scholarly journals 2081

2017 ◽  
Vol 1 (S1) ◽  
pp. 55-56
Author(s):  
Farha Sherani ◽  
Duane Moogk ◽  
Anuj Bapodra ◽  
Karolina Malecek ◽  
Una Moran ◽  
...  

OBJECTIVES/SPECIFIC AIMS: To characterize the CD4+ T-cell response during CTLA-4 blockade immunotherapy with ipilimumab in patients with metastatic melanoma by correlating cytokine profiles with phenotypic changes in the intratumoral lymphocyte compartment of tumor biopsies obtained before and after treatment. METHODS/STUDY POPULATION: Peripheral blood mononuclear cell samples were obtained from patients with metastatic melanoma undergoing monotherapy with ipilimumab via the Interdisciplinary Melanoma Cooperative Group at New York University Langone Medical Center. We isolated CD4+ T-cells and used a cytometric bead array assay following in vitro activation with anti-CD3, anti-CD28 antibodies to characterize cytokine expression profiles by quantifying IFN gamma, IL-2, IL-4, IL-6, IL-10, IL-17, and TNF-α at 5 time points during therapy. In total, 53 peripheral blood samples were included from 12 patients. To correlate cytokine profiles with CD4+ T-cell phenotypes in the intratumoral lymphocyte compartment, multiplex immunofluorescence was performed using CD4, CD8, CCR7, CD45RO, and FOXP3 antibodies on tumors before and after treatment with ipilimumab. RESULTS/ANTICIPATED RESULTS: Patients with evidence of clinical benefit (CB), as defined by having achieved partial response or stable disease, were compared with nonresponders (NR). All patients had an increase in IFN-γ, IL-2, and IL-10 secretion by CD4+ T-cells during ipilimumab therapy. NR had a statistically higher increase in all 3 cytokines. Mean IL-10 secretion was 22.3-fold higher compared with patients with CB (p value 0.0458; 95% CI=0.6676–43.89). Mean IFN-γ secretion was 12.4-fold higher from baseline levels in NR compared with CB (p value 0.046; 95% CI=0.3589–24.35). Mean IL-2 secretion was 6.9-fold higher in NR compared with CB (p value 0.032; 95% CI=0.9688–12.75). There were no statistically significant differences seen in the secretion of IL-4, IL-6, IL-17, or TNF-α. Multiplex immunofluorescence for immune profiling of 20 pre and post treatment tumor biopsies is ongoing. We expect to see distinct intratumoral lymphocyte compartment changes which correlate with clinical response and the above described differential cytokine profiles. Specifically, we anticipate CB patients will have increased intratumoral effector T-cells and decreased regulatory T-cells when compared with their NR counterparts. DISCUSSION/SIGNIFICANCE OF IMPACT: Cytokine expression profiles of peripheral blood CD4+ T-cells have not been previously correlated with patient response in patients undergoing treatment with ipilimumab. We describe distinct secretion profiles for IFN-γ, IL-2, and IL-10 for CB Versus NR patients. NR had a statistically higher increase in IL-10, an inhibitory cytokine which typically indicates upregulation of regulatory T-cells and consequent immune escape. Increased secretion of IL-2 and IFN-γ suggests skewing towards a Th1 type, anti-tumor effector T-cell response; these cytokines increased with ipilimumab treatment in both patient groups. However, the mean increase was several fold higher in NR. Recent evidence suggests loss of the interferon gamma pathway in tumor cells confers resistance to anti-CTLA4 therapy. Chronic IFN-γ secretion is associated with an exhausted T-cell phenotype and impaired tumor rejection. Therefore, higher increases in IFN-γ secretion by CD4+ T-cells in NR suggest impaired IFN-γ dependent tumor rejection in these patients. Our findings suggest IFN-γ, IL-2, and IL-10 cytokine expression profiles can be useful as biomarkers for response to ipilimumab treatment.

2010 ◽  
Vol 207 (3) ◽  
pp. 505-520 ◽  
Author(s):  
Xiaoyuan Huang ◽  
Xiangyang Bai ◽  
Yang Cao ◽  
Jingyi Wu ◽  
Mei Huang ◽  
...  

Angiogenesis is increasingly recognized as an important prognosticator associated with the progression of lymphoma and as an attractive target for novel modalities. We report a previously unrecognized mechanism by which lymphoma endothelium facilitates the growth and dissemination of lymphoma by interacting with circulated T cells and suppresses the activation of CD4+ T cells. Global gene expression profiles of microdissected endothelium from lymphoma and reactive lymph nodes revealed that T cell immunoglobulin and mucin domain–containing molecule 3 (Tim-3) was preferentially expressed in lymphoma-derived endothelial cells (ECs). Clinically, the level of Tim-3 in B cell lymphoma endothelium was closely correlated to both dissemination and poor prognosis. In vitro, Tim-3+ ECs modulated T cell response to lymphoma surrogate antigens by suppressing activation of CD4+ T lymphocytes through the activation of the interleukin-6–STAT3 pathway, inhibiting Th1 polarization, and providing protective immunity. In a lymphoma mouse model, Tim-3–expressing ECs promoted the onset, growth, and dissemination of lymphoma by inhibiting activation of CD4+ T cells and Th1 polarization. Our findings strongly argue that the lymphoma endothelium is not only a vessel system but also a functional barrier facilitating the establishment of lymphoma immune tolerance. These findings highlight a novel molecular mechanism that is a potential target for enhancing the efficacy of tumor immunotherapy and controlling metastatic diseases.


Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5375
Author(s):  
Catherine S. Forconi ◽  
David H. Mulama ◽  
Priya Saikumar Lakshmi ◽  
Joslyn Foley ◽  
Juliana A. Otieno ◽  
...  

Children diagnosed with endemic Burkitt lymphoma (eBL) are deficient in interferon-γ (IFN-γ) responses to Epstein–Barr Nuclear Antigen1 (EBNA1), the viral protein that defines the latency I pattern in this B cell tumor. However, the contributions of immune-regulatory cytokines and phenotypes of the EBNA1-specific T cells have not been characterized for eBL. Using a bespoke flow cytometry assay we measured intracellular IFN-γ, IL-10, IL-17A expression and phenotyped CD4+ and CD8+ T cell effector memory subsets specific to EBNA1 for eBL patients compared to two groups of healthy children with divergent malaria exposures. In response to EBNA1 and a malaria antigen (PfSEA-1A), the three study groups exhibited strikingly different cytokine expression and T cell memory profiles. EBNA1-specific IFN-γ-producing CD4+ T cell response rates were lowest in eBL (40%) compared to children with high malaria (84%) and low malaria (66%) exposures (p < 0.0001 and p = 0.0004, respectively). However, eBL patients did not differ in CD8+ T cell response rates or the magnitude of IFN-γ expression. In contrast, eBL children were more likely to have EBNA1-specific CD4+ T cells expressing IL-10, and less likely to have polyfunctional IFN-γ+IL-10+ CD4+ T cells (p = 0.02). They were also more likely to have IFN-γ+IL-17A+, IFN-γ+ and IL-17A+ CD8+ T cell subsets compared to healthy children. Cytokine-producing T cell subsets were predominantly CD45RA+CCR7+ TNAIVE-LIKE cells, yet PD-1, a marker of persistent activation/exhaustion, was more highly expressed by the central memory (TCM) and effector memory (TEM) T cell subsets. In summary, our study suggests that IL-10 mediated immune regulation and depletion of IFN-γ+ EBNA1-specific CD4+ T cells are complementary mechanisms that contribute to impaired T cell cytotoxicity in eBL pathogenesis.


2019 ◽  
Vol 133 (17) ◽  
pp. 1917-1934
Author(s):  
Madhuparna Nandi ◽  
Sourina Pal ◽  
Sumantra Ghosh ◽  
Bidhan Chandra Chakraborty ◽  
Debangana Dey ◽  
...  

Abstract During chronic hepatitis B (CHB), CD8+ T cells down-regulate CD28, the primary co-stimulation molecule for T-cell activation. Diverse functional attributes of CD8+CD28− T cells are suggested in various disease contexts. The present study aimed to characterize CD8+CD28− T cells in different phases of chronic Hepatitis B virus (HBV) infection (CHI)- Immune-tolerance (IT), Hepatitis B e-antigen-positive CHB (EP-CHB), Inactive carriers (IC) and Hepatitis B e-antigen-negative CHB (EN-CHB), to appraise their contribution in HBV-related disease pathophysiology. Flow cytometry analysis of T cells in peripheral blood of study subjects revealed enhanced CD8+CD28− T-cell accumulation in EP-/EN-CHB, compared with IT/IC and they expanded equivalently in HBV-specific and non-specific CD8+ T-cell compartments. Profound increase in CD8+CD28− T cells expressing perforin/granzyme-B/CD57/IFN-γ/TNF-α and markers of terminal differentiation were observed exclusively in EP-/EN-CHB. Further, activation with anti-NKG2D resulted in heightened IFN-γ/TNF-α production selectively from CD8+CD28− T cells, suggesting NKG2D-mediated alternative co-stimulation. CD8+CD28− T cells sorted from CHB patients induced enhanced apoptosis of peripheral blood mononuclear cells (PBMC), including CD4+ T cells. However, NKG2D-ligand (major histocompatibility complex class I chain-related molecule A/B (MICA/B)) was preferentially expressed by HBV-specific CD4+ T cells of CHB patients, making these cells a potential target to NKG2D-dependent CD8+CD28− T-cell killing. Both CD28+ and CD28− T cells in CHB expressed CXCR3 at similar levels and thus capable of homing to the liver. A positive correlation was seen between CD8+CD28− T-cell frequency and serum-alanine transaminase (ALT) levels and CHB-derived CD8+CD28− T cells caused pronounced cell death in HBV-transfected Huh7 cells. Immunofluorescence staining identified greater intrahepatic incidence of CD8+CD28− T cells but decline in CD4+ T cells in CHB than IC. Collectively, CD8+CD28− T cells demonstrated differential distribution and phenotypic/functional skewing in different CHI phases and contribute to disease progression by Perforin-Granzyme- or IFN-γ-TNF-α-mediated cytotoxicity while restraining antiviral immunity through NKG2D-dependent HBV-specific CD4+ T-cell depletion.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3526-3526
Author(s):  
Fanli Hua ◽  
Feng Li ◽  
Shanhua Zou ◽  
Weiguang Wang ◽  
Yunfeng Cheng

Abstract Background and Objective Immune thrombocytopenia (ITP) is a typical autoimmune-mediated bleeding disorder in which isolated thrombocytopenia is resulted from increased platelet clearance and/or impaired thrombocytogenesis. In addition to producing antibodies and acting as antigen presenting cells, B cells have been proven to play an important role in regulating immune response mainly via production of interleukin 10 (IL-10). CD5+ B cells are able to produce IL-10, and CD5 is deemed as a hallmark of regulatory B cells. We have previously demonstrated insufficient IL-10 secretion by CD5+ B cells in patients with ITP. The objective of the current study was to investigate the alteration in regulatory functions of peripheral blood CD5+B cells in ITP patients. Methods Peripheral blood CD5+ B cells, CD5- B cells and CD4+ T cells were magnetically isolated from 7 adult patients with newly diagnosed ITP and 10 healthy controls. CD4+ T cells were labeled with CFSE (5(6)-Carboxyfluorescein N-hydroxysuccinimidyl ester) before cultured in RPMI1640 in the presence of CD3mAb/CD3mAb/IL-2 for 72 hours with or without CD5+/CD5- B cells at gradient B/T ratios. The proliferation of CD4+ T cells was assessed by the dilution of CFSE expression on a flow cytometry. After 72-hour culture, cells were stained with APC-CD4/FITC-Annexin-V/PI to evaluate the apoptosis of CD4+T cells. The concentrations of IL-4 and IFN-γ in cell culture supernatants were determined by ELISA. Results Purified CD5+ B cells from healthy subjects were capable of suppressing the proliferation of CD4+ T cells in a dose-dependent manner when co-cultured for 72 hours. The percentage of CD4+ T cells that underwent proliferation showed a statistically significant reduction (72.8 ± 9.4% vs 61.6 ± 12.8%; p = 0.039) in the presence of CD5+ B cells at 1:3 B/T ratio. With the B/T ratio increased to 1:1, the proportion of proliferating CD4+ T cells decreased to 43.7 ± 16.4% (p < 0.001). The apoptosis of CD4+ T cells was promoted by CD5+ B cells as the percentage of apoptotic CD4+ T cells was increased when co-cultured with CD5+ B cells at 1:1 B/T ratio (3.75 ± 0.82% vs 6.03 ± 2.51%; p = 0.014). In contrast, CD5- B cells did not suppress the proliferation of CD4+ T cells, quite contrary, the proportion of proliferating CD4+ T cells was slightly increased, though not statistically significant, when co-cultured at 1:1 with CD5- B cells for 72 hours as compared with CD4+ T cell cultured alone (72.8 ± 9.4% vs 78.9 ± 8.5%; p = 0.145). No effect of CD5- B cells on the apoptosis of CD4+T cells was observed. In ITP patients, CD5+ B cells showed compromised regulatory functions as the proliferation of CD4+ T cells was not altered by CD5+ B cells until the B/T ratio increased to 3:1 (1:1 B/T: 74.6 ± 12.5% vs 72.1 ± 16.2%, p = 0.752; 3:1 B/T: 74.6 ± 12.5% vs 60.7 ± 10.3%, p = 0.042, respectively). The ability of CD5+ B cells to promote the apoptosis of CD4+ T cells was also impaired in ITP patients: no difference in the percentage of apoptotic CD4+ T cells was found when CD5+ B cells (1:1 ratio of B to T) were added to the T cell culture system (2.97 ± 1.07% vs 3.24 ± 1.45%; p = 0.699). We also evaluated the ability of CD5+ B cells to suppress the secretion of IFN-γ, one of the Th1-type cytokines. In healthy subjects, the IFN-γ secretion by CD4+ T cells was decreased by CD5+ B cells at a minimal B/T ratio of 1:5 (2427.99 ± 632.62 pg/mL vs 1734.41 ± 507.16 pg/mL; p = 0.014) and dramatically dropped to 395.22 ± 136.54 pg/mL when the ratio of B/T increased to 1:1 (p < 0.001). The secretion of IL-4, a representative cytokine of Th2 subset, was not influenced by CD5+ B cells. CD5+ B cells from ITP patients showed no capacity for suppressing the IFN-γ secretion until the ratio of B/T increased as high as to 1:1 (3060.02 ± 493.98 pg/mL vs 2394.57 ± 417.42 pg/mL; p = 0.019) and, even under the condition of 5:1 B/T ratio, CD4+ T cells from ITP patients retained about 30% of the ability of IFN-γ secretion (1067.37 ± 499.70 pg/mL; p < 0.001 ). Conclusions CD5+ B cells from normal controls are competent for inhibiting the proliferation of CD4+ T cells and suppressing the secretion of IFN-γ by CD4+ T cells, suggesting potent immune regulatory functions of CD5+ B cells. While in patients with ITP, CD5+ B cells are severely functionally impaired, indicating that the immune regulatory dysfunctions in CD5+ B cells may participate in the pathogenesis of ITP. Disclosures: No relevant conflicts of interest to declare.


2004 ◽  
Vol 199 (11) ◽  
pp. 1595-1605 ◽  
Author(s):  
Ramon Arens ◽  
Koen Schepers ◽  
Martijn A. Nolte ◽  
Michiel F. van Oosterwijk ◽  
René A.W. van Lier ◽  
...  

In vivo priming of antigen-specific CD8+ T cells results in their expansion and differentiation into effector T cells followed by contraction into a memory T cell population that can be maintained for life. Recent evidence suggests that after initial antigenic stimulation, the magnitude and kinetics of the CD8+ T cell response are programmed. However, it is unclear to what extent CD8+ T cell instruction in vivo is modulated by costimulatory signals. Here, we demonstrate that constitutive ligation of the tumor necrosis factor receptor family member CD27 by its ligand CD70 quantitatively augments CD8+ T cell responses to influenza virus infection and EL-4 tumor challenge in vivo by incrementing initial expansion and maintaining higher numbers of antigen-specific T cells in the memory phase. Concomitantly, the quality of antigen-specific T cells improved as evidenced by increased interferon (IFN)-γ production and a greater cytotoxic potential on a per cell basis. As an apparent consequence, the superior effector T cell formation induced by CD70 protected against a lethal dose of poorly immunogenic EL4 tumor cells in a CD8+ T cell– and IFN-γ–dependent manner. Thus, CD70 costimulation enhances both the expansion and per cell activity of antigen-specific CD8+ T cells.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2973-2973
Author(s):  
Il-Kang Na ◽  
Anne Letsch ◽  
Ines Noack ◽  
Sandra Bauer ◽  
Jens Geginat ◽  
...  

Abstract Introduction Adoptive cell transfer of ex vivo primed and expanded human cytotoxic T lymphocytes (CTLs) has emerged as a promising approach to treat both infectious and malignant diseases in humans. First clinical studies have shown that transfer of Cytomegalovirus (CMV)-specific CD8+ T cells is safe and effective in reconstitution of cellular immunity against CMV disease. Efficacy of adoptive T cell therapy is limited by the numbers of CTLs in vitro and the survival and function after infusion. CD4+ T cells may enhance activity via direct or indirect effector functions (Matloubian 1994 [1]). In this study we have analysed whether bone marrow is superior to peripheral blood for expansion of CMV-specific T cells. Experimental design Paired peripheral blood and bone marrow samples were obtained from patients who underwent total hip arthroplasty. By using two different protocols T cells were expanded in the presence of IL-2 and IL-7 either from bulk culture with exposure of two different peptide pools (IE1 and pp65) or after selection via IFN-γ secretion by stimulation with pp65. CMV specific immune responses were assessed by using multiparameter flow cytometry staining cells for CD3, CD4, CD8, CCR7 and CD45RA and for the cytokines IFN-γ IL-2 and TNF at day 0 and after 10 days of in vitro expansion. Results Similar frequencies of cytokine-producing pp65– and IE1-specific CD4+ and CD8+ T cells were found in unmanipulated paired PB and BM samples. Expansion of CMV-specific T cells from BM resulted in significantly higher frequencies of specific CD4+ T cells than from PB, whereas no difference in frequencies of CMV-specific CD8+ T cells was observed. Interestingly, significantly higher frequencies of BM pp65 and IE1-specific CD4+ T cells were multifunctional, characterized by producing simultaneously IFN-γ, TNF and IL-2 (IE1: BM mean 0.44% ± 0.16; PB mean 0.09% ± 0.05, p=0.031; pp65: BM mean 3.87% ± 2.46; PB mean 1.24% ± 0.90, p=0.031). Expansion of multi-functional CD4+ T cells from BM was observed with both the bulk and selection assay protocol. Both PB and BM CMV-specific CD4+ and CD8+ T cell lines had a predominant CD45RA-CCR7- effector memory phenotype. Conclusions This study implicates the use of human bone marrow as a source for expansion of multifunctional CMV-specific CD4+ T cells. Recent studies in HIV and Leishmania support the crucial role of multifunctional T cells in disease control (Darrah 2007 [2]).


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2668-2668 ◽  
Author(s):  
Alice Bertaina ◽  
Perla Filippini ◽  
Valentina Bertaina ◽  
Barbarella Lucarelli ◽  
Aurelie Bauquet ◽  
...  

Abstract Background Blinatumomab is a bi-specific monoclonal antibody designed to engage and tether cytotoxic T-cells (CTL) to CD19-expressing target B cells. An ongoing phase I multicenter study in pediatric patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL) has shown that blinatumomab induces morphological and molecular remissions, defined as minimal residual disease (MRD) levels <10-4, in 47% of patients [Gore L, et al. J Clin Oncol 31, 2013 (suppl; abstr 10007)]. It is presently unknown whether and to what extent blinatumomab affects T-cell phenotype and function in pediatric patients with BCP-ALL. Patients and Methods Eight children diagnosed with relapsed/refractory BCP-ALL at the Bambino Gesù Children’s Hospital in Rome (median age at diagnosis 5.8 years, range 0.5-14.6) received blinatumomab as continuous intravenous infusion for 28 consecutive days, followed by a 2-week drug-free period. Four out of 8 patients were given repeated treatment courses. Peripheral blood samples were collected before treatment (day 0) and weekly thereafter, for 4 consecutive weeks. Bone marrow (BM) aspirates were available on days 0 and +29 of each drug course. Peripheral blood mononuclear cells (PBMC) were labeled with appropriate combinations of fluorochrome-conjugated monoclonal antibodies to quantitate naïve/memory T cells, αβ/γδ-expressing T cells and other immune effectors with potential anti-leukemia activity, such as CD3+CD56+ natural killer (NK) T cells and CD3-CD56+ NK cells. T-cell production of interferon (IFN)-γ, interleukin (IL)-4 and IL-17 was measured at the single-cell level, after short-term (4-hour) stimulation with phorbol myristate acetate (PMA) and ionomycin. The TCR-Vβ Repertoire Kit® (Beckman Coulter, Milan, Italy) allowed the flow cytometry analysis of 24 different Vβ specificities on T cells, thus covering approximately 70% of the normal human TCR-Vβ repertoire. Results Peripheral blood lymphocytes reached their nadir on day +1 (median 300/µL of blood [inter-quartile range 40-380] compared with 1,080/µL of blood at baseline [inter-quartile range 360-2,310]; p=0.0037 by Mann-Whitney U test for paired data), expanded within 7 days up to 3.5-fold above baseline, and included both CD4+ and CD8+ T cells. By contrast, the frequency of both CD3+CD56+ NK T cells and CD3-CD56+ NK cells remained unchanged compared to baseline. IFN-γ production by patient-derived CD4+ T cells exceeded that observed in CD4+ T cells from healthy controls by 2-fold, indicating robust T helper type 1 (Th1) polarization. The frequency of Th2/Th17 cells, defined as CD4+IL-4+ and CD4+IL-17+ cells, respectively, was not different after treatment compared to baseline. CD31 expression on recovering CD45RA+ naïve T cells, a surrogate phenotypic feature for recent thymic emigrants (RTEs), suggested that thymic output may contribute to T-cell expansion after blinatumomab administration. Non-significant changes in the relative proportion of TCR-αβ and TCR-γδ-expressing CD3+ T cells were detected after treatment (median 79.5% TCR-αβ+ T cells and 19.3% TCR-γδ+ T cells among total CD3+ cells) compared with baseline (median 87.4% TCR-αβ+ T cells and 12.2% TCR-γδ+ T cells among total CD3+ cells). Importantly, both CD3+CD8bright T cells and NK cells expressed lytic granule proteins, such as perforin and granzyme-B, at levels that increased during treatment. The analysis of Vβ TCR repertoire revealed a restricted usage of single Vβ domains by BM-resident CD8+ T cells, but not by CD4+ T cells. Specifically, the sum of Vβ within CD8+ T cells in the BM averaged 56.7±6.2% after blinatumomab, compared with 78±5.1% in healthy controls (p=0.04; Mann-Whitney U test for unpaired data). Conclusions Blinatumomab expands both CD31+CD45RA+ thymic-naïve and memory T cells with heightened IFN-γ production and is highly effective at clearing MRD in children with BCP-ALL. Skewing of the Vβ repertoire within BM-resident CD8+ T cells may be consistent with clonal expansions. Disclosures: Zugmaier: Amgen: Employment.


2002 ◽  
Vol 76 (7) ◽  
pp. 3329-3337 ◽  
Author(s):  
Laurie E. Harrington ◽  
Robbert van der Most ◽  
J. Lindsay Whitton ◽  
Rafi Ahmed

ABSTRACT Recombinant vaccinia viruses (rVV) have been extensively used as vaccines, but there is little information about the total magnitude of the VV-specific T-cell response and how this compares to the immune response to the foreign gene(s) expressed by the rVV. To address this issue, we quantitated the T-cell responses to both the viral vector and the insert following the infection of mice with VV expressing a cytotoxic T lymphocyte (CTL) epitope (NP118-126) from lymphocytic choriomeningitis virus (LCMV). The LCMV epitope-specific response was quantitated by intracellular cytokine staining after stimulation with the specific peptide. To analyze the total VV-specific response, we developed a simple intracellular cytokine staining assay using VV-infected major histocompatibility complex class I and II matched cells as stimulators. Using this approach, we made the following determinations. (i) VV-NP118 induced potent and long-lasting CD8 and CD4 T-cell responses to the vector; at the peak of the response (∼1 week), there were ∼107 VV-specific CD8 T cells (25% of the CD8 T cells) and ∼106 VV-specific CD4 T cells (∼5% of the CD4 T cells) in the spleen. These numbers decreased to ∼5 × 105 CD8 T cells (∼5% frequency) and ∼105 CD4 T cells (∼0.5% frequency), respectively, by day 30 and were then stably maintained at these levels for >300 days. The size of this VV-specific T-cell response was comparable to that of the T-cell response induced following an acute LCMV infection. (ii) VV-specific CD8 and CD4 T cells were capable of producing gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin-2; all cells were able to make IFN-γ, a subset produced both IFN-γ and TNF-α, and another subset produced all three cytokines. (iii) The CD8 T-cell response to the foreign gene (LCMV NP118-126 epitope) was coordinately regulated with the response to the vector during all three phases (expansion, contraction, and memory) of the T-cell response. The total number of CD8 T cells responding to NP118-126 were ∼20- to 30-fold lower than the number responding to the VV vector (∼1% at the peak and 0.2% in memory). This study provides a better understanding of T-cell immunity induced by VV-based vaccines, and in addition, the technique described in the study can be readily extended to other viral vectors to determine the ratio of the T-cell response to the insert versus the vector. This information will be useful in optimizing prime-boost regimens for vaccination.


2021 ◽  
Vol 9 (6) ◽  
pp. e002269
Author(s):  
Shota Aoyama ◽  
Ryosuke Nakagawa ◽  
Satoshi Nemoto ◽  
Patricio Perez-Villarroel ◽  
James J Mulé ◽  
...  

BackgroundThe temporal response to checkpoint blockade (CB) is incompletely understood. Here, we profiled the tumor infiltrating lymphocyte (TIL) landscape in response to combination checkpoint blockade at two distinct timepoints of solid tumor growth.MethodsC57BL/6 mice bearing subcutaneous MC38 tumors were treated with anti-PD-1 and/or anti-CTLA-4 antibodies. At 11 or 21 days, TIL phenotype and effector function were analyzed in excised tumor digests using high parameter flow cytometry. The contributions of major TIL populations toward overall response were then assessed using ex vivo cytotoxicity and in vivo tumor growth assays.ResultsThe distribution and effector function among 37 distinct TIL populations shifted dramatically between early and late MC38 growth. At 11 days, the immune response was dominated by Tumor necrosis factor alpha (TNFα)-producing NKT, representing over half of all TIL. These were accompanied by modest frequencies of natural killer (NK), CD4+, or CD8+ T cells, producing low levels of IFN-γ. At 21 days, NKT populations were reduced to a combined 20% of TIL, giving way to increased NK, CD4+, and CD8+ T cells, with increased IFN-γ production. Treatment with CB accelerated this switch. At day 11, CB reduced NKT to less than 20% of all TIL, downregulated TNFα across NKT and CD4+ T cell populations, increased CD4+ and CD8+ TIL frequencies, and significantly upregulated IFN-γ production. Degranulation was largely associated with NK and NKT TIL. Blockade of H-2kb and/or CD1d during ex vivo cytotoxicity assays revealed NKT has limited direct cytotoxicity against parent MC38. However, forced CD1d overexpression in MC38 cells significantly diminished tumor growth, suggesting NKT TIL exerts indirect control over MC38 growth.ConclusionsDespite an indirect benefit of early NKT activity, CB accelerates a switch from TNFα, NKT-driven immune response toward an IFN-γ driven CD4+/CD8+ T cell response in MC38 tumors. These results uncover a novel NKT/T cell switch that may be a key feature of CB response in CD1d+ tumors.


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.


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