1
|
Convergence, plasticity, and tissue residence of regulatory T cell response via TCR repertoire prism. eLife 2024; 12:RP89382. [PMID: 38591522 PMCID: PMC11003740 DOI: 10.7554/elife.89382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024] Open
Abstract
Suppressive function of regulatory T cells (Treg) is dependent on signaling of their antigen receptors triggered by cognate self, dietary, or microbial peptides presented on MHC II. However, it remains largely unknown whether distinct or shared repertoires of Treg TCRs are mobilized in response to different challenges in the same tissue or the same challenge in different tissues. Here we use a fixed TCRβ chain FoxP3-GFP mouse model to analyze conventional (eCD4) and regulatory (eTreg) effector TCRα repertoires in response to six distinct antigenic challenges to the lung and skin. This model shows highly 'digital' repertoire behavior with easy-to-track challenge-specific TCRα CDR3 clusters. For both eCD4 and eTreg subsets, we observe challenge-specific clonal expansions yielding homologous TCRα clusters within and across animals and exposure sites, which are also reflected in the draining lymph nodes but not systemically. Some CDR3 clusters are shared across cancer challenges, suggesting a response to common tumor-associated antigens. For most challenges, eCD4 and eTreg clonal response does not overlap. Such overlap is exclusively observed at the sites of certain tumor challenges, and not systematically, suggesting transient and local tumor-induced eCD4=>eTreg plasticity. This transition includes a dominant tumor-responding eCD4 CDR3 motif, as well as characteristic iNKT TCRα CDR3. In addition, we examine the homeostatic tissue residency of clonal eTreg populations by excluding the site of challenge from our analysis. We demonstrate that distinct CDR3 motifs are characteristic of eTreg cells residing in particular lymphatic tissues, regardless of the challenge. This observation reveals the tissue-resident, antigen-specific clonal Treg populations.
Collapse
|
2
|
CD49b defines functionally mature Treg cells that survey skin and vascular tissues. J Exp Med 2018; 215:2796-2814. [PMID: 30355617 PMCID: PMC6219731 DOI: 10.1084/jem.20181442] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/22/2018] [Accepted: 09/25/2018] [Indexed: 12/12/2022] Open
Abstract
Fan et al. have identified a population of recirculating Treg cells with greater suppressive ability and a unique tissue distribution. Using single-cell RNA-seq, they place these Treg cells at the apex of the Treg developmental trajectory and show that similar cells may exist in humans. Regulatory T (Treg) cells prevent autoimmunity by limiting immune responses and inflammation in the secondary lymphoid organs and nonlymphoid tissues. While unique subsets of Treg cells have been described in some nonlymphoid tissues, their relationship to Treg cells in secondary lymphoid organs and circulation remains unclear. Furthermore, it is possible that Treg cells from similar tissue types share largely similar properties. We have identified a short-lived effector Treg cell subset that expresses the α2 integrin, CD49b, and exhibits a unique tissue distribution, being abundant in peripheral blood, vasculature, skin, and skin-draining lymph nodes, but uncommon in the intestines and in viscera-draining lymph nodes. CD49b+ Treg cells, which display superior functionality revealed by in vitro and in vivo assays, appear to develop after multiple rounds of cell division and TCR-dependent activation. Accordingly, single-cell RNA-seq analysis placed these cells at the apex of the Treg developmental trajectory. These results shed light on the identity and development of a functionally potent subset of mature effector Treg cells that recirculate through and survey peripheral tissues.
Collapse
|
3
|
ZFP36 RNA-binding proteins restrain T cell activation and anti-viral immunity. eLife 2018; 7:33057. [PMID: 29848443 PMCID: PMC6033538 DOI: 10.7554/elife.33057] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 05/26/2018] [Indexed: 01/07/2023] Open
Abstract
Dynamic post-transcriptional control of RNA expression by RNA-binding proteins (RBPs) is critical during immune response. ZFP36 RBPs are prominent inflammatory regulators linked to autoimmunity and cancer, but functions in adaptive immunity are less clear. We used HITS-CLIP to define ZFP36 targets in mouse T cells, revealing unanticipated actions in regulating T-cell activation, proliferation, and effector functions. Transcriptome and ribosome profiling showed that ZFP36 represses mRNA target abundance and translation, notably through novel AU-rich sites in coding sequence. Functional studies revealed that ZFP36 regulates early T-cell activation kinetics cell autonomously, by attenuating activation marker expression, limiting T cell expansion, and promoting apoptosis. Strikingly, loss of ZFP36 in vivo accelerated T cell responses to acute viral infection and enhanced anti-viral immunity. These findings uncover a critical role for ZFP36 RBPs in restraining T cell expansion and effector functions, and suggest ZFP36 inhibition as a strategy to enhance immune-based therapies. The immune system must quickly respond to anything that may cause disease – from cancerous cells to viruses. For instance, a type of white blood cell called a T cell patrols the body, looking for potential threats. If a T cell identifies such a threat, it “activates” and undergoes various changes so that it can help to eliminate the problem. One way that T cells change is by switching on different genes to make specific proteins. The information in the genes is first used as a template to produce a molecule called a messenger RNA (mRNA), which is then translated to build proteins. So-called RNA-binding proteins help control events before, during and after the translation stage in the process. Previous studies have shown that one particular RNA-binding protein, called ZFP36, controls the translation of proteins that are important for how the immune system recognizes the body’s own tissue and deals with cancer cells. However, it was less clear if it also helped T cells to activate and defeat viruses. Now, using cutting-edge technology, Moore et al. have identified thousands of new mRNAs controlled by ZFP36 in mice, many of which did indeed make proteins that help T cells activate and spread throughout the body. Further experiments showed that mice that lack ZFP36 in the T cells were much quicker at responding to viruses than other mice. This suggests that ZFP36 actually restrains T cells and slows down the body’s immune system. Knowing more about how T cells work could lead to new treatments for diseases; it may, for example, allow scientists to engineer T cells to better attack cancer cells, However, other studies have shown that mice without ZFP36 often go on to develop autoimmune diseases, which result from the immune system attacking healthy cells by mistake. As such, it seems that there is a fine line between improving the body’s immune system and increasing the risk of autoimmune diseases, and that RNA-binding proteins play an important role in managing this delicate balance.
Collapse
|
4
|
Comparative analysis of murine T-cell receptor repertoires. Immunology 2017; 153:133-144. [PMID: 29080364 DOI: 10.1111/imm.12857] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/06/2017] [Accepted: 10/06/2017] [Indexed: 12/21/2022] Open
Abstract
For understanding the rules and laws of adaptive immunity, high-throughput profiling of T-cell receptor (TCR) repertoires becomes a powerful tool. The structure of TCR repertoires is instructive even before the antigen specificity of each particular receptor becomes available. It embodies information about the thymic and peripheral selection of T cells; the readiness of an adaptive immunity to withstand new challenges; the character, magnitude and memory of immune responses; and the aetiological and functional proximity of T-cell subsets. Here, we describe our current analytical approaches for the comparative analysis of murine TCR repertoires, and show several examples of how these approaches can be applied for particular experimental settings. We analyse the efficiency of different metrics used for estimation of repertoire diversity, repertoire overlap, V-gene and J-gene segments usage similarity, and amino acid composition of CDR3. We discuss basic differences of these metrics and their advantages and limitations in different experimental models, and we provide guidelines for choosing an efficient way to lead a comparative analysis of TCR repertoires. Applied to the various known and newly developed mouse models, such analysis should allow us to disentangle multiple sophisticated puzzles in adaptive immunity.
Collapse
|
5
|
Suppression of lethal autoimmunity by regulatory T cells with a single TCR specificity. J Exp Med 2017; 214:609-622. [PMID: 28130403 PMCID: PMC5339675 DOI: 10.1084/jem.20161318] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 11/06/2016] [Accepted: 12/23/2016] [Indexed: 12/31/2022] Open
Abstract
Levine et al. investigate the extent to which regulatory T cells with either a monoclonal T cell receptor (TCR) or random TCR repertoire in place of their developmentally selected specificities maintain TCR-dependent gene expression and immunosuppressive function. The regulatory T cell (T reg cell) T cell receptor (TCR) repertoire is highly diverse and skewed toward recognition of self-antigens. TCR expression by T reg cells is continuously required for maintenance of immune tolerance and for a major part of their characteristic gene expression signature; however, it remains unknown to what degree diverse TCR-mediated interactions with cognate self-antigens are required for these processes. In this study, by experimentally switching the T reg cell TCR repertoire to a single T reg cell TCR, we demonstrate that T reg cell function and gene expression can be partially uncoupled from TCR diversity. An induced switch of the T reg cell TCR repertoire to a random repertoire also preserved, albeit to a limited degree, the ability to suppress lymphadenopathy and T helper cell type 2 activation. At the same time, these perturbations of the T reg cell TCR repertoire led to marked immune cell activation, tissue inflammation, and an ultimately severe autoimmunity, indicating the importance of diversity and specificity for optimal T reg cell function.
Collapse
|
6
|
A mechanism for expansion of regulatory T-cell repertoire and its role in self-tolerance. Nature 2015; 528:132-136. [PMID: 26605529 PMCID: PMC4862833 DOI: 10.1038/nature16141] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 10/12/2015] [Indexed: 12/26/2022]
Abstract
T-cell receptor (TCR) signalling has a key role in determining T-cell fate. Precursor cells expressing TCRs within a certain low-affinity range for complexes of self-peptide and major histocompatibility complex (MHC) undergo positive selection and differentiate into naive T cells expressing a highly diverse self-MHC-restricted TCR repertoire. In contrast, precursors displaying TCRs with a high affinity for 'self' are either eliminated through TCR-agonist-induced apoptosis (negative selection) or restrained by regulatory T (Treg) cells, whose differentiation and function are controlled by the X-chromosome-encoded transcription factor Foxp3 (reviewed in ref. 2). Foxp3 is expressed in a fraction of self-reactive T cells that escape negative selection in response to agonist-driven TCR signals combined with interleukin 2 (IL-2) receptor signalling. In addition to Treg cells, TCR-agonist-driven selection results in the generation of several other specialized T-cell lineages such as natural killer T cells and innate mucosal-associated invariant T cells. Although the latter exhibit a restricted TCR repertoire, Treg cells display a highly diverse collection of TCRs. Here we explore in mice whether a specialized mechanism enables agonist-driven selection of Treg cells with a diverse TCR repertoire, and the importance this holds for self-tolerance. We show that the intronic Foxp3 enhancer conserved noncoding sequence 3 (CNS3) acts as an epigenetic switch that confers a poised state to the Foxp3 promoter in precursor cells to make Treg cell lineage commitment responsive to a broad range of TCR stimuli, particularly to suboptimal ones. CNS3-dependent expansion of the TCR repertoire enables Treg cells to control self-reactive T cells effectively, especially when thymic negative selection is genetically impaired. Our findings highlight the complementary roles of these two main mechanisms of self-tolerance.
Collapse
MESH Headings
- Animals
- Cell Differentiation
- Cell Lineage
- Conserved Sequence/genetics
- Enhancer Elements, Genetic/genetics
- Epigenesis, Genetic
- Female
- Forkhead Transcription Factors/genetics
- Introns/genetics
- Male
- Mice
- Promoter Regions, Genetic/genetics
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Interleukin-2/immunology
- Receptors, Interleukin-2/metabolism
- Self Tolerance/immunology
- Signal Transduction
- T-Lymphocytes, Regulatory/cytology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
- Transcription Factors/deficiency
- AIRE Protein
Collapse
|
7
|
A Distinct Function of Regulatory T Cells in Tissue Protection. Cell 2015; 162:1078-89. [PMID: 26317471 PMCID: PMC4603556 DOI: 10.1016/j.cell.2015.08.021] [Citation(s) in RCA: 643] [Impact Index Per Article: 71.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 08/07/2015] [Accepted: 08/10/2015] [Indexed: 01/29/2023]
Abstract
Regulatory T (Treg) cells suppress immune responses to a broad range of non-microbial and microbial antigens and indirectly limit immune inflammation-inflicted tissue damage by employing multiple mechanisms of suppression. Here, we demonstrate that selective Treg cell deficiency in amphiregulin leads to severe acute lung damage and decreased blood oxygen concentration during influenza virus infection without any measureable alterations in Treg cell suppressor function, antiviral immune responses, or viral load. This tissue repair modality is mobilized in Treg cells in response to inflammatory mediator IL-18 or alarmin IL-33, but not by TCR signaling that is required for suppressor function. These results suggest that, during infectious lung injury, Treg cells have a major direct and non-redundant role in tissue repair and maintenance-distinct from their role in suppression of immune responses and inflammation-and that these two essential Treg cell functions are invoked by separable cues.
Collapse
|
8
|
Abstract
Regulatory T (Treg) cells enforce T cell homeostasis and maintain peripheral T cell tolerance. Here we report a previously unappreciated phenomenon of acute T cell lymphopenia in secondary lymphoid organs and non-lymphoid tissues triggered by Treg cell depletion that precedes the expansion of self-reactive T cells. Lymphopenia affects both neonates and adults indicating a dominant role of Treg cells in maintaining peripheral T cell numbers regardless of the developmental stage. The lymphopenia was neither triggered by caspase-dependent apoptosis nor macrophage-mediated clearance of T cells, nor diminished survival of naïve or recently activated T cells due to paucity of IL-7. It is possible that transient lymphopenia associated with congenital or acute Treg cell deficiency may contribute to the development of T cell mediated autoimmune disorders.
Collapse
|
9
|
Unique type I interferon responses determine the functional fate of migratory lung dendritic cells during influenza virus infection. PLoS Pathog 2011; 7:e1002345. [PMID: 22072965 PMCID: PMC3207893 DOI: 10.1371/journal.ppat.1002345] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 09/15/2011] [Indexed: 12/24/2022] Open
Abstract
Migratory lung dendritic cells (DCs) transport viral antigen from the lungs to the draining mediastinal lymph nodes (MLNs) during influenza virus infection to initiate the adaptive immune response. Two major migratory DC subsets, CD103+ DCs and CD11bhigh DCs participate in this function and it is not clear if these antigen presenting cell (APC) populations become directly infected and if so whether their activity is influenced by the infection. In these experiments we show that both subpopulations can become infected and migrate to the draining MLN but a difference in their response to type I interferon (I-IFN) signaling dictates the capacity of the virus to replicate. CD103+ DCs allow the virus to replicate to significantly higher levels than do the CD11bhigh DCs, and they release infectious virus in the MLNs and when cultured ex-vivo. Virus replication in CD11bhigh DCs is inhibited by I-IFNs, since ablation of the I-IFN receptor (IFNAR) signaling permits virus to replicate vigorously and productively in this subset. Interestingly, CD103+ DCs are less sensitive to I-IFNs upregulating interferon-induced genes to a lesser extent than CD11bhigh DCs. The attenuated IFNAR signaling by CD103+ DCs correlates with their described superior antigen presentation capacity for naïve CD8+ T cells when compared to CD11bhigh DCs. Indeed ablation of IFNAR signaling equalizes the competency of the antigen presenting function for the two subpopulations. Thus, antigen presentation by lung DCs is proportional to virus replication and this is tightly constrained by I-IFN. The “interferon-resistant” CD103+ DCs may have evolved to ensure the presentation of viral antigens to T cells in I-IFN rich environments. Conversely, this trait may be exploitable by viral pathogens as a mechanism for systemic dissemination. Migratory lung dendritic cells (DCs) control the initiation of the adaptive immune responses to influenza virus by expanding virus-specific T cells in draining lymph nodes (MLNs) that will subsequently clear the pathogen from the respiratory tract. Here we demonstrate that both subsets of lung DCs, CD103+ DCs and CD11bhigh DCs become infected by influenza virus in vivo and migrate to the MLNs, but only CD103+ DCs support productive virus replication. Enhanced virus replication in CD103+ DCs compared to CD11bhigh DCs was responsible for their superior antigen presentation efficacy for naïve CD8+ T cells and originated from a difference in sensitivity of the two DC populations to type I interferon (I-IFN). These data show that in contrast to most other immune cell types, DCs can become productively infected with influenza virus and I-IFN operates as a master regulator controlling which DC subset will present antigen during a viral infection. A deeper understanding of basic innate and adaptive immune response mechanisms regulated by I-FN may lead to the development of cutting edge therapies and improve vaccine efficacy against influenza and other viruses.
Collapse
|
10
|
[Hemocyanins as immunostimulants]. Rev Med Chil 2011; 139:236-246. [PMID: 21773663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Hemocyanins, the giant oxygen transporter glycoproteins of diverse mollusks, are xenogenic to the mammalian immune system and they display a remarkable immuno-genicity. Therefore they are ideal non-specific immunostimulants to treat some types of cancer. They are used as an alternative therapy for superficial urinary bladder cancer (SBC), that has been traditionally treated with Bacillus Calmette-Guerin (BCG). In contrast to BCG, hemocyanins do not cause side-effects, making them ideal for long-term repetitive treatments. Hemocyanins have also been exploited as carriers to develop antibodies against hapten molecules and peptides, as carrier-adjuvants for cutting-edge vaccines against cancer, drug addiction, and infectious diseases and in the diagnosis of parasitic diseases, such as Schistosomiasis. The hemocyanin from Megathura crenulata, also known as keyhole limpet hemocyanin (KLH), has been used for over thirty years for the purposes described above. More recently, hemoc yanin from the Chilean mollusk Concholepas concholepas (CCH) has proved to be a reliable alternative to KLH, either as carrier protein, and as a likely alternative for the immunotherapy of SBC. Despite KLH and CCH differ significantly in their origin and structure, we have demonstrated that both hemocyanins stimulate the immune system of mammals in a similar way by inducing a potent Thl-polarized cellular and humoral response.
Collapse
|
11
|
Buying time-the immune system determinants of the incubation period to respiratory viruses. Viruses 2010; 2:2541-58. [PMID: 21994630 PMCID: PMC3185581 DOI: 10.3390/v2112541] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 11/01/2010] [Accepted: 11/02/2010] [Indexed: 12/20/2022] Open
Abstract
Respiratory viruses cause disease in humans characterized by an abrupt onset of symptoms. Studies in humans and animal models have shown that symptoms are not immediate and appear days or even weeks after infection. Since the initial symptoms are a manifestation of virus recognition by elements of the innate immune response, early virus replication must go largely undetected. The interval between infection and the emergence of symptoms is called the incubation period and is widely used as a clinical score. While incubation periods have been described for many virus infections the underlying mechanism for this asymptomatic phase has not been comprehensively documented. Here we review studies of the interaction between human pathogenic respiratory RNA viruses and the host with a particular emphasis on the mechanisms used by viruses to inhibit immunity. We discuss the concept of the "stealth phase", defined as the time between infection and the earliest detectable inflammatory response. We propose that the "stealth phase" phenomenon is primarily responsible for the suppression of symptoms during the incubation period and results from viral antagonism that inhibits major pathways of the innate immune system allowing an extended time of unhindered virus replication.
Collapse
|
12
|
Antiviral instruction of bone marrow leukocytes during respiratory viral infections. Cell Host Microbe 2010; 7:343-53. [PMID: 20478536 PMCID: PMC2874206 DOI: 10.1016/j.chom.2010.04.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 02/04/2010] [Accepted: 03/26/2010] [Indexed: 12/19/2022]
Abstract
Respiratory viral infections trigger a robust inflammatory response in the lung, producing cytokines, chemokines, and growth factors that promote infiltration of effector leukocytes. Whereas the role of chemokines and infiltrating leukocytes in antiviral immunity is well studied, the effect that lung cytokines have on leukocytes in distal hematopoietic and lymphoid tissues and their role in antiviral immunity is unknown. We show that, during infection with influenza or Sendai virus, the lung communicates with the sterile bone marrow, the primary site of hematopoiesis, through type I interferons. While in the bone marrow, leukocytes exposed to type I interferons activate an antiviral transcriptional program and become resistant to infection with different viruses. The protected bone marrow leukocytes are capable of migrating to the infected lung and contribute to virus clearance. These findings show that appropriate instruction of cells during their development in the bone marrow is needed for effective control of infection.
Collapse
|
13
|
Cutting Edge: Stealth Influenza Virus Replication Precedes the Initiation of Adaptive Immunity. THE JOURNAL OF IMMUNOLOGY 2009; 183:3569-73. [DOI: 10.4049/jimmunol.0900091] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
14
|
Immunodominant role of CCHA subunit of Concholepas hemocyanin is associated with unique biochemical properties. Int Immunopharmacol 2009; 9:330-9. [PMID: 19159699 DOI: 10.1016/j.intimp.2008.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Revised: 12/05/2008] [Accepted: 12/17/2008] [Indexed: 10/21/2022]
|
15
|
Immunotherapeutic effect of Concholepas hemocyanin in the murine bladder cancer model: evidence for conserved antitumor properties among hemocyanins. J Urol 2006; 176:2690-5. [PMID: 17085197 DOI: 10.1016/j.juro.2006.07.136] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE We determined the antitumor properties of a newly available hemocyanin obtained from the Chilean gastropod Concholepas concholepas (Biosonda Corp., Santiago, Chile) in a syngeneic heterotopic mouse bladder carcinoma model. Since keyhole limpet hemocyanin (Pierce, Rockford, Illinois) is used increasingly in biomedicine as a carrier for vaccines and an immunotherapeutic agent for bladder transitional cell carcinoma, there is a growing interest in finding new substances that share its potent immunomodulatory properties. Considering that keyhole limpet hemocyanin and Concholepas concholepas hemocyanin differ significantly, it was not possible to predict a priori the antitumor properties of Concholepas concholepas hemocyanin. MATERIALS AND METHODS C3H/He mice were primed with Concholepas concholepas hemocyanin before subcutaneous implantation of mouse bladder tumor-2 cells. Treatment consisted of a subcutaneous dose of Concholepas concholepas hemocyanin (1 mg or 100 mug) at different intervals after implantation. Keyhole limpet hemocyanin and phosphate buffered saline served as positive and negative controls, respectively. In addition, experiments were designed to determine which elements of the immune response were involved in its adjuvant immunostimulatory effect. RESULTS Mice treated with Concholepas concholepas hemocyanin showed a significant antitumor effect, as demonstrated by decreased tumor growth and incidence, prolonged survival and lack of toxic effects. These effects were similar to those achieved with keyhole limpet hemocyanin. We found that each hemocyanin increased natural killer cell activity but the effect of Concholepas concholepas hemocyanin was stronger. Analysis of serum from treated mice showed an increased interferon-gamma and low interleukin-4, which correlated with antibody isotypes, confirming that hemocyanins induce a T helper type 1 cytokine profile. CONCLUSIONS To our knowledge our results are the first demonstration of the antitumor effect of a hemocyanin other than keyhole limpet hemocyanin. They suggest that this is an ancient conserved immunogenic mechanism shared by those hemocyanins that is able to enhance T helper type 1 immunity and lead to antitumor activity. Therefore, Concholepas concholepas hemocyanin may be an alternative candidate for providing safe and effective immunotherapy for human superficial bladder cancer.
Collapse
|
16
|
Intensified and protective CD4+ T cell immunity in mice with anti-dendritic cell HIV gag fusion antibody vaccine. ACTA ACUST UNITED AC 2006; 203:607-17. [PMID: 16505141 PMCID: PMC2118242 DOI: 10.1084/jem.20052005] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Current human immunodeficiency virus (HIV) vaccine approaches emphasize prime boost strategies comprising multiple doses of DNA vaccine and recombinant viral vectors. We are developing a protein-based approach that directly harnesses principles for generating T cell immunity. Vaccine is delivered to maturing dendritic cells in lymphoid tissue by engineering protein antigen into an antibody to DEC-205, a receptor for antigen presentation. Here we characterize the CD4+ T cell immune response to HIV gag and compare efficacy with other vaccine strategies in a single dose. DEC-205–targeted HIV gag p24 or p41 induces stronger CD4+ T cell immunity relative to high doses of gag protein, HIV gag plasmid DNA, or recombinant adenovirus-gag. High frequencies of interferon (IFN)-γ– and interleukin 2–producing CD4+ T cells are elicited, including double cytokine-producing cells. In addition, the response is broad because the primed mice respond to an array of peptides in different major histocompatibility complex haplotypes. Long-lived T cell memory is observed. After subcutaneous vaccination, CD4+ and IFN-γ–dependent protection develops to a challenge with recombinant vaccinia-gag virus at a mucosal surface, the airway. We suggest that a DEC-targeted vaccine, in part because of an unusually strong and protective CD4+ T cell response, will improve vaccine efficacy as a stand-alone approach or with other modalities.
Collapse
MESH Headings
- AIDS Vaccines/administration & dosage
- AIDS Vaccines/genetics
- AIDS Vaccines/immunology
- Adenoviridae
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/immunology
- Antigen Presentation/drug effects
- Antigen Presentation/immunology
- Antigens, CD/genetics
- Antigens, CD/immunology
- CD4-Positive T-Lymphocytes/immunology
- Dendritic Cells/immunology
- Dose-Response Relationship, Immunologic
- Gene Products, gag/administration & dosage
- Gene Products, gag/genetics
- Gene Products, gag/immunology
- Genetic Vectors/administration & dosage
- Genetic Vectors/genetics
- Genetic Vectors/immunology
- HIV-1/genetics
- HIV-1/immunology
- Haplotypes/genetics
- Haplotypes/immunology
- Humans
- Immunity, Mucosal/drug effects
- Immunity, Mucosal/immunology
- Immunologic Memory/drug effects
- Immunologic Memory/immunology
- Injections, Subcutaneous
- Lectins, C-Type/deficiency
- Lectins, C-Type/genetics
- Lectins, C-Type/immunology
- Major Histocompatibility Complex/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Knockout
- Minor Histocompatibility Antigens
- Receptors, Cell Surface/deficiency
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/immunology
- Recombinant Fusion Proteins/administration & dosage
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- Vaccinia virus
Collapse
|
17
|
TLR-Independent Induction of Dendritic Cell Maturation and Adaptive Immunity by Negative-Strand RNA Viruses. THE JOURNAL OF IMMUNOLOGY 2004; 173:6882-9. [PMID: 15557183 DOI: 10.4049/jimmunol.173.11.6882] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TLR signaling leads to dendritic cell (DC) maturation and immunity to diverse pathogens. The stimulation of TLRs by conserved viral structures is the only described mechanism leading to DC maturation after a virus infection. In this report, we demonstrate that mouse myeloid DCs mature normally after in vivo and in vitro infection with Sendai virus (SeV) in the absence of TLR3, 7, 8, or 9 signaling. DC maturation by SeV requires virus replication not necessary for TLR-mediated triggering. Moreover, DCs deficient in TLR signaling efficiently prime for Th1 immunity after infection with influenza or SeV, generating IFN-gamma-producing T cells, CTLs and antiviral Abs. We have previously demonstrated that SeV induces DC maturation independently of the presence of type I IFN, which has been reported to mature DCs in a TLR-independent manner. The data presented here provide evidence for the existence of a novel intracellular pathway independent of TLR-mediated signaling responsible for live virus triggering of DC maturation and demonstrate its critical role in the onset of antiviral immunity. The revelation of this pathway should stimulate invigorating research into the mechanism for virus-induced DC maturation and immunity.
Collapse
MESH Headings
- Adaptor Proteins, Signal Transducing
- Animals
- Antigens, Differentiation/genetics
- Antigens, Differentiation/physiology
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cells, Cultured
- Dendritic Cells/cytology
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Dendritic Cells/virology
- Immunity, Innate/genetics
- Influenza A virus/immunology
- Interferon-gamma/metabolism
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myeloid Differentiation Factor 88
- Receptors, Cell Surface/physiology
- Receptors, Immunologic/deficiency
- Receptors, Immunologic/genetics
- Receptors, Immunologic/physiology
- Respiratory Syncytial Viruses/immunology
- Respirovirus Infections/genetics
- Respirovirus Infections/immunology
- Sendai virus/immunology
- Signal Transduction/genetics
- Signal Transduction/immunology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
- Th1 Cells/immunology
- Th1 Cells/metabolism
- Toll-Like Receptor 3
- Toll-Like Receptors
Collapse
|
18
|
In vivo targeting of antigens to maturing dendritic cells via the DEC-205 receptor improves T cell vaccination. ACTA ACUST UNITED AC 2004; 199:815-24. [PMID: 15024047 PMCID: PMC2212731 DOI: 10.1084/jem.20032220] [Citation(s) in RCA: 704] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic α-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4+ and CD8+ T cell repertoire. Unexpectedly, the αDEC-205 antigen conjugates, given s.c., targeted to dendritic cells systemically and for long periods, and ovalbumin peptide was presented on MHC class I for 2 weeks. This was associated with stronger CD8+ T cell–mediated immunity relative to other forms of antigen delivery, even when the latter was given at a thousand times higher doses. In parallel, the mice showed enhanced resistance to an established rapidly growing tumor and to viral infection at a mucosal site. By better harnessing the immunizing functions of maturing dendritic cells, antibody-mediated antigen targeting via the DEC-205 receptor increases the efficiency of vaccination for T cell immunity, including systemic and mucosal resistance in disease models.
Collapse
MESH Headings
- Animals
- Antibodies/immunology
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/metabolism
- Antigen Presentation
- Antigens, CD/immunology
- Antigens, CD/metabolism
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD40 Antigens/immunology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Female
- Flow Cytometry
- Histocompatibility Antigens Class I/immunology
- Immunohistochemistry
- Lectins, C-Type/immunology
- Lectins, C-Type/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Minor Histocompatibility Antigens
- Ovalbumin/immunology
- Ovalbumin/metabolism
- Receptors, Cell Surface/immunology
- Receptors, Cell Surface/metabolism
- Vaccination
Collapse
|
19
|
Hemocyanin of the Molluscan Concholepas concholepas Exhibits an Unusual Heterodecameric Array of Subunits. J Biol Chem 2004; 279:26134-42. [PMID: 15075320 DOI: 10.1074/jbc.m400903200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We describe here the structure of the hemocyanin from the Chilean gastropod Concholepas concholepas (CCH), emphasizing some attributes that make it interesting among molluscan hemocyanins. CCH exhibits a predominant didecameric structure as revealed by electron microscopy and a size of 8 MDa by gel filtration, and, in contrast with other mollusc hemocyanins, its stabilization does not require additional Ca(2+) and/or Mg(2+) in the medium. Polyacrylamide gel electrophoresis studies, analyses by a MonoQ FPLC column, and Western blots with specific monoclonal antibodies showed that CCH is made by two subunits noncovalently linked, named CCH-A and CCH-B, with molecular masses of 405 and 350 kDa, respectively. Interestingly, one of the subunits undergoes changes within the macromolecule; we demonstrated that CCH-A has an autocleavage site that under reducing conditions is cleaved to yield two polypeptides, CCH-A1 (300 kDa) and CCH-A2 (108 kDa), whereas CCH-B remains unchanged. The CCH-A nick occurs at 4 degrees C, increases at 37 degrees C, and is not inhibited by the addition of protease inhibitors and/or divalent cations. Since the CCH structure is a heterodimer, we investigated whether subunits would be either intermingled, forming heterodecamers, or assembled as two homogeneous decamers. Light scattering and electron microscope studies of the in vitro reassociation of purified CCH subunits demonstrated that the sole addition of Mg(2+) is needed for its reassembly into the native decameric molecule; no homodecamer reorganization was found with either CCH-A or CCH-B subunits alone. Our evidence showed that C. concholepas hemocyanin is an unusual example of heterodecameric organization.
Collapse
|
20
|
Monoclonal antibodies to molluskan hemocyanin from Concholepas concholepas demonstrate common and specific epitopes among subunits. HYBRIDOMA AND HYBRIDOMICS 2002; 21:365-74. [PMID: 12470479 DOI: 10.1089/153685902761022715] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We studied the reactivity of mouse monoclonal antibodies (MAbs) against the hemocyanin from the Chilean marine gastropod Concholepas concholepas (CCH). This protein has been successfully used as a carrier to produce antibodies to haptens and peptides. All MAbs (13) belonging to IgG subclass exhibit dissociation constants (K(d)) from 1 x 10(-7) M to 1 x 10(-9) M. MAbs were characterized by enzyme-linked immunosorbant assay (ELISA) using CCH treated with different procedures, including dissociation into CCH-A and CCH-B subunits, Western blot, enzymatic digestion, chemical deglycosylation, and thermal denaturation. MAbs were classified into three categories, according to subunit specificity by ELISA. The epitope distribution shows that CCH subunits display common epitopes (group I, 5 MAbs, 1H5, 2A8, 3A5, 3B3, and 3E3), as well as specific epitopes for CCH-A subunits (group II, 3 MAbs, 1B8, 4D8, and 8E5) and for CCH-B subunits (group III, 5 MAbs, 1A4, 1E4, 2H10, 3B7, and 7B4). The results can be summarized as follows: (1). six antibodies react with thermal denatured CCH, suggesting that they recognize linear epitopes, whereas seven recognize conformational epitopes; (2). oxidation of carbohydrate moieties does not affect the binding of the MAbs; (3). enzymatic digestion of CCH decreases the reactivity of all antibodies irrespective of the protease used (elastase or trypsin); (4). bringing together the above data, in addition to epitopic complementarity analysis, we identified 12 different epitopes on the CCH molecule recognized by these MAbs. The anti-CCH MAbs presented here can be useful tools to understand the subunit organization of the CCH and its complex structure, which can explain its immunogenic and immunostimulating properties in mammals.
Collapse
|