scholarly journals HLA-G1+ Expression in GGTA1KO Pigs Suppresses Human and Monkey Anti-Pig T, B and NK Cell Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Joseph Sushil Rao ◽  
Nora Hosny ◽  
Ramesh Kumbha ◽  
Raza Ali Naqvi ◽  
Amar Singh ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Cell Surface ◽  
Nk Cell ◽  
Human Leukocyte ◽  
Genetically Engineered ◽  
Mhc I ◽  
Rosa26 Locus ◽  
Classical Class ◽  
And Function

The human leukocyte antigen G1 (HLA-G1), a non-classical class I major histocompatibility complex (MHC-I) protein, is a potent immunomodulatory molecule at the maternal/fetal interface and other environments to regulate the cellular immune response. We created GGTA1-/HLAG1+ pigs to explore their use as organ and cell donors that may extend xenograft survival and function in both preclinical nonhuman primate (NHP) models and future clinical trials. In the present study, HLA-G1 was expressed from the porcine ROSA26 locus by homology directed repair (HDR) mediated knock-in (KI) with simultaneous deletion of α-1-3-galactotransferase gene (GGTA1; GTKO) using the clustered regularly interspersed palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) (CRISPR/Cas9) gene-editing system. GTKO/HLAG1+ pigs showing immune inhibitory functions were generated through somatic cell nuclear transfer (SCNT). The presence of HLA-G1 at the ROSA26 locus and the deletion of GGTA1 were confirmed by next generation sequencing (NGS) and Sanger’s sequencing. Fibroblasts from piglets, biopsies from transplantable organs, and islets were positive for HLA-G1 expression by confocal microscopy, flow cytometry, or q-PCR. The expression of cell surface HLA-G1 molecule associated with endogenous β2-microglobulin (β2m) was confirmed by staining genetically engineered cells with fluorescently labeled recombinant ILT2 protein. Fibroblasts obtained from GTKO/HLAG1+ pigs were shown to modulate the immune response by lowering IFN-γ production by T cells and proliferation of CD4+ and CD8+ T cells, B cells and natural killer (NK) cells, as well as by augmenting phosphorylation of Src homology region 2 domain-containing phosphatase-2 (SHP-2), which plays a central role in immune suppression. Islets isolated from GTKO/HLA-G1+ genetically engineered pigs and transplanted into streptozotocin-diabetic nude mice restored normoglycemia, suggesting that the expression of HLA-G1 did not interfere with their ability to reverse diabetes. The findings presented here suggest that the HLA-G1+ transgene can be stably expressed from the ROSA26 locus of non-fetal maternal tissue at the cell surface. By providing an immunomodulatory signal, expression of HLA-G1+ may extend survival of porcine pancreatic islet and organ xenografts.

scholarly journals The Role of HLA-G in Tumor Escape: Manipulating the Phenotype and Function of Immune Cells

2020 ◽  
Vol 10 ◽  
Author(s):  
Lu Liu ◽  
Lijun Wang ◽  
Lihong Zhao ◽  
Chen He ◽  
Ganlu Wang
Keyword(s):  
T Cells ◽  
Tumor Immunity ◽  
Immune Cells ◽  
Human Leukocyte ◽  
Therapeutic Benefit ◽  
Tumor Escape ◽  
Class I Mhc ◽  
Mhc I ◽  
Suppressive Phenotype ◽  
And Function

Human leukocyte antigen-G (HLA-G) is a non-classical major histocompatibility complex class I (MHC I) molecule, and under physiological conditions, its expression is strictly restricted to the maternal–fetal interface and immune-privileged organs where HLA-G is expected to contribute to establishment and maintenance of immune tolerance. However, the expression of HLA-G has been found in various types of tumors, and the level of its expression frequently correlates with high-grade histology and poor prognosis, raising the possibility that it may play a negative role in tumor immunity. ILT2 and ILT4, present on a broad of immune cells, have been identified as the main receptors engaging HLA-G, and their interactions have been found to allow the conversion of effectors like NK cells and T cells to anergic or unresponsive state, activated DCs to tolerogenic state, and to drive the differentiation of T cells toward suppressive phenotype. Therefore, tumors can employ HLA-G to modulate the phenotype and function of immune cells, allowing them to escape immune attack. In this review, we discuss the mechanism underlying HLA-G expression and function, its role played in each step of the tumor-immunity cycle, as well as the potential to target it for therapeutic benefit.

scholarly journals From Chickens to Humans: The Importance of Peptide Repertoires for MHC Class I Alleles

2020 ◽  
Vol 11 ◽  
Author(s):  
Jim Kaufman
Keyword(s):  
Cell Surface ◽  
Cell Function ◽  
Nk Cell ◽  
Class I ◽  
Ligand Interaction ◽  
Mhc I ◽  
Peptide Motifs ◽  
Classical Class ◽  
Histocompatibility Complex ◽  
High Level

In humans, killer immunoglobulin-like receptors (KIRs), expressed on natural killer (NK) and thymus-derived (T) cells, and their ligands, primarily the classical class I molecules of the major histocompatibility complex (MHC) expressed on nearly all cells, are both polymorphic. The variation of this receptor-ligand interaction, based on which alleles have been inherited, is known to play crucial roles in resistance to infectious disease, autoimmunity, and reproduction in humans. However, not all the variation in response is inherited, since KIR binding can be affected by a portion of the peptide bound to the class I molecules, with the particular peptide presented affecting the NK response. The extent to which the large multigene family of chicken immunoglobulin-like receptors (ChIRs) is involved in functions similar to KIRs is suspected but not proven. However, much is understood about the two MHC-I molecules encoded in the chicken MHC. The BF2 molecule is expressed at a high level and is thought to be the predominant ligand of cytotoxic T lymphocytes (CTLs), while the BF1 molecule is expressed at a much lower level if at all and is thought to be primarily a ligand for NK cells. Recently, a hierarchy of BF2 alleles with a suite of correlated properties has been defined, from those expressed at a high level on the cell surface but with a narrow range of bound peptides to those expressed at a lower level on the cell surface but with a very wide repertoire of bound peptides. Interestingly, there is a similar hierarchy for human class I alleles, although the hierarchy is not as wide. It is a question whether KIRs and ChIRs recognize class I molecules with bound peptide in a similar way, and whether fastidious to promiscuous hierarchy of class I molecules affect both T and NK cell function. Such effects might be different from those predicted by the similarities of peptide-binding based on peptide motifs, as enshrined in the idea of supertypes. Since the size of peptide repertoire can be very different for alleles with similar peptide motifs from the same supertype, the relative importance of these two properties may be testable.

scholarly journals TCR Recognition of Peptide–MHC-I: Rule Makers and Breakers

2020 ◽  
Vol 22 (1) ◽  
pp. 68
Author(s):  
Christopher Szeto ◽  
Christian A. Lobos ◽  
Andrea T. Nguyen ◽  
Stephanie Gras
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Adaptive Immune System ◽  
Human Leukocyte ◽  
Activated T Cells ◽  
Mhc I ◽  
Mhc Molecules

T cells are a critical part of the adaptive immune system that are able to distinguish between healthy and unhealthy cells. Upon recognition of protein fragments (peptides), activated T cells will contribute to the immune response and help clear infection. The major histocompatibility complex (MHC) molecules, or human leukocyte antigens (HLA) in humans, bind these peptides to present them to T cells that recognise them with their surface T cell receptors (TCR). This recognition event is the first step that leads to T cell activation, and in turn can dictate disease outcomes. The visualisation of TCR interaction with pMHC using structural biology has been crucial in understanding this key event, unravelling the parameters that drive this interaction and their impact on the immune response. The last five years has been the most productive within the field, wherein half of current unique TCR–pMHC-I structures to date were determined within this time. Here, we review the new insights learned from these recent TCR–pMHC-I structures and their impact on T cell activation.

Expression and function of NK cell receptors in CD8+ T cells

2001 ◽  
Vol 13 (4) ◽  
pp. 465-470 ◽  
Author(s):  
Christopher W McMahon ◽  
David H Raulet
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Cell Receptors ◽  
Nk Cell Receptors ◽  
And Function

scholarly journals The self-peptide repertoire plays a critical role in transplant tolerance induction

2020 ◽  
Author(s):  
Eric T. Son ◽  
Pouya Faridi ◽  
Moumita Paul-Heng ◽  
Mario Leong ◽  
Kieran English ◽  
...  
Keyword(s):  
T Cells ◽  
Critical Role ◽  
Tolerance Induction ◽  
Genetically Engineered ◽  
Solid Organ ◽  
Transplant Tolerance ◽  
Mhc I ◽  
Definitive Evidence ◽  
Antigen Presentation Pathway ◽  
Presentation Pathway

AbstractWhile direct allorecognition underpins both solid organ allograft rejection and tolerance induction, the specific molecular targets of most directly-alloreactive CD8+T cells have not been defined. In this study, we used a combination of genetically-engineered MHC I constructs, mice with a hepatocyte-specific mutation in the class I antigen-presentation pathway and immunopeptidomic analysis to provide definitive evidence for the contribution of the peptide cargo of allogeneic MHC I molecules to transplant tolerance induction. We established a systematic approach for the discovery of directly-recognised pMHC epitopes, and identified 17 strongly immunogenic H-2Kb-associated peptides recognised by CD8+T cells from B10.BR (H-2k) mice, 13 of which were also recognised by BALB/c (H-2d) mice. As few as five different tetramers used together were able to identify almost 40% of alloreactive T cells within a polyclonal population, suggesting that there are immunodominant allogeneic MHC-peptide complexes that can account for a large proportion of the alloresponse.

scholarly journals Tim-3 Induces Th2-Biased Immunity and Alternative Macrophage Activation during Schistosoma japonicum Infection

2015 ◽  
Vol 83 (8) ◽  
pp. 3074-3082 ◽  
Author(s):  
Nan Hou ◽  
Xianyu Piao ◽  
Shuai Liu ◽  
Chuang Wu ◽  
Qijun Chen
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Schistosoma Japonicum ◽  
Immune Cell ◽  
Nk Cell ◽  
Alternative Activation ◽  
Interleukin 12 ◽  
Content Type

T cell immunoglobulin- and mucin-domain-containing molecule 3 (Tim-3) has been regarded as an important regulatory factor in both adaptive and innate immunity. Recently, Tim-3 was reported to be involved in Th2-biased immune responses in mice infected withSchistosoma japonicum, but the exact mechanism behind the involvement of Tim-3 remains unknown. The present study aims to understand the role of Tim-3 in the immune response againstS. japonicuminfection. Tim-3 expression was determined by flow cytometry, and increased Tim-3 expression was observed on CD4+and CD8+T cells, NK1.1+cells, and CD11b+cells from the livers ofS. japonicum-infected mice. However, the increased level of Tim-3 was lower in the spleen than in the liver, and no increase in Tim-3 expression was observed on splenic CD8+T cells or CD11b+cells. The schistosome-induced upregulation of Tim-3 on natural killer (NK) cells was accompanied by reduced NK cell numbersin vitroandin vivo. Tim-3 antibody blockade led to upregulation of inducible nitric oxide synthase and interleukin-12 (IL-12) mRNA in CD11b+cells cocultured with soluble egg antigen and downregulation of Arg1 and IL-10, which are markers of M2 macrophages. In summary, we observed schistosome-induced expression of Tim-3 on critical immune cell populations, which may be involved in the Th2-biased immune response and alternative activation of macrophages during infection.

scholarly journals ALLOANTISERUM-INDUCED INHIBITION OF IMMUNE RESPONSE GENE PRODUCT FUNCTION

1974 ◽  
Vol 139 (3) ◽  
pp. 679-695 ◽  
Author(s):  
Ethan M. Shevach ◽  
Ira Green ◽  
William E. Paul
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Lymphocytes ◽  
Cell Surface ◽  
Glutamic Acid ◽  
Gene Product ◽  
Lymphoid Cells ◽  
Immune Response Gene ◽  
Ga Response ◽  
Ir Genes

It has been previously demonstrated that alloantisera can specifically block the activation of T lymphocytes by antigens, the response to which is linked to the presence of histocompatibility (H) types against which the alloantisera are directed. Thus, strain 13 anti-2 serum can inhibit the activation of (2 x 13)F1 T lymphocytes by a DNP derivative of a copolymer of L-glutamic acid and L-lysine (DNP-GL), an antigen the response to which is controlled by a 2-linked Ir gene. It was proposed that alloantisera can inhibit T-lymphocyte antigen recognition through interference with the activity of immune response (Ir) gene products. In order to further study whether the inhibitory antibodies within the alloantisera are directed against H antigens or against the products of the Ir genes, we have examined whether the anti-2 serum can inhibit the function of an Ir gene (the L-glutamic acid and L-alanine [GA] gene), which is normally linked to strain 2 H genes when this gene occurs in an outbred animal lacking strain 2 H genes. In the majority of cases, the anti-2 serum was capable of inhibiting the in vitro proliferative response to GA of T cells derived from animals that were GA+2+, but the serum had little if any effect on the GA response of T cells from GA+2- animals. Furthermore, an antiserum prepared in strain 13 animals against the lymphoid cells of a GA+2- outbred animal was devoid of inhibitory activity on the GA response of cells from a (2 x 13)F1, while an antiserum prepared in strain 13 animals against the lymphoid cells of a GA+2+ outbred animal was capable of specifically inhibiting the response to GA. It thus appears that the inhibition of the GA response by the anti-2 serum is primarily mediated via antibodies directed toward strain 2 H antigens rather than antibodies specific for the product of the GA Ir gene. The mechanism of alloantiserum induced suppression of Ir gene function would then be by steric interference with the Ir gene product on the cell surface, rather than by direct binding to it. This conclusion implies that the products of both the H genes and the Ir genes are physically related on the cell surface. The implications of such a relationship in terms of the fluid-mosaic model of the lymphocyte surface are discussed.

scholarly journals Cytotoxic CD8+T lymphocytes expressing ALS-causing SOD1 mutant selectively trigger death of spinal motoneurons

2019 ◽  
Vol 116 (6) ◽  
pp. 2312-2317 ◽  
Author(s):  
Emmanuelle Coque ◽  
Céline Salsac ◽  
Gabriel Espinosa-Carrasco ◽  
Béla Varga ◽  
Nicolas Degauque ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Interaction Strength ◽  
Adaptive Immune Response ◽  
Clonal Diversity ◽  
Mhc I ◽  
Mutant Sod1 ◽  
Cytotoxicity Activity

Adaptive immune response is part of the dynamic changes that accompany motoneuron loss in amyotrophic lateral sclerosis (ALS). CD4+T cells that regulate a protective immunity during the neurodegenerative process have received the most attention. CD8+T cells are also observed in the spinal cord of patients and ALS mice although their contribution to the disease still remains elusive. Here, we found that activated CD8+T lymphocytes infiltrate the central nervous system (CNS) of a mouse model of ALS at the symptomatic stage. Selective ablation of CD8+T cells in mice expressing the ALS-associated superoxide dismutase-1 (SOD1)G93Amutant decreased spinal motoneuron loss. Using motoneuron-CD8+T cell coculture systems, we found that mutant SOD1-expressing CD8+T lymphocytes selectively kill motoneurons. This cytotoxicity activity requires the recognition of the peptide-MHC-I complex (where MHC-I represents major histocompatibility complex class I). Measurement of interaction strength by atomic force microscopy-based single-cell force spectroscopy demonstrated a specific MHC-I-dependent interaction between motoneuron andSOD1G93ACD8+T cells. Activated mutant SOD1 CD8+T cells produce interferon-γ, which elicits the expression of the MHC-I complex in motoneurons and exerts their cytotoxic function through Fas and granzyme pathways. In addition, analysis of the clonal diversity of CD8+T cells in the periphery and CNS of ALS mice identified an antigen-restricted repertoire of their T cell receptor in the CNS. Our results suggest that self-directed immune response takes place during the course of the disease, contributing to the selective elimination of a subset of motoneurons in ALS.

Elevated CD54 Expression Renders CD4+ T Cells Susceptible to Natural Killer Cell-Mediated Killing

2019 ◽  
Vol 220 (12) ◽  
pp. 1892-1903 ◽  
Author(s):  
Xi Chen ◽  
Huihui Chen ◽  
Zining Zhang ◽  
Yajing Fu ◽  
Xiaoxu Han ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Cd4 T Cells ◽  
Nk Cell ◽  
Killer Cell ◽  
Adaptive Immune Response ◽  
Phenotypic Analysis

Abstract Background Natural killer (NK) cells are an important type of effector cell in the innate immune response, and also have a role in regulation of the adaptive immune response. Several studies have indicated that NK cells may influence CD4+ T cells during HIV infection. Methods In total, 51 HIV-infected individuals and 15 healthy controls participated in this study. We performed the flow cytometry assays and real-time PCR for the phenotypic analysis and the functional assays of NK cell-mediated deletion of CD4+ T cells, phosphorylation of nuclear factor-κB (NF-κB/p65) and the intervention of metformin. Results Here we detected high CD54 expression on CD4+ T cells in HIV-infected individuals, and demonstrate that upregulated CD54 is associated with disease progression in individuals infected with HIV. We also show that CD54 expression leads to the deletion of CD4+ T cells by NK cells in vitro, and that this is modulated by NF-κB/p65 signaling. Further, we demonstrate that metformin can suppress CD54 expression on CD4+ T cells by inhibiting NF-κB/p65 phosphorylation. Conclusions Our data suggest that further studies to evaluate the potential role of metformin as adjunctive therapy to reconstitute immune function in HIV-infected individuals are warranted.

scholarly journals Natural Killer Cells as Novel Helpers in Anti-Herpes Simplex Virus Immune Response

2008 ◽  
Vol 82 (21) ◽  
pp. 10820-10831 ◽  
Author(s):  
Subhadra Nandakumar ◽  
Stacie N. Woolard ◽  
Dorothy Yuan ◽  
Barry T. Rouse ◽  
Uday Kumaraguru
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Nk Cells ◽  
Nk Cell ◽  
Adaptive Immune Response ◽  
T Cell Response ◽  
Simplex Virus

ABSTRACT Innate defenses help to eliminate infection, but some of them also play a major role in shaping the magnitude and efficacy of the adaptive immune response. With regard to influencing subsequent adaptive immunity, NK cells aided by dendritic cells may be the most relevant components of the innate reaction to herpes simplex virus (HSV) infection. We confirm that mice lacking or depleted of NK cells are susceptible to HSV-induced lesions. The quantity and quality of CD8+ cytotoxic T lymphocytes generated in the absence of NK cells were diminished, thereby contributing to susceptibility to HSV-induced encephalitis. We demonstrate a novel helper role for NK cells, in that NK cells compensate for the loss of CD4 helper T cells and NK cell supplementation enhances the function of wild type anti-HSV CD8 T cells. In addition, NK cells were able to partially rescue the dysfunctional CD8+ T cells generated in the absence of CD4 T helper cells, thereby performing a novel rescue function. Hence, NK cells may well be exploited for enhancing and rescuing the T-cell response in situations where the CD4 helper response is affected.

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