The ALF-161 monoclonal antibody reacts with precursor, secreted and membrane-associated forms of mouse IL-1α (interleukin 1 alpha) also known as lymphocyte activating factor (LAF and mononuclear cell factor (MCF). IL-1α is a 17 kDa pro-inflammatory cytokine produced by a variety of cells, including macrophages, dendritic cells, T and B lymphocytes. IL-1α exerts a wide range of immune and inflammatory responses on a many cell types including lymphocytes, epithelial cells and fibroblasts. 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, a 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 ALF-161 antibody has been shown to neutralize the bioactivity of natural or recombinant IL-1α.'

InVivoMAb anti-mouse IL-1α (Clone: ALF-161)

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.

Rogers, H. W., et al. (1992). "Interleukin 1 participates in the development of anti-Listeria responses in normal and SCID mice." Proc Natl Acad Sci U S A 89(3): 1011-1015. PubMed

Using T- and B-cell deficient C.B-17 mice with the scid mutation, we have previously documented the existence of a T-cell-independent but interferon gamma-dependent pathway of macrophage activation that confers upon the host partial resistance to the facultative intracellular bacterium Listeria monocytogenes. This pathway is operative in both normal and SCID mice and consists of at least four components: interferon gamma, tumor necrosis factor, macrophages, and natural killer cells. Here we demonstrate that interleukin 1 also participates in this pathway but at a different site of action. Using monoclonal antibodies that neutralize the biologic activities of interleukin 1 alpha and interleukin 1 beta, we document that interleukin 1 participates neither directly in the induction of interferon gamma from isolated SCID natural killer cells nor in the antigen-specific activation of CD4+ T cells derived from Listeria-immune C.B-17 mice. In contrast, injection of a mixture of anti-interleukin 1 alpha, anti-interleukin 1 beta, and a newly derived monoclonal antibody specific for the murine type I interleukin-1 receptor into either SCID or normal C.B-17 mice blocked the in vivo elaboration of class II major histocompatibility complex-positive macrophages after infection of the animals with Listeria. Moreover, SCID mice treated with the anti-interleukin-1 mixture failed to control the growth of Listeria in vivo and eventually succumbed to the infection. These results document that endogenously produced interleukin 1 plays an obligate role in the Listeria-dependent induction of activated macrophages in vivo and demonstrate that the action of interleukin 1 is distinct from the generation of natural killer cell-derived interferon gamma.