Search results for "Immunologic"
showing 10 items of 1115 documents
Dextrans produced by lactic acid bacteria exhibit antiviral and immunomodulatory activity against salmonid viruses
2015
36 p.-7 fig.-1 tab.-1 fig. supl.
Updated insights into the mechanism of action and clinical profile of the immunoadjuvant QS-21: A review
2019
Background Vaccine adjuvants are compounds that significantly enhance/prolong the immune response to a co-administered antigen. The limitations of the use of aluminium salts that are unable to elicite cell responses against intracellular pathogens such as those causing malaria, tuberculosis, or AIDS, have driven the development of new alternative adjuvants such as QS-21, a triterpene saponin purified from Quillaja saponaria. Purpose The aim of this review is to attempt to clarify the mechanism of action of QS-21 through either receptors or signaling pathways in vitro and in vivo with special emphasis on the co-administration with other immunostimulants in new adjuvant formulations, called a…
Exploring a regulatory role for mast cells: 'MCregs'?
2010
Regulatory cells can mould the fate of the immune response by direct suppression of specific subsets of effector cells, or by redirecting effectors against invading pathogens and infected or neoplastic cells. These functions have been classically, although not exclusively, ascribed to different subsets of T cells. Recently, mast cells have been shown to regulate physiological and pathological immune responses, and thus to act at the interface between innate and adaptive immunity assuming different functions and behaviors at discrete stages of the immune response. Here, we focus on these poorly defined, and sometimes apparently conflicting, functions of mast cells.
Host-directed therapies for COVID-19
2021
Purpose of review Severe acute respiratory syndrome coronavirus-2-induced hyperinflammation is a major cause of death or end-organ dysfunction in COVID-19 patients. We review adjunct host-directed therapies (HDTs) for COVID-19 management. Recent findings The use of umbilical cord-derived mesenchymal stem cells as HDT for COVID-19 has been shown to be safe in phase 1 and 2 trials. Trials of anti-interleukin-6 receptor antibodies show promising mortality benefit in hospitalized COVID-19 patients. Repurposed drugs and monoclonal antibodies targeting specific cytokines acting on different aspects of the pro- and anti-inflammatory cascades are under evaluation. Summary A range of HDTs shows prom…
Drug-induced expansion and differentiation of Vγ9Vδ2 T cells in vivo: The role of exogenous IL-2
2005
Human Vgamma9Vdelta2 T cells recognize nonpeptidic Ags generated by the 1-deoxy-d-xylulose 5-phosphate (many eubacteria, algae, plants, and Apicomplexa) and mevalonate (eukaryotes, archaebacteria, and certain eubacteria) pathways of isoprenoid synthesis. The potent Vgamma9Vdelta2 T cell reactivity 1) against certain cancer cells or 2) induced by infectious agents indicates that therapeutic augmentations of Vgamma9Vdelta2 T cell activities may be clinically beneficial. The functional characteristics of Vgamma9Vdelta2 T cells from Macaca fascicularis (cynomolgus monkey) are very similar to those from Homo sapiens. We have found that the i.v. administration of nitrogen-containing bisphosphonat…
Do Immune Complexes Formed with Autoantibodies Have a Role in the Maintenance of Immune Homeostasis Through Interaction with FC Receptors
2000
Natural autoantibodies play an important regulatory role in the maintenance of immune homeostasis. They act as a first line of defense against environmental pathogens like toxins, bacteria and erythrocytes. In humans they are mainly produced by CD5+ B cells that are under the control of a regulatory T cell population. Fc-gamma receptors are involved in antigen recognition and signal transduction and tuning, and some of the members of the FcR family have structural similarity to MHC molecules; they may interact with multiple Ig ligands and with non-Ig ligands. We discuss the interactions between immune-complexes formed with natural autoantibodies and Fc-gamma receptors and suggest that such …
Multifunctional CD4(+) T cells correlate with active Mycobacterium tuberculosis infection.
2010
Th1 CD4(+) T cells and their derived cytokines are crucial for protection against Mycobacterium tuberculosis. Using multiparametic flow cytometry, we have evaluated the distribution of seven distinct functional states (IFN-gamma/IL-2/TNF-alpha triple expressors, IFN-gamma/IL-2, IFN-gamma/TNF-alpha or TNF-alpha/IL-2 double expressors or IFN-gamma, IL-2 or TNF-alpha single expressors) of CD4(+) T cells in individuals with latent M. tuberculosis infection (LTBI) and active tuberculosis (TB). We found that triple expressors, while detectable in 85-90%TB patients, were only present in 10-15% of LTBI subjects. On the contrary, LTBI subjects had significantly higher (12- to 15-fold) proportions of…
Differential expression patterns of cytokines in complex regional pain syndrome.
2007
Complex regional pain syndromes (CRPS) are characterized by persistent and severe pain after trauma or surgery. Neuro-immune alterations are assumed to play a pathophysiological role. Here we set out to investigate whether patients with CRPS have altered systemic pro- and anti-inflammatory cytokine profiles compared to controls on mRNA and protein level. We studied blood cytokine mRNA and protein levels of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF), interleukin-2 (IL-2) and IL-8 and the anti-inflammatory cytokines IL-4, IL-10, and transforming growth factor-beta1 (TGF beta 1) in 40 prospectively recruited patients with CRPS I, two patients with CRPS II, and 34 controls…
Uremic serum inhibits monocyte-dependent, but not interleukin-2-dependent steps of T cell proliferation.
1990
We examined the influence of uremic serum on antigen receptor triggered T cell proliferation in dialysis patients with impaired immune function, i.e., 12 nonresponders to hepatitis B vaccination. The dialysis patients showed a monocyte dysfunction and an increased responsiveness to interleukin 2 (IL-2) according to our previous findings. In vitro the addition of IL-2 completely reconstituted the defect. Uremic serum inhibited monocyte-dependent T cell proliferation of patients and of healthy controls. Contrary, monocyte-independent steps of T cell proliferation were not impaired by uremic serum. When IL-2 was added to cultures, the T cell proliferation in the presence of uremic serum was ev…
Cloned T helper cells reverting to a resting state develop increasing sensitivity in their antigen-mediated interaction with accessory cells.
1988
A cloned murine T cell line, KIII5, specific for the polypeptide poly-L(Tyr,Glu)-poly-D,L-Ala--poly-L-Lys [(T,G)-A--L] was compared at different stages after antigenic stimulation with respect to the conditions required for the reinduction of growth by varying concentrations of antigen presented on different types of accessory cells (AC). We show that the dose of antigen necessary for inducing half maximal proliferation in the presence of splenic AC shifts to considerably lower concentrations when the T cell blasts revert to a resting state (100 micrograms/ml on day 7 to 10 micrograms/ml on day 21-35). During the same time period the expression of interleukin 2 (IL2) receptor and the reacti…