scholarly journals Potentiating the Antitumor Activity of Cytotoxic T Cells via the Transmembrane Domain of IGSF4 That Increases TCR Avidity

2021 ◽  
Vol 11 ◽  
Author(s):  
Hye-Ran Kim ◽  
Jeong-Su Park ◽  
Yasmin Fatima ◽  
Maiza Kausar ◽  
Jin-Hwa Park ◽  
...  

A robust T-cell response is an important component of sustained antitumor immunity. In this respect, the avidity of TCR in the antigen-targeting of tumors is crucial for the quality of the T-cell response. This study reports that the transmembrane (TM) domain of immunoglobulin superfamily member 4 (IGSF4) binds to the TM of the CD3 ζ-chain through an interaction between His177 and Asp36, which results in IGSF4-CD3 ζ dimers. IGSF4 also forms homo-dimers through the GxxVA motif in the TM domain, thereby constituting large TCR clusters. Overexpression of IGSF4 lacking the extracellular (IG4ΔEXT) domain potentiates the OTI CD8+ T cells to release IFN-γ and TNF-α and to kill OVA+-B16F10 melanoma cells. In animal models, IG4ΔEXT significantly reduces B16F10 tumor metastasis as well as tumor growth. Collectively, the results indicate that the TM domain of IGSF4 can regulate TCR avidity, and they further demonstrate that TCR avidity regulation is critical for improving the antitumor activity of cytotoxic T cells.

1978 ◽  
Vol 147 (4) ◽  
pp. 1236-1252 ◽  
Author(s):  
T J Braciale ◽  
K L Yap

This report examines the requirement for infectious virus in the induction of influenza virus-specific cytotoxic T cells. Infectious influenza virus was found to be highly efficient at generating both primary and secondary cytotoxic T-cell response in vivo. Inactivated influenza virus however, failed to stimulate a detectable cytotoxic T-cell response in vivo even at immunizing doses 10(5)-10(6)-fold higher than the minimum stimulatory dose of infectious virus. Likewise inactivated virus failed to sensitize target cells for T cell-mediated lysis in vitro but could stimulate a specific cytotoxic response from primed cells in vitro. Possible requirements for the induction of virus-specific cytotoxic T-cell responses are discussed in light of these observations and those of other investigators.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1354-1354
Author(s):  
Annkristin Heine ◽  
Tobias Holderried ◽  
Frank Grünebach ◽  
Silke Appel ◽  
Markus M. Weck ◽  
...  

Abstract Transfection of dendritic cells (DC) with in vitro transcribed RNA was shown to be a highly efficient method to generate antigen specific T cells, probably due to the induction of a polyclonal T cell response directed against multiple antigens presented on different HLA allels. However, the experimental evidence of this assumption remains to be demonstrated. To accomplish this, we used monocyte derived DC that were electroporated with RNA coding for the CMV pp65 antigen. The induction and expansion of antigen specific CD8+ and CD4+ T cells was assessed using a pannel of peptides derived from this antigen and presented on HLA-A2, -A1, -A11, -A24, -B35 and -B7 in IFN-g ELISPOT, 51Cr-release and proliferation assays. Autologous DC generated from CMV positive healthy donors were pulsed with peptides or transfected with pp65 RNA and utilized as stimulators. Autologous purified CD8+ and CD4+ lymphocytes were used as effector cells. By applying this approach we found that transfection of DC with pp65 RNA induces an expansion of polyclonal CD8+ mediated T cell responses that recognized peptide antigens presented on different HLA molecules. These in vitro generated cytotoxic T cells were able to efficiently lyse DC pulsed with pp65 derived peptides or transfected with the cognate RNA in an antigen specific manner after several in vitro restimulations. Furthermore, this experimental approach allowed the identification of the immunodominace of T cell epitopes presented upon RNA transfection. The HLA-2 directed responses were more pronounced as compared to the HLA-A1, -A11, -A24 or -B35 allels. In contrast, in 7 out of 7 HLA-A2 and HLA-B7 positive donors B7-peptides elicited a stronger T cell response than the A2-peptide, indicating the immunodominance of HLA-B7 epitopes. Interestingly, transfection of DC with pp65 RNA resulted in the induction of CD4+ antigen specific T cells that produced IFN-g and proliferated upon stimulation with transfected DC. In the next set of experiments we analyzed the possible induction of CMV specific T cells that recognize epitopes deduced from different antigens. Co-transfection of DC with a mixture of RNAs coding for the CMV pp65 and IE1 antigens elicited polyclonal T lymphocytes specific for peptides derived from both antigens. More importantly, polyclonal cytotoxic T cells could be elicited in peripheral blood of 2 out of 3 CMV negative donors demonstrating the efficiency of this approach. Our results demonstrate that DC transfected with RNA can elicit polyclonal T cell responses and have implications for the development of immunotherapeutic strategies to target viral or tumor associated antigens.


2021 ◽  
Vol 12 ◽  
Author(s):  
Anita Tewari ◽  
Miglena G. Prabagar ◽  
Sophie L. Gibbings ◽  
Kavita Rawat ◽  
Claudia V. Jakubzick

Every immune response has accelerators and brakes. Depending on the pathogen or injury, monocytes can play either role, promoting or resolving immunity. Poly I:C, a potent TLR3 ligand, licenses cross-presenting dendritic cells (DC1) to accelerate a robust cytotoxic T cells response against a foreign antigen. Poly I:C thus has promise as an adjuvant in cancer immunotherapy and viral subunit vaccines. Like DC1s, monocytes are also abundant in the LNs. They may act as either immune accelerators or brakes, depending on the inflammatory mediator they encounter. However, little is known about their contribution to adaptive immunity in the context of antigen and Poly I:C. Using monocyte-deficient and chimeric mice, we demonstrate that LN monocytes indirectly dampen a Poly I:C induced antigen-specific cytotoxic T cell response, exerting a “braking” function. This effect is mediated by IL-10 production and induction of suppressor CD4+ T cells. In a metastatic melanoma model, we show that a triple-combination prophylactic treatment consisting of anti-IL-10, tumor peptides and Poly I:C works because removing IL-10 counteracts the monocytic brake, resulting in significantly fewer tumors compared to mice treated with tumor peptides and Poly I:C alone. Finally, in human LN tissue, we observed that monocytes (unlike DCs) express high levels of IL-10, suggesting that anti-IL-10 may be an important addition to treatments. Overall, our data demonstrates that LN monocytes regulate the induction of a robust DC1-mediated immune response. Neutralization of either IL-10 or monocytes can augment Poly I:C-based treatments and enhance T cell cytotoxicity.


Blood ◽  
2003 ◽  
Vol 101 (1) ◽  
pp. 259-264 ◽  
Author(s):  
Andreas Burchert ◽  
Stefan Wölfl ◽  
Manuel Schmidt ◽  
Cornelia Brendel ◽  
Barbara Denecke ◽  
...  

Abstract Chronic myeloid leukemia (CML) is a clonal disease of hematopoietic stem cells caused by a reciprocal translocation of the long arms of chromosomes 9 and 22. In human leukocyte antigen A*0201+ (HLA-A*0201+) individuals, response after interferon-α (IFN-α) was shown to be associated with the emergence of CML-specific cytotoxic T cells that recognize PR-1, a myeloblastin (MBN)–derived nonapeptide. In contrast, imatinib potently induces remissions from CML by specific inhibition of the ABL tyrosine kinase. Here, we explored molecular regulations associated with CML responses under different treatment forms using cDNA-array. Expression of MBN was found to be down-regulated in remission under imatinib therapy (0 of 7MBN+ patients). In contrast, MBNtranscription was readily detectable in the peripheral blood in 8 of 8 tested IFN-α patients in complete remission (P = .0002). IFN-α–dependent MBNtranscription was confirmed in vitro by stimulation of peripheral blood mononuclear cells (PBMCs) with IFN-α and by IFN-α–mediated activation of the MBN promoter in reporter gene assays. Finally, with the use of HLA-A*0201–restricted,MBN-specific tetrameric complexes, it was demonstrated that all of 4 IFN-α–treated patients (100%), but only 2 of 11 imatinib patients (19%), in complete hematological or cytogenetic remission developed MBN-specific cytotoxic T cells (P = .011). Together, the induction of MBNexpression by IFN-α, but not imatinib, may contribute to the specific ability of IFN-α to induce an MBN-specific T-cell response in CML patients. This also implies that the character of remissions achieved with either drug may not be equivalent and therefore a therapy modality combining IFN-α and imatinib may be most effective.


2006 ◽  
Vol 74 (4) ◽  
pp. 2477-2481 ◽  
Author(s):  
Fanny Tzelepis ◽  
Bruna C. G. de Alencar ◽  
Marcus L. O. Penido ◽  
Ricardo T. Gazzinelli ◽  
Pedro M. Persechini ◽  
...  

ABSTRACT The kinetics of effector CD8+-T-cell responses to specific Trypanosoma cruzi epitopes was investigated after challenge. Our results suggest that the delayed kinetics differs from that observed in other microbial infections and facilitates the establishment of the disease in naïve mice. In contrast, in vaccinated mice, the swift CD8+-T-cell response helps host survival after challenge.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amanda W. K. AuYeung ◽  
Robert C. Mould ◽  
Ashley A. Stegelmeier ◽  
Jacob P. van Vloten ◽  
Khalil Karimi ◽  
...  

AbstractVaccination can prevent viral infections via virus-specific T cells, among other mechanisms. A goal of oncolytic virotherapy is replication of oncolytic viruses (OVs) in tumors, so pre-existing T cell immunity against an OV-encoded transgene would seem counterproductive. We developed a treatment for melanomas by pre-vaccinating against an oncolytic vesicular stomatitis virus (VSV)-encoded tumor antigen. Surprisingly, when the VSV-vectored booster vaccine was administered at the peak of the primary effector T cell response, oncolysis was not abrogated. We sought to determine how oncolysis was retained during a robust T cell response against the VSV-encoded transgene product. A murine melanoma model was used to identify two mechanisms that enable this phenomenon. First, tumor-infiltrating T cells had reduced cytopathic potential due to immunosuppression. Second, virus-induced lymphopenia acutely removed virus-specific T cells from tumors. These mechanisms provide a window of opportunity for replication of oncolytic VSV and rationale for a paradigm change in oncolytic virotherapy, whereby immune responses could be intentionally induced against a VSV-encoded melanoma-associated antigen to improve safety without abrogating oncolysis.


2016 ◽  
Vol 90 (10) ◽  
pp. 5187-5199 ◽  
Author(s):  
Qingsong Qin ◽  
Shwetank ◽  
Elizabeth L. Frost ◽  
Saumya Maru ◽  
Aron E. Lukacher

ABSTRACTMouse polyomavirus (MPyV) is a ubiquitous persistent natural mouse pathogen. A glutamic acid (E)-to-glycine (G) difference at position 91 of the VP1 capsid protein shifts the profile of tumors induced by MPyV from an epithelial to a mesenchymal cell origin. Here we asked if this tropism difference affects the MPyV-specific CD8 T cell response, which controls MPyV infection and tumorigenesis. Infection by the laboratory MPyV strain RA (VP1-91G) or a strain A2 mutant with an E-to-G substitution at VP1 residue 91 [A2(91G)] generated a markedly smaller virus-specific CD8 T cell response than that induced by A2(VP1-91E) infection. Mutant A2(91G)-infected mice showed a higher frequency of memory precursor (CD127hiKLRG1lo) CD8 T cells and a higher recall response than those of A2-infected mice. Using T cell receptor (TCR)-transgenic CD8 T cells and immunization with peptide-pulsed dendritic cells, we found that early bystander inflammation associated with A2 infection contributed to recruitment of the larger MPyV-specific CD8 T cell response. Beta interferon (IFN-β) transcripts were induced early during A2 or A2(91G) infections. IFN-β inhibited replication of A2 and A2(91G)in vitro. Using mice lacking IFN-αβ receptors (IFNAR−/−), we showed that type I IFNs played a role in controlling MPyV replicationin vivobut differentially affected the magnitude and functionality of virus-specific CD8 T cells recruited by A2 and A2(91G) viral infections. These data indicate that type I IFNs are involved in protection against MPyV infection and that their effect on the antiviral CD8 T cell response depends on capsid-mediated tropism properties of the MPyV strain.IMPORTANCEIsolates of the human polyomavirus JC virus from patients with the frequently fatal demyelinating brain disease progressive multifocal leukoencephalopathy (PML) carry single amino acid substitutions in the domain of the VP1 capsid protein that binds the sialic acid moiety of glycoprotein/glycolipid receptors on host cells. These VP1 mutations may alter neural cell tropism or enable escape from neutralizing antibodies. Changes in host cell tropism can affect recruitment of virus-specific CD8 T cells. Using mouse polyomavirus, we demonstrate that a single amino acid difference in VP1 known to shift viral tropism profoundly affects the quantity and quality of the anti-polyomavirus CD8 T cell response and its differentiation into memory cells. These findings raise the possibility that CD8 T cell responses to infections by human polyomaviruses may be influenced by VP1 mutations involving domains that engage host cell receptors.


2014 ◽  
Vol 20 (10) ◽  
pp. 1312-1321 ◽  
Author(s):  
Jyothi T Mony ◽  
Reza Khorooshi ◽  
Trevor Owens

Background: Myelin-specific T cells are implicated in multiple sclerosis (MS) and drive experimental autoimmune encephalomyelitis (EAE). EAE is commonly induced with short peptides, whereas in MS, whole myelin proteins are available for immune response. We asked whether immunization with the immunoglobulin-like domain of myelin oligodendrocyte glycoprotein (MOGIgd, residues 1–125) might induce distinct CD4+ T-cell response and/or a stronger CD8+ T-cell response, compared to the 21 amino acid immunodominant MHC II-associating peptide (p35–55). Objectives: Compare both EAE and T-cell responses in C57BL/6 mice immunized with MOGIgd and MOG p35–55. Methods: Cytokine production, and chemokine receptor expression by CD4+ and CD8+ T cells in the mouse central nervous system (CNS), were analyzed by flow cytometry. Results: MOGIgd triggered progression to more severe EAE than MOG p35–55, despite similar time of onset and overall incidence. EAE in MOGIgd-immunized mice was characterized by an increased percentage of CXCR3+ interferon-γ-producing CD4+ T cells in CNS. The CD8+ T-cell response to both immunogens was similar. Conclusions: Increased incidence of severe disease following MOGIgd immunization, accompanied by an increased percentage of CD4+ T cells in the CNS expressing CXCR3 and producing interferon-γ, identifies a pathogenic role for interferon-γ that is not seen when disease is induced with a single Major Histocompatibility Complex (MHC) II-associating epitope.


2005 ◽  
Vol 79 (15) ◽  
pp. 9419-9429 ◽  
Author(s):  
Nicole E. Miller ◽  
Jennifer R. Bonczyk ◽  
Yumi Nakayama ◽  
M. Suresh

ABSTRACT Although it is well documented that CD8 T cells play a critical role in controlling chronic viral infections, the mechanisms underlying the regulation of CD8 T-cell responses are not well understood. Using the mouse model of an acute and chronic lymphocytic choriomeningitis virus (LCMV) infection, we have examined the relative importance of peripheral T cells and thymic emigrants in the elicitation and maintenance of CD8 T-cell responses. Virus-specific CD8 T-cell responses were compared between mice that were either sham thymectomized or thymectomized (Thx) at ∼6 weeks of age. In an acute LCMV infection, thymic deficiency did not affect either the primary expansion of CD8 T cells or the proliferative renewal and maintenance of virus-specific lymphoid and nonlymphoid memory CD8 T cells. Following a chronic LCMV infection, in Thx mice, although the initial expansion of CD8 T cells was normal, the contraction phase of the CD8 T-cell response was exaggerated, which led to a transient but striking CD8 T-cell deficit on day 30 postinfection. However, the virus-specific CD8 T-cell response in Thx mice rebounded quickly and was maintained at normal levels thereafter, which indicated that the peripheral T-cell repertoire is quite robust and capable of sustaining an effective CD8 T-cell response in the absence of thymic output during a chronic LCMV infection. Taken together, these findings should further our understanding of the regulation of CD8 T-cell homeostasis in acute and chronic viral infections and might have implications in the development of immunotherapy.


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