Pharmacokinetics and pharmacodynamics of pegylated interferon lambda-1 in cynomolgus monkeys.

Type III lambda interferons (IFNs) have activity similar to type I IFNs, but a more restricted receptor distribution. A pegylated human IFN lambda-1 (pegIFNλ) is under development for chronic hepatitis C. Induction of receptor signaling (STAT1 phosphorylation) and expression of interferon-stimulated genes (ISGs) by pegIFNλ were assessed in, respectively, cynomolgus monkey leukocyte subsets and hepatocytes stimulated in vitro. ISG induction by pegIFNλ or IFNα was also assessed in peripheral leukocytes and liver biopsies after single and repeat (x3) dosing of pegIFNλ (0.03, 0.3, 3.0 mg/kg) or unpegylated IFNα-2b (10(7) IU/kg). Single-dose pharmacokinetics of pegIFNλ were evaluated. Strong ISG induction occurred in cultured hepatocytes and liver biopsies with both pegIFNλ and IFNα. However, STAT1 phosphorylation, MHC class 1 upregulation, and ISG induction in leukocytes only occurred with IFNα. Serum neopterin was unaffected by pegIFNλ; however, ß-2-microglobulin was elevated at all doses. The terminal half-life of pegIFNλ was 23 h with a 59 mL/kg volume of distribution, consistent with other pegylated IFNs. Serum exposure was dose-proportional across the dosing range. These data demonstrate the suitability of cynomolgus monkeys for the preclinical evaluation of pegIFNλ. Additionally, the absence of pegIFNλ pharmacologic activity in leukocytes is consistent with its low receptor expression in blood.

IL-28A (IFN-λ2) modulates lung DC function to promote Th1 immune skewing and suppress allergic airway disease.

IL-28 (IFN-λ) cytokines exhibit potent antiviral and antitumor function but their full spectrum of activities remains largely unknown. Recently, IL-28 cytokine family members were found to be profoundly down-regulated in allergic asthma. We now reveal a novel role of IL-28 cytokines in inducing type 1 immunity and protection from allergic airway disease. Treatment of wild-type mice with recombinant or adenovirally expressed IL-28A ameliorated allergic airway disease, suppressed Th2 and Th17 responses and induced IFN-γ. Moreover, abrogation of endogenous IL-28 cytokine function in IL-28Rα(-/-) mice exacerbated allergic airway inflammation by augmenting Th2 and Th17 responses, and IgE levels. Central to IL-28A immunoregulatory activity was its capacity to modulate lung CD11c(+) dendritic cell (DC) function to down-regulate OX40L, up-regulate IL-12p70 and promote Th1 differentiation. Consistently, IL-28A-mediated protection was absent in IFN-γ(-/-) mice or after IL-12 neutralization and could be adoptively transferred by IL-28A-treated CD11c(+) cells. These data demonstrate a critical role of IL-28 cytokines in controlling T cell responses in vivo through the modulation of lung CD11c(+) DC function in experimental allergic asthma.

Interferon lambda as a potential new therapeutic for hepatitis C.

Interferon lambdas (IFN-lambda) are Type III interferons with biological activity, including induction of antiviral genes, similar to Type I IFNs, but signal through a distinct receptor complex. The expression pattern for the IFN-lambda receptor is more cell specific than the widely distributed IFN-alpha receptor, suggesting in vivo, IFN-lambda may have fewer side effects than IFN-alpha, such as less hematologic toxicities. A PEGylated form of IFN-lambda (PEG-rIL-29) was well tolerated in animals and did not result in hematologic toxicity. Clinical data from initial studies of PEG-rIL-29 has demonstrated antiviral effects in patients with hepatitis C without producing hematologic toxicity. These preclinical and early clinical data support PEG-rIL-29 as a potential new therapeutic agent for treatment of patients with hepatitis C.

Interleukin-29 uses a type 1 interferon-like program to promote antiviral responses in human hepatocytes.

Interleukin-28A (IL-28A), IL-28B and IL-29 are a family of class II cytokines that stimulate antiviral responses through a heterodimeric receptor that is distinct from the type I interferon (IFN) receptor. To better understand how this newly described family of cytokines regulates the antiviral state, we compared various cellular responses elicited by IL-29 and IFN-alpha. Here we show that these cytokines stimulate similar patterns of signal transducer and activator of transcription 1 (STAT-1), -2, -3, and -5 phosphorylation and nearly identical patterns of gene expression when analyzed in two distinct cell types by microarray analysis. Interestingly, the IL-29 receptor is preferentially expressed on primary hepatocytes within normal liver and pegylated forms of IL-29 and IFN-alpha induced equivalent 2'5' oligoadenylate synthetase (OAS) and MX1 gene expression in this cell type. Pegylated IL-29 also produced a significant reduction in human hepatitis B and hepatitis C viral load in vitro and reduced the cytopathic effect caused by the fully replicating flavivirus, West Nile virus. In conclusion, IL-29 and IFN-alpha stimulate identical antiviral responses despite their utilization of different receptors. This fact, combined with significant receptor expression in hepatitis virus-infected livers, suggests that IL-29 may have therapeutic value against chronic viral hepatitis in human patients.

Gene expression and antiviral activity of alpha/beta interferons and interleukin-29 in virus-infected human myeloid dendritic cells.

Dendritic cells (DCs) respond to microbial infections by undergoing phenotypic maturation and by producing multiple cytokines. In the present study, we analyzed the ability of influenza A and Sendai viruses to induce DC maturation and activate tumor necrosis factor alpha (TNF-alpha), alpha/beta interferon (IFN-alpha/beta), and IFN-like interleukin-28A/B (IFN-lambda2/3) and IL-29 (IFN-lambda1) gene expression in human monocyte-derived myeloid DCs (mDC). The ability of influenza A virus to induce mDC maturation or enhance the expression of TNF-alpha, IFN-alpha/beta, interleukin-28 (IL-28), and IL-29 genes was limited, whereas Sendai virus efficiently induced mDC maturation and enhanced cytokine gene expression. Influenza A virus-induced expression of TNF-alpha, IFN-alpha, IFN-beta, IL-28, and IL-29 genes was, however, dramatically enhanced when cells were pretreated with IFN-alpha. IFN-alpha priming led to increased expression of Toll-like receptor 3 (TLR3), TLR7, TLR8, MyD88, TRIF, and IFN regulatory factor 7 (IRF7) genes and enhanced influenza-induced phosphorylation and DNA binding of IRF3. Influenza A virus also enhanced the binding of NF-kappaB to the respective NF-kappaB elements of the promoters of IFN-beta and IL-29 genes. In mDC IL-29 induced MxA protein expression and possessed antiviral activity against influenza A virus, although this activity was lower than that of IFN-alpha or IFN-beta. Our results show that in human mDCs viruses can readily induce the expression of IL-28 and IL-29 genes whose gene products are likely to contribute to the host antiviral response.

IL-28, IL-29 and their class II cytokine receptor IL-28R.

Cytokines play a critical role in modulating the innate and adaptive immune systems. Here, we have identified from the human genomic sequence a family of three cytokines, designated interleukin 28A (IL-28A), IL-28B and IL-29, that are distantly related to type I interferons (IFNs) and the IL-10 family. We found that like type I IFNs, IL-28 and IL-29 were induced by viral infection and showed antiviral activity. However, IL-28 and IL-29 interacted with a heterodimeric class II cytokine receptor that consisted of IL-10 receptor beta (IL-10Rbeta) and an orphan class II receptor chain, designated IL-28Ralpha. This newly described cytokine family may serve as an alternative to type I IFNs in providing immunity to viral infection.