifying pathways involved in the regulation of a pathologic fibrotic response against a Diphyllobothriidae cestode.

Signatures of GVHD and relapse after posttransplant cyclophosphamide revealed by immune profiling and machine learning

The key immunologic signatures associated with clinical outcomes after posttransplant cyclophosphamide (PTCy)-based HLA-haploidentical (haplo) and HLA-matched bone marrow transplantation (BMT) are largely unknown. To address this gap in knowledge, we used machine learning to decipher clinically relevant signatures from immunophenotypic, proteomic, and clinical data and then examined transcriptome changes in the lymphocyte subsets that predicted major posttransplant outcomes. Kinetics of immune subset reconstitution after day 28 were similar for 70 patients undergoing haplo and 75 patients undergoing HLA-matched BMT. Machine learning based on 35 candidate factors (10 clinical, 18 cellular, and 7 proteomic) revealed that combined elevations in effector CD4+ conventional T cells (Tconv) and CXCL9 at day 28 predicted acute graft-versus-host disease (aGVHD). Furthermore, higher NK cell counts predicted improved overall survival (OS) due to a reduction in both nonrelapse mortality and relapse. Transcriptional and flow-cytometric analyses of recovering lymphocytes in patients with aGVHD identified preserved hallmarks of functional CD4+ regulatory T cells (Tregs) while highlighting a Tconv-driven inflammatory and metabolic axis distinct from that seen with conventional GVHD prophylaxis. Patients developing early relapse displayed a loss of inflammatory gene signatures in NK cells and a transcriptional exhaustion phenotype in CD8+ T cells. Using a multimodality approach, we highlight the utility of systems biology in BMT biomarker discovery and offer a novel understanding of how PTCy influences alloimmune responses. Our work charts future directions for novel therapeutic interventions after these increasingly used GVHD prophylaxis platforms. Specimens collected on NCT0079656226 and NCT0080927627 https://clinicaltrials.gov/.

Correlation between carotid bifurcation calcium burden on non-enhanced CT and percentage stenosis, as confirmed by digital subtraction angiography

OBJECTIVES

Previous evidence supports a direct relationship between the calcium burden (volume) on post-contrast CT with the percent internal carotid artery (ICA) stenosis at the carotid bifurcation. We sought to further investigate this relationship by comparing non-enhanced CT (NECT) and digital subtraction angiography (DSA).

METHODS

50 patients (aged 41-82 years) were retrospectively identified who had undergone cervical NECT and DSA. A 64-multidetector array CT (MDCT) scanner was utilised and the images reviewed using preset window widths/levels (30/300) optimised to calcium, with the volumes measured via three-dimensional reconstructive software. Stenosis measurements were performed on DSA and luminal diameter stenoses >40% were considered "significant". Volume thresholds of 0.01, 0.03, 0.06, 0.09 and 0.12 cm(3) were utilised and Pearson'S correlation coefficient (r) was calculated to correlate the calcium volume with percent stenosis.

RESULTS

Of 100 carotid bifurcations, 88 were available and of these 7 were significantly stenotic. The NECT calcium volume moderately correlated with percent stenosis on DSA r=0.53 (p<0.01). A moderate-strong correlation was found between the square root of calcium volume on NECT with percent stenosis on DSA (r=0.60, p<0.01). Via a receiver operating characteristic curve, 0.06 cm(3) was determined to be the best threshold (sensitivity 100%, specificity 90.1%, negative predictive value 100% and positive predictive value 46.7%) for detecting significant stenoses.

CONCLUSION

This preliminary investigation confirms a correlation between carotid bifurcation calcium volume and percent ICA stenosis and is promising for the optimal threshold for stenosis detection. Future studies could utilise calcium volumes to create a "score" that could predict high grade stenosis.

Linking psychosocial stressors and childhood obesity

Research has established a wide array of genetic and environmental factors that are associated with childhood obesity. The focus of this review is on recent work that has established the relationship between one set of environmental factors, stressors and childhood obesity. These stressors are particularly prevalent for low-income children, a demographic group that has high rates of obesity in the USA and other developed countries. In this review, we begin by summarizing the psychosocial stressors faced by children followed by health outcomes associated with exposure to these stressors documented in the literature. We then summarize 11 articles which examined the connection between psychosocial stressors in the household and obesity and eight articles which examined the connection between individual psychosocial stressors and obesity. Policy recommendations emerging from this research include recognizing reductions in childhood obesity as a potential added benefit of social safety net programmes that reduce financial stress among families. In addition, policies and programmes geared towards childhood obesity prevention should focus on helping children build resources and capacities to teach them how to cope effectively with stressor exposure. We conclude with suggestions for future research.

Confirmation of T1-bright vein of Galen aneurysm spontaneous thrombosis by subtraction magnetic resonance venography: a case report

Spontaneous thrombosis of a vein of Galen aneurysmal malformation (VOGM) is rare. We describe a 2-month-old patient with a patent VOGM and hydrocephalus, also confirmed patent at 6 months, but with subsequent lack of filling on preembolization catheter digital subtraction angiography (DSA) at 9 months' age. Due to the presence of T1- and T2-bright signal, noncontrast T1-weighted images (T1WI), T2-weighted images (T2WI), two-dimensional (2D) time-of-flight (TOF) magnetic resonance venography (MRV), and postcontrast T1WI were ambiguous for patency. However, subtracting the pre- from the postcontrast MRV images confirmed closure compared to subtracted images at 6 months' age. The factors contributing to thrombosis were likely a combination of a disproportionately small straight sinus, ventriculostomy, and contrast medium from DSA.

Syndrome of megalencephaly, polydactyly, and polymicrogyria lacking frank hydrocephalus, with associated MR imaging findings

Megalencephaly, polymicrogyria, polydactyly, and hydrocephalus (MPPH) syndrome has been recently recognized and is very rare. Each case reported so far has demonstrated hydrocephalus to varying degrees. We report an infant with MPPH syndrome, but lacking frank hydrocephalus. The additional finding of an abnormally elongated pituitary infundibulum has not been described in this syndrome and, along with the presence of a regressing cystic cavum septum pellucidum, suggests that chronic underlying hydrocephalus may have been present.

Nasal immunization of nonhuman primates with simian immunodeficiency virus p55gag and cholera toxin adjuvant induces Th1/Th2 help for virus-specific immune responses in reproductive tissues

Female rhesus macaques were nasally immunized with p55gag (p55) of SIV and cholera toxin as a mucosal adjuvant. Nasal immunization induced Ag-specific IgA and IgG Abs in mucosal secretions (e.g., cervicovaginal secretions, rectal washes, and saliva) and serum. Furthermore, high numbers of p55-specific IgA and IgG Ab-forming cells were induced in mucosal effector sites, i.e., uterine cervix, intestinal lamina propria, and nasal passage. p55-specific CD4+ T cells in both systemic and mucosal compartments expressed IFN-gamma and IL-2 (Th1-type)- as well as IL-5, IL-6, and IL-10 (Th2-type)-specific mRNA. Moreover, p55-specific CTL activity was demonstrated in lymphocytes from blood, tonsils, and other lymphoid tissues. These results show that nasal immunization with SIV p55 with cholera toxin elicits both Th1- and selective Th2-type cytokine responses associated with the induction of SIV-specific mucosal and serum Abs, and CTL activity. These results offer a promise for the development of protective mucosal immunity to SIV.

Reduced virus load in rhesus macaques immunized with recombinant gp160 and challenged with simian immunodeficiency virus

As a safe alternative to inactivated and live-attenuated whole-virus SIV vaccines, we have evaluated the potential of SIVmac239 gp160 expressed by recombinant vaccinia virus (vSIVgp160) and baculovirus (bSIVgp160) to protectively immunize rhesus macaques against intravenous (i.v.) infection with pathogenic SIVmac isolates. Macaques were immunized with live vSIVgp160 and/or bSIVgp160 protein partially purified from insect cells. The challenge viruses, propagated in rhesus peripheral blood mononuclear cells, consisted of the molecular clone SIVmac239 and another genetically similar, uncloned isolate, SIVmac251. Although antibodies that bind gp130 were induced in all animals following immunization with SIVgp160, neutralizing antibodies were undetectable 1 week prior to virus challenge. These results differ from those for macaques vaccinated with inactivated, whole SIV. All animals became infected after i.v. inoculation with 1-10 AID50 of either challenge virus. For animals challenged with SIVmac251, but not those challenged with SIVmac239, the cell-free infectious virus load in plasma of vSIVgp160-primed, bSIVgp160-boosted macaques was significantly lower than in unimmunized controls at 2 weeks postchallenge. Virus virulence, immunization regimen, and challenge with homologous or heterologous virus are factors critical to the outcome of the study. Immunization with surface glycoprotein may not necessarily provide protective immunity against infection but may reduce virus load. The relationship between reduction in virus load by vaccination and delay in onset of disease remains to be determined.

Immunization with a live, attenuated simian immunodeficiency virus (SIV) prevents early disease but not infection in rhesus macaques challenged with pathogenic SIV

An infectious, virulence-attenuated molecular clone of simian immunodeficiency virus (SIV), SIVMAC-1A11, was derived from an SIV isolate that causes fatal immunodeficiency in rhesus macaques. When inoculated intravenously in rhesus macaques, SIVMAC-1A11 induced transient viremia (1 to 6 weeks) without clinical disease and a persistent humoral antibody response. The antibodies were directed mainly against the viral envelope glycoproteins, as determined by immunoblots and virus neutralization. The potential of this virulence-attenuated virus to protect against intravenous challenge with a pathogenic SIVMAC strain was assessed. Five rhesus macaques were each given two intravenous inoculations with SIVMAC-1A11 7 months apart. Three of the five immunized monkeys and four naive control animals were then challenged with 100 to 1,000 100% animal infectious doses of pathogenic SIVMAC. All seven animals became persistently viremic following the challenge. Four of four unimmunized animals developed severe clinical signs of simian acquired immunodeficiency syndrome by 38 to 227 days after challenge and were euthanatized 91 to 260 days postchallenge. However, no signs of illness were seen in immunized monkeys until 267 to 304 days postchallenge, when two of three immunized animals developed mild thrombocytopenia and lymphopenia; one of these animals died with clinical signs of simian immunodeficiency disease at 445 days after challenge. The two SIVMAC-1A11-immunized monkeys that were not challenged were healthy and antibody positive 22 months after the initial immunization. Thus, although live SIVMAC-1A11 was immunogenic and did not induce any disease, it failed to protect rhesus macaques against infection with a moderately high dose of pathogenic virus. However, immunization prevented severe, early disease and prolonged the lives of monkeys subsequently infected with pathogenic SIV.