Functional domains of HSP70 stimulate generation of cytokines and chemokines, maturation of dendritic cells and adjuvanticity

2004 ◽  
Vol 32 (4) ◽  
pp. 629-632 ◽  
Author(s):  
T. Lehner ◽  
Y. Wang ◽  
T. Whittall ◽  
E. McGowan ◽  
C.G. Kelly ◽  
...  

Microbial HSP70 (heat-shock protein 70) consists of three functionally distinct domains: an N-terminal 44 kDa ATPase portion (amino acids 1–358), followed by an 18 kDa peptide-binding domain (amino acids 359–494) and a C-terminal 10 kDa fragment (amino acids 495–609). Immunological functions of these three different domains in stimulating monocytes and dendritic cells have not been fully defined. However, the C-terminal portion (amino acids 359–610) stimulates the production of CC chemokines, IL-12 (interleukin-12), TNFα(tumour necrosis factor α), NO and maturation of dendritic cells and also functions as an adjuvant in the induction of immune responses. In contrast, the ATPase domain of microbial HSP70 mostly lacks these functions. Since the receptor for HSP70 is CD40, which with its CD40 ligand constitutes a major co-stimulatory pathway in the interaction between antigen-presenting cells and T-cells, HSP70 may function as an alternative ligand to CD40L. HSP70–CD40 interaction has been demonstrated in non-human primates to play a role in HIV infection, in protection against Mycobacterium tuberculosis and in conversion of tolerance to immunity.

Blood ◽  
2004 ◽  
Vol 104 (9) ◽  
pp. 2810-2817 ◽  
Author(s):  
Anna Smed-Sörensen ◽  
Karin Loré ◽  
Lilian Walther-Jallow ◽  
Jan Andersson ◽  
Anna-Lena Spetz

Abstract Dendritic cells (DCs) are antigen-presenting cells with the capacity to prime naive T cells for efficient cellular responses against pathogens such as HIV-1. DCs are also susceptible to HIV-1 infection, which may impair their ability to induce immunity. Here, we examined the ability of HIV-1-infected, in vitro-derived DCs to respond to CD40 ligand (CD40L) stimulation with the aim to study events during early HIV-1 infection. HIV-1BaL-infected p24+ DCs were detected after only 3 days of exposure to highly concentrated virus. We show that HIV-1-infected DCs up-regulated costimulatory molecules, but were skewed in their production of effector cytokines in response to CD40L stimulation. CD40L stimulation induced significant secretion of tumor necrosis factor α (TNFα) and interleukin 12 (IL-12) p70 from both HIV-1-exposed and unexposed DCs. Intracellular stainings of HIV-1-exposed DCs revealed that TNFα could be detected in both the p24- and p24+ DCs, but IL-12 p70 could be found only in the p24- DCs. Thus, although p24+ DCs showed a mature phenotype similar to p24- DCs after CD40L stimulation, they appeared to have an impaired cytokine profile. These observations suggest that HIV-1 infection disables DC function, a phenomenon that may be relevant for optimal induction of HIV-1-specific immune responses. (Blood. 2004;104:2810-2817)


Blood ◽  
1998 ◽  
Vol 91 (9) ◽  
pp. 3112-3117 ◽  
Author(s):  
Claudia Rieser ◽  
Christine Papesh ◽  
Manfred Herold ◽  
Günther Böck ◽  
Reinhold Ramoner ◽  
...  

The endotoxin (lipopolysaccharide)-induced cytokine response is followed by a state of unresponsiveness to lipopolysaccharide (LPS) referred to as LPS tolerance or endotoxin desensitization. LPS tolerance, which can be experimentally induced in vitro and in vivo, is also known to occur in septic disease. Here, we evaluated whether dendritic cells (DC), the most potent antigen-presenting cells, are also subject to this phenomenon. Single doses of LPS added at the initiation of DC culture inhibited in a dose-dependent fashion the production of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and IL-12, but not the production of IL-8, in response to a second LPS challenge in day-5 DC. In addition, the LPS-induced expression of the CD83 maturation antigen was inhibited in these cells. Moreover, the endocytic activity of DC generated in the presence of LPS was dramatically reduced. DC desensitized with LPS were potent stimulators of T-cell proliferation but poor inducers of interferon-γ (IFN-γ) production in the allogeneic mixed leukocyte reaction. TNF-α and prostaglandin E2, two major products of LPS stimulation, could replace LPS for the induction of tolerance to LPS. Moreover, treatment of desensitized DC with TNF-α plus prostaglandin E2 fully restored CD83 expression and partially restored IL-12 production as well as the IFN-γ–inducing activity of DC in the mixed leukocyte reaction. Our data show that human DC are highly susceptible to the induction of LPS tolerance, which seems to be a state of differential deactivation in which some functions are impaired whereas others are retained. Tolerization at the level of the professional antigen-presenting cell by inflammatory mediators may play an important role in septic disease and in the origin of cancers associated with chronic inflammation.


2008 ◽  
Vol 83 (3) ◽  
pp. 1216-1227 ◽  
Author(s):  
Fan-ching Lin ◽  
Yue Peng ◽  
Leslie A. Jones ◽  
Paulo H. Verardi ◽  
Tilahun D. Yilma

ABSTRACT A vaccine for the prevention of human immunodeficiency virus (HIV) infection is desperately needed to control the AIDS pandemic. To address this problem, we developed vesicular stomatitis virus glycoprotein-pseudotyped replication-defective simian immunodeficiency viruses (dSIVs) as an AIDS vaccine strategy. The dSIVs retain characteristics of a live attenuated virus without the drawbacks of potential virulence caused by replicating virus. To improve vaccine immunogenicity, we incorporated CD40 ligand (CD40L) into the dSIV envelope. CD40L is one of the most potent stimuli for dendritic cell (DC) maturation and activation. Binding of CD40L to its receptor upregulates expression of major histocompatibility complex class I, class II, and costimulatory molecules on DCs and increases production of proinflammatory cytokines and chemokines, especially interleukin 12 (IL-12). This cytokine polarizes CD4+ T cells to Th1-type immune responses. DC activation and mixed lymphocyte reaction (MLR) studies were performed to evaluate the immunogenicity of CD40L-dSIV in vitro. Expression levels of CD80, CD86, HLA-DR, and CD54 on DCs transduced with the dSIV incorporating CD40L (CD40L-dSIV) were significantly higher than on those transduced with dSIV. Moreover, CD40L-dSIV-transduced DCs expressed up to 10-fold more IL-12 than dSIV-transduced DCs. CD40L-dSIV-transduced DCs enhanced proliferation and gamma interferon secretion by naive T cells in an MLR. In addition, CD40L-dSIV-immunized mice exhibited stronger humoral and cell-mediated immune responses than dSIV-vaccinated animals. The results show that incorporating CD40L into the dSIV envelope significantly enhances immunogenicity. As a result, CD40L-dSIVs can be strong candidates for development of a safe and highly immunogenic AIDS vaccine.


Blood ◽  
1998 ◽  
Vol 91 (9) ◽  
pp. 3112-3117 ◽  
Author(s):  
Claudia Rieser ◽  
Christine Papesh ◽  
Manfred Herold ◽  
Günther Böck ◽  
Reinhold Ramoner ◽  
...  

Abstract The endotoxin (lipopolysaccharide)-induced cytokine response is followed by a state of unresponsiveness to lipopolysaccharide (LPS) referred to as LPS tolerance or endotoxin desensitization. LPS tolerance, which can be experimentally induced in vitro and in vivo, is also known to occur in septic disease. Here, we evaluated whether dendritic cells (DC), the most potent antigen-presenting cells, are also subject to this phenomenon. Single doses of LPS added at the initiation of DC culture inhibited in a dose-dependent fashion the production of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and IL-12, but not the production of IL-8, in response to a second LPS challenge in day-5 DC. In addition, the LPS-induced expression of the CD83 maturation antigen was inhibited in these cells. Moreover, the endocytic activity of DC generated in the presence of LPS was dramatically reduced. DC desensitized with LPS were potent stimulators of T-cell proliferation but poor inducers of interferon-γ (IFN-γ) production in the allogeneic mixed leukocyte reaction. TNF-α and prostaglandin E2, two major products of LPS stimulation, could replace LPS for the induction of tolerance to LPS. Moreover, treatment of desensitized DC with TNF-α plus prostaglandin E2 fully restored CD83 expression and partially restored IL-12 production as well as the IFN-γ–inducing activity of DC in the mixed leukocyte reaction. Our data show that human DC are highly susceptible to the induction of LPS tolerance, which seems to be a state of differential deactivation in which some functions are impaired whereas others are retained. Tolerization at the level of the professional antigen-presenting cell by inflammatory mediators may play an important role in septic disease and in the origin of cancers associated with chronic inflammation.


Author(s):  
Kaveh Rahimi ◽  
Kambiz Hassanzadeh ◽  
Hashem Khanbabaei ◽  
Saeed Mohammadian Haftcheshmeh ◽  
Abbas Ahmadi ◽  
...  

: Dendritic cells (DCs) are the most powerful antigen-presenting cells which link the innate and adaptive immune responses. Depending on the context DCs initiate the immune responses or contribute to immune tolerance. Any disturbance in their phenotypes and functions may initiate inflammatory or autoimmune diseases. Hence, dysregulated DCs are the most attractive pharmacological target for the development of new therapies aiming at reducing their immunogenicity and at enhancing their tolerogenicity. Curcumin is the polyphenolic phytochemical component of the spice turmeric with a wide range of pharmacological activities. It acts in several ways as a modulator of DCs and converts them into tolerogenic DCs. Tolerogenic DCs possess anti-inflammatory and immunomodulatory activities that regulate the immune responses in health and disease. Curcumin by blocking maturation markers, cytokines and chemokines expression, and disrupting the antigen-presenting machinery of DCs render them non- or hypo-responsive to immunostimulants. It also reduces the expression of co-stimulatory and adhesion molecules on DCs and prevents them from both migration and antigen presentation but enhances their endocytosis capacity. Hence, curcumin causes DCs-inducing regulatory T cells and dampens CD4+ T helper 1 (Th1), Th2, and Th17 polarization. Inhibition of transcription factors such as NF-κB, AP-1, MAPKs (p38, JNK, ERK) and other intracellular signaling molecules such as JAK/STAT/SOCS provide a plausible explanation for most of these observations. In this review, we summarize the potential effects of curcumin on the phenotypes and functions of DCs as the key players in orchestration, stimulation, and modulation of the immune responses.


2001 ◽  
Vol 194 (8) ◽  
pp. 1021-1032 ◽  
Author(s):  
Raelene Grumont ◽  
Hubertus Hochrein ◽  
Meredith O'Keeffe ◽  
Raffi Gugasyan ◽  
Christine White ◽  
...  

Interleukin 12 (IL-12) is a 70-kD proinflammatory cytokine produced by antigen presenting cells that is essential for the induction of T helper type 1 development. It comprises 35-kD (p35) and 40-kD (p40) polypeptides encoded by separate genes that are induced by a range of stimuli that include lipopolysaccharide (LPS), DNA, and CD40 ligand. To date, the regulation of IL-12 expression at the transcriptional level has mainly been examined in macrophages and restricted almost exclusively to the p40 gene. Here we show that in CD8+ dendritic cells, major producers of IL-12 p70, the Rel/nuclear factor (NF)-κB signaling pathway is necessary for the induction of IL-12 in response to microbial stimuli. In contrast to macrophages which require c-Rel for p40 transcription, in CD8+ dendritic cells, the induced expression of p35 rather than p40 by inactivated Staphylococcus aureus, DNA, or LPS is c-Rel dependent and regulated directly by c-Rel complexes binding to the p35 promoter. This data establishes the IL-12 p35 gene as a new target of c-Rel and shows that the regulation of IL-12 p70 expression at the transcriptional level by Rel/NF-κB is controlled through both the p35 and p40 genes in a cell type–specific fashion.


1998 ◽  
Vol 188 (11) ◽  
pp. 2075-2082 ◽  
Author(s):  
Bali Pulendran ◽  
J.L. Smith ◽  
M. Jenkins ◽  
M. Schoenborn ◽  
E. Maraskovsky ◽  
...  

Injections of soluble proteins are poorly immunogenic, and often elicit antigen-specific tolerance. The mechanism of this phenomenon has been an enduring puzzle, but it has been speculated that tolerance induction may be due to antigen presentation by poorly stimulatory, resting B cells, which lack specific immunoglobulin receptors for the protein. In contrast, adjuvants, or infectious agents, which cause the release of proinflammatory cytokines such as tumor necrosis factor α and interleukin 1β in vivo are believed to recruit and activate professional antigen-presenting cells to the site(s) of infection, thereby eliciting immunity. Here we show that administration of Flt3 ligand (FL), a cytokine capable of inducing large numbers of dendritic cells (DCs) in vivo, (a) dramatically enhances the sensitivity of antigen-specific B and T cell responses to systemic injection of a soluble protein, through a CD40–CD40 ligand–dependent mechanism; (b) influences the class of antibody produced; and (c) enables productive immune responses to otherwise tolerogenic protocols. These data support the hypothesis that the delicate balance between immunity and tolerance in vivo is pivotally controlled by DCs, and underscore the potential of FL as a vaccine adjuvant for immunotherapy in infectious disease and other clinical settings.


2002 ◽  
Vol 70 (7) ◽  
pp. 3874-3880 ◽  
Author(s):  
Sandrine Henri ◽  
Joan Curtis ◽  
Hubertus Hochrein ◽  
David Vremec ◽  
Ken Shortman ◽  
...  

ABSTRACT Dendritic cells (DCs) are professional antigen-presenting cells which initiate and regulate T-cell immune responses. Here we show that murine splenic DCs can be ranked on the basis of their ability to phagocytose and harbor the obligately intracellular parasite Leishmania major. CD4+ CD8− DCs are the most permissive host cells for L. major amastigotes, followed by CD4− CD8− DCs; CD4− CD8+ cells are the least permissive. However, the least susceptible CD4− CD8+ DC subset was the best interleukin-12 producer in response to infection. Infection did not induce in any DC subset production of the proinflammatory cytokine gamma interferon and nitric oxide associated with the induction of Th1 responses. The number of parasites phagocytosed by DCs was low, no more than 3 organisms per cell, compared to more than 10 organisms per macrophage. In infected DCs, the parasites are located in a parasitophorous vacuole containing both major histocompatibility complex (MHC) class II and lysosome-associated membrane protein 1 molecules, similar to their location in the infected macrophage. The parasite-driven redistribution of MHC class II to this compartment indicates that infected DCs should be able to present parasite antigen.


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