scholarly journals Adults 65 Years Old and Older Have Reduced Numbers of Functional Memory T Cells to Respiratory Syncytial Virus Fusion Protein

2012 ◽  
Vol 20 (2) ◽  
pp. 239-247 ◽  
Author(s):  
Anu Cherukuri ◽  
Kathryn Patton ◽  
Robert A. Gasser ◽  
Fengrong Zuo ◽  
Jennifer Woo ◽  
...  
Keyword(s):  
T Cells ◽  
Young Adults ◽  
Respiratory Syncytial Virus ◽  
Mononuclear Cells ◽  
Neutralizing Antibody ◽  
The Elderly ◽  
Peripheral Blood Mononuclear ◽  
Healthy Elderly ◽  
Syncytial Virus ◽  
Cellular Immune

ABSTRACTRespiratory syncytial virus (RSV) infects elderly (≥65 years) adults, causing medically attended illness and hospitalizations. While RSV neutralizing antibody levels correlate inversely with RSV-associated hospitalization in the elderly, the role of RSV-specific T cells in preventing disease in the elderly remains unclear. We examined RSV-specific humoral, mucosal, and cellular immune profiles in healthy elderly (65 to 85 years) and young (20 to 30 years) adults. RSV neutralization antibody titers in the elderly (10.5 ± 2.2 log2) and young (10.5 ± 2.1 log2) were similar. In contrast, levels of RSV F protein-specific gamma interferon (IFN-γ)-producing T cells were lower in elderly (180 ± 80 spot-forming cells [SFC]/106peripheral blood mononuclear cells [PBMC]) than in young adults (1,250 ± 420 SFC/106PBMC). Higher levels of interleukin-13 (IL-13; 3,000 ± 1,000 pg/ml) in cultured PBMC supernatants and lower frequency of RSV F-specific CD107a+CD8+T cells (3.0% ± 1.6% versus 5.0% ± 1.6%) were measured in PBMC from elderly than young adults. These results suggest that deficient RSV F-specific T cell responses contribute to susceptibility to severe RSV disease in elderly adults.

scholarly journals The Anthrax Vaccine Adsorbed Vaccine Generates Protective Antigen (PA)-Specific CD4+ T Cells with a Phenotype Distinct from That of Naïve PA T Cells

2008 ◽  
Vol 76 (10) ◽  
pp. 4538-4545 ◽  
Author(s):  
William W. Kwok ◽  
Junbao Yang ◽  
Eddie James ◽  
John Bui ◽  
Laurie Huston ◽  
...  
Keyword(s):  
T Cells ◽  
Mononuclear Cells ◽  
Protective Antigen ◽  
Ex Vivo ◽  
Cytokine Profile ◽  
T Cell Epitopes ◽  
Peripheral Blood Mononuclear ◽  
Anthrax Vaccine ◽  
Cellular Immune

ABSTRACT Cellular immune responses against protective antigen (PA) of Bacillus anthracis in subjects that received the anthrax vaccine adsorbed (AVA) vaccine were examined. Multiple CD4+ T-cell epitopes within PA were identified by using tetramer-guided epitope mapping. PA-reactive CD4+ T cells with a CD45RA− phenotype were also detected by direct ex vivo staining of peripheral blood mononuclear cells (PBMC) with PA-specific tetramers. Surprisingly, PA-specific T cells were also detected in PBMC of nonvaccinees after a single cycle of in vitro PA stimulation. However, PA-reactive CD4+ T cells in nonvaccinees occurred at lower frequencies than those in vaccinees. The majority of PA-reactive T cells from nonvaccinees were CD45RA+ and exhibited a Th0/Th1 cytokine profile. In contrast, phenotyping and cytokine profile analyses of PA-reactive CD4+ T cells from vaccinees indicated that vaccination leads to commitment of PA-reactive T cells to a Th2 lineage, including generation of PA-specific, pre-Th2 central memory T cells. These results demonstrate that the current AVA vaccine is effective in skewing the development of PA CD4+ T cells to the Th2 lineage. The data also demonstrated the feasibility of using class II tetramers to analyze CD4+ cell responses and lineage development after vaccination.

scholarly journals The analysis of the long-term impact of SARS-CoV-2 on the cellular immune system in individuals recovering from COVID-19 reveals a profound NKT cell impairment

2020 ◽  
Author(s):  
jia liu ◽  
Xuecheng Yang ◽  
Hua Wang ◽  
Ziwei Li ◽  
Hui Deng ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
Cd8 T Cells ◽  
Mononuclear Cells ◽  
Annexin V ◽  
Double Positive ◽  
Peripheral Blood Mononuclear ◽  
Cellular Immune System ◽  
Cellular Immune

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects millions of people and killed hundred-thousands of individuals. While acute and intermediate interactions between SARS-CoV-2 and the immune system have been studied extensively, long-term impacts on the cellular immune system remained to be analyzed. Here, we comprehensively characterized immunological changes in peripheral blood mononuclear cells in 49 COVID-19 convalescent individuals (CI) in comparison to 27 matched SARS-CoV-2 unexposed individuals (UI). Despite recovery from the disease for more than 2 months, CI showed significant decreases in frequencies of invariant NKT and NKT-like cells compared to UI. Concomitant with the decrease in NKT-like cells, an increase in the percentage of Annexin V and 7-AAD double positive NKT-like cells was detected, suggesting that the reduction in NKT-like cells results from cell death months after recovery. Significant increases in regulatory T cell frequencies, TIM-3 expression on CD4 and CD8 T cells, as well as PD-L1 expression on B cells were also observed in CI, while the cytotoxic potential of T cells and NKT-like cells, defined by GzmB expression, was significantly diminished. However, both CD4 and CD8 T cells of CI showed increased Ki67 expression and were fully capable to proliferate and produce effector cytokines upon TCR stimulation. Collectively, we provide the first comprehensive characterization of immune signatures in patients recovering from SARS-CoV-2 infection, suggesting that the cellular immune system of COVID-19 patients is still under a sustained influence even months after the recovery from disease.

scholarly journals Cholera Caused by Vibrio cholerae O1 Induces T-Cell Responses in the Circulation

2009 ◽  
Vol 77 (5) ◽  
pp. 1888-1893 ◽  
Author(s):  
Taufiqur Rahman Bhuiyan ◽  
Samuel B. Lundin ◽  
Ashraful Islam Khan ◽  
Anna Lundgren ◽  
Jason B. Harris ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
Vibrio Cholerae ◽  
Mononuclear Cells ◽  
Acute Stage ◽  
Healthy Controls ◽  
Peripheral Blood Mononuclear ◽  
Vibrio Cholerae O1 ◽  
Ifn Γ ◽  
Cellular Immune

ABSTRACT Considerable effort is being made to understand the acute and memory antibody responses in natural cholera infection, while rather less is known about the roles of cellular immune responses involving T and B lymphocytes. We studied responses in adult patients hospitalized with cholera caused by Vibrio cholerae O1. Peripheral blood mononuclear cells from patients (n = 15) were analyzed by flow cytometry after stimulation with V. cholerae O1 membrane protein (MP) or toxin-coregulated pilus antigen (TcpA). The gamma interferon (IFN-γ) and interleukin-13 (IL-13) responses in stimulated-lymphocyte supernatants were studied. The responses were compared with those of healthy controls (n = 10). Patients responded with increased frequencies of gut-homing CD4+ T cells (CD4+ β7+), gut-homing CD8+ T cells (CD8+ β7+), and gut-homing B cells (CD19+ β7+) at the early and/or late convalescent stages compared to the acute stage. After stimulation with MP or TcpA, proliferation of CD4+ and CD8+ T cells was increased at the acute stage and/or early convalescent stage compared to healthy controls. Increased IL-13 and IFN-γ responses were observed after antigenic stimulation at the acute and convalescent stages compared to healthy controls. Thus, increases in the levels of gut-homing T and B cells, as well as involvement of CD8 and CD4 Th1-mediated (IFN-γ) and CD4 Th2-mediated (IL-13) cytokine responses, take place in acute dehydrating disease caused by V. cholerae O1. Further studies are needed to determine if such responses are also stimulated after immunization with oral cholera vaccines and if these responses play a role in protection following exposure to cholera.

scholarly journals Novel Respiratory Syncytial Virus-Like Particle Vaccine Composed of the Postfusion and Prefusion Conformations of the F Glycoprotein

2016 ◽  
Vol 23 (6) ◽  
pp. 451-459 ◽  
Author(s):  
Velasco Cimica ◽  
Hélène Boigard ◽  
Bipin Bhatia ◽  
John T. Fallon ◽  
Alexandra Alimova ◽  
...  
Keyword(s):  
Immune Response ◽  
Respiratory Syncytial Virus ◽  
Matrix Protein ◽  
Neutralizing Antibody ◽  
The Elderly ◽  
Mouse Lung ◽  
Oil Emulsion ◽  
Cytokines And Chemokines ◽  
Virus Like Particle ◽  
Syncytial Virus

ABSTRACTRespiratory syncytial virus (RSV) is the leading cause of severe respiratory disease in infants and children and represents an important global health burden for the elderly and the immunocompromised. Despite decades of research efforts, no licensed vaccine for RSV is available. We have developed virus-like particle (VLP)-based RSV vaccines assembled with the human metapneumovirus (hMPV) matrix protein (M) as the structural scaffold and the RSV fusion glycoprotein (F) in either the postfusion or prefusion conformation as its prime surface immunogen. Vaccines were composed of postfusion F, prefusion F, or a combination of the two conformations and formulated with a squalene-based oil emulsion as adjuvant. Immunization with these VLP vaccines afforded full protection against RSV infection and prevented detectable viral replication in the mouse lung after challenge. Analyses of lung cytokines and chemokines showed that VLP vaccination mostly induced the production of gamma interferon (IFN-γ), a marker of the Th1-mediated immune response, which is predominantly required for viral protection. Conversely, immunization with a formalin-inactivated RSV (FI-RSV) vaccine induced high levels of inflammatory chemokines and cytokines of the Th2- and Th17-mediated types of immune responses, as well as severe lung inflammation and histopathology. The VLP vaccines showed restricted production of these immune mediators and did not induce severe bronchiolitis or perivascular infiltration as seen with the FI-RSV vaccine. Remarkably, analysis of the serum from immunized mice showed that the VLP vaccine formulated using a combination of postfusion and prefusion F elicited the highest level of neutralizing antibody and enhanced the Th1-mediated immune response.

scholarly journals Abnormal phenotypic distribution of regulatory and effector T cells in octogenarian and nonagenarian women

2015 ◽  
Vol 61 (4) ◽  
pp. 329-335
Author(s):  
Wilson de Melo Cruvinel ◽  
Danilo Mesquita Júnior ◽  
Júlio Antônio Pereira Araújo ◽  
Karina Carvalho Samazi ◽  
Esper Georges Kállas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mononuclear Cells ◽  
Elderly Women ◽  
The Elderly ◽  
Effector T Cells ◽  
T Cell Subsets ◽  
Healthy Elderly ◽  
T Cell Phenotypes ◽  
Effects Of Aging

SummaryIntroduction:aging is associated with several immunologic changes. Regulatory (Treg) and effector T cells are involved in the pathogenesis of infectious, neoplastic, and autoimmune diseases. Little is known about the effects of aging on the frequency and function of these T cell subpopulations.Methods:peripheral blood mononuclear cells (PBMC) were obtained from 26 young (under 44 years old) and 18 elderly (above 80 years old) healthy women. T cell subpopulations were analyzed by flow cytometry.Results:elderly individuals had lower frequency of several activated effector T cell phenotypes as compared with young individuals: CD3+CD4+CD25+ (3.82±1.93 versus 9.53±4.49; p<0.0001); CD3+CD4+CD25+CD127+(2.39±1.19 versus 7.26±3.84; p<0.0001); CD3+CD4+CD25+ (0.41±0.22 versus 1.86±0.85, p<0.0001); and CD3+CD4+CD25highCD127+(0.06±0.038 versus 0.94±0.64, p<0.0001). Treg (CD3+CD4+CD25+CD127øFoxp3+) presented lower frequency in elderly individuals as compared to young adults (0.34±0.18 versus 0.76±0.48; p=0.0004) and its frequency was inversely correlated with age in the whole group (r=-0.439; p=0.013). The elderly group showed higher frequency of two undefined CD25øFoxp3+ phenotypes: CD3+CD4+CD25øFoxp3+(15.05±7.34 versus 1.65±1.71; p<0.0001) and CD3+CD4+CD25øCD127øFoxp3+(13.0±5.52 versus 3.51±2.87; p<0.0001).Conclusions:the altered proportion of different T cell subsets herein documented in healthy elderly women may be relevant to the understanding of the immunologic behavior and disease susceptibility patterns observed in geriatric patients.

scholarly journals Enzyme-Linked Immunospot Assay for Detection of Human Respiratory Syncytial Virus F Protein-Specific Gamma Interferon-Producing T Cells

2014 ◽  
Vol 21 (5) ◽  
pp. 628-635 ◽  
Author(s):  
Kathryn Patton ◽  
Shahin Aslam ◽  
Jim Lin ◽  
Li Yu ◽  
Stacie Lambert ◽  
...  
Keyword(s):  
T Cells ◽  
Respiratory Syncytial Virus ◽  
T Cell ◽  
Elispot Assay ◽  
T Cell Responses ◽  
The Elderly ◽  
Assay Sensitivity ◽  
Cell Responses ◽  
Ifn Γ ◽  
Syncytial Virus

ABSTRACTRespiratory syncytial virus (RSV) causes significant disease in elderly adults, and we have previously reported that individuals 65 years of age and older have reduced RSV F protein-specific gamma interferon (IFN-γ)-producing T cells compared to healthy younger adults. To measure RSV F-specific memory T cell responses in the elderly following infection or vaccination, we optimized and qualified an IFN-γ enzyme-linked immunospot (ELISPOT) assay. Since peripheral blood mononuclear cells (PBMC) from the elderly could be more fragile, we established optimal cryopreservation techniques and minimal viability acceptance criteria. The number of cells per well, types and concentrations of stimulation antigens, and incubation times were evaluated to maximize assay sensitivity and precision. The optimized assay uses 300,000 cells/well, 2 μg/ml of an RSV F peptide pool (RSV Fpp), and incubation for 22 ± 2 h in serum-free CTL-Test medium. The assay was qualified by 3 analysts using 3 RSV F-responding donor PBMC samples (high, medium, and low responders) tested on 5 different assay days. The assay sensitivity or limit of detection (LOD) was determined to be 21 spot-forming cells (SFC) per 106PBMC, and the lower limit of quantitation (LLOQ) was estimated to be 63 SFC/106PBMC. The intra- and interassay percent coefficients of variation (CV) were <10.5% and <31%, respectively. The results of the qualification study demonstrate that a robust, precise, and sensitive IFN-γ ELISPOT assay has been developed that is fit for measuring RSV F-specific IFN-γ T cell responses in subjects enrolled in a vaccine clinical trial or in epidemiology studies.

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