355,196 research outputs found
Host immune response to cytomegalovirus
To confirm that immediate-early (IE) genes of murine cytomegalovirus (MCMV) give rise to antigens recognized by specific cytolytic T lymphocytes (CTL), a 10.8-kilobase fragment of MCMV DNA which is abundantly transcribed at IE times was transfected into L cells expressing the Ld class I major histocompatibility glycoprotein. The viral genome fragment contains sequences of the three IE transcription units of MCMV: ie1, ie2, and ie3. In the transfected cell lines, only the predominant 2.75-kilobase transcript of ie1 and its translation product pp89 could be detected. The transfectants were analyzed for membrane expression of an IE antigen by employing clone IE1, an IE-specific CTL clone, as the probe. Only cells that expressed both the MCMV IE gene(s) and the Ld gene were recognized by the CTL clone
Modelling cross-reactivity and memory in the cellular adaptive immune response to influenza infection in the host
The cellular adaptive immune response plays a key role in resolving influenza
infection. Experiments where individuals are successively infected with
different strains within a short timeframe provide insight into the underlying
viral dynamics and the role of a cross-reactive immune response in resolving an
acute infection. We construct a mathematical model of within-host influenza
viral dynamics including three possible factors which determine the strength of
the cross-reactive cellular adaptive immune response: the initial naive T cell
number, the avidity of the interaction between T cells and the epitopes
presented by infected cells, and the epitope abundance per infected cell. Our
model explains the experimentally observed shortening of a second infection
when cross-reactivity is present, and shows that memory in the cellular
adaptive immune response is necessary to protect against a second infection.Comment: 35 pages, 12 figure
Immune Response Modulation by Tumor-Secreted Glycosphingolipids
Although originally considered merely structural components of cellular membranes, glycosphingolipids (GSL) arenow recognized as having critical effects on cellular physiology, including proliferation, differentiation, viraltransformation and ontogenesis. In addition, a vast majority of human cancers have modified GSL compositioncompared to parental normal cells. These modifications may contribute to both tumor survival and exert strikingeffects on anti-tumor immunity. In this review, we discuss mechanisms of immune modulation by tumor-secreted GSL.Fil: Lardone, Ricardo Dante. John Wayne Cancer Institute at Providence Saint John’s Health Center. Santa Monica; Estados Unidos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Centro de Investigaciones en QuĂmica BiolĂłgica de CĂłrdoba. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂmicas. Centro de Investigaciones en QuĂmica BiolĂłgica de CĂłrdoba; ArgentinaFil: Cely, Ingrid. John Wayne Cancer Institute at Providence Saint John’s Health Center. Santa Monica; Estados UnidosFil: Sieling, Peter A.. John Wayne Cancer Institute at Providence Saint John’s Health Center. Santa Monica; Estados UnidosFil: Lee, Delphine. John Wayne Cancer Institute at Providence Saint John’s Health Center. Santa Monica; Estados Unido
Expression kinetics and innate immune response after electroporation and LNP-mediated delivery of a self-amplifying mRNA in the skin
In this work, we studied the expression kinetics and innate immune response of a self-amplifying mRNA (sa-RNA) after electroporation and lipid-nanoparticle (LNP)-mediated delivery in the skin of mice. Intradermal electroporation of the sa-RNA resulted in a plateau-shaped expression, with the plateau between day 3 and day 10. The overall protein expression of sa-RNA was significantly higher than that obtained after electroporation of plasmid DNA (pDNA) or non-replication mRNAs. Moreover, using IFN-beta reporter mice, we elucidated that intradermal electroporation of sa-RNA induced a short-lived moderate innate immune response, which did not affect the expression of the sa-RNA. A completely different expression profile and innate immune response were observed when LNPs were used. The expression peaked 24 h after intradermal injection of sa-RNA-LNPs and subsequently showed a sharp drop. This drop might be explained by a translational blockage caused by the strong innate immune response that we observed in IFN-beta reporter mice shortly (4 h) after intradermal injection of sa-RNA-LNPs. A final interesting observation was the capacity of sa-RNA-LNPs to transfect the draining lymph nodes after intradermal injection
Contact-allergy time
The most commonly used techniques for the in vivo evaluation of the cellular
immune response include intracutaneous testing with microbial recall antigens
or sensitization with neoantigens. The reliability of these tests for the individual
patient usually is low due to the lack of standardization and quantification.
Moreover only the efferent branch of the immune response can be judged.
The dinitrochlorobenzene-contact allergy time (DNCB-CAT) is a quantitative
approach for the assessment of the cellular immune response. 2% DNCBointment
is applied on the upper arm in a 1 cm2 area. On the following days
patch-testing with 0.05% DNCB-ointment is done on the homolateral forearm
in alternating localizations till an allergic contact dermatitis reaction appears.
As assessed in patients with malignant melanoma (MM, n=\\5) and with
lymphoproliferative disorders (LD, η = 25), the DNCB-CAT correlates with
the age of the patients and can be expressed by a formula given by the age
(years) χ factor (MM = 0.16; LD = 0.17) + constant figure (MM = 5.5;
LD = 4.3). There was no significant difference between the two groups or subgroups
investigated.
By DNCB-CAT quantitative analysis of the cellular immune response in
vivo is possible. It is an appropriate model for further investigations of the
cellular immunity under different clinical, histological, prognostic, and therapeutic
aspects
Time-delayed model of immune response in plants
In the studies of plant infections, the plant immune response is known to play an essential role. In this paper we derive and analyse a new mathematical model of plant immune response with particular account for post-transcriptional gene silencing (PTGS). Besides biologically accurate representation of the PTGS dynamics, the model explicitly includes two time delays to represent the maturation time of the growing plant tissue and the non-instantaneous nature of the PTGS. Through analytical and numerical analysis of stability of the steady states of the model we identify parameter regions associated with recovery
and resistant phenotypes, as well as possible chronic infections. Dynamics of the system in these regimes is illustrated by numerical simulations of the model
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