The B122 monoclonal antibody reacts with precursor and mature secreted forms of mouse and rat IL-1β a 17 kDa pro-inflammatory cytokine produced primarily by monocytes. IL-1β is an important mediator of the inflammatory response, and is involved in a variety of cellular activities, including cell proliferation, differentiation, apoptosis, and T and B lymphocyte activation. IL-1 is made up of IL-1α and IL-1β which are the products of distinct genes, but which are recognized by two distinct IL-1 receptors. The IL-1 receptor type I, an 80 kDa transmembrane protein with demonstrated IL-1 signaling function and the IL-1 receptor type II, a 68 kDa membrane protein with a relatively short cytoplasmic tail. The type II receptor acts as a decoy target for IL-1, inhibiting IL-1 activities by preventing the binding of IL-1 to the type I receptor. The B122 antibody has been reported to neutralize the bioactivity of natural or recombinant IL-1β.'

InVivoMAb anti-mouse/rat IL-1β (Clone: B122)

 Coffelt, S. B., et al. (2015). "IL-17-producing gammadelta T cells and neutrophils conspire to promote breast cancer metastasis." Nature 522(7556): 345-348. PubMed

Metastatic disease remains the primary cause of death for patients with breast cancer. The different steps of the metastatic cascade rely on reciprocal interactions between cancer cells and their microenvironment. Within this local microenvironment and in distant organs, immune cells and their mediators are known to facilitate metastasis formation. However, the precise contribution of tumour-induced systemic inflammation to metastasis and the mechanisms regulating systemic inflammation are poorly understood. Here we show that tumours maximize their chance of metastasizing by evoking a systemic inflammatory cascade in mouse models of spontaneous breast cancer metastasis. We mechanistically demonstrate that interleukin (IL)-1beta elicits IL-17 expression from gamma delta (gammadelta) T cells, resulting in systemic, granulocyte colony-stimulating factor (G-CSF)-dependent expansion and polarization of neutrophils in mice bearing mammary tumours. Tumour-induced neutrophils acquire the ability to suppress cytotoxic T lymphocytes carrying the CD8 antigen, which limit the establishment of metastases. Neutralization of IL-17 or G-CSF and absence of gammadelta T cells prevents neutrophil accumulation and downregulates the T-cell-suppressive phenotype of neutrophils. Moreover, the absence of gammadelta T cells or neutrophils profoundly reduces pulmonary and lymph node metastases without influencing primary tumour progression. Our data indicate that targeting this novel cancer-cell-initiated domino effect within the immune system--the gammadelta T cell/IL-17/neutrophil axis--represents a new strategy to inhibit metastatic disease.

Copenhaver, A. M., et al. (2015). "IL-1R signaling enables bystander cells to overcome bacterial blockade of host protein synthesis." Proc Natl Acad Sci U S A 112(24): 7557-7562. PubMed

The innate immune system is critical for host defense against microbial pathogens, yet many pathogens express virulence factors that impair immune function. Here, we used the bacterial pathogen Legionella pneumophila to understand how the immune system successfully overcomes pathogen subversion mechanisms. L. pneumophila replicates within macrophages by using a type IV secretion system to translocate bacterial effectors into the host cell cytosol. As a consequence of effector delivery, host protein synthesis is blocked at several steps, including translation initiation and elongation. Despite this translation block, infected cells robustly produce proinflammatory cytokines, but the basis for this is poorly understood. By using a reporter system that specifically discriminates between infected and uninfected cells within a population, we demonstrate here that infected macrophages produced IL-1alpha and IL-1beta, but were poor producers of IL-6, TNF, and IL-12, which are critical mediators of host protection. Uninfected bystander cells robustly produced IL-6, TNF, and IL-12, and this bystander response required IL-1 receptor (IL-1R) signaling during early pulmonary infection. Our data demonstrate functional heterogeneity in production of critical protective cytokines and suggest that collaboration between infected and uninfected cells enables the immune system to bypass pathogen-mediated translation inhibition to generate an effective immune response.

Hernandez, P. P., et al. (2015). "Interferon-lambda and interleukin 22 act synergistically for the induction of interferon-stimulated genes and control of rotavirus infection." Nat Immunol 16(7): 698-707. PubMed

The epithelium is the main entry point for many viruses, but the processes that protect barrier surfaces against viral infections are incompletely understood. Here we identified interleukin 22 (IL-22) produced by innate lymphoid cell group 3 (ILC3) as an amplifier of signaling via interferon-lambda (IFN-lambda), a synergism needed to curtail the replication of rotavirus, the leading cause of childhood gastroenteritis. Cooperation between the receptor for IL-22 and the receptor for IFN-lambda, both of which were 'preferentially' expressed by intestinal epithelial cells (IECs), was required for optimal activation of the transcription factor STAT1 and expression of interferon-stimulated genes (ISGs). These data suggested that epithelial cells are protected against viral replication by co-option of two evolutionarily related cytokine networks. These data may inform the design of novel immunotherapy for viral infections that are sensitive to interferons.

Lawlor, K. E., et al. (2015). "RIPK3 promotes cell death and NLRP3 inflammasome activation in the absence of MLKL." Nat Commun 6: 6282. PubMed

RIPK3 and its substrate MLKL are essential for necroptosis, a lytic cell death proposed to cause inflammation via the release of intracellular molecules. Whether and how RIPK3 might drive inflammation in a manner independent of MLKL and cell lysis remains unclear. Here we show that following LPS treatment, or LPS-induced necroptosis, the TLR adaptor protein TRIF and inhibitor of apoptosis proteins (IAPs: X-linked IAP, cellular IAP1 and IAP2) regulate RIPK3 and MLKL ubiquitylation. Hence, when IAPs are absent, LPS triggers RIPK3 to activate caspase-8, promoting apoptosis and NLRP3-caspase-1 activation, independent of RIPK3 kinase activity and MLKL. In contrast, in the absence of both IAPs and caspase-8, RIPK3 kinase activity and MLKL are essential for TLR-induced NLRP3 activation. Consistent with in vitro experiments, interleukin-1 (IL-1)-dependent autoantibody-mediated arthritis is exacerbated in mice lacking IAPs, and is reduced by deletion of RIPK3, but not MLKL. Therefore RIPK3 can promote NLRP3 inflammasome and IL-1beta inflammatory responses independent of MLKL and necroptotic cell death.

Russell, R. F., et al. (2015). "Partial Attenuation of Respiratory Syncytial Virus with a Deletion of a Small Hydrophobic Gene Is Associated with Elevated Interleukin-1beta Responses." J Virol 89(17): 8974-8981. PubMed

The small hydrophobic (SH) gene of respiratory syncytial virus (RSV), a major cause of infant hospitalization, encodes a viroporin of unknown function. SH gene knockout virus (RSV DeltaSH) is partially attenuated in vivo, but not in vitro, suggesting that the SH protein may have an immunomodulatory role. RSV DeltaSH has been tested as a live attenuated vaccine in humans and cattle, and here we demonstrate that it protected against viral rechallenge in mice. We compared the immune response to infection with RSV wild type and RSV DeltaSH in vivo using BALB/c mice and in vitro using epithelial cells, neutrophils, and macrophages. Strikingly, the interleukin-1beta (IL-1beta) response to RSV DeltaSH infection was greater than to wild-type RSV, in spite of a decreased viral load, and when IL-1beta was blocked in vivo, the viral load returned to wild-type levels. A significantly greater IL-1beta response to RSV DeltaSH was also detected in vitro, with higher-magnitude responses in neutrophils and macrophages than in epithelial cells. Depleting macrophages (with clodronate liposome) and neutrophils (with anti-Ly6G/1A8) demonstrated the contribution of these cells to the IL-1beta response in vivo, the first demonstration of neutrophilic IL-1beta production in response to viral lung infection. In this study, we describe an increased IL-1beta response to RSV DeltaSH, which may explain the attenuation in vivo and supports targeting the SH gene in live attenuated vaccines. IMPORTANCE: There is a pressing need for a vaccine for respiratory syncytial virus (RSV). A number of live attenuated RSV vaccine strains have been developed in which the small hydrophobic (SH) gene has been deleted, even though the function of the SH protein is unknown. The structure of the SH protein has recently been solved, showing it is a pore-forming protein (viroporin). Here, we demonstrate that the IL-1beta response to RSV DeltaSH is greater in spite of a lower viral load, which contributes to the attenuation in vivo. This potentially suggests a novel method by which viruses can evade the host response. As all Pneumovirinae and some Paramyxovirinae carry similar SH genes, this new understanding may also enable the development of live attenuated vaccines for both RSV and other members of the Paramyxoviridae.

Chen, K. W., et al. (2014). "The neutrophil NLRC4 inflammasome selectively promotes IL-1beta maturation without pyroptosis during acute Salmonella challenge." Cell Rep 8(2): 570-582. PubMed

The macrophage NLRC4 inflammasome drives potent innate immune responses against Salmonella by eliciting caspase-1-dependent proinflammatory cytokine production (e.g., interleukin-1beta [IL-1beta]) and pyroptotic cell death. However, the potential contribution of other cell types to inflammasome-mediated host defense against Salmonella was unclear. Here, we demonstrate that neutrophils, typically viewed as cellular targets of IL-1beta, themselves activate the NLRC4 inflammasome during acute Salmonella infection and are a major cell compartment for IL-1beta production during acute peritoneal challenge in vivo. Importantly, unlike macrophages, neutrophils do not undergo pyroptosis upon NLRC4 inflammasome activation. The resistance of neutrophils to pyroptotic death is unique among inflammasome-signaling cells so far described and allows neutrophils to sustain IL-1beta production at a site of infection without compromising the crucial inflammasome-independent antimicrobial effector functions that would be lost if neutrophils rapidly lysed upon caspase-1 activation. Inflammasome pathway modification in neutrophils thus maximizes host proinflammatory and antimicrobial responses during pathogen challenge.

Gopinath, S., et al. (2014). "Role of disease-associated tolerance in infectious superspreaders." Proc Natl Acad Sci U S A 111(44): 15780-15785. PubMed

Natural populations show striking heterogeneity in their ability to transmit disease. For example, a minority of infected individuals known as superspreaders carries out the majority of pathogen transmission events. In a mouse model of Salmonella infection, a subset of infected hosts becomes superspreaders, shedding high levels of bacteria (>10(8) cfu per g of feces) but remain asymptomatic with a dampened systemic immune state. Here we show that superspreader hosts remain asymptomatic when they are treated with oral antibiotics. In contrast, nonsuperspreader Salmonella-infected hosts that are treated with oral antibiotics rapidly shed superspreader levels of the pathogen but display signs of morbidity. This morbidity is linked to an increase in inflammatory myeloid cells in the spleen followed by increased production of acute-phase proteins and proinflammatory cytokines. The degree of colonic inflammation is similar in antibiotic-treated superspreader and nonsuperspreader hosts, indicating that the superspreader hosts are tolerant of antibiotic-mediated perturbations in the intestinal tract. Importantly, neutralization of acute-phase proinflammatory cytokines in antibiotic-induced superspreaders suppresses the expansion of inflammatory myeloid cells and reduces morbidity. We describe a unique disease-associated tolerance to oral antibiotics in superspreaders that facilitates continued transmission of the pathogen.

Khmaladze, I., et al. (2014). "Mannan induces ROS-regulated, IL-17A-dependent psoriasis arthritis-like disease in mice." Proc Natl Acad Sci U S A 111(35): E3669-3678. PubMed

Psoriasis (Ps) and psoriasis arthritis (PsA) are poorly understood common diseases, induced by unknown environmental factors, affecting skin and articular joints. A single i.p. exposure to mannan from Saccharomyces cerevisiae induced an acute inflammation in inbred mouse strains resembling human Ps and PsA-like disease, whereas multiple injections induced a relapsing disease. Exacerbation of disease severity was observed in mice deficient for generation of reactive oxygen species (ROS). Interestingly, restoration of ROS production, specifically in macrophages, ameliorated both skin and joint disease. Neutralization of IL-17A, mainly produced by gammadelta T cells, completely blocked disease symptoms. Furthermore, mice depleted of granulocytes were resistant to disease development. In contrast, certain acute inflammatory mediators (C5, Fcgamma receptor III, mast cells, and histamine) and adaptive immune players (alphabeta T and B cells) were redundant in disease induction. Hence, we propose that mannan-induced activation of macrophages leads to TNF-alpha secretion and stimulation of local gammadelta T cells secreting IL-17A. The combined action of activated macrophages and IL-17A produced in situ drives neutrophil infiltration in the epidermis and dermis of the skin, leading to disease manifestations. Thus, our finding suggests a new mechanism triggered by exposure to exogenous microbial components, such as mannan, that can induce and exacerbate Ps and PsA.

Botelho, F. M., et al. (2011). "IL-1alpha/IL-1R1 expression in chronic obstructive pulmonary disease and mechanistic relevance to smoke-induced neutrophilia in mice." PLoS One 6(12): e28457. PubMed

BACKGROUND: Cigarette smoking is the main risk factor for the development of chronic obstructive pulmonary disease (COPD), a major cause of morbidity and mortality worldwide. Despite this, the cellular and molecular mechanisms that contribute to COPD pathogenesis are still poorly understood. METHODOLOGY AND PRINCIPAL FINDINGS: The objective of this study was to assess IL-1 alpha and beta expression in COPD patients and to investigate their respective roles in perpetuating cigarette smoke-induced inflammation. Functional studies were pursued in smoke-exposed mice using gene-deficient animals, as well as blocking antibodies for IL-1alpha and beta. Here, we demonstrate an underappreciated role for IL-1alpha expression in COPD. While a strong correlation existed between IL-1alpha and beta levels in patients during stable disease and periods of exacerbation, neutrophilic inflammation was shown to be IL-1alpha-dependent, and IL-1beta- and caspase-1-independent in a murine model of cigarette smoke exposure. As IL-1alpha was predominantly expressed by hematopoietic cells in COPD patients and in mice exposed to cigarette smoke, studies pursued in bone marrow chimeric mice demonstrated that the crosstalk between IL-1alpha+ hematopoietic cells and the IL-1R1+ epithelial cells regulates smoke-induced inflammation. IL-1alpha/IL-1R1-dependent activation of the airway epithelium also led to exacerbated inflammatory responses in H1N1 influenza virus infected smoke-exposed mice, a previously reported model of COPD exacerbation. CONCLUSIONS AND SIGNIFICANCE: This study provides compelling evidence that IL-1alpha is central to the initiation of smoke-induced neutrophilic inflammation and suggests that IL-1alpha/IL-1R1 targeted therapies may be relevant for limiting inflammation and exacerbations in COPD.

Gonzalez-Navajas, J. M., et al. (2010). "Interleukin 1 receptor signaling regulates DUBA expression and facilitates Toll-like receptor 9-driven antiinflammatory cytokine production." J Exp Med 207(13): 2799-2807. PubMed

The interleukin 1 receptor (IL-1R) and the Toll-like receptors (TLRs) are highly homologous innate immune receptors that provide the first line of defense against infection. We show that IL-1R type I (IL-1RI) is essential for TLR9-dependent activation of tumor necrosis factor receptor-associated factor 3 (TRAF3) and for production of the antiinflammatory cytokines IL-10 and type I interferon (IFN). Noncanonical K63-linked ubiquitination of TRAF3, which is essential for type I IFN and IL-10 production, was impaired in Il1r1(-/-) CD11c(+) dendritic cells. In contrast, degradative ubiquitination of TRAF3 was not affected in the absence of IL-1R1 signaling. Deubiquitinating enzyme A (DUBA), which selectively cleaves K63-linked ubiquitin chains from TRAF3, was up-regulated in the absence of IL-1R1 signaling. DUBA short interference RNA augmented the TLR9-dependent type I IFN response. Mice deficient in IL-1RI signaling showed reduced expression of IL-10 and type I IFN and increased susceptibility to dextran sulphate sodium-induced colitis and failed to mount a protective type I IFN response after TLR9 ligand (CpG) administration. Our data identifies a new molecular pathway by which IL-1 signaling attenuates TLR9-mediated proinflammatory responses.

Gekara, N. O., et al. (2009). "Signals triggered by a bacterial pore-forming toxin contribute to toll-like receptor redundancy in gram-positive bacterial recognition." J Infect Dis 199(1): 124-133. PubMed

BACKGROUND: Toll-like receptor (TLR) 2 is the principal recognition receptor for gram-positive microbes. However, in some gram-positive bacterial infections, TLR2 is dispensable. One of the outstanding questions regarding host-bacteria interactions is why TLR2 is essential in some infections but dispensable in others. METHODS: We used a combination of bacterial plating, flow cytometry, enzyme-linked immunosorbent assay, and reverse-transcriptase polymerase chain reaction to analyze the inflammatory responses induced by Listeria monocytogenes and its toxin listeriolysin O (LLO) in vitro and in vivo. We analyzed wild-type, TLR2(-/-)-, TLR4(-/-)-, MyD88(-/-)-, interleukin (IL)-1beta(-/-)-, and IL-18(-/-)-deficient mice and the bone marrow-derived mast cells obtained from these respective groups. RESULTS: TLR2(-/-) mice had unaltered L. monocytogenes clearance and did not experience impairment of cytokine/chemokine induction and neutrophil mobilization by L. monocytogenes or purified LLO, but they were unresponsive to the LLO-deficient mutant L. monocytogenes (LmDeltahly). We show that L. monocytogenes and LLO mediate such responses in part via interleukin (IL)-1beta and IL-18-MyD88 pathways. CONCLUSIONS: The results illustrate that signals triggered by LLO contribute to TLR2 redundancy in recognition of L. monocytogenes. Under normal conditions, multiple and, sometimes, redundant pathways cooperate to induce a rapid antimicrobial defense. When one signaling pathway-in this case, TLR2-is removed from the system, the other pathways are still capable of mounting a sufficient response to ensure survival of the host.