scholarly journals Dynamic causal modelling of immune heterogeneity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thomas Parr ◽  
Anjali Bhat ◽  
Peter Zeidman ◽  
Aimee Goel ◽  
Alexander J. Billig ◽  
...  

AbstractAn interesting inference drawn by some COVID-19 epidemiological models is that there exists a proportion of the population who are not susceptible to infection—even at the start of the current pandemic. This paper introduces a model of the immune response to a virus. This is based upon the same sort of mean-field dynamics as used in epidemiology. However, in place of the location, clinical status, and other attributes of people in an epidemiological model, we consider the state of a virus, B and T-lymphocytes, and the antibodies they generate. Our aim is to formalise some key hypotheses as to the mechanism of resistance. We present a series of simple simulations illustrating changes to the dynamics of the immune response under these hypotheses. These include attenuated viral cell entry, pre-existing cross-reactive humoral (antibody-mediated) immunity, and enhanced T-cell dependent immunity. Finally, we illustrate the potential application of this sort of model by illustrating variational inversion (using simulated data) of this model to illustrate its use in testing hypotheses. In principle, this furnishes a fast and efficient immunological assay—based on sequential serology—that provides a (1) quantitative measure of latent immunological responses and (2) a Bayes optimal classification of the different kinds of immunological response (c.f., glucose tolerance tests used to test for insulin resistance). This may be especially useful in assessing SARS-CoV-2 vaccines.

Author(s):  
Fengyu Zhang ◽  
Claude Hughes

Coronavirus disease 2019 (COVID-19) is a new infectious respiratory disease that has caused the ongoing global pandemic. The primary purpose of this article is to describe evolving clinical epidemiology of COVID-19, including 1) infection and testing, 2) clinical spectrum including classification of clinical type, asymptomatic cases, severe cases and comorbidity, and clinical and immunological response, 3) regional variation in clinical presentation, 4) population distribution by age, sex, and occupation, and finally, 5) case-fatality. This content may provide important information on detailed clinical type and presentation of the disease, in which appropriate clinical outcomes can be derived for developing prevention strategies and clinical studies or trials that aim to test potential therapeutics or products for different patient populations.


2019 ◽  
Vol 26 (36) ◽  
pp. 6519-6543 ◽  
Author(s):  
Adriana Egui ◽  
Paola Lasso ◽  
Elena Pérez-Antón ◽  
M. Carmen Thomas ◽  
Manuel Carlos López

Chagas disease courses with different clinical phases and has a variable clinical presentation and progression. The acute infection phase mostly exhibits a non-specific symptomatology. In the absence of treatment, the acute phase is followed by a chronic phase, which is initially asymptomatic. This chronic asymptomatic phase of the disease is characterized by a fragile balance between the host’s immune response and the parasite replication. The loss of this balance is crucial for the progression of the sickness. The virulence and tropism of the T. cruzi infecting strain together to the inflammation processes in the cardiac tissue are the main factors for the establishment and severity of the cardiomyopathy. The efficacy of treatment in chronic Chagas disease patients is controversial. However, several studies carried out in chronic patients demonstrated that antiparasitic treatment reduces parasite load in the bloodstream and leads to an improvement in the immune response against the Trypanosoma cruzi parasite. The present review is mainly focused on the cellular patterns associated to the clinical status and the evolution of the disease in chronic patients, as well as the effectiveness of the treatment related to T. cruzi infection control. Therefore, an emphasis is placed on the dynamics of specific-antigens T cell subpopulations, their memory and activation phenotypes, their functionality and their contribution to pathogenesis or disease control, as well as their association with risk of congenital transmission of the parasite.


Parasitology ◽  
1998 ◽  
Vol 117 (2) ◽  
pp. 123-132 ◽  
Author(s):  
J. H. OUMA ◽  
A. J. C. FULFORD ◽  
H. C. KARIUKI ◽  
G. KIMANI ◽  
R. F. STURROCK ◽  
...  

The relocation of several thousand members of the Kamba tribe from the Kyulu Hills to the Thange valley near Masongaleni in Kenya provides an excellent opportunity to study the development of the immune response to schistosomiasis mansoni in a population with little or no previous experience of the infection. An adjacent, well-established Kamba community with similar patterns of water contact provides a suitable endemic control population. The immigrants were, uniquely, examined shortly after their arrival in the endemic area, while the prevalence of infection was still low. At this time faecal egg counts peaked atypically around 30 years of age. Over the next 12–18 months infection increased rapidly, especially among teenagers, producing a pattern of infection more typical of endemic communities. This substantially narrows estimates of the time required to develop the important determinants of the age–intensity profile, supporting the notion that changes related to age per se, rather than duration of infection, dominate. Age-dependent factors might include behaviour or physiology, including immune response. This paper provides the background for continuing longitudinal studies on the development of immunological responses to this parasite.


BMJ Open ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. e048317
Author(s):  
Wega Setiabudi ◽  
Daniel Hungerford ◽  
Krishanthi Subramaniam ◽  
Natasha Marcella Vaselli ◽  
Victoria E Shaw ◽  
...  

IntroductionThe emergence and rapid spread of COVID-19 have caused widespread and catastrophic public health and economic impact, requiring governments to restrict societal activity to reduce the spread of the disease. The role of household transmission in the population spread of SARS-CoV-2, and of host immunity in limiting transmission, is poorly understood. This paper describes a protocol for a prospective observational study of a cohort of households in Liverpool City Region, UK, which addresses the transmission of SARS-CoV-2 between household members and how immunological response to the infection changes over time.Methods and analysisHouseholds in the Liverpool City Region, in which members have not previously tested positive for SARS-CoV-2 with a nucleic acid amplification test, are followed up for an initial period of 12 weeks. Participants are asked to provide weekly self-throat and nasal swabs and record their activity and presence of symptoms. Incidence of infection and household secondary attack rates of COVID-19 are measured. Transmission of SARS-CoV-2 will be investigated against a range of demographic and behavioural variables. Blood and faecal samples are collected at several time points to evaluate immune responses to SARS-CoV-2 infection and prevalence and risk factors for faecal shedding of SARS-CoV-2, respectively.Ethics and disseminationThe study has received approval from the National Health Service Research Ethics Committee; REC Reference: 20/HRA/2297, IRAS Number: 283 464. Results will be disseminated through scientific conferences and peer-reviewed open access publications. A report of the findings will also be shared with participants. The study will quantify the scale and determinants of household transmission of SARS-CoV-2. Additionally, immunological responses before and during the different stages of infection will be analysed, adding to the understanding of the range of immunological response by infection severity.


2007 ◽  
Vol 123 (2) ◽  
pp. 190-198 ◽  
Author(s):  
Daniele Saverino ◽  
Renata Brizzolara ◽  
Rita Simone ◽  
Alessandra Chiappori ◽  
Francesca Milintenda-Floriani ◽  
...  

2021 ◽  
Vol 62 ◽  
pp. 9-15
Author(s):  
Marta Karaliutė ◽  
Kęstutis Dučinskas

In this article we focus on the problem of supervised classifying of the spatio-temporal Gaussian random field observation into one of two classes, specified by different mean parameters. The main distinctive feature of the proposed approach is allowing the class label to depend on spatial location as well as on time moment. It is assumed that the spatio-temporal covariance structure factors into a purely spatial component and a purely temporal component following AR(p) model. In numerical illustrations with simulated data, the influence of the values of spatial and temporal covariance parameters to the derived error rates for several prior probabilities models are studied.


2021 ◽  
Vol 129 (10) ◽  
pp. 1227
Author(s):  
А.В. Силантьев

The anticommutative Green’s functions were derived in an analytical form, and the energy spectra of С80 fullerene and endohedral Y3N@C80 fullerene of symmetry group Ih were obtained within the Hubbard model in the mean-field approximation. Using group theory methods, the classification of energy states was carried out, and the allowed transitions in the energy spectra of С80 and Y3N@C80 molecules of symmetry group Ih were determined.


2015 ◽  
Vol 14 (4) ◽  
pp. 18-21
Author(s):  
Y. S. Andozhskaya ◽  
A. N. Galileyeva

Introduction and aim. In this study discrete plasmapheres method possibilities in the treatment of the patients with III stage of peripheral artery disease were investigated. The aim of current investigation was to find out the changes of the peripheral microcirculation. Materials and methods: microcirculation was investigated with Minimax-Doppler Ê device before and after treatment of 48 patients with intermittent claudication. Results and discussion. It was found that peripheral microcirculation data and spectral characteristics of Doppler flow changes and clinical status of the patients eventually improved after treatment by suggested method. In conclusion, treatment by suggested method of discrete plasmapheres is effective on one of the most complicated group of patients with III stage of ischemia according to Fontaine-Pokrovsky classification of atherosclerosis of the arteries of low extremities.


2021 ◽  
Author(s):  
Christine T. Mwenge Kahinda

Bacterial mastitis in small ruminants is a complex disease, with massive economic loss in dairy sheep/goat industry due to poor productivity. The current mastitis prevention strategy relies on culling of infected ewes or does and or the use of antimicrobial agents to eliminate the bacterial infection. This has a potential risk for developing antibiotic resistant bacteria, posing human health risk from consumption of raw sheep or goat dairy products. Existing experimental and licensed vaccines on the market are ineffective against reducing the risk of mastitis in herds or flocks. Raising the needs for development of improved vaccines against mastitis for use in sheep and goats. This review examines, current understanding of the pathological processes and immunological responses against bacterial mastitis, using S. aureus as an example. By highlighting the protective defense mechanism induced in the udder against S. aureus mastitis. Based on evidence from published studies on pathological process and protective immune response mechanism, the need for improved vaccines for prevention of mastitis in small ruminant is highlighted and the development of a vaccine capable of enhancing immune response mechanism, that reduce the establishment of intramammary infection through induction of local IgA, IgG2 and Th17 immune responses is proposed.


1996 ◽  
Vol 10 (12) ◽  
pp. 1397-1423 ◽  
Author(s):  
MASA-AKI OZAKI ◽  
EIJI MIYAI ◽  
TOMOAKI KONISHI ◽  
KAORU HANAFUSA

This paper describes group theoretical classification of superconducting states (SC) in the extended Hubbard model with on-site repulsion (U), nearest neighbor attraction (V) and nearest neighbour exchange interaction (J) on the two-dimensional square lattice using the mean field approach. By decomposing the pairing interaction into irreducible parts; A1g, B1g and Eu of D4h point symmetry, we have derived two singlet SCs (s-wave and d-wave) from A1g and B1g, eight triplet SCs from Eu. The first three types of triplet SC have pairing by electrons with antiparallel spin, the second two types have pairing by electrons with equal spin and the last three types are non-unitary and have pairing by only up-spin electrons. We showed that three non-unitary states have to be accompanied with a ferromagnetic order from the structure of the maximal little groups. We performed numerical studies for these SCs. For parameters and electron density favorable for the ferromagnetic order, a non-unitary SC coexistent with ferromagnetism is most stable.


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