Abstract Alzheimer’s disease (AD) is associated with amyloid-beta (Aβ) deposition and neuroinflammation, possibly driven by activation of the NLRP3 inflammasome. Nucleoside reverse transcriptase inhibitors (NRTI) hamper the assembly of the NLRP3 inflammasome; we analyzed whether stavudine (D4T), a prototypical NRTI, modulates Aβ-mediated inflammasome activation; because neuroinflammation impairs Aβ clearance by phagocytes, phagocytosis and autophagy were examined as well. THP-1-derived macrophages were stimulated in vitro with Aβ 42 alone or after LPS priming with/without D4T. NLRP3 and TREM2 expression was analyzed by RT-PCR, phagocytosis and ASC-Speck by AmnisFlowSight, NLRP3-produced cytokines by ELISA, authophagy by P-ELISA evaluation of P-ERK and P-AKT. Results showed that IL1β, IL18 and caspase-1 were increased whereas Aβ-phagocytosis and TREM2 were reduced in LPS+Aβ 42 -stimulated cells. D4T reduced NLRP3 assembly as well as IL18 and caspase-1 production, but not IL1β, phagocytosis, and TREM2. P-AKT expression was augmented and P-ERK was reduced by D4T, suggesting a stimulatory effect on autophagy. D4T reduces NLRP3 inflammasome-associated inflammation, possibly restoring autophagy, in an in vitro model of AD; it will be interesting to verify its possibly beneficial effects in the clinical scenario.
T lymphocytes costimulatory molecules, including CD80, CD86, CD28, CTLA4, PD-1, PD-L1, and B7-H3, are associated with the preferential production of pro- or anti-inflammatory cytokines. We analyzed the expression of these molecules and myelin basic protein (MBP)-specific IL-10 and IFN-gamma production in patients with multiple sclerosis (MS) with relapsing-remitting acute (AMS, n = 40) or stable (SMS, n = 38). Twenty-two patients successfully undergoing therapy with glatimer acetate (n = 12) or IFNbeta (n = 10) were also analyzed. MBP-specific and PD-1-expressing T lymphocytes, PD-L1-expressing CD19(+) cells, and PD-L1(+)/IL-10(+)/CD14(+) and CD19(+) cells were significantly augmented in SMS patients. Additionally, MBP-specific and annexin V-expressing CD4(+) and CD8(+) (apoptotic) T lymphocytes were augmented and pAkt-positive (proliferating) cells were decreased in SMS compared with AMS patients. PD-1 ligation resulted in the increase of pAkt(+) lymphocytes in AMS patients alone. B7-H3 expression and IFN-gamma production were comparable in all individuals but the PD-L1(+)/IL-10(+) over B7-H3(+)/IFN-gamma(+) ratio was significantly lower in AMS compared with SMS patients. Finally, PD-L1 expression on immune cells was reduced in treated patients, suggesting that therapy-induced disease remission is not associated with the modulation of the expression of this molecule. The PD-1/PD-L1 pathway plays an important role in modulating immune functions in MS patients; monitoring and targeting these proteins could offer diagnostic and therapeutic advantages.
The use of natalizumab in multiple sclerosis (MS) may favour JC virus reactivation; this phenomenon is usually asymptomatic but can, albeit rarely, evolve into frank progressive multifocal leucoencephalopathy (PML).JCV-specific CD8+ T lymphocytes were evaluated by flow cytometry over a 24-month period in 24 natalizumab-treated MS patients in whom JCV DNA was or was not detected in blood using quantitative real-time polymerase chain reaction; all these cases were asymptomatic.Perforin- and grazymes-containing VP-1-specific CD8+ T lymphocytes were reduced whereas CD107a-expressing cells were increased in JCV positive patients, suggesting an active degranulation of these cells; naïve CD8+ T lymphocytes were also decreased whereas memory cells were increased in patients in whom JCV reactivation was observed.The presence of a CD8+ T lymphocyte-mediated effector immune response offers a greater insight into reactivation of JCV and its clinical sequelae, and may help the monitoring of patients on natalizumab therapy.
Regulatory T lymphocytes (Treg) play a fundamental importance in modulating the relative balance between inflammation and immune tolerance, and alterations of these cells are observed in inflammatory diseases. To better characterize the neuroinflammatory processes suggested to be associated with Alzheimer's disease (AD) and to clarify the possible role of Treg cells in this process, we extensively analyzed these cells (CD4 + CD25highFoxp3+) in patients with either severe AD (n=25) or mild cognitive impairment (MCI) (n=25), comparing the results with those of two groups of healthy controls (HC) (n=55). Because the intra- or extracellular expression of programmed death receptor 1 (PD1) identifies functionally diverse subsets of Treg we also analyzed such subpopulations. Results showed that, whereas both Treg and PD1pos Treg are increased in MCI and AD patients compared to HC, PD1neg Treg, the subpopulation of Treg cells endowed with the strongest suppressive ability, are significantly augmented in MCI patients alone. In these patients amyloid-β-stimulated-T cells proliferation was reduced and Treg-mediated suppression was more efficient compared to both AD and HC. The observation that PD1neg Treg, cells are increased in MCI patients reinforces the inflammatory origin of AD and supports a possible beneficial role of these cells in MCI that is lost in patients with full-blown AD.
These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.
Interleukin-1 beta (IL-1β) and its key regulator, the inflammasome, are suspected to play a role in the neuroinflammation observed in Alzheimer's disease (AD); no conclusive data are nevertheless available in AD patients. mRNA for inflammasome components (NLRP1, NLRP3, PYCARD, caspase 1, 5 and 8) and downstream effectors (IL-1β, IL-18) was up-regulated in severe and MILD AD. Monocytes co-expressing NLRP3 with caspase 1 or caspase 8 were significantly increased in severe AD alone, whereas those co-expressing NLRP1 and NLRP3 with PYCARD were augmented in both severe and MILD AD. Activation of the NLRP1 and NLRP3 inflammasomes in AD was confirmed by confocal microscopy proteins co-localization and by the significantly higher amounts of the pro-inflammatory cytokines IL-1β and IL-18 being produced by monocytes. In MCI, the expression of NLRP3, but not the one of PYCARD or caspase 1 was increased, indicating that functional inflammasomes are not assembled in these individuals: this was confirmed by lack of co-localization and of proinflammatory cytokines production. The activation of at least two different inflammasome complexes explains AD-associated neuroinflammation. Strategies targeting inflammasome activation could be useful in the therapy of AD.
Finding new solutions for the management of multiple sclerosis (MS) is crucial: further research is needed to study the effect of non-pharmacological interventions on the symptoms and the course of the disease, especially on lifestyle. Benefits from a proper lifestyle are evident not only on a clinical level but also on immune and neuro-endocrine systems. A brief high-impact multidimensional rehabilitation program (b-HIPE) was proposed for a sample of people with MS (pwMS) with a medium level of disease disability. We tested the change on clinical parameters and quality of life (QoL) after participation in B-HIPE. We furthermore decided to measure beta-endorphin and catecholamines concentrations pre- and post-participation in the b-HIPE program, due to the relationship between these hormones and the immune system in neurodegenerative diseases. Our results showed that after the b-HIPE program, an improvement of clinical parameters and QoL occurred. Moreover, we found higher levels of beta-endorphin and noradrenaline after participation in the program. These findings highlight the importance of implementing lifestyle interventions in the clinical management of MS. Furthermore, we hypothesize that the B-HIPE program increased beta-endorphin and noradrenaline levels, helping to reduce the inflammation related to MS disease.