IFN type I and type II independent enhancement of B cell TLR7 expression by natural killer cells

Role of natural killer and B cell interaction in inducing pathogen specific immune responses

The innate lymphoid cell (ILC) system comprising of the circulating and tissue-resident cells is known to clear infectious pathogens, establish immune homeostasis as well as confer antitumor immunity. Human natural killer cells (hNKs) and other ILCs carry out mopping of the infectious pathogens and perform cytolytic activity regulated by the non-adaptive immune system. The NK cells generate immunological memory and rapid recall response tightly regulated by the adaptive immunity. The interaction of NK and B cell, and its role to induce the pathogen specific immunity is not fully understood. Hence, present article sheds light on the interaction between NK and B cells and resulting immune responses in the infectious diseases. The immune responses elicited by the NK-B cell interaction is of particular importance for developing therapeutic vaccines against the infectious pathogens. Further, experimental evidences suggest the immune-response driven by NK cell population elicits the host-specific antibodies and memory B cells. Also, recently developed humanized immune system (HIS) mice and their importance in to understanding the NK-B cell interaction and resulting pathogen specific immunity has been discussed.

Recombinant virus expressing hIFN-λ1 (rL-hIFN-λ1) has important effects on endoplasmic reticulum stress, autophagy and apoptosis in small cell lung cancer

BACKGROUND

Small cell lung cancer (SCLC) is an aggressive tumor with a poor prognosis. Human IFN-λ1 (IL-29), belonging to the type III IFN family, captured increasing attention recently due to its crucial role in developing tumors. Recent studies have revealed that the recombinant Newcastle Disease Virus (NDV) expressing human IFN-λ1 (rL-hIFN-λ1) plays a critical role in the development of tumors. However, the role of rL-hIFN-λ1 in SCLC is still unknown.

METHODS

We determined the concentration of the virus intervention, followed by successfully infection in virus. We also investigated the effects of rL-hIFN-λ1 on endoplasmic reticulum stress (ERS), apoptosis and autophagy in H446 cells, and explored the interaction among the three.

RESULTS

We found that the ERS, autophagy and apoptosis related proteins were significantly upregulated after infected with rL-hIFN-λ1 or NDV. In addition, both 4-phenylbutyric acid (4-PBA) or 3-Methyladenine (3-MA) could downregulate the expression of related proteins which increased by rL-hIFN-λ1. Furthermore, we found that both B-cell lymphoma-2 (BCL-2) knockdown or Rapamycin (Rapa) could increase ERS, autophagy and apoptosis.

CONCLUSIONS

Our findings suggest that rL-hIFN-λ1 can induce ERS, autophagy and apoptosis in SCLC H446 cells, particularly, autophagy plays an important role during this process. Furthermore, rL-hIFN-λ1 might provide a potential biological treatment target for lung cancer treatment.

Type of RNA Packed in VLPs Impacts IgG Class Switching-Implications for an Influenza Vaccine Design

Nucleic acid packed within virus-like particles (VLPs) is shown to shape the immune response and to induce stronger B cell responses in different immunisation models. Here, using a VLP displaying the highly conserved extracellular domain of the M2 protein (M2e) from the influenza viruses as an antigen, we demonstrate that the type of RNA packaged into VLPs can alter the quality of the induced humoral response. By comparing prokaryotic RNA (pRNA), eukaryotic RNA (eRNA) and transfer RNA (tRNA), we find that pRNA induces the most protective IgG subclasses using a murine influenza model. We provide evidence that this process is predominantly dependent on endosomal Toll-like receptor (TLR7), and rule out a role for cytoplasmic mitochondrial antiviral signalling protein (MAVS) and its upstream retinoic acid-inducible gene-I-like receptors (RIG-I). Our findings provide considerations for the rational design of VLP-based vaccines and the immunomodulation exerted by TLR7 ligands packaged within the particles. Based on this work, we conclude that VLPs packing prokaryotic RNA must be preferred whenever a response dominated by IgG2 is desired, while eukaryotic RNA should be employed in order to induce a response dominated by IgG1.

Harnessing Nanoparticles for Immunomodulation and Vaccines

The first successful use of nanoparticles (NPs) for vaccination was reported almost 40 years ago with a virus-like particle-based vaccine against Hepatitis B. Since then, the term NP has been expanded to accommodate a large number of novel nano-sized particles engineered from a range of materials. The great interest in NPs is likely not only a result of the two successful vaccines against hepatitis B and Human Papilloma Virus (HPV) that use this technology, but also due to the versatility of those small-sized particles, as indicated by the wide range of applications reported so far, ranging from medicinal and cosmetics to purely technical applications. In this review, we will focus on the use of NPs, especially virus-like particles (VLPs), in the field of vaccines and will discuss their employment as vaccines, antigen display platforms, adjuvants and drug delivery systems.

IFN-λ is able to augment TLR-mediated activation and subsequent function of primary human B cells

During the past decade, increased emphasis has been placed on finding alternatives to IFN-α-based therapies. One such alternative, IFN-λ, has shown therapeutic promise in a variety of diseases, but research of this family of cytokines has been primarily focused on their antiviral activities. The goal of the present study was to investigate the role of IFN-λ in the regulation and modulation of B cell function. We show that, similar to IFN-α, IFN-λ1 is able to augment TLR-mediated B cell activation, partially attributed to an upregulation of TLR7 expression, and that both naïve and memory B cells express the limiting type III IFN receptor component, IFN-λR1. Furthermore, this IFN-λ-enhanced B cell activation resulted in increased cytokine and Ig production during TLR7 challenge, most prominently after the addition of helper T cell signals. Ultimately, these elevated cytokine and Ig levels could be partially attributed to the increase in proliferation of TLR7-challenged B cells by both type I and type III IFNs. These findings demonstrate the ability of IFN-λ to boost humoral immunity, an important attribute to consider for further studies on immunity to pathogens, vaccine development, and ongoing advancement of therapeutic strategies aimed at replacing IFN-α-based treatments with IFN-λ.

Chronic lymphocytic leukaemia cells become both activated and immunosuppressive following interaction with CD3 and CD28 stimulated PBMC

Chronic lymphocytic leukaemia (CLL) is associated with immunosuppression. The activation of CLL cells induced by interaction with other cell types, particularly activated T-cells, within the tumour micro-environment is thought to be important for CLL progression. However it is unclear whether activated CLL cells (CLL(Act)) have immunosuppressive capacity. We report that co-culture of CLL cells with normal PBMC in the context of CD3/CD28 T-cell activation generates CLL(Act) with increased CD38 expression that are capable of suppressing the proliferative responses of both CD4+ and CD8+ T-cells. The suppression required cell contact but did not involve induction of T-cell apoptosis.

IL-12 secretion by Langerhans cells stimulated with Candida skin test reagent is mediated by dectin-1 in some healthy individuals

OBJECTIVE

Our group and others have shown that serial intra-lesional injections of common warts with skin testing reagents such as Candida, mumps and Trichophyton are effective in regressing injected and non-injected warts. Anti-HPV T-cell responses appear to be induced. The goal of this study was to understand the mechanisms of how Candida skin testing reagent enhances immune responses.

METHODS

The following immunological features were studied to understand how Candida induces immune responses in healthy subjects: (1) proliferative capacity of T-cells upon exposure to Candida through monocyte-derived human Langerhans cells (LCs) measured using alamarBlue, (2) cytokine (IL-1β, IL-6, IL-8, IL-10, IL-12p40, IL-23Ap19, IFN-γ, and TNF- expression upon Candida stimulation of LCs by quantitative reverse transcription (qRT)-PCR and cytokine secretion by ELISA, (3) expression of pattern recognition receptors (PRRs) known to associate with Candida albicans (DC-SIGN, dectin-1, dectin-2, galectin-3, mincle, mannose receptor, Toll-like receptors 1, 2, 4, 6, and 9) on LCs by qRT-PCR, (4) role of dectin-1 in IL-12 production by antibody blocking, and (5) induction of Th1, Th2, and/or Th17 responses by intracellular cytokine staining of CD4 cells exposed to Candida pulsed LCs for IFN-γ, IL-4, and IL-17A.

RESULTS

T-cell proliferation upon stimulation with Candida-pulsed LCs was significantly higher compared to proliferation in the absence of Candida (p=0.004). The most frequently expressed cytokine in stimulated LCs was IL-12p40 mRNA, and IL-12p40 and IL-12p70 were also detected at protein levels. All other cytokine mRNAs examined were detected in the following order of decreasing frequency: IL23Ap19, IFN-γ, IL-1β, IL-6, IL-8, and IL-10. LCs expressed all PRRs examined. Anti-dectin-1 inhibited IL-12p40 mRNA production upon Candida stimulation of LCs from some healthy subjects. IFN-γ secretion was increased and IL-4 secretion was decreased in CD4 cells of a few healthy subjects, but IL-17A was essentially unchanged upon Candida treatment.

CONCLUSIONS

Proliferation of T-cells in a substantial majority of healthy subjects can be demonstrated with Candida stimulation. We show Th1 promotion and dectin-1 stimulation of LCs as potential mechanisms in some healthy subjects.

Candida skin test reagent as a novel adjuvant for a human papillomavirus peptide-based therapeutic vaccine

A vaccine adjuvant that can effectively promote cell-mediated immunity is currently not available. Because of the ability of a Candida skin test reagent injection to induce common wart regression, our group is using it as a novel adjuvant in a clinical trial of a peptide-based human papillomavirus therapeutic vaccine. The goal of this current study was to investigate the mechanisms of how Candida enhances the vaccine immune responses. Maturation effects on Langerhans cells, capacity to proliferate T-cells, expression of cytokines and pattern recognition receptors by Langerhans cells, and ability to induce Th1, Th2, and Th17 responses were investigated in healthy subjects. The vaccine, human papillomavirus peptides with Candida, demonstrated partial maturation effects on Langerhans cells indicated by significantly up-regulated CD40 (p=0.00007) and CD80 (p<0.00001) levels, and showed T-cell proliferative capacity (p<0.00001) when presented by Langerhans cells in vitro. Interestingly, the maturation effects were due to the peptides while Candida was responsible for the T-cell proliferation. The cytokine profile (IL-1β, IL-6, IL-8, IL-10, IL-12p40, IL-23Ap19, IFN-γ and TNF-α) of Langerhans cells treated with the vaccine or Candida alone showed that IL-12p40 mRNA was most frequently induced, and IL-12p70 protein was detected in the supernatants. The presence of pattern recognition receptors known to associate with Candida albicans (DC-SIGN, dectin-1, dectin-2, galectin-3, mincle, mannose receptor, Toll-like receptors-1, 2, 4, 6 and 9) were demonstrated in all subjects. On the other hand, the induction of Th1 response demonstrated by IFN-γ secretion by CD4 cells stimulated with the vaccine or Candida pulsed Langerhans cells was demonstrated only in one subject. In summary, the Langerhans cell maturation effects of the vaccine were due to the peptides while the T-cell proliferative capacity was derived from Candida, and the most frequently induced cytokine was IL-12.

Interferon-λs: special immunomodulatory agents and potential therapeutic targets

Interferon (IFN)-λs are a new addition to the old IFN family and share many similarities, such as antiviral and antiproliferative characteristics, with type I IFNs. IFN-λs also exhibit unique characteristics in immunomodulation. Accumulating studies have indicated the interactions between IFN-λs and immune cells, which lead to the regulation of the latter. IFN-λs can influence dendritic cells (DCs) and their product, IFN-λs-DCs, can then regulate the function of T cells. On the other hand, IFN-λs can also directly affect T cells through inhibition of the T helper 2 cell (Th2) responses. IFN-λs have varying immunomodulatory functions under different physiological conditions or in different organs and can inhibit tumor growth via regulation of the immune system. Diseases associated with IFN-λs include asthma, allergy, and systemic lupus erythematosus. In this review, we summarize the current knowledge of the biology of IFN-λs and their immunomodulatory function in relevant human diseases.