Interleukin-10 (IL-10), first recognized for its ability to inhibit activation and effector function of T cells, monocytes, and macrophages, is a multifunctional cytokine with diverse effects on most hemopoietic cell types. The principal routine function of IL-10 appears to be to limit and ultimately terminate inflammatory responses. In addition to these activities, IL-10 regulates growth and/or differentiation of B cells, NK cells, cytotoxic and helper T cells, mast cells, granulocytes, dendritic cells, keratinocytes, and endothelial cells. IL-10 plays a key role in differentiation and function of a newly appreciated type of T cell, the T regulatory cell, which may figure prominently in control of immune responses and tolerance in vivo. Uniquely among hemopoietic cytokines, IL-10 has closely related homologs in several virus genomes, which testify to its crucial role in regulating immune and inflammatory responses. This review highlights findings that have advanced our understanding of IL-10 and its receptor, as well as its in vivo function in health and disease.

Interleukin-10 and the interleukin-10 receptor.

A large number of changes, distant from the site or sites of inflammation and involving many organ systems, may accompany inflammation. In 1930 interest was focused on these changes by the discovery of C-reactive protein (so named because it reacted with the pneumococcal C-polysaccharide) in the plasma of patients during the acute phase of pneumococcal pneumonia.1 Accordingly, these systemic changes have since been referred to as the acute-phase response,2 even though they accompany both acute and chronic inflammatory disorders. New acute-phase phenomena continue to be recognized, and the mechanisms mediating them are becoming better understood. This review summarizes much of . . .

Acute-Phase Proteins and Other Systemic Responses to Inflammation

Biologic basis for interleukin-1 in disease

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(05)71142-9.pdf

Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders.

More than any other cytokine family, the interleukin (IL)-1 family is closely linked to the innate immune response. This linkage became evident upon the discovery that the cytoplasmic domain of the IL-1 receptor type I is highly homologous to the cytoplasmic domains of all Toll-like receptors (TLRs). Thus, fundamental inflammatory responses such as the induction of cyclooxygenase type 2, increased expression of adhesion molecules, or synthesis of nitric oxide are indistinguishable responses of both IL-1 and TLR ligands. Both families nonspecifically affect antigen recognition and lymphocyte function. IL-1β is the most studied member of the IL-1 family because of its role in mediating autoinflammatory diseases. Although the TLR and IL-1 families evolved to assist in host defense against infection, unlike the TLR family, the IL-1 family also includes members that suppress inflammation, both specifically within the IL-1 family but also nonspecifically for TLR ligands and the innate immune response.

Immunological and Inflammatory Functions of the Interleukin-1 Family

The discovery of 3-(N-alkyl)aminopropylphosphonic acids as potent S1P receptor agonists.

L-749,345 is a carbapenem antibiotic, currently in phase II clinical trials, which possesses a broad antibacterial spectrum and extended half-life. The time courses of levels of the drugs in plasma and urinary recovery were evaluated for L-749,345, imipenem-cilastatin (IPM), and ceftriaxone (CTX) in male rhesus monkeys (Macaca mulatta) and a chimpanzee (Pan troglodytes). The chimpanzee pharmacokinetics was predictive of human results and indicated a compound that was superior to IPM and approached CTX in its ability to persist in the circulation. Levels of binding to protein, in the range of clinically relevant concentrations in serum, are virtually equivalent for L-749,345 and CTX in humans. Results of a crossover bioassay versus those of a high-pressure liquid chromatography assay of 1-g human samples showed that there were no bioactive metabolites of L-749,345. The extended half-life at elimination phase of L-749,345 allows consideration of single daily dosing. In contrast to results with IPM, the improved stability of L-749,345 with respect to hydrolysis by the renal dehydropeptidase I (0.25 times the rate of IPM) results in urinary recovery sufficient for the drug9s use as a single agent.

Pharmacokinetics of L-749,345, a long-acting carbapenem antibiotic, in primates.

The effect of in vivo treatment with anti-CD11b (MAC-1) antibody (Ab) was examined in an inflammatory disease model, the viable moth-eaten (mev) mutant mouse. The autosomal recessive mev gene occurred spontaneously as a point mutation of the hematopoietic cell protein tyrosine phosphatase in C57BL/6 mice. Homozygotes (mev/mev) develop a chronic myelomonocytic inflammation, involving accumulation of myelomonocytic cells in lungs and skin, resulting in interstitial pneumonitis and severe edema in the paws. These mice also exhibit abnormalities in lymphoid development, thymic atrophy, with T cell and NK cell dysfunction. These inflammatory changes are transferrable by bone marrow cells of mev/mev mice, indicating that mev mutation is due to a stem cell defect in the myelomonocytic pathway. An anti-CD-11b (5C6) Ab inhibited the immunopathologic changes in the bone marrow chimeras, when the Ab treatment was initiated on day -1 or day 0 of the bone marrow transplant. The lungs, paws, and thymus all remained normal after treatment. Furthermore, the Ab also delayed the onset of the mev syndromes when the Ab was given 10 days after the bone marrow transfer. Therefore anti-CD11b Ab inhibited inflammation both prophylactically and therapeutically, and restored normal function of T and NK cells in this disease model. These results support the contention that CD11b molecules expressed in the myelomonocytic cells play a critical role in this naturally occurring inflammatory disease.

Anti-CD11b antibody prevents immunopathologic changes in viable moth-eaten bone marrow chimeric mice.

Sphingosine-1-phosphate (S1P) has been considered to play an important role in ischemia/reperfusion (I/R) injury. We used SEW2871 (SEW), a novel receptor-selective agonist for S1P1, to elucidate the role of S1P1 in myocardial I/R. Isolated perfused rat hearts exposed to S1P (1 and 10 mM) or SEW (1 and 0.1 mM) were subjected to 30 minutes of global no-flow ischemia and 2 hours of reperfusion. S1P at 1 and 10 mM significantly reduced infarct size and CK release compared with vehicle-control. The effect of 0.1 microM SEW on infarct size was modest. After I/R, S1P at both doses and SEW at 0.1 microM improved developed pressure (LVDP). SEW at 1 mM significantly prolonged the duration of ventricular tachycardia and ventricular fibrillation, leading to irreversible reperfusion tachyarrhythmias in 60% of the hearts. This is the first demonstration of the critical role of the S1P1 receptor in I/R injury.

Hugh Rosen

Papers

The discovery of 3-(N-alkyl)aminopropylphosphonic acids as potent S1P receptor agonists.

Pharmacokinetics of L-749,345, a long-acting carbapenem antibiotic, in primates.

Anti-CD11b antibody prevents immunopathologic changes in viable moth-eaten bone marrow chimeric mice.

S1P1-selective agonist SEW2871 exacerbates reperfusion arrhythmias.

Author response: Small molecule proteostasis regulators that reprogram the ER to reduce extracellular protein aggregation