CD8+ T-Cell Priming against a NonsecretedListeria monocytogenes Antigen Is Independent of the Antimicrobial Activities of Gamma Interferon

ABSTRACT Sublethal infection of mice with recombinant Listeria monocytogenes expressing a model epitope in either secreted or nonsecreted form results in similar CD8+ T-cell priming. Since nonsecreted bacterial proteins have no obvious access to the endogenous major histocompatibility complex (MHC) class I presentation pathway, presentation of these antigens requires destruction of the bacterium to reveal the nonsecreted molecules to an exogenous MHC class I presentation pathway. Gamma interferon (IFN-γ), a cytokine made by multiple cell types in response to L. monocytogenesinfection, could be required for exogenous presentation of nonsecreted bacterial antigens via its capacity to upregulate the expression of molecules involved in antigen presentation, its capacity to activate macrophages to kill bacteria to expose nonsecreted molecules or both. IFN-γ knockout (KO) mice were used to address the requirement for IFN-γ in CD8+ T-cell priming against (i) a model exogenous antigen and (ii) secreted and nonsecreted L. monocytogenes antigens. We demonstrate that IFN-γ KO mice are capable of cross-presenting the model exogenous antigen ovalbumin to prime CD8+ T-cell responses that are only slightly weaker than that in wild-type (WT) mice. Despite their extreme susceptibility to primary L. monocytogenes infection, previously immunized and naive IFN-γ KO mice were able to generate CD8+ T-cell responses against both secreted and nonsecreted L. monocytogenes antigens which were similar to responses of WT mice. Interestingly, IFN-γ KO mice were as capable as WT mice in mediating the characteristic drop in bacterial load in the liver at 4 h postinfection, although the IFN-γ KO mice have exacerbated bacterial loads as early as 24 h postinfection. These results demonstrate that the regulatory functions of IFN-γ are not required for priming of CD8+ T cells by cross-presentation of a model exogenous antigen or in response to a nonsecreted L. monocytogenes antigen. In addition, the capacity of IFN-γ to activate the microbicidal activities of macrophages is not required for the very early innate immune response to L. monocytogenesor priming of CD8+ T cells against a nonsecreted bacterial antigen.

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Conditional silencing of H-2Dbclass I molecule expression on dendritic cells modulates the protective and pathogenic kinetics of virus-antigen specific CD8 T cell responses during Theiler’s Virus infection

10.1101/632265 ◽

2019 ◽

Author(s):

Zachariah P. Tritz ◽

Robin C. Orozco ◽

Courtney S. Malo ◽

Lila T Yokanovich ◽

Katayoun Ayasoufi ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Antigen Presentation ◽

Mhc Class I ◽

Cd8 T Cells ◽

T Cell Responses ◽

Cd8 T Cell ◽

Class I ◽

Viral Control ◽

Cell Responses

ABSTRACTTheiler’s murine encephalomyelitis virus (TMEV) infection of the central nervous system is rapidly cleared in C57BL/6 mice by an anti-viral CD8 T cell response restricted by the MHC class I molecule, H-2Db. While the CD8 T cell response against neurotropic viruses is well characterized, the identity and function of the antigen presenting cell(s) involved in this process is(are) less well defined. To address this gap in knowledge, we developed a novel C57BL/6 H-2Dbconditional knockout mouse that expresses an H-2Dbtransgene in which the transmembrane domain locus is flanked by LoxP sites. We crossed these H-2DbLoxP mice with MHC class I-deficient mice expressing Cre-recombinase under either the CD11c or LysM promoter in order to silence H-2Dbrestricted antigen presentation predominantly in dendritic cells or macrophages, respectively. Upon challenge with intracranial TMEV infection, we observe that CD11c+ APCs are critical for early priming of CD8 T cells against the immunodominant TMEV peptide VP2121-130 presented in the context of the H-2Dbmolecule. This stands in stark contrast to later time points post TMEV infection where CD11c+ APCs appear dispensable for the activation of antigen-specific T cells; the functionality of these late-arising antiviral CD8 T cells is reflected in the restoration of viral control at later time points. These late-arising CD8 T cells also retain their capacity to induce blood-brain barrier disruption. In contrast, when H-2Dbrestricted antigen presentation was selectively silenced in LysM+ APCs there was no overt impact on the priming of Db:VP2121-130 epitope-specific CD8 T cells, although a modest reduction in immune cell entry into the CNS was observed. This work establishes a model system which enables critical dissection of MHC class I restricted antigen presentation to T cells, revealing cell specific and temporal features involved in the generation of antiviral CD8 T cell responses. Employing this novel system, we established CD11c+ cells as a pivotal driver of acute, but not later-arising, antiviral CD8 T cell responses against the TMEV immunodominant epitope VP2121-130, with functional implications both for T cell-mediated viral control and immunopathology.

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Identification of Novel MHC Class I and Class II Epitopes of WT1 Using a Peptide Library Screen.

Blood ◽

10.1182/blood.v106.11.2764.2764 ◽

2005 ◽

Vol 106 (11) ◽

pp. 2764-2764 ◽

Cited By ~ 1

Author(s):

Katayoun Rezvani ◽

Stephan Mielke ◽

Yasemin Kilical ◽

Matthias Grube ◽

Hiroshi Fujiwara ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Mhc Class I ◽

Cd8 T Cells ◽

T Cell Responses ◽

Cd8 T Cell ◽

Class Ii ◽

Peptide Library ◽

Class I ◽

Cell Responses

Abstract Although several HLA-A*0201-restricted immunodominant peptides from the leukemia-restricted protein WT-1 are characterized, T cell responses to peptide sequences binding to other common class I and II epitopes of WT-1 remain almost completely unexplored. A more comprehensive definition of the WT-1 antigen would extend peptide antigen vaccines to individuals lacking HLA-A*0201 and *2402 and improve vaccine potency by recruiting both CD4+ and CD8+ T cell responses. Here we used a WT1 peptide library to identify WT-1 peptide sequences inducing CD4+ and CD8+ T cell responses in normal individuals and patients with AML and other myeloid leukemias. Six cases were studied. The library consisted of 110 15mer peptides overlapping by 11aa covering the entire WT-1 protein in 21 pools. Monocytes were isolated by plastic adherence and pulsed with peptide pools for 3 hours. Autologous CD8+ and CD4+ T cells were then added. Pools of peptides were prepared in such a way that each peptide was represented in two different peptide pools, allowing the identification of the respective peptide by responses in the two corresponding pools. Cells were harvested for RNA extraction and reverse transcription. Real time PCR (RQ-PCR) was used to identify peptide-specific induction of IFN-γ and IL-2 in CD8+ and CD4+ T cells. The SYFPEITHI binding motif software was then used to predict the probable HLA restriction for the candidate epitopes. To confirm candidate peptide immunogenecity and HLA restriction, selected peptides were synthesized and tested individually. In addition to the known HLA-A*0201 peptides WT37, WT126, WT187 and WT235 we identified 20 new MHC class I and II epitopes of WT1. Four were restricted by more than one HLA allele, demonstrating the promiscuity of epitope binding. One epitope (VPGVAPTLV) was restricted to HLA-A*0201 and HLA-B*5101. One epitope (SGQFTGTAGACRYGP) was restricted by a class I HLA allele, namely HLA-*6801 and a class II HLA allele, DR*1501. Two epitopes (YGPFGPPPPSQASGQ and QKKFARSDELVRHHN) were restricted by multiple MHC class II alleles. The proliferative response of CD4+ and CD8+ T cells to candidate peptides was confirmed using CFSE labeling. We now plan to characterize the antileukemic effects of CD4+ and CD8+ T cells induced by these peptides with a view to designing broad-spectrum vaccines inducing leukemia-reactive T cells across a wide range of HLA types.

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MHC class I-presented tumor antigen appraisable for T-cell responses against ovarian cancer

Bangladesh Journal of Pharmacology ◽

10.3329/bjp.v10i3.23076 ◽

2015 ◽

Vol 10 (3) ◽

pp. 524

Author(s):

Jing Yao Wang ◽

Nan Zhang ◽

Xiaojie Yang ◽

Danli Gao ◽

Lirong Yin ◽

...

Keyword(s):

Ovarian Cancer ◽

T Cells ◽

T Cell ◽

Mhc Class I ◽

Tumor Antigen ◽

Human Leukocyte ◽

T Cell Responses ◽

Mean Value ◽

Class I ◽

Cell Responses

<p>The purpose of this study is to assess whether MHC class I-presented tumor antigen is appraisable for T-cell responses against ovarian cancer. In ovarian cancer cell, human leukocyte antigen A2 (HLA-A2) associated with peptides was used to promote the activation of naive T cells so as to activate antigen-specific T cells. 7 or 4 patients were observed grade 1 or 2 injection site reactions, respectively. 5, 2 or 1 patients were observed grade 1, 2 or 3 pain reactions, respectively. 4 or 1 patients were observed grade 1 or 2 induration reactions. Total number mean value of patients experiencing response to the particular peptide was 7.73, and total number mean value of peptides to which the patients responded was 7.45. MHC class I-presented tumor antigen is appraisable for T-cell responses against ovarian cancer in China.</p>

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Novel Role of CD8+ T Cells and Major Histocompatibility Complex Class I Genes in the Generation of Protective CD4+ Th1 Responses during Retrovirus Infection in Mice

Journal of Virology ◽

10.1128/jvi.76.16.7942-7948.2002 ◽

2002 ◽

Vol 76 (16) ◽

pp. 7942-7948 ◽

Cited By ~ 18

Author(s):

Karin E. Peterson ◽

Ingunn Stromnes ◽

Ron Messer ◽

Kim Hasenkrug ◽

Bruce Chesebro

Keyword(s):

T Cells ◽

Major Histocompatibility Complex ◽

T Cell ◽

Mhc Class I ◽

Mhc Class Ii ◽

T Cell Responses ◽

Class I ◽

Major Histocompatibility ◽

Cell Responses ◽

Histocompatibility Complex

ABSTRACT CD4+ Th1 responses to virus infections are often necessary for the development and maintenance of virus-specific CD8+ T-cell responses. However, in the present study with Friend murine retrovirus (FV), the reverse was also found to be true. In the absence of a responder H-2b allele at major histocompatibility complex (MHC) class II loci, a single H-2Db MHC class I allele was sufficient for the development of a CD4+ Th1 response to FV. This effect of H-2Db on CD4+ T-cell responses was dependent on CD8+ T cells, as demonstrated by depletion studies. A direct effect of CD8+ T-cell help in the development of CD4+ Th1 responses to FV was also shown in vaccine studies. Vaccination of nonresponder H-2a/a mice induced FV-specific responses of H-2Dd -restricted CD8+ cytotoxic T lymphocytes (CTL). Adoptive transfer of vaccine-primed CD8+ T cells to naive H-2a/a mice prior to infection resulted in the generation of FV-specific CD4+ Th1 responses. This novel helper effect of CD8+ T cells could be an important mechanism in the development of CD4+ Th1 responses following vaccinations that induce CD8+ CTL responses. The ability of MHC class I genes to facilitate CD4+ Th1 development could also be considerable evolutionary advantage by allowing a wider variety of MHC genotypes to generate protective immune responses against intracellular pathogens.

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608 Immunodominant listeria epitopes compete with vaccine-directed cd8+ t-cell responses rescued by peptide-MHC stabilizing modifications

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0608 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A644-A644

Author(s):

John Flickinger ◽

Jagmohan Singh ◽

Yanki Yarman ◽

Robert Carlson ◽

Scott Waldman ◽

...

Keyword(s):

Listeria Monocytogenes ◽

T Cell ◽

Cell Line ◽

Mhc Class I ◽

T Cell Responses ◽

Cd8 T Cell ◽

Class I ◽

Peptide Ligand ◽

Altered Peptide Ligand ◽

Cell Responses

BackgroundThe Gram-positive bacterium Listeria monocytogenes (Lm) is a promising vector for cancer immunotherapy due to its ability to directly infect antigen-presenting cells, induce potent CD8+ T-cell immunity, and remodel immunosuppressive tumor microenvironments.1 Recent clinical trials have demonstrated safety and immunogenicity of Lm-based cancer vaccines in lung, cervical, pancreatic, and other cancers. In colorectal cancer, the transmembrane receptor guanylyl cyclase C (GUCY2C) is an emerging target for immunotherapy.2 Here, we examined the immunogenicity of a recombinant strain of Listeria monocytogenes secreting GUCY2C (Lm-GUCY2C). Surprisingly, Lm-GUCY2C vaccination induced robust Lm-specific CD8+ T-cell immunity but failed to prime GUCY2C-specific CD8+ T-cell responses. These studies explore the hypothesis that immunodominant Lm antigens suppress primary immunity to subdominant GUCY2C epitopes in Lm-GUCY2CMethodsLm-GUCY2C expresses the extracellular domain of mouse GUCY2C23-429 downstream of an ActA promoter integrated into the genome of the live, attenuated delta actA delta inlB Lm strain. Altered peptide ligands were designed based on NetMHCpan 4.0 peptide-MHC binding algorithms and similarly cloned into Lm. Peptide-MHC class I complex stability was quantified by FACS-based surface peptide-MHC dissociation on the TAP-deficient cell line, RMA-S H-2Kd.3In vivo efficacy studies employed IFNγ-ELISpot quantification of T-cell responses and tumor challenge studies with the CT26 colorectal cancer cell line. Adenovirus expressing GUCY2C was used as a positive control.2 4ResultsLm-GUCY2C vaccination of BALB/c mice generated Lm-specific CD8+ T-cell responses but an absence of GUCY2C-specific immunity. Peptide-MHC stability studies revealed poor stability of the dominant GUCY2C254-262 epitope complexed with H-2Kd compared to H-2Kd-restricted Lm epitopes derived from the LLO and p60 Lm antigens. Mutation of the GUCY2C254-262 peptide at critical anchoring residues for binding H-2Kd revealed that the altered peptide ligand with an F255Y mutation significantly improved the stability of the GUCY2C254-262-H-2Kd complex. Similarly, vaccination of mice with recombinant Lm-GUCY2C expressing the altered peptide ligand (Lm-GUCY2CF255Y) restored GUCY2C immunogenicity and antitumor immunity.ConclusionsImmunodominant Lm antigens may interfere with immune responses directed to the vaccine target antigen GUCY2C by competing with GUCY2C epitope for MHC class I binding and presentation. Moreover, use of a substituted GUCY2C -peptide ligand with enhanced peptide-MHC class I stability restored GUCY2C-specific immunity in the context of Lm-GUCY2C, an approach that can be translated to patients. Importantly, these studies also suggest that ongoing Lm-based vaccine development programs targeting a variety of antigens in other cancer types may be similarly limited by the immunodominance of Lm epitopes.AcknowledgementsThe authors thank Dr. Peter Lauer for providing the pPL2 integration vector used in cloning Lm-GUCY2C and Dr. Sean Murphy for providing the RMA-S H-2Kd cell line.Ethics ApprovalStudies were approved by the Thomas Jefferson University IACUC (Protocol # 01956).ReferencesFlickinger JC, Rodeck U, Snook AE. Listeria monocytogenes as a Vector for Cancer Immunotherapy: Current Understanding and Progress. Vaccines (Basel) 2018;6. doi:10.3390/vaccines6030048.Snook AE, Baybutt TR, Xiang B, Abraham TS, Flickinger JC, Hyslop T, et al. Split tolerance permits safe Ad5-GUCY2C-PADRE vaccine-induced T-cell responses in colon cancer patients. J Immunother Cancer 2019;7:104. doi:10.1186/s40425-019-0576-2.Müllbacher A, Lobigs M, Kos FJ, Langman R. Alloreactive cytotoxic T-cell function, peptide nonspecific. Scand J Immunol 1999;49:563–9.Flickinger J. JC, Singh J, Carlson R, Leong E, Baybutt T, Barton J, et al. Chimeric Ad5.F35 vector evades anti-adenovirus serotype 5 neutralization opposing GUCY2C-targeted antitumor immunity. J Immunother Cancer 2020.

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Batf3-Dependent Dendritic Cells Promote Optimal CD8 T Cell Responses against Respiratory Poxvirus Infection

Journal of Virology ◽

10.1128/jvi.00495-18 ◽

2018 ◽

Vol 92 (16) ◽

Cited By ~ 9

Author(s):

Pritesh Desai ◽

Vikas Tahiliani ◽

Georges Abboud ◽

Jessica Stanfield ◽

Shahram Salek-Ardakani

Keyword(s):

T Cells ◽

Dendritic Cells ◽

T Cell ◽

Vaccinia Virus ◽

Respiratory Infection ◽

Host Resistance ◽

T Cell Responses ◽

Cell Responses ◽

Ifn Γ ◽

The Impact

ABSTRACTRespiratory infection with vaccinia virus (VacV) elicits robust CD8+T cell responses that play an important role in host resistance. In the lung, VacV encounters multiple tissue-resident antigen-presenting cell (APC) populations, but which cell plays a dominant role in priming of virus-specific CD8+effector T cell responses remains poorly defined. We used Batf3−/−mice to investigate the impact of CD103+and CD8α+dendritic cell (DC) deficiency on anti-VacV CD8+T cell responses. We found that Batf3−/−mice were more susceptible to VacV infection, exhibiting profound weight loss, which correlated with impaired accumulation of gamma interferon (IFN-γ)-producing CD8+T cells in the lungs. This was largely due to defective priming since early in the response, antigen-specific CD8+T cells in the draining lymph nodes of Batf3−/−mice expressed significantly reduced levels of Ki67, CD25, and T-bet. These results underscore a specific role for Batf3-dependent DCs in regulating priming and expansion of effector CD8+T cells necessary for host resistance against acute respiratory VacV infection.IMPORTANCEDuring respiratory infection with vaccinia virus (VacV), a member ofPoxviridaefamily, CD8+T cells play important role in resolving the primary infection. Effector CD8+T cells clear the virus by accumulating in the infected lungs in large numbers and secreting molecules such as IFN-γ that kill virally infected cells. However, precise cell types that regulate the generation of effector CD8+T cells in the lungs are not well defined. Dendritic cells (DCs) are a heterogeneous population of immune cells that are recognized as key initiators and regulators of T-cell-mediated immunity. In this study, we reveal that a specific subset of DCs that are dependent on the transcription factor Batf3 for their development regulate the magnitude of CD8+T cell effector responses in the lungs, thereby providing protection during pulmonary VacV infection.

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Peripheral T-Cell Reactivity to Heat Shock Protein 70 and Its Cofactor GrpE from Tropheryma whipplei Is Reduced in Patients with Classical Whipple's Disease

Infection and Immunity ◽

10.1128/iai.00363-17 ◽

2017 ◽

Vol 85 (8) ◽

Cited By ~ 3

Author(s):

Lucia Trotta ◽

Kathleen Weigt ◽

Katina Schinnerling ◽

Anika Geelhaar-Karsch ◽

Gerrit Oelkers ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Heat Shock ◽

Heat Shock Protein ◽

Heat Shock Protein 70 ◽

T Cell Responses ◽

Tropheryma Whipplei ◽

Content Type ◽

Cell Responses ◽

Ifn Γ

ABSTRACT Classical Whipple's disease (CWD) is characterized by the lack of specific Th1 response toward Tropheryma whipplei in genetically predisposed individuals. The cofactor GrpE of heat shock protein 70 (Hsp70) from T. whipplei was previously identified as a B-cell antigen. We tested the capacity of Hsp70 and GrpE to elicit specific proinflammatory T-cell responses. Peripheral mononuclear cells from CWD patients and healthy donors were stimulated with T. whipplei lysate or recombinant GrpE or Hsp70 before levels of CD40L, CD69, perforin, granzyme B, CD107a, and gamma interferon (IFN-γ) were determined in T cells by flow cytometry. Upon stimulation with total bacterial lysate or recombinant GrpE or Hsp70 of T. whipplei, the proportions of activated effector CD4+ T cells, determined as CD40L+ IFN-γ+, were significantly lower in patients with CWD than in healthy controls; CD8+ T cells of untreated CWD patients revealed an enhanced activation toward unspecific stimulation and T. whipplei-specific degranulation, although CD69+ IFN-γ+ CD8+ T cells were reduced upon stimulation with T. whipplei lysate and recombinant T. whipplei-derived proteins. Hsp70 and its cofactor GrpE are immunogenic in healthy individuals, eliciting effective responses against T. whipplei to control bacterial spreading. The lack of specific T-cell responses against these T. whipplei-derived proteins may contribute to the pathogenesis of CWD.

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Natural CD8 + T-cell responses against MHC class I epitopes of the HER-2/ neu oncoprotein in patients with epithelial tumors

Cancer Immunology Immunotherapy ◽

10.1007/s00262-003-0420-9 ◽

2003 ◽

Vol 52 (12) ◽

pp. 771-779 ◽

Cited By ~ 21

Author(s):

Panagiota A. Sotiropoulou ◽

Sonia A. Perez ◽

Volfgang Voelter ◽

Hartmut Echner ◽

Ioannis Missitzis ◽

...

Keyword(s):

T Cell ◽

Mhc Class I ◽

T Cell Responses ◽

Cd8 T Cell ◽

Class I ◽

Cell Responses ◽

Epithelial Tumors ◽

Her 2

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TLR3 essentially promotes protective class I–restricted memory CD8+ T-cell responses to Aspergillus fumigatus in hematopoietic transplanted patients

Blood ◽

10.1182/blood-2011-06-362582 ◽

2012 ◽

Vol 119 (4) ◽

pp. 967-977 ◽

Cited By ~ 79

Author(s):

Agostinho Carvalho ◽

Antonella De Luca ◽

Silvia Bozza ◽

Cristina Cunha ◽

Carmen D'Angelo ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Aspergillus Fumigatus ◽

Cd8 T Cells ◽

T Cell Responses ◽

Cd8 T Cell ◽

Class I ◽

Class I Mhc ◽

Cell Responses ◽

Memory Cd8 T Cell

Abstract Aspergillus fumigatus is a model fungal pathogen and a common cause of severe infections and diseases. CD8+ T cells are present in the human and murine T-cell repertoire to the fungus. However, CD8+ T-cell function in infection and the molecular mechanisms that control their priming and differentiation into effector and memory cells in vivo remain elusive. In the present study, we report that both CD4+ and CD8+ T cells mediate protective memory responses to the fungus contingent on the nature of the fungal vaccine. Mechanistically, class I MHC-restricted, CD8+ memory T cells were activated through TLR3 sensing of fungal RNA by cross-presenting dendritic cells. Genetic deficiency of TLR3 was associated with susceptibility to aspergillosis and concomitant failure to activate memory-protective CD8+ T cells both in mice and in patients receiving stem-cell transplantations. Therefore, TLR3 essentially promotes antifungal memory CD8+ T-cell responses and its deficiency is a novel susceptibility factor for aspergillosis in high-risk patients.

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