Interleukin-1 alpha: its possible roles in cancer therapy

NLRP3 inflammasomes that induce antitumor immunity

Inflammasomes have emerged as context-dependent regulators of inflammation and protective immunity in vertebrates. Depending on the cell type and stimulus, inflammasome activities lead to interleukin (IL)-1 release from living (hyperactive) or dead (pyroptotic) cells. Herein, we review the mechanisms by which inflammasomes can impact CD8⁺ T cell-mediated antitumor immunity. We describe recent work demonstrating the differential impact of pyroptosis in cancer cells and dendritic cells (DCs) on antitumor immunity. We further highlight the surprising ability of inflammasomes within hyperactive DCs to facilitate the use of tumor lysates as immunogens, promoting CD8⁺ T cell-mediated antitumor responses. These context-dependent roles of inflammasomes in living and dead cells offer much opportunity for future research and should inform discussions of next-generation immunotherapy development.

A study of differential circRNA and lncRNA expressions in COVID-19-infected peripheral blood

To conquer the worldwide outbreak of COVID-19 virus, a large number of studies have been carried out on COVID-19 infection, transmission and treatment. However, few studies have been conducted from the perspectives of circRNA and lncRNA, which are known to be involved in regulating many life activities, such as immune tolerance and immune escapes, and hence may provide invaluable information in the emerging COVID-19 infection and recurrence. Moreover, exosomes has been reported to play an important role in COVID-19 recurrence, and thus may interact with the expression of circRNA and lncRNA. In this work, we sequenced circRNA, lncRNA and mRNA from recurrent COVID-19 patients and healthy people, and compared the differences. GO and KEGG enrichment analysis show that differentially expressed circRNA and lncRNA are mainly involved in the regulation of host cell cycle, apoptosis, immune inflammation, signaling pathway and other processes. The comparison to exosomes related databases shows that there are 114 differentially expressed circRNA, and 10 differentially expressed lncRNA related to exosomes. These studies provide reference for exploring circRNA and lncRNA to study the infection mechanism of COVID-19, their diagnostic and therapeutic values, as well as the possibility to employ them as biomarkers.

Role of cytokines in myocardial ischemia and reperfusion

Mediators of myocardial inflammation, predominantly cytokines, have for many years been implicated in the healing processes after infarction. In recent years, however, more attention has been paid to the possibility that the inflammation may result in deleterious complications for myocardial infarction. The proinflammatory cytokines may mediate myocardial dysfunction associated with myocardial infarction, severe congestive heart failure, and sepsis. A growing body of literature suggests that inflammatory mediators could play a crucial role in ischemia–reperfusion injury. Furthermore, ischemia–reperfusion not only results in the local transcriptional and translational upregulation of cytokines but also leads to tissue infiltration by inflammatory cells. These inflammatory cells are a ready source of a variety of cytokines which could be lethal for the cardiomyocytes. At the cellular level it has been shown that hypoxia causes a series of well documented changes in cardiomyocytes that includes loss of contractility, changes in lipid metabolism and subsequent irreversible cell membrane damage leading to cell death. For instance, hypoxic cardiomyocytes produce interleukin-6 (IL-6) which could contribute to the myocardial dysfunction observed in ischemia reperfusion injury. Ischemia followed by reperfusion induces a number of other multi-potent cytokines, such as IL-1, IL-8, tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1) as well as an angiogenic cytokine/ growth factor, vascular endothelial growth factor (VEGF), in the heart. Intrestingly, these multipotent cytokines (e.g. TNF-α) may induce an adaptive cytoprotective response in the reperfused myocardium. In this review, we have included a number of cytokines that may contribute to ventricular dysfunction and/or to the cytoprotective and adaptive changes in the reperfused heart.

Absence of significant effects by levamisole on circulating neutrophil levels in normal mice treated with 5-FU

When B6C3F1 mice were given a single intravenous (i.v.) injection of 150 mg/kg 5-fluorouracil (5-FU) their levels of circulating neutrophils plummeted, reaching a nadir at 6 to 7 days postdosing and then gradually increasing to normal and above-normal levels. Neutropenia (actual neutrophil count (ANC) below 100 ANC/microliters) extended until 8.7 +/- 0.2 days after 5-FU injection. When these mice were also given levamisole (2.5 mg/kg, po) on days 0-2 the mean time to ANC recovery greater than 100/microliters was 7.7 +/- 0.3 days, (p < 0.05 vs. controls), while IL-1 (2 micrograms/day, ip) positive controls yielded a mean time to > 100 ANC of 6.5 +/- 0.2 days. Although levamisole-treated mice attained normal neutrophil levels one day faster than controls did and this more rapid recovery led to their neutrophil levels being between 2- and 3-fold greater, these differences were not statistically significant. Effects were only manifested on neutrophil recoveries. There were no differences between levamisole-treated mice and controls when recovery rates for platelets, monocytes or lymphocytes were examined. These results demonstrate that levamisole has, at best, only weak myelopoietic properties against 5-FU-induced myelotoxicity in mice.

Effects of behavioral stimuli on plasma interleukin-1 activity in humans at rest

Interleukin-1 (IL-1) bioassays were done on 208 serum samples drawn from 7 volunteers, over several hours at 5-minute intervals, before, during, and after a relaxation-related behavioral stimulus. Individuals showed up to a 267% increase (t[29] = 7.750, p = 1 x 10(-7).) in IL-1, and for the group, a mean 48.1% elevation (t[5] = 4.128, p = .003) occurred, during the stimulus interval relative to baseline. When baselines were repeated, IL-1 activity rapidly returned toward baseline values. Suggestions to picture one's immune cells fighting illness appeared to have no uniform effect for all subjects. Such rapid changes in plasma IL-1, concomitant with stimuli, indicate a new way to alter immune function and further understand disease susceptibility.

Macrophage-T cell interaction is essential for the induction of p75 interleukin 2 (IL-2) receptor and IL-2 responsiveness in human CD4+ T cells

Fresh human CD8+ T cells showed a strong proliferative response to a high concentration of interleukin 2 (IL-2) in the absence of macrophages. In contrast, CD4+ T cells revealed no significant IL-2 responsiveness in the absence of macrophages. However, if CD4+ T cells were cocultured with macrophages, they showed higher proliferative response to IL-2 than CD8+ T cells. In accordance with the magnitude of IL-2 responsiveness, freshly isolated CD8+ T cells expressed significant amounts of p75 IL-2 receptor, while fresh CD4+ T cells did not express p75 IL-2 receptor. The expression of p75 IL-2 receptor on CD4+ T cells was induced by coculture with macrophages. The macrophage-induced p75 IL-2 receptor acquisition was blocked by monoclonal antibody (mAb) against class II antigen. Moreover, the addition of anti-CD4 mAb or anti-class II mAb to the culture caused a great inhibition of IL-2 responsiveness of CD4+ T cells. These results strongly suggest that macrophage-T cell interaction through CD4 and/or class II molecules is essential for the expression of p75 IL-2 receptor and IL-2 responsiveness in human CD4+, but not CD8+ T cells.

Distribution and characterization of autoantibodies to interleukin 1 alpha in normal human sera

Antibodies against IL-1 alpha were detected in sera of apparently healthy individuals. The immunoglobulins belonged to the IgG class, particularly IgG1, IgG2, and IgG4. [125I]rIL-1 alpha bound to Fab fragments of IgG, and IgG immune complexes of molecular weights from 160 to 700 kDa were formed in the sera by [125I]rIL-1 alpha. The occurrence of detectable anti-IL-1 alpha IgG in sera of 32 male and 32 female donors was 25 and 22% respectively. As judged by Scatchard analysis of the binding data, the capacity and avidity of binding were greater in the male than in the female sera (mean capacity to bind [125I]rIL-1 alpha: 10 [0.7-27] versus 3.3 [0.5-7.3] ng/ml; and mean Kd: 5.5 [5-7] versus 11 [4-16] pM). The antibodies did not cross-bind human recombinant IL-1 beta, IL-2, IL-6, or tumour necrosis factor alpha (TNF-alpha). It is concluded that native IL-1 alpha seems to trigger production of specific, high-avidity IgG antibodies in a relatively large number of normal individuals. These autoantibodies may regulate immunoinflammatory processes involving IL-1 alpha.