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1.
Pathologe ; 42(Suppl 1): 89-97, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1971686

ABSTRACT

BACKGROUND: A dysregulated immune response is considered one of the major factors leading to severe COVID-19. Previously described mechanisms include the development of a cytokine storm, missing immunoglobulin class switch, antibody-mediated enhancement, and aberrant antigen presentation. OBJECTIVES: To understand the heterogeneity of immune response in COVID-19, a thorough investigation of histomorphological patterns in regional lymph nodes was performed. MATERIALS AND METHODS: Lymph nodes from the cervical, mediastinal, and hilar regions were extracted from autopsies of patients with lethal COVID-19 (n = 20). Histomorphological characteristics, SARS-CoV­2 qRT-PCR, and gene expression profiling on common genes involved in immunologic response were analyzed. RESULTS: Lymph nodes displayed moderate to severe capillary stasis and edema, an increased presence of extrafollicular plasmablasts, mild to moderate plasmacytosis, a dominant population of CD8+ T­cells, and CD11c/CD68+ histiocytosis with hemophagocytic activity. Out of 20 cases, 18 presented with hypoplastic or missing germinal centers with a decrease of follicular dendritic cells and follicular T­helper cells. A positive viral load was detected by qRT-PCR in 14 of 20 cases, yet immunohistochemistry for SARS-CoV-2 N-antigen revealed positivity in sinus histiocytes of only one case. Gene expression analysis revealed an increased expression of STAT1, CD163, granzyme B, CD8A, MZB1, and PAK1, as well as CXCL9. CONCLUSIONS: Taken together, our findings imply a dysregulated immune response in lethal COVID-19. The absence/hypoplasia of germinal centers and increased presence of plasmablasts implies a transient B­cell response, implying an impaired development of long-term immunity against SARS-CoV­2 in such occasions.


Subject(s)
COVID-19 , CD8-Positive T-Lymphocytes , Humans , Lung , Lymph Nodes , SARS-CoV-2
2.
Viruses ; 12(1)2020 01 20.
Article in English | MEDLINE | ID: covidwho-1969491

ABSTRACT

Middle East respiratory syndrome (MERS) is an acute, high-mortality-rate, severe infectious disease caused by an emerging MERS coronavirus (MERS-CoV) that causes severe respiratory diseases. The continuous spread and great pandemic potential of MERS-CoV make it necessarily important to develop effective vaccines. We previously demonstrated that the application of Gram-positive enhancer matrix (GEM) particles as a bacterial vector displaying the MERS-CoV receptor-binding domain (RBD) is a very promising MERS vaccine candidate that is capable of producing potential neutralization antibodies. We have also used the rabies virus (RV) as a viral vector to design a recombinant vaccine by expressing the MERS-CoV S1 (spike) protein on the surface of the RV. In this study, we compared the immunological efficacy of the vaccine candidates in BALB/c mice in terms of the levels of humoral and cellular immune responses. The results show that the rabies virus vector-based vaccine can induce remarkably earlier antibody response and higher levels of cellular immunity than the GEM particles vector. However, the GEM particles vector-based vaccine candidate can induce remarkably higher antibody response, even at a very low dose of 1 µg. These results indicate that vaccines constructed using different vaccine vector platforms for the same pathogen have different rates and trends in humoral and cellular immune responses in the same animal model. This discovery not only provides more alternative vaccine development platforms for MERS-CoV vaccine development, but also provides a theoretical basis for our future selection of vaccine vector platforms for other specific pathogens.


Subject(s)
Coronavirus Infections/immunology , Middle East Respiratory Syndrome Coronavirus/immunology , Viral Vaccines/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Cell Line , Coronavirus Infections/prevention & control , Genetic Vectors , Humans , Immunization , Immunoglobulin G/blood , Immunoglobulin G/immunology , Lactococcus lactis/genetics , Mice , Mice, Inbred BALB C , Middle East Respiratory Syndrome Coronavirus/genetics , Rabies virus/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes/immunology , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/immunology , Viral Vaccines/administration & dosage
3.
Food Sci Nutr ; 8(8): 3971-3976, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-1898719

ABSTRACT

This review focused on the use of plant-based foods for enhancing the immunity of all aged groups against COVID-19. In humans, coronaviruses are included in the spectrum of viruses that cause the common cold and, recently, severe acute respiratory syndrome (SARS). Emerging infectious diseases, such as SARS present a major threat to public health. The novel coronavirus has spread rapidly to multiple countries and has been declared a pandemic by the World Health Organization. COVID-19 is usually caused a virus to which most probably the people with low immunity response are being affected. Plant-based foods increased the intestinal beneficial bacteria which are helpful and make up of 85% of the immune system. By the use of plenty of water, minerals like magnesium and Zinc, micronutrients, herbs, food rich in vitamins C, D and E, and better life style one can promote the health and can overcome this infection. Various studies investigated that a powerful antioxidant glutathione and a bioflavonoid quercetin may prevent various infections including COVID-19. In conclusion, the plant-based foods play a vital role to enhance the immunity of people to control of COVID-19.

4.
J Clin Invest ; 131(12)2021 06 15.
Article in English | MEDLINE | ID: covidwho-1731387

ABSTRACT

The characterization of the adaptive immune response to COVID-19 vaccination in individuals who recovered from SARS-CoV-2 infection may define current and future clinical practice. To determine the effect of the 2-dose BNT162b2 mRNA COVID-19 vaccination schedule in individuals who recovered from COVID-19 (COVID-19-recovered subjects) compared with naive subjects, we evaluated SARS-CoV-2 Spike-specific T and B cell responses, as well as specific IgA, IgG, IgM, and neutralizing antibodies titers in 22 individuals who received the BNT162b2 mRNA COVID-19 vaccine, 11 of whom had a previous history of SARS-CoV-2 infection. Evaluations were performed before vaccination and then weekly until 7 days after second injection. Data obtained clearly showed that one vaccine dose is sufficient to increase both cellular and humoral immune response in COVID-19-recovered subjects without any additional improvement after the second dose. On the contrary, the second dose proved mandatory in naive subjects to further enhance the immune response. These findings were further confirmed at the serological level in a larger cohort of naive (n = 68) and COVID-19-recovered (n = 29) subjects, tested up to 50 days after vaccination. These results question whether a second vaccine injection in COVID-19-recovered subjects is required, and indicate that millions of vaccine doses may be redirected to naive individuals, thus shortening the time to reach herd immunity.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , COVID-19 Vaccines , COVID-19 , Immunity, Humoral/drug effects , Immunologic Memory/drug effects , SARS-CoV-2 , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , COVID-19/prevention & control , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , Female , Humans , Male , Middle Aged , SARS-CoV-2/immunology , SARS-CoV-2/metabolism
5.
Crit Rev Microbiol ; 46(6): 689-702, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-1730391

ABSTRACT

Intensive worldwide efforts are underway to determine both the pathogenesis of SARS-CoV-2 infection and the immune responses in COVID-19 patients in order to develop effective therapeutics and vaccines. One type of cell that may contribute to these immune responses is the γδ T lymphocyte, which plays a key role in immunosurveillance of the mucosal and epithelial barriers by rapidly responding to pathogens. Although found in low numbers in blood, γδ T cells consist the majority of tissue-resident T cells and participate in the front line of the host immune defense. Previous studies have demonstrated the critical protective role of γδ T cells in immune responses to other respiratory viruses, including SARS-CoV-1. However, no studies have profoundly investigated these cells in COVID-19 patients to date. γδ T cells can be safely expanded in vivo using existing inexpensive FDA-approved drugs such as bisphosphonate, in order to test its protective immune response to SARS-CoV-2. To support this line of research, we review insights gained from previous coronavirus research, along with recent findings, discussing the potential role of γδ T cells in controlling SARS-CoV-2. We conclude by proposing several strategies to enhance γδ T cell's antiviral function, which may be used in developing therapies for COVID-19.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , T-Lymphocyte Subsets/immunology , Animals , Betacoronavirus/genetics , COVID-19 , Coronavirus Infections/virology , Humans , Pandemics , Pneumonia, Viral/virology , SARS-CoV-2 , Virus Replication
6.
Int J Vitam Nutr Res ; 92(1): 35-48, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1721399

ABSTRACT

Recently, the outbreak of severe acute respiratory syndrome cornoavirus-2 (SARS-CoV-2), causing coronavirus disease 2019 (COVID-19), has become a great perturbation all around the globe and has many devastating effects on every aspect of life. Apart from the oxygen therapy and extracorporeal membrane oxygenation, Remdesivir and Dexamethasone have been proven to be efficacious against COVID-19, along with various vaccine candidates and monoclonal antibody cocktail therapy for Regeneron. All of these are currently at different stages of clinical trials. People with weak immunity are more prone to a severe infection of SARS-CoV-2. Therefore, early and judicious nutritional supplementation along with pharmacological treatment and clinician collaborations are critical in restituting the current situation. Nutritional supplements help in acquiring strong immunity to prevent the progression of disease any further. Vitamin C, vitamin D, selenium, zinc and many other nutritional and dietary supplements inhibit the production of inflammatory cytokines during a viral infection and prevents several unwanted symptoms of infection. Many dietary components like citrus fruits, black elderberry, ginger, and probiotics have the ability to attack viral replication. These supplements can also tame the overriding immune system during coronavirus infection. Keeping in view these facts, nutritional and dietary supplements can be used along with other management modalities. These nutritional and dietary supplements are potential candidates to curb the convulsive unfolding of novel COVID-19, in combination with other standard treatment protocols. In this review, various search engines were used to exploit available literature in order to provide a comprehensive review on nutritional and dietary supplements with respect to the viral infections. It will also provide a brief overview on some of the clinical trials that are in progress to assess the role of nutritional supplements, either alone or in combination with other pharmacological drugs, in fight against COVID-19.


Subject(s)
COVID-19 , Clinical Trials as Topic , Dietary Supplements , Humans , SARS-CoV-2 , Vitamin D , Vitamins
7.
Cell Host Microbe ; 27(6): 879-882.e2, 2020 06 10.
Article in English | MEDLINE | ID: covidwho-1719463

ABSTRACT

The inflammatory response to SARS-coronavirus-2 (SARS-CoV-2) infection is thought to underpin COVID-19 pathogenesis. We conducted daily transcriptomic profiling of three COVID-19 cases and found that the early immune response in COVID-19 patients is highly dynamic. Patient throat swabs were tested daily for SARS-CoV-2, with the virus persisting for 3 to 4 weeks in all three patients. Cytokine analyses of whole blood revealed increased cytokine expression in the single most severe case. However, most inflammatory gene expression peaked after respiratory function nadir, except expression in the IL1 pathway. Parallel analyses of CD4 and CD8 expression suggested that the pro-inflammatory response may be intertwined with T cell activation that could exacerbate disease or prolong the infection. Collectively, these findings hint at the possibility that IL1 and related pro-inflammatory pathways may be prognostic and serve as therapeutic targets for COVID-19. This work may also guide future studies to illuminate COVID-19 pathogenesis and develop host-directed therapies.


Subject(s)
Coronavirus Infections/genetics , Coronavirus Infections/immunology , Pneumonia, Viral/genetics , Pneumonia, Viral/immunology , Adult , Aged , Biological Variation, Individual , COVID-19 , Cluster Analysis , Coronavirus Infections/blood , Coronavirus Infections/pathology , Cytokines/blood , Gene Expression Regulation , Humans , Male , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/pathology , Transcriptome , Up-Regulation
8.
Biophys J ; 120(14): 2902-2913, 2021 07 20.
Article in English | MEDLINE | ID: covidwho-1605015

ABSTRACT

The ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2 continues to rage with devastating consequences on human health and global economy. The spike glycoprotein on the surface of coronavirus mediates its entry into host cells and is the target of all current antibody design efforts to neutralize the virus. The glycan shield of the spike helps the virus to evade the human immune response by providing a thick sugar-coated barrier against any antibody. To study the dynamic motion of glycans in the spike protein, we performed microsecond-long molecular dynamics simulation in two different states that correspond to the receptor binding domain in open or closed conformations. Analysis of this microsecond-long simulation revealed a scissoring motion on the N-terminal domain of neighboring monomers in the spike trimer. The roles of multiple glycans in shielding of spike protein in different regions were uncovered by a network analysis, in which the high betweenness centrality of glycans at the apex revealed their importance and function in the glycan shield. Microdomains of glycans were identified featuring a high degree of intracommunication in these microdomains. An antibody overlap analysis revealed the glycan microdomains as well as individual glycans that inhibit access to the antibody epitopes on the spike protein. Overall, the results of this study provide detailed understanding of the spike glycan shield, which may be utilized for therapeutic efforts against this crisis.

9.
Clin Infect Dis ; 73(11): 2073-2082, 2021 12 06.
Article in English | MEDLINE | ID: covidwho-1560084

ABSTRACT

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic poses an urgent need for the development of effective therapies for coronavirus disease 2019 (COVID-19). METHODS: We first tested SARS-CoV-2-specific T-cell (CοV-2-ST) immunity and expansion in unexposed donors, COVID-19-infected individuals (convalescent), asymptomatic polymerase chain reaction (PCR)-positive subjects, vaccinated individuals, non-intensive care unit (ICU) hospitalized patients, and ICU patients who either recovered and were discharged (ICU recovered) or had a prolonged stay and/or died (ICU critical). CoV-2-STs were generated from all types of donors and underwent phenotypic and functional assessment. RESULTS: We demonstrate causal relationship between the expansion of endogenous CoV-2-STs and the disease outcome; insufficient expansion of circulating CoV-2-STs identified hospitalized patients at high risk for an adverse outcome. CoV-2-STs with a similarly functional and non-alloreactive, albeit highly cytotoxic, profile against SARS-CoV-2 could be expanded from both convalescent and vaccinated donors generating clinical-scale, SARS-CoV-2-specific T-cell products with functional activity against both the unmutated virus and its B.1.1.7 and B.1.351 variants. In contrast, critical COVID-19 patient-originating CoV-2-STs failed to expand, recapitulating the in vivo failure of CoV-2-specific T-cell immunity to control the infection. CoV-2-STs generated from asymptomatic PCR-positive individuals presented only weak responses, whereas their counterparts originating from exposed to other seasonal coronaviruses subjects failed to kill the virus, thus disempowering the hypothesis of protective cross-immunity. CONCLUSIONS: Overall, we provide evidence on risk stratification of hospitalized COVID-19 patients and the feasibility of generating powerful CoV-2-ST products from both convalescent and vaccinated donors as an "off-the shelf" T-cell immunotherapy for high-risk patients.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Immunotherapy, Adoptive , T-Lymphocytes
10.
Pan Afr Med J ; 38: 93, 2021.
Article in French | MEDLINE | ID: covidwho-1547720

ABSTRACT

INTRODUCTION: SARS-CoV-2 serology tests could play a crucial role in estimating the prevalence of COVID-19. The purpose of this study was to estimate the prevalence of COVID-19 among travellers and workers in Bukavu, a city in eastern Democratic Republic of the Congo. METHODS: between May and August 2020, the Cellex qSARS-CoV-2 IgG/IgM Rapid Test (Cellex, Inc., USA), lateral flow immunoassay was used to rapidly detect and differentiate antibodies against SARS-CoV-2 among travellers and workers seeking medical certification. RESULTS: among the 684 residents of the city of Bukavu screened for COVID-19 (4.2% Hispanic, 2.8% other African, 0.9% Asian), the seroprevalence anti-SARS-CoV-2 antibodies was 40.8% (IgG+/IgM+: 34.6%; IgG+/IgM-: 0.5%; IgG-/IgM+: 5.4%). Cumulative seroprevalence of anti-SARS-CoV-2 IgG antibodies increased from 24.5% to 35.2% from May to August 2020. Independent predictors of SARS-CoV-2 antibodies were age > 60 years [adjusted OR = 2.07(1.26-3.38)] and non-membership of the medical staff [adjusted OR = 2.28 (1.22-4.26)]. Thirteen point nine percent of patients seropositive for SARS-CoV-2 antibodies were symptomatic and hospitalized. CONCLUSION: this study shows a very high seroprevalence of SARS-CoV-2 antibodies among travellers and workers in Bukavu, a city in eastern Democratic Republic of the Congo, which may positively affect community immunity in the study population. Thus, the management of COVID-19 should be contextualized according to local realities.


Subject(s)
Antibodies, Viral/blood , COVID-19/epidemiology , SARS-CoV-2/isolation & purification , Travel , Adult , Age Factors , Aged , COVID-19/diagnosis , Democratic Republic of the Congo/epidemiology , Female , Hospitalization/statistics & numerical data , Humans , Immunoassay , Male , Middle Aged , SARS-CoV-2/immunology , Seroepidemiologic Studies
11.
J Infect Dis ; 224(9): 1473-1488, 2021 11 16.
Article in English | MEDLINE | ID: covidwho-1522215

ABSTRACT

BACKGROUND: Postdischarge immunity and its correlation with clinical features among patients recovered from coronavirus disease 2019(COVID-19) are poorly described. This prospective cross-sectional study explored the inflammatory profiles and clinical recovery of patients with COVID-19 at 3 months after hospital discharge. METHODS: Patients with COVID-19 discharged from 4 hospitals in Wuhan, recovered asymptomatic patients (APs) from an isolation hotel, and uninfected healthy controls (HCs) were recruited. Viral nucleic acid and antibody detection, laboratory examination, computed tomography, pulmonary function assessment, multiplex cytokine assay, and flow cytometry were performed. RESULTS: The72 age-, sex- and body mass index-matched participants included 19 patients with severe/critical COVID-19 (SPs), 20 patients with mild/moderate COVID-19 (MPs), 16 APs, and 17 HCs. At 3 months after discharge, levels of proinflammatory cytokines and factors related to vascular injury/repair in patients recovered from COVID-19 had not returned to those of the HCs, especially among recovered SPs compared with recovered MPs and APs. These cytokines were significantly correlated with impaired pulmonary function and chest computed tomographic abnormalities. However, levels of immune cells had returned to nearly normal levels and were not significantly correlated with abnormal clinical features. CONCLUSION: Vascular injury, inflammation, and chemotaxis persisted in patients with COVID-19 and were correlated with abnormal clinical features 3 months after discharge, especially in recovered SPs.


Subject(s)
COVID-19/diagnosis , COVID-19/immunology , Cytokines/immunology , Survivors/psychology , Aftercare , Anti-Bacterial Agents/therapeutic use , Antiviral Agents/therapeutic use , COVID-19/epidemiology , COVID-19/therapy , China/epidemiology , Cross-Sectional Studies , Humans , Patient Discharge , Prospective Studies , Retrospective Studies , SARS-CoV-2 , Treatment Outcome , Vascular System Injuries
12.
World J Clin Cases ; 8(21): 5099-5103, 2020 Nov 06.
Article in English | MEDLINE | ID: covidwho-1527033

ABSTRACT

The coronavirus disease 2019 pandemic has become a major global public health problem. Governments are taking the necessary steps to reduce the movement of people to contain the spread of the virus. However, these measures have caused considerable distress to patients with gastric cancer who are newly diagnosed or are undergoing treatment. In addition to the cancer, they must deal with longer waiting times for surgery and poor communication with doctors. Furthermore, gastric cancer patients generally have low immunity and a poor nutritional status, so they are a high-risk group for infection with the novel coronavirus. Therefore, it is necessary to formulate reasonable outpatient management strategies to reduce the adverse effects of the pandemic on their treatment. We summarize the management strategies for patients with gastric cancer during the pandemic.

13.
Infect Disord Drug Targets ; 21(4): 541-552, 2021.
Article in English | MEDLINE | ID: covidwho-1496791

ABSTRACT

BACKGROUND: Since December 2019, a novel coronavirus, SARS-CoV-2, has caused global public health issues after being reported for the first time in Wuhan province of China. So far, there have been approximately 14.8 million confirmed cases and 0.614 million deaths due to the SARS-CoV-2 infection globally, and still, numbers are increasing. Although the virus has caused a global public health concern, no effective treatment has been developed. OBJECTIVE: One of the strategies to combat the COVID-19 disease caused by SARS-CoV-2 is the development of vaccines that can make humans immune to these infections. Considering this approach, in this study, an attempt has been made to design epitope-based vaccine for combatting COVID-19 disease by analyzing the complete proteome of the virus by using immuno-informatics tools. METHODS: The protein sequence of the SARS-CoV-2 was retrieved and the individual proteins were checked for their allergic potential. Then, from non-allergen proteins, antigenic epitopes were identified that could bind with MHCII molecules. The epitopes were modeled and docked to predict the interaction with MHCII molecules. The stability of the epitope-MHCII complex was further analyzed by performing a molecular dynamics simulation study. The selected vaccine candidates were also analyzed for their global population coverage and conservancy among SARS-related coronavirus species. RESULTS: The study has predicted 5 peptide molecules that can act as potential candidates for epitope- based vaccine development. Among the 5 selected epitopes, the peptide LRARSVSPK can be the most potent epitope because of its high geometric shape complementarity score, low ACE and very high response towards it by the world population (81.81% global population coverage). Further, molecular dynamic simulation analysis indicated the formation of a stable epitope-MHCII complex. The epitope LRARSVSPK was also found to be highly conserved among the SARS-CoV- -2 isolated from different countries. CONCLUSION: The study has predicted T-cell epitopes that can elicit a robust immune response in the global human population and act as potential vaccine candidates. However, the ability of these epitopes to act as vaccine candidate needs to be validated in wet lab studies.


Subject(s)
COVID-19 , Vaccines , Epitopes, B-Lymphocyte , Epitopes, T-Lymphocyte , Humans , Molecular Docking Simulation , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
14.
J Clin Microbiol ; 59(7): e0083721, 2021 06 18.
Article in English | MEDLINE | ID: covidwho-1486488

ABSTRACT

We assessed the performance of the CoronaCHEK lateral flow assay on samples from Uganda and Baltimore to determine the impact of geographic origin on assay performance. Plasma samples from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PCR-positive individuals (Uganda, 78 samples from 78 individuals, and Baltimore, 266 samples from 38 individuals) and from prepandemic individuals (Uganda, 1,077, and Baltimore, 532) were evaluated. Prevalence ratios (PR) were calculated to identify factors associated with a false-positive test. After the first positive PCR in Ugandan samples, the sensitivity was 45% (95% confidence interval [CI], 24,68) at 0 to 7 days, 79% (95% CI, 64 to 91) at 8 to 14 days, and 76% (95% CI, 50 to 93) at >15 days. In samples from Baltimore, sensitivity was 39% (95% CI, 30 to 49) at 0 to 7 days, 86% (95% CI, 79 to 92) at 8 to 14 days, and 100% (95% CI, 89 to 100) at 15 days after positive PCR. The specificity of 96.5% (95% CI, 97.5 to 95.2) in Ugandan samples was significantly lower than that in samples from Baltimore, 99.3% (95% CI, 98.1 to 99.8; P < 0.01). In Ugandan samples, individuals with a false-positive result were more likely to be male (PR, 2.04; 95% CI, 1.03,3.69) or individuals who had had a fever more than a month prior to sample acquisition (PR, 2.87; 95% CI, 1.12 to 7.35). Sensitivity of the CoronaCHEK was similar in samples from Uganda and Baltimore. The specificity was significantly lower in Ugandan samples than in Baltimore samples. False-positive results in Ugandan samples appear to correlate with a recent history of a febrile illness, potentially indicative of a cross-reactive immune response in individuals from East Africa.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , Female , Humans , Male , Sensitivity and Specificity , Uganda
15.
Front Pediatr ; 9: 638871, 2021.
Article in English | MEDLINE | ID: covidwho-1457675

ABSTRACT

With birth, the newborn is transferred from a quasi-sterile environment to the outside world. At this time, the neonatal immune system is inexperienced and continuously subject to a process of development as it encounters different antigenic stimuli after birth. It is initially characterized by a bias toward T helper 2 phenotype, reduced T helper 1, and cytotoxic responses to microbial stimuli, low levels of memory, and effector T and B cells and a high production of suppressive T regulatory cells. The aim of this setting, during fetal life, is to maintain an anti-inflammatory state and immune-tolerance. Maternal antibodies are transferred during pregnancy through the placenta and, in the first weeks of life of the newborn, they represent a powerful tool for protection. Thus, optimization of vaccination in pregnancy represents an important strategy to reduce the burden of neonatal infections and sepsis. Beneficial effects of maternal immunization are universally recognized, although the optimal timing of vaccination in pregnancy remains to be defined. Interestingly, the dynamic exchange that takes place at the fetal-maternal interface allows the transfer not only of antibodies, but also of maternal antigen presenting cells, probably in order to stimulate the developing fetal immune system in a harmless way. There are still controversial effects related to maternal immunization including the so called "immunology blunting," i.e., a dampened antibody production following infant's vaccination in those infants who received placentally transferred maternal immunity. However, clinical relevance of this phenomenon is still not clear. This review will provide an overview of the evolution of the immune system in early life and discuss the benefits of maternal vaccination. Current maternal vaccination policies and their rationale will be summarized on the road to promising approaches to enhance immunity in the neonate.

16.
Ann Intern Med ; 174(8): 1073-1080, 2021 08.
Article in English | MEDLINE | ID: covidwho-1456490

ABSTRACT

BACKGROUND: Assessing the evolution of SARS-CoV-2 immune response among patients receiving dialysis can define its durability in a highly clinically relevant context because patients receiving dialysis share the characteristics of persons most susceptible to SARS-CoV-2 infection. OBJECTIVE: To evaluate the persistence of SARS-CoV-2 receptor-binding domain (RBD) IgG in seroprevalent patients receiving dialysis. DESIGN: Prospective. SETTING: Nationwide sample from dialysis facilities. PATIENTS: 2215 patients receiving dialysis who had evidence of SARS-CoV-2 infection as of July 2020. MEASUREMENTS: Remainder plasma from routine monthly laboratories was used to measure semiquantitative RBD IgG index value over 6 months. RESULTS: A total of 2063 (93%) seroprevalent patients reached an assay detectable response (IgG index value ≥1). Most (n = 1323, 60%) had responses in July with index values classified as high (IgG ≥10); 1003 (76%) remained within this stratum. Adjusted median index values declined slowly but continuously (July vs. December values were 21 vs. 13; P < 0.001). The trajectory of the response did not vary by age group, sex, race/ethnicity, or diabetes status. Patients without an assay detectable response (n = 137) were more likely to be White and in the younger (18 to 44 years) or older (≥80 years) age groups and less likely to have diabetes and hypoalbuminemia. LIMITATION: Lack of data on symptoms or reverse transcriptase polymerase chain reaction diagnosis, cohort of persons who survived infection, and use of a semiquantitative assay. CONCLUSION: Despite impaired immunity, most seropositive patients receiving dialysis maintained RBD antibody levels over 6 months. A slow and continual decline in median antibody levels over time was seen, but no indication that subgroups with impaired immunity had a shorter-lived humoral response was found. PRIMARY FUNDING SOURCE: Ascend Clinical Laboratories.


Subject(s)
Antibodies, Viral/blood , COVID-19/immunology , Immunoglobulin G/blood , Protein Domains/immunology , Renal Dialysis , Spike Glycoprotein, Coronavirus/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/immunology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , SARS-CoV-2 , Young Adult
17.
J Med Virol ; 93(10): 5805-5815, 2021 10.
Article in English | MEDLINE | ID: covidwho-1453606

ABSTRACT

Aggressive immune response, due to overexpressed proinflammatory molecules, has been characterized in coronavirus disease 2019 (COVID-19) patients. Some of those mediators have a dual and opposite role on immune systems at play behind differential disease severities. We investigated the expression of some cytokines and chemokines in COVID-19 patients in Bangladesh. We diagnosed the patients by detecting severe acute respiratory syndrome coronavirus 2 RNA in nasal swab samples by the real-time RT-PCR method. Thirty adult patients were preselected based on their disease severities and grouped into mild, moderate, and severe cases. Nine healthy volunteers participated in this study as a control. Relative expression of nine cytokines/chemokine in total leukocytes was semi-quantified in SYBRgreen-based real-time quantitative reverse-transcriptase polymerase chain reaction. We performed statistical tests on transformed log data using SPSS 24.0. At the onset of symptoms (Day 1), angiotensin-converting enzyme 2 (ACE2) (p < 0.05) and interleukin (IL)-6 (p > 0.05) were upregulated in all COVID-19 groups, although the expression levels did not significantly correlate with disease severities. However, expressions of IL-6, monocyte chemotactic protein-1, macrophage inflammatory protein-1α, tumor necrosis factor-α (TNF-α), RANTES (regulated upon activation, normal T cell expressed and secreted), and ACE2, on Day 14, were positively correlated with disease severities. Relative viral load at Day 1 showed no significant correlation with cytokine expression but had a significant positive correlation with RANTES and ACE2 expression on Day 14 (p < 0.05). Male patients had a higher level of IL-6 than female patients on Day 1 (p < 0.05). All COVID-19 patients showed upregulated cytokines and chemokines on Day 14 compared to Day 1 except TNF-α. Female patients had a higher expression of ACE2 and IL-12 on Day 14. Upregulated cytokines/chemokines at the convalescent stage, especially IL-6, may help in targeting anticytokine therapy in post-COVID-19 patients' management.


Subject(s)
COVID-19/diagnosis , Cytokines/blood , Adult , Bangladesh/epidemiology , COVID-19/epidemiology , COVID-19/immunology , COVID-19/virology , Chemokines/blood , Female , Humans , Male , Middle Aged , SARS-CoV-2/isolation & purification , Severity of Illness Index , Viral Load
18.
Res Sq ; 2021 Mar 17.
Article in English | MEDLINE | ID: covidwho-1431222

ABSTRACT

Coronavirus-associated acute respiratory disease, called coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). More than 90 million people have been infected with SARS-CoV-2 and more than 2 million people have died of complications due to COVID-19 worldwide. COVID-19, in its severe form, presents with an uncontrolled, hyperactive immune response and severe immunological injury or organ damage that accounts for morbidity and mortality. Even in the absence of complications, COVID-19 can last for several months with lingering effects of an overactive immune system. Dysregulated myeloid and lymphocyte compartments have been implicated in lung immunopathology. Currently, there are limited clinically-tested treatments of COVID-19 with disparities in the apparent efficacy in patients. Accurate model systems are essential to rapidly evaluate promising discoveries but most currently available in mice, ferrets and hamsters do not recapitulate sustained immunopathology described in COVID19 patients. Here, we present a comprehensively humanized mouse COVID-19 model that faithfully recapitulates the innate and adaptive human immune responses during infection with SARS-CoV-2 by adapting recombinant adeno-associated virus (AAV)-driven gene therapy to deliver human ACE2 to the lungs 1 of MISTRG6 mice. Our unique model allows for the first time the study of chronic disease due to infection with SARS-CoV-2 in the context of patient-derived antibodies to characterize in real time the potential culprits of the observed human driving immunopathology; most importantly this model provides a live view into the aberrant macrophage response that is thought to be the effector of disease morbidity and ARDS in patients. Application of therapeutics such as patient-derived antibodies and steroids to our model allowed separation of the two aspects of the immune response, infectious viral clearance and immunopathology. Inflammatory cells seeded early in infection drove immune-patholgy later, but this very same early anti-viral response was also crucial to contain infection.

20.
Kidney Int ; 99(6): 1470-1477, 2021 06.
Article in English | MEDLINE | ID: covidwho-1386157

ABSTRACT

Patients with end stage kidney disease receiving in-center hemodialysis (ICHD) have had high rates of SARS-CoV-2 infection. Following infection, patients receiving ICHD frequently develop circulating antibodies to SARS-CoV-2, even with asymptomatic infection. Here, we investigated the durability and functionality of the immune responses to SARS-CoV-2 infection in patients receiving ICHD. Three hundred and fifty-six such patients were longitudinally screened for SARS-CoV-2 antibodies and underwent routine PCR-testing for symptomatic and asymptomatic infection. Patients were regularly screened for nucleocapsid protein (anti-NP) and receptor binding domain (anti-RBD) antibodies, and those who became seronegative at six months were screened for SARS-CoV-2 specific T-cell responses. One hundred and twenty-nine (36.2%) patients had detectable antibody to anti-NP at time zero, of whom 127 also had detectable anti-RBD. Significantly, at six months, 71/111 (64.0%) and 99/116 (85.3%) remained anti-NP and anti-RBD seropositive, respectively. For patients who retained antibody, both anti-NP and anti-RBD levels were reduced significantly after six months. Eleven patients who were anti-NP seropositive at time zero, had no detectable antibody at six months; of whom eight were found to have SARS-CoV-2 antigen specific T cell responses. Independent of antibody status at six months, patients with baseline positive SARS-CoV-2 serology were significantly less likely to have PCR confirmed infection over the following six months. Thus, patients receiving ICHD mount durable immune responses six months post SARS-CoV-2 infection, with fewer than 3% of patients showing no evidence of humoral or cellular immunity.


Subject(s)
Antibodies, Viral/analysis , COVID-19/immunology , Kidney Failure, Chronic/therapy , Renal Dialysis/adverse effects , SARS-CoV-2/immunology , COVID-19 Testing , Female , Humans , Immunity , Male , Pandemics , Polymerase Chain Reaction , Reinfection , SARS-CoV-2/isolation & purification , Serologic Tests/methods
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