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1.
Bioorg Med Chem ; 113: 117926, 2024 Sep 13.
Article in English | MEDLINE | ID: mdl-39306973

ABSTRACT

Amyloid beta peptide (Aß) and hyperphosphorylated neuronal tau proteins accumulate in neurofibrillary tangles in Alzheimer's disease (AD), a chronic neurodegenerative illness. Chronic inflammation in the brain, which promotes disease progression, is another feature of the Alzheimer's disease pathogenesis. Approximately 60-70 % of dementia cases are caused by AD. The development of effective therapies for the treatment of AD is urgently needed given the severity of the condition and its rapidly rising prevalence. Cholinesterase inhibitors, beta-amyloid (A-beta), tau inhibitors, and many other medications are currently used as preventive medicine for AD. These medications can temporarily suppress dementia symptoms but cannot halt or reverse the disease's progression. Many international pharmaceutical companies have tried numerous times to develop an amyloid clearing medication based on the amyloid hypothesis, but without success. Therefore, the amyloid theory may not be entirely plausible. This review mainly covers the recent and important reported pharmacophores as the starting point to discuss already known targets like tau, butyrylcholinesterase, amyloid beta, and acetylcholinesterase and covers the literature between years 2019-2024.

2.
Eur Heart J Imaging Methods Pract ; 2(1): qyae046, 2024 Jan.
Article in English | MEDLINE | ID: mdl-39224093

ABSTRACT

Aims: Underlying mechanisms responsible for acute coronary syndrome (ACS) in young patients compared with older counterparts are yet to be explored with optical coherence tomography (OCT). This study aims to explore underlying mechanisms of ACS in ≤35- (very young) and >35-year-old (older counterparts) ACS patients using OCT. Methods and results: This was a prospective, single-centre, investigational study. Patients were divided into groups according to age (≤35 and >35 years) and further subdivided according to the underlying mechanism i.e. plaque rupture (PR) and plaque erosion (PE). A total of 93 patients were analysed. Thin-cap fibroatheroma (TCFA) was significantly higher among older counterparts than very young patients for both PR (80.0% vs. 31.8%, P = 0.002) and PE (66.7% vs. 6.3%, P < 0.001) groups. Microchannels were also significantly more prevalent among older than very young patients for both PR (65.0% vs. 18.2%, P = 0.004) and PE groups (55.6% vs.12.5%, P = 0.013). Macrophages were significantly higher in older than very young patients for both PR (25.0% vs. 0%, P = 0.018) and PE (44.4% vs. 0%, P = 0.003) groups. In contrast, fibrous cap thickness was greater in very young than older patients for both PR (105.71 ± 48.02 vs. 58.00 ± 15.76 µm, P < 0.001) and PE (126.67 ± 48.22 vs. 54.38 ± 24.21 µm, P < 0.001) groups. Intimal thickness was greater in older than very young patients for both PR (728.00 ± 313.92 vs. 342.27 ± 142.02 µm, P < 0.001) and PE (672.78 ± 334.57 vs. 295.00 ± 99.60 µm, P < 0.001) groups. Conclusion: Frequency of TCFA, microchannels, macrophages, and intimal thickness was significantly higher in older ACS patients compared with very young patients. However, fibrous cap thickness was significantly greater in very young ACS patients compared with older patients.

3.
Open Forum Infect Dis ; 11(8): ofae457, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39205925

ABSTRACT

M1UK is associated with current surges in invasive infection globally, partly due to increased production of superantigen streptococcal pyrogenic exotoxin A. We show that M1UK is now the dominant invasive emm1 lineage in Aotearoa New Zealand and is genomically related to community infections, suggesting that measures that effectively prevent group A Streptococcus pharyngitis in children could reduce invasive disease.

4.
iScience ; 27(8): 110558, 2024 Aug 16.
Article in English | MEDLINE | ID: mdl-39184444

ABSTRACT

Understanding the immune profile of acute rheumatic fever (ARF), a serious post-infectious sequelae of Streptococcal pyogenes (group A Streptococcus [GAS]), could inform disease pathogenesis and management. Circulating cytokines, immunoglobulins, and complement were analyzed in participants with first-episode ARF, swab-positive GAS pharyngitis and matched healthy controls. A striking elevation of total IgG3 was observed in ARF (90% > clinical reference range for normal). ARF was also associated with an inflammatory triad with significant correlations between interleukin-6, C-reactive protein, and complement C4 absent in controls. Quantification of GAS-specific antibody responses revealed that subclass polarization was remarkably consistent across the disease spectrum; conserved protein antigens polarized to IgG1, while M-protein responses polarized to IgG3 in all groups. However, the magnitude of responses was significantly higher in ARF. Taken together, these findings emphasize the association of exaggerated GAS antibody responses, IgG3, and inflammatory cytokines in ARF and suggest IgG3 testing could beneficially augment clinical diagnosis.

5.
J Clin Neurosci ; 128: 110779, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39142038

ABSTRACT

Hyperventilation-induced intracranial pressure reduction might be impaired in cerebral venous thrombosis (CVT) patients. Using transcranial Doppler, we assessed carbon dioxide-vasomotor reactivity (CO2-VMR) within 24 hours of admission in CVT patients and studied its correlation with patient outcomes. Adult moderate-severe CVT patients (participants of another large observational study) were included. CO2-VMR was calculated as the percentage change in peak flow velocities during maximal hypercapnia and hypocapnia. Outcome was assessed with the modified Rankin scale (mRS) at one - month post-discharge, dichotomized into favourable (mRS≤2) and unfavourable (mRS>2). Twenty patients' data was analysed. Impaired CO2-VMR (<70 %) was observed in 13 patients in the affected hemisphere; among them, 10 had impairments in both hemispheres. CO2-VMR correlated negatively with mRS (Rho = -0.688, p = 0.001). Odds for unfavourable outcomes were reduced by 92 % in patients with intact VMR on the ipsilateral hemisphere (Odds ratio (OR) 0.08, Confidence interval (CI) 0.006---0.636, p = 0.027) and by 94 % with VMR intact on the contralateral hemisphere (OR 0.063, CI 0.003---0.569, p = 0.03). Thus, impaired CO2-VMR in moderate to severe CVT patients is associated with unfavourable outcomes, and has the potential to prognosticate CVT patients objectively.


Subject(s)
Carbon Dioxide , Intracranial Thrombosis , Ultrasonography, Doppler, Transcranial , Humans , Male , Female , Ultrasonography, Doppler, Transcranial/methods , Adult , Middle Aged , Intracranial Thrombosis/diagnostic imaging , Intracranial Thrombosis/physiopathology , Prospective Studies , Prognosis , Venous Thrombosis/diagnostic imaging , Venous Thrombosis/physiopathology , Cerebrovascular Circulation/physiology , Aged , Blood Flow Velocity/physiology
7.
Indian J Ophthalmol ; 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38990622

ABSTRACT

CONTEXT: Effect of serum ferritin on severity of coronavirus disease 2019 (COVID-19)-associated rhino-orbito-cerebral mucormycosis. PURPOSE: To study the association between increased serum ferritin and severity of orbital disease in COVID-19-associated rhino-orbito-cerebral mucormycosis. SETTINGS AND DESIGN: A cross-sectional study. METHODS: Hundred (n) out of 155 treatment-naive patients of COVID-19 infection presenting with the signs and symptoms of rhino-orbito-cerebral mucormycosis were enrolled in study. Based on the classification proposed by Honavar, the study patients were classified into four stages: Stage 1: involvement of the nasal mucosa (n = 11), Stage 2: involvement of paranasal sinuses (n = 14), Stage 3: involvement of the orbit (n = 37), Stage 4: involvement of the central nervous system (n = 38). Stage 3 was further divided into four substages: 3a: nasolacrimal duct, medial orbit, vision unaffected (n = 4); 3b: diffuse orbital involvement (>1 quadrant or >2 structures), vision unaffected (n = 15); 3c: central retinal artery occlusion or ophthalmic artery occlusion, superior ophthalmic vein thrombosis, involvement of superior orbital fissure, inferior orbital fissure, orbital apex, diminution or loss of vision (n = 13); 3d: bilateral orbital involvement (n = 5). Fasting blood sugar (FBS), postprandial blood sugar (PPBS), and inflammatory markers (serum ferritin, interleukin-6, C-reactive protein, and D-dimer) were assessed. Serum level of ferritin was analyzed by using chemiluminescence immunoassay method. RESULTS: Mean FBS (mg/dl) was 165.03 ± 70.43 for stage 1, 185.67 ± 64.82 for stage 2, 159.05 ± 68.60 for stage 3, and 158.20 ± 62.05 for stage 4. Mean PPBS (mg/dl) was 238.70 ± 141.29 for stage 1, 252 ± 103.69 for stage 2, 257.09 ± 103.48 for stage 3, and 229.53 ± 76.81 for stage 4. Mean serum ferritin (µg/l) was 302.67 ± 266.95 in stage 1, 444.19 ± 116.36 in stage 2, 504.85 ± 205.99 in stage 3, and 825.95 ± 777.30 in stage 4. A statistically significant increase in serum ferritin levels with severity of disease (P = 0.005) was noted. Similar trend was observed in substages of stage 3. Pearson correlation analysis showed a positive correlation between serum ferritin and severity of disease (P = 0.0007). CONCLUSION: Increased serum ferritin was significantly independently associated with severity of orbital disease in COVID-19-associated rhino-orbito-cerebral mucormycosis.

8.
Pediatr Neurol ; 156: 162-169, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38788278

ABSTRACT

BACKGROUND: Guillain-Barré syndrome (GBS) is an autoimmune disorder characterized by demyelination of peripheral nerves. GBS-associated posterior reversible encephalopathy syndrome (PRES) is a rare and potentially life-threatening complication in the pediatric population. We aimed to report and analyze the clinical features, management, and outcomes of three cases of GBS-associated PRES in our setting in the light of the existing literature. METHODS: Medical records of 75 pediatric patients with GBS were reviewed for autonomic changes and GBS-associated PRES. Thirty-one developed dysautonomia while three were identified to have PRES. Clinical, radiological, laboratory, and treatment data were collected and analyzed. RESULTS: All three patients were male and presented with symptoms of acute flaccid paralysis and respiratory distress requiring mechanical ventilation. All three patients experienced various complications, including hypertension, seizures, and hyponatremia, and were subsequently diagnosed with PRES. Multimodal intensive care resulted in patient improvement and discharge in an ambulatory state after an average of 104 days of care. CONCLUSIONS: GBS-associated PRES is a rare and potentially life-threatening complication that can occur in pediatric patients with GBS. Our findings suggest that early recognition, prompt intervention, and multimodal intensive care can improve patient outcomes. Further studies are needed to determine optimal treatment strategies for GBS-associated PRES.


Subject(s)
Guillain-Barre Syndrome , Posterior Leukoencephalopathy Syndrome , Humans , Guillain-Barre Syndrome/therapy , Guillain-Barre Syndrome/complications , Guillain-Barre Syndrome/physiopathology , Male , Posterior Leukoencephalopathy Syndrome/etiology , Posterior Leukoencephalopathy Syndrome/diagnostic imaging , Posterior Leukoencephalopathy Syndrome/therapy , Posterior Leukoencephalopathy Syndrome/physiopathology , Child , Adolescent , Child, Preschool
9.
Neurol India ; 72(2): 379-383, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38817174

ABSTRACT

Guillain-Barré syndrome is the most common cause of acute flaccid paralysis in children, but several diseases mimic GBS. We aimed to identify and report the clinical pointers and battery of tests required to differentiate Guillain-Barré syndrome from its observed mimics in the pediatric population admitted to our neuro-critical care unit. We conducted a retrospective record analysis of all pediatric patients admitted over ten years from 2008-2018, whose initial presentation was compatible with a clinical diagnosis of GBS. Eighty-three patients were at first treated as GBS, of which seven (8.4%) were found to have an alternate diagnosis-three cases of paralytic rabies, one case each of acute disseminated encephalomyelitis, cervical myeloradiculopathy, neuromyelitis optica, and a case of community-acquired Staphylococcus aureus pneumonia associated sepsis. Neurophysiological and neuro-virological testing, central nervous system imaging, and sepsis screening helped to confirm the alternate diagnosis. Our case series provides knowledge of subtle clinical differences along with the mindful use of diagnostic testing to facilitate the accurate diagnosis of GBS mimics.


Subject(s)
Guillain-Barre Syndrome , Tertiary Care Centers , Humans , Guillain-Barre Syndrome/diagnosis , Guillain-Barre Syndrome/physiopathology , Child , Retrospective Studies , Female , Male , Diagnosis, Differential , Child, Preschool , Adolescent , Intensive Care Units , Infant , Encephalomyelitis, Acute Disseminated/diagnosis
10.
J Oral Maxillofac Pathol ; 28(1): 96-99, 2024.
Article in English | MEDLINE | ID: mdl-38800416

ABSTRACT

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the most common genetic disorders affecting approximately 400 million people worldwide. Several recent studies have reported a relationship between G6PD deficiency and the incidence of diabetes. Objectives: The aim of the present study was to evaluate and compare levels of G6PD deficiency in diabetes mellitus patients. Materials and Methods: G6PD activity and fasting glucose levels were measured in blood samples of 49 diabetic patients and 21 healthy controls. Results: G6PD activity was decreased in patients with diabetes mellitus as compared to healthy controls and showed that overall G6PD deficiency was significantly associated with diabetes mellitus as compared to nondiabetics. Conclusion: The study concluded that G6PD deficiency is noted in diabetics than in nondiabetics and can be a biomarker of oxidative stress and poor glycemic control in diabetes mellitus.

11.
J Neurosci Rural Pract ; 15(2): 384-386, 2024.
Article in English | MEDLINE | ID: mdl-38746525

ABSTRACT

Lesions at the cerebellopontine angle (CP angle) are associated with various brain-heart interactions, which can include those from stimulation of the fifth cranial nerve along the scalp incision in a retrosigmoid suboccipital surgical approach. A 27-year-old male patient with recently diagnosed hypertension (on calcium channel blocker) underwent left CP angle lesion decompression. Transient episodes of bradycardia, hypotension, and bradypnea were observed from the skin incision onward, exacerbated during tumor manipulation. Most episodes subsided with cessation of the surgical stimulus while some required intervention. Postoperatively, blood pressure decreased below the pre-operative levels. Thus, trigeminocardiac reflex can occur as early as the skin incision even in a retrosigmoid approach due to stimulation of the mandibular division, when specific risk factors exist. Such episodes may serve as early warning signs for subsequent intraoperative occurrences. Brainstem compression can be a possible etiology of hypertension in young patients. It underscores the importance of considering brain-heart interactions in surgical interventions involving the CP angle.

13.
Cureus ; 16(2): e53898, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38465139

ABSTRACT

Spinal muscular atrophy (SMA) indicates a set of inherited autosomal recessive genetic disorders, where, specifically, the anterior horn cell motor neurons in the brain and spinal cord are affected, leading to a severe form of hypotonia and muscle weakness. The incidence is exceptionally rare, commonly manifesting as slowly progressive muscular weakness and atrophy of lower limbs. As per our existing knowledge, this is the first case of SMA associated with hyperlordosis in a patient. Hyperlordosis is a deformity in spinal curvature characterized by an excessive forward spinal curve in the region of the lower back, forming the characteristic C-shape curvature in the lumbar region, just above the buttocks. Parents brought an 11-year-old male child with complaints of inability to get up from a sitting position along with difficulty in walking for the past six months. Upon physical examination, deep tendon reflexes were absent; there was severe hyperlordosis, proximal limb weakness, and notable hypotonia. In our study, we aim to understand the clinical presentation, impact, and association of hyperlordosis in a child diagnosed with SMA. This case report describes the complaints and successful diagnosis of a patient of survivor motor neuron (SMN) gene-related SMA along with severe hyperlordosis backed by evidences of electrophysiology and neuropathology. However, a complete cure and normal lifestyle are not possible due to the lack of affordable and easily accessible therapies.

14.
Cureus ; 16(2): e53722, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38455824

ABSTRACT

Mobility has been characterized as the capacity to move across an environment safely, pleasantly, elegantly, and autonomously. India's current population is 1.4 billion, out of which 2.3%, i.e., 32 million people, are suffering from some kind of disability. With the rise in the geriatric population, the incidence of non-communicable and communicable diseases also rises and presents the risk of disorders that may progress to disability. People often neglect their disability and learn to live with it, even when most of them can use rehabilitation programs in conjunction with various mobility aids. Affordable access to adequate healthcare and assistive devices is limited, contributing to the challenges faced by disabled adults. Despite the potential for many disabled individuals to engage in productive work, their employment rates remain significantly lower. Mobility aids can provide significant benefits to individuals affected by a range of medical conditions, including arthritis, cerebral palsy, developmental disabilities, diabetic ulcers and wounds, fractures or broken bones, injuries, and walking impairments resulting from brain injury or stroke. Each person is different and may require help in a certain way for their disability, so choosing the most appropriate aid is crucial for the individual's well-being. Commonly used mobility aids are canes, walking sticks, walkers, and wheelchairs, with prostheses being used less commonly. With the advent of techniques such as state-of-the-art 3D printing and challenging surgeries, various Indian tech companies, along with non-governmental organizations (NGOs), have brought about many significant changes in the world of prosthesis by making it better, affordable, and accessible.

15.
Int J Gynaecol Obstet ; 166(2): 617-625, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38343269

ABSTRACT

Postpartum depression (PPD), as a common condition occurring in women in the postnatal period, is underdiagnosed, seldom identified, and infrequently treated. Undiagnosed PPD can have negative consequences for overall quality-of-life outcomes in the mother, psychological growth of the infant, and bonding between the infant and its mother. However, early diagnosis and prompt treatment of PPD can lead to an improvement in postpartum maternal health and a healthier relationship between the mother and her infant. Additionally, early identification of risk factors in the prenatal and antenatal period can enable preventive treatment and ensure that the expectant or pregnant woman remains free of disease after giving birth. Therefore, we propose a protocol for the risk assessment, screening, diagnosis, assessment, and therapy of postnatal depression (RASDAT). The RASDAT protocol recommends assessment of risk factors for PPD in the perinatal period as well as early diagnosis and treatment in the early-to-mid postpartum period. It also recognizes, for the first time, insomnia and anxiety as important predictors, comorbidities, and poor prognostic factors in postpartum depression. Further studies are necessary to determine the feasibility and applicability of this novel tool, including costs of availing health facilities, burden on the health system, and knowledge, attitudes, and practices among physicians and clinical pharmacists regarding PPD and its resolution.


Subject(s)
Depression, Postpartum , Humans , Female , Depression, Postpartum/diagnosis , Depression, Postpartum/therapy , Risk Assessment , Risk Factors , Pregnancy , Mass Screening/methods , Quality of Life , Early Diagnosis , Anxiety/diagnosis , Anxiety/therapy
16.
Nat Commun ; 15(1): 1399, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38360692

ABSTRACT

Despite their highly anisotropic complex-oxidic nature, certain delafossite compounds (e.g., PdCoO2, PtCoO2) are the most conductive oxides known, for reasons that remain poorly understood. Their room-temperature conductivity can exceed that of Au, while their low-temperature electronic mean-free-paths reach an astonishing 20 µm. It is widely accepted that these materials must be ultrapure to achieve this, although the methods for their growth (which produce only small crystals) are not typically capable of such. Here, we report a different approach to PdCoO2 crystal growth, using chemical vapor transport methods to achieve order-of-magnitude gains in size, the highest structural qualities yet reported, and record residual resistivity ratios ( > 440). Nevertheless, detailed mass spectrometry measurements on these materials reveal that they are not ultrapure in a general sense, typically harboring 100s-of-parts-per-million impurity levels. Through quantitative crystal-chemical analyses, we resolve this apparent dichotomy, showing that the vast majority of impurities are forced to reside in the Co-O octahedral layers, leaving the conductive Pd sheets highly pure (∼1 ppm impurity concentrations). These purities are shown to be in quantitative agreement with measured residual resistivities. We thus conclude that a sublattice purification mechanism is essential to the ultrahigh low-temperature conductivity and mean-free-path of metallic delafossites.

17.
Clin Case Rep ; 11(10): e8022, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37841884

ABSTRACT

Key Clinical Message: Embolic stroke may rarely be the first presenting symptom of atrial myxoma. Multiple infarcts should be evaluated for embolic causes. Correct etiological diagnosis in cardio-embolic stroke guides proper management strategy. It reinforces on the importance of early echocardiogram in the initial evaluation of patients presenting with ischemic stroke. Abstract: Atrial myxoma is a benign cardiac tumor found most commonly in the left atrium in 80% of the cases. Almost 1 in 10 myxomas are familial and are most common in women. Cardiac myxoma mostly present with dyspnea, fatigue, or palpitations. Previously undiagnosed left atrial myxoma (LA) presenting as stroke is extremely rare. Authors describe the case of a middle-aged man with LA myxoma presenting with acute ischemic embolic stroke that was surgically excised. This case report emphasizes on the rare presentation as embolic stroke and the role of cardiac imaging in patients presenting with ischemic stroke. Early and coordinated teamwork among the neurologist, cardiologist, and cardiothoracic surgeon help establish the etiology and provide appropriate treatment.

18.
Mol Biol Rep ; 50(11): 9191-9202, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37776411

ABSTRACT

BACKGROUND: Wheat is a major staple crop and helps to reduce worldwide micronutrient deficiency. Investigating the genetics that control the concentrations of iron (Fe) and zinc (Zn) in wheat is crucial. Hence, we undertook a comprehensive study aimed at elucidating the genomic regions linked to the contents of Fe and Zn in the grain. METHODS AND RESULTS: We performed the multi-locus genome-wide association (ML-GWAS) using a panel of 161 wheat-Aegilops substitution and addition lines to dissect the genomic regions controlling grain iron (GFeC), and grain zinc (GZnC) contents. The wheat panel was genotyped using 10,825 high-quality SNPs and phenotyped in three different environments (E1-E3) during 2017-2019. A total of 111 marker-trait associations (MTAs) (at p-value < 0.001) were detected that belong to all three sub-genomes of wheat. The highest number of MTAs were identified for GFeC (58), followed by GZnC (44) and yield (9). Further, six stable MTAs were identified for these three traits and also two pleiotropic MTAs were identified for GFeC and GZnC. A total of 1291 putative candidate genes (CGs) were also identified for all three traits. These CGs encode a diverse set of proteins, including heavy metal-associated (HMA), bZIP family protein, AP2/ERF, and protein previously associated with GFeC, GZnC, and grain yield. CONCLUSIONS: The significant MTAs and CGs pinpointed in this current study are poised to play a pivotal role in enhancing both the nutritional quality and yield of wheat, utilizing marker-assisted selection (MAS) techniques.


Subject(s)
Aegilops , Iron , Iron/metabolism , Genome-Wide Association Study , Zinc/metabolism , Triticum/genetics , Triticum/metabolism , Aegilops/genetics , Aegilops/metabolism , Genome, Plant , Edible Grain/genetics
19.
mSphere ; 8(5): e0017923, 2023 10 24.
Article in English | MEDLINE | ID: mdl-37729548

ABSTRACT

Group A Streptococcus (GAS) is a leading human pathogen for which there is no licensed vaccine. Infections are most common in young children and the elderly suggesting immunity accumulates with exposure until immune senescence in older age. Though protection has been postulated to be strain type specific, based on the M-protein (emm-type), the antigenic basis of population-level immunity remains poorly understood. Naturally acquired GAS antibody responses were investigated using intravenous immunoglobulin (IVIG), which contains pooled immunoglobulins from thousands of healthy human donors, as a surrogate for population immunity. Functional opsonophagocytic killing assays were conducted with GAS strains (n = 6) representing the three major emm-pattern types (emm12, A-C pattern; emm53, D-pattern; and emm75, E-pattern). While IVIG induced opsonophagocytic killing of all GAS strains tested, specificity assays showed the profile of protective antibodies differed considerably between emm-types. Antibodies targeting the M-protein were a major component of the functional IVIG antibody response for emm12 and emm53 strains but not for emm75 strains. The striking differences in the contribution of M-protein specific antibodies to killing suggest naturally acquired immunity differs between strains from the major emm-patterns. This challenges the dogma that M-protein is the primary protective antigen across all GAS straintypes. IMPORTANCE Group A Streptococcus (GAS) is a globally important pathogen. With the surge of invasive GAS infections that have occurred in multiple countries, contemporaneous with the relaxation of COVID-19 pandemic restrictions, there is increased interest in the mechanisms underpinning GAS immunity. We utilized intravenous immunoglobulin (IVIG), pooled immunoglobulins from thousands of healthy donors, as a surrogate for population-level immunity to GAS, and explored the contribution of strain-specific (M-type specific) antibodies to GAS immunity using functional killing assays. This revealed striking differences between major strain types as to the contribution of strain specific antibodies to killing. For GAS strains belonging to the E pattern group, M-type specific antibodies do not mediate killing and immunity, which contrasts with strains belonging to pattern A-C and D groups. This challenges the historical dogma, originally proposed by Rebecca Lancefield in the 1950-1960s, that the M-protein is the major protective antigen across all GAS strain types.


Subject(s)
Antigens, Bacterial , Immunoglobulins, Intravenous , Child , Humans , Child, Preschool , Aged , Antibody Formation , Pandemics , Streptococcus pyogenes
20.
Dis Model Mech ; 16(10)2023 10 01.
Article in English | MEDLINE | ID: mdl-37718909

ABSTRACT

Sezary syndrome (SS) is a rare, aggressive leukemic variant of cutaneous T-cell lymphoma (CTCL) that lacks adequate therapeutic options and representative small-animal models. Here, we demonstrate that IL-15 is a critical CTCL growth factor. Importantly, an immunodeficient knock-in mouse model genetically engineered to express human IL-15 uniquely supported the growth of SS patient samples relative to conventional immunodeficient mouse strains. SS patient-derived xenograft (PDX) models recapacitated key pathological features of the human disease, including skin infiltration and spread of leukemic cells to the periphery, and maintained the dependence on human IL-15 upon serial in vivo passaging. Detailed molecular characterization of the engrafted cells by single-cell transcriptomic analysis revealed congruent neoplastic gene expression signatures but distinct clonal engraftment patterns. Overall, we document an important dependence of Sezary cell survival and proliferation on IL-15 signaling and the utility of immunodeficient humanized IL-15 mice as hosts for SS - and potentially other T and NK cell-derived hematologic malignancies - PDX model generation. Furthermore, these studies advocate the thorough molecular understanding of the resultant PDX models to maximize their translational impact.


Subject(s)
Lymphoma, T-Cell, Cutaneous , Sezary Syndrome , Skin Neoplasms , Humans , Animals , Mice , Skin Neoplasms/metabolism , Interleukin-15 , Lymphoma, T-Cell, Cutaneous/pathology , Sezary Syndrome/metabolism , Sezary Syndrome/pathology , Lymphocytes/metabolism , Tumor Microenvironment
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