scholarly journals Defective SARS-CoV-2 immune responses in an immunocompromised individual with prolonged viral replication

2021 ◽  
Author(s):  
Claire L Gordon ◽  
Olivia C Smibert ◽  
Natasha E Holmes ◽  
Kyra Y L Chua ◽  
Rose Morgan ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
Immune Responses ◽  
Viral Replication ◽  
Specific Antibody ◽  
Late Onset ◽  
Antibody Responses ◽  
Hla Dr ◽  
Immunocompromised Individual ◽  
Immunocompromised Hosts

Abstract We describe SARS-CoV-2-specific immune responses in a patient with lymphoma and recent PD-1 inhibitor therapy with late onset of severe COVID-19 disease and prolonged SARS-CoV-2 replication, in comparison to age-matched and immunocompromised controls. High levels of HLA-DR +/CD38 +-activation, IL-6 and IL-18 in the absence of B cells and PD-1 expression was observed. SARS-CoV-2-specific antibody responses were absent and SARS-CoV-2 specific T cells were minimally detected. This case highlights challenges in managing immunocompromised hosts who may fail to mount effective virus-specific immune responses.

scholarly journals Impaired Cellular Immunity to SARS-CoV-2 in Severe COVID-19 Patients

2021 ◽  
Vol 12 ◽  
Author(s):  
Ling Ni ◽  
Meng-Li Cheng ◽  
Yu Feng ◽  
Hui Zhao ◽  
Jingyuan Liu ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Cellular Immunity ◽  
Specific Antibody ◽  
Peripheral Blood ◽  
Neutralizing Antibodies ◽  
Acute Infection ◽  
Peripheral Blood Lymphocytes ◽  
Antibody Responses ◽  
Humoral Immune

The high infection rate and rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) make it a world-wide pandemic. Individuals infected by the virus exhibited different degrees of symptoms, and most convalescent individuals have been shown to develop both cellular and humoral immune responses. However, virus-specific adaptive immune responses in severe patients during acute phase have not been thoroughly studied. Here, we found that in a group of COVID-19 patients with acute respiratory distress syndrome (ARDS) during hospitalization, most of them mounted SARS-CoV-2-specific antibody responses, including neutralizing antibodies. However, compared to healthy controls, the percentages and absolute numbers of both NK cells and CD8+ T cells were significantly reduced, with decreased IFNγ expression in CD4+ T cells in peripheral blood from severe patients. Most notably, their peripheral blood lymphocytes failed in producing IFNγ against viral proteins. Thus, severe COVID-19 patients at acute infection stage developed SARS-CoV-2-specific antibody responses but were impaired in cellular immunity, which emphasizes on the role of cellular immunity in COVID-19.

Naturally Occurring Regulatory T Cells Modulate Immune Responses Against Exogenous Factor VIII in Hemophilic Balb/c Mice but Not in C57BL/6J Mice.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1160-1160
Author(s):  
Christina Hausl ◽  
Josenato Ilas ◽  
Christian Lubich ◽  
Rafi U. Ahmad ◽  
Eva M. Muchitsch ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
Regulatory T Cells ◽  
Immune Responses ◽  
Factor Viii ◽  
Matched Control ◽  
Antibody Responses ◽  
Protein Antigens ◽  
Naturally Occurring

Abstract Antibody responses against factor VIII (FVIII) are the major complication that arises when patients with hemophilia A are treated with factor VIII products. Therefore, understanding regulation of anti-FVIII immune responses is of outmost importance. Antibody responses are well established to result from differentiation of B cells into antibody-secreting plasma cells. B cells need help from activated CD4+ T cells to develop high-affinity antibody responses against protein antigens such as FVIII. Recently, naturally occurring CD4+CD25+ regulatory T cells have been shown to modulate antibody responses by either suppressing the function of CD4+ T helper cells or by directly acting on B cells. However, the potential importance of CD4+CD25+ T cells in regulating antibody responses to foreign protein antigens is controversial. Furthermore, the extent to which naturally occurring CD4+CD25+ T cells regulate antibody responses against exogenous proteins such as FVIII when these proteins are given to previously untreated patients is unclear. To obtain information on how important naturally occurring CD4+CD25+ T cells are under such conditions, we asked whether these cells regulate anti-FVIII antibody responses in murine hemophilia A. We studied E17 hemophilic mice with two different genetic backgrounds (C57BL/6J and Balb/c) and treated them with four intravenous doses of human FVIII given at weekly intervals. Before the first dose of FVIII, CD4+CD25+ T cells were depleted in vivo using an anti-CD25 antibody that has been shown to deplete naturally occurring CD4+CD25+ T cells in mice. In vivo depletion of regulatory T cells using the same antibody has been successfully applied in a variety of mouse studies to evaluate the significance of naturally occurring CD4+CD25+ T cells in different immunological systems. An isotype-matched control antibody was used as a negative control. A week after the second and the fourth dose of FVIII, plasma samples were taken and tested for anti-FVIII antibodies. We found differences in titers of anti-FVIII antibodies between mice treated with anti-CD25 antibodies and control mice in Balb/c mice but not in C57BL/6J mice. Hemophilic Balb/c mice that had been pre-treated with anti-CD25 antibodies developed higher titers of anti-FVIII antibodies than mice that had been pre-treated with an isotype-matched control antibody. Differences were seen as a statistical trend (p=0.091) after two doses of FVIII and reached statistical significance (p=0.024) after four doses of FVIII. No differences in antibody titers were observed in hemophilic C57BL/6J mice. Our results strongly indicate that the ability of naturally occurring regulatory T cells to modulate anti-FVIII antibody responses in hemophilic mice depends on the genetic background of these mice. Immunoregulatory factors such as cytokines or chemokines as well as differences in the number and functional activity of naturally occurring regulatory T cells that are found in secondary lymphoid organs are likely to determine the regulatory capacity of these cells. Based on our results we conclude that differences in number and functional activity of naturally occurring regulatory T cells should be considered in the search for risk factors associated with the development of FVIII inhibitors in patients.

scholarly journals Genetic control of immune responses in vitro. VI. Experimental conditions for the development of helper T-cell activity specific for the terpolymer L-glutamic aicd60-L-alanine30-L-tyrosine10 (GAT) in nonresponder mice.

1975 ◽  
Vol 142 (1) ◽  
pp. 50-60 ◽  
Author(s):  
J A Kapp ◽  
C W Pierce ◽  
B Benacerraf
Keyword(s):  
T Cells ◽  
Bovine Serum Albumin ◽  
Immune Responses ◽  
Specific Antibody ◽  
Cell Activity ◽  
Antibody Responses ◽  
Helper T Cells ◽  
Experimental Conditions

Mice which are genetic nonresponders to the random terpolymer of L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT) not only fail to develop GAT-specific antibody responses when stimulated with soluble GAT either in vivo or in vitro, but develop GAT-specific T cells which suppress the GAT-specific plaque-forming cell response of normal nonresponder mice stimulated with GAT complexed to methylated bovine serum albumin (MBSA).Thus, both responder and nonresponder mice have T cells which recognize GAT. However, nonresponder mice can develop GAT-specific helper T cells if immunized with GAT bound to MBSA or to macrophages. The relevance of Ir gene-controlled responses is discussed.

scholarly journals GENETIC CONTROL OF IMMUNE RESPONSES IN VITRO

1974 ◽  
Vol 140 (1) ◽  
pp. 185-198 ◽  
Author(s):  
Baruj Benacerraf ◽  
Judith A. Kapp ◽  
Carl W. Pierce ◽  
David H. Katz
Keyword(s):  
T Cells ◽  
B Cells ◽  
Immune Responses ◽  
Antibody Responses ◽  
Specific Response ◽  
Gene Products ◽  
Spleen Cells ◽  
Culture Initiation ◽  
Cooperative Interactions

The conditions for cooperative interactions between nonresponder B10.S B cells and GAT-primed irradiated (C57BL/6 x SJL)F1 T cells in the response by cultures of mouse spleen cells to GAT were investigated. GAT-specific antibody responses could be elicited by soluble GAT in cultures of GAT-primed irradiated (C57BL/6 x SJL)F1 T cells with C57BL/6 B cells but not with B10.S B cells. In contrast, when GAT was presented to the cultures on F1 macrophages or as aggregates of GAT with MBSA, GAT-specific PFC responses were observed with both B10.S or C57BL/6 B cells. Irradiated GAT-primed T cells were nevertheless essential for the development of these responses. The GAT-specific response of B10.S B cells in these cultures was inhibited by the addition of soluble GAT at culture initiation. These results indicate that genetic disparity at Ir loci is not an absolute barrier to T-B-cell cooperative interactions in the response to antigens under Ir gene control. The significance of these data for the function of Ir gene products in immunocompetent cells is discussed.

scholarly journals Heterologous vaccination regimens with self-amplifying RNA and adenoviral COVID vaccines induce robust immune responses in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexandra J. Spencer ◽  
Paul F. McKay ◽  
Sandra Belij-Rammerstorfer ◽  
Marta Ulaszewska ◽  
Cameron D. Bissett ◽  
...  
Keyword(s):  
Immune Response ◽  
Clinical Trials ◽  
T Cells ◽  
Immune Responses ◽  
Viral Vectors ◽  
Cytotoxic T Cells ◽  
Antibody Responses ◽  
Limited Data ◽  
Vectored Vaccine ◽  
Cellular Immune

AbstractSeveral vaccines have demonstrated efficacy against SARS-CoV-2 mediated disease, yet there is limited data on the immune response induced by heterologous vaccination regimens using alternate vaccine modalities. Here, we present a detailed description of the immune response, in mice, following vaccination with a self-amplifying RNA (saRNA) vaccine and an adenoviral vectored vaccine (ChAdOx1 nCoV-19/AZD1222) against SARS-CoV-2. We demonstrate that antibody responses are higher in two-dose heterologous vaccination regimens than single-dose regimens. Neutralising titres after heterologous prime-boost were at least comparable or higher than the titres measured after homologous prime boost vaccination with viral vectors. Importantly, the cellular immune response after a heterologous regimen is dominated by cytotoxic T cells and Th1+ CD4 T cells, which is superior to the response induced in homologous vaccination regimens in mice. These results underpin the need for clinical trials to investigate the immunogenicity of heterologous regimens with alternate vaccine technologies.

scholarly journals Expanded circulating follicular dendritic cells facilitate immune responses in chronic HBV infection

2020 ◽  
Author(s):  
Xiaoyi Li ◽  
Qifan Zhang ◽  
Wanyue Zhang ◽  
Guofu Ye ◽  
Yanchen Ma ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
B Cells ◽  
Hepatitis B ◽  
Immune Responses ◽  
Cd4 T Cells ◽  
Hbv Infection ◽  
Follicular Dendritic Cells ◽  
Chronic Hbv Infection ◽  
Chronic Hbv

Abstract Background: The restoration of host hepatitis B virus (HBV)-specific antiviral immunity is an effective strategy for hepatitis B recovery. Follicular dendritic cells (FDCs) play a crucial role in immune regulation. The goal of the present study was to investigate the characteristics and functions of FDCs in chronic HBV infection. Methods: The frequencies of FDCs in peripheral blood, liver, and spleen were measured in patients with chronic HBV infection. Isolated FDCs from splenic tissues of HBV-related liver cirrhosis-induced hypersplenism patients were cultured with autologous intrasplenic CD4 + T cells and CD19 + B cells.Results: We found that patients with chronic HBV infection had a significantly increased frequency of circulating FDCs compared with that of healthy controls. Additionally, the frequency of circulating FDCs was positively correlated with that of intrahepatic and intrasplenic counterparts. Moreover, a positive correlation between the frequency of circulating FDCs and plasmablast and memory B cells, as well as C-X-C motif chemokine receptor type 5 (CXCR5) + CD4 + T cells and CXCR5 + CD8 + T cells was also observed. Notably, in vitro experiments demonstrated that FDCs derived from splenic tissues of chronic HBV patients facilitated interferon-γ and interleukin-21 production from autologous intrasplenic CD4 + T cells and promoted the proliferation of autologous intrasplenic CD19 + B cells. Conclusions: Expanded FDCs in patients with chronic HBV infection may favor the host immune responses against HBV. The identification of this unique population may contribute to a better understanding of the immune regulatory mechanisms and provide a potential immunotherapeutic target in chronic HBV infection.

scholarly journals Development and validation of an assay for detection of Japanese Encephalitis virus specific antibody responses

2020 ◽  
Author(s):  
Pradeep Darshana Pushpakumara ◽  
Chandima Jeewandara ◽  
Laksiri Gomes ◽  
Yashodha Perera ◽  
Ananda Wijewickrama ◽  
...  
Keyword(s):  
Immune Responses ◽  
Japanese Encephalitis Virus ◽  
Disease Severity ◽  
Japanese Encephalitis ◽  
Specific Antibody ◽  
Encephalitis Virus ◽  
Antibody Responses ◽  
Specific Antibodies ◽  
Dengue Disease ◽  
Conserved Regions

AbstractBackgroundAlthough immune responses to the Japanese Encephalitis virus (JEV), and the dengue viruses (DENV) have a potential to modulate the immune responses to each other, this has been poorly investigated. Therefore, we developed an ELISA to identify JEV specific, DENV non cross-reactive antibody responses by identifying JEV specific, highly conserved regions of the virus and proceeded to investigate if the presence of JEV specific antibodies associate with dengue disease severity.Methodology/Principal findings20 JEV specific peptides were identified from highly conserved regions of the virus and the immunogenicity and specificity of these peptides were assessed in individuals who were non-immune to JEV and DENV (JEV-DENV-, N=30), those who were only immune to the JEV and not DENV (JEV+DENV-, N=30), those who were only immune to DENV(JEV-DENV+, N=30) and in those who were immune to both viruses (JEV+DENV+, N=30). 7/20 peptides were found to be highly immunogenic and specific and these 7 peptides were used as a pool to further evaluate JEV-specific responses. All 30/30 JEV+DENV-and 30/30 JEV+DENV+individuals, and only 3/30 (10%) JEV-DENV+individuals responded to this pool. We further evaluated this pool of 7 peptides in patients following primary and secondary dengue infection during the convalescent period and found that the JEV-specific peptides, were unlikely to cross react with DENV IgG antibodies. We further compared this in-house ELISA developed with the peptide pool with an existing commercial JEV IgG assay to identify JEV-specific IgG following vaccination, and our in-house ELISA was found to be more sensitive. We then proceeded to investigate if the presence of JEV-specific antibodies were associated with dengue disease severity, and we found that those who had past severe dengue (n=175) were significantly more likely (p<0.0001) to have JEV-specific antibodies than those with past non-severe dengue (n=175) (OR 5.3, 95% CI 3.3 to 8.3).Conclusions/SignificanceAs our data show that this assay is highly sensitive and specific for detection of JEV-specific antibody responses, it would be an important tool to determine how JEV seropositivity modulate dengue immunity and disease severity when undertaking dengue vaccine trials.Author summaryBoth Japanese Encephalitis virus (JEV), and the dengue viruses (DENV) co-circulate in the same geographical region and have a potential to modulate the immune responses to each other. However, due to the difficulty in identifying antibody responses specific to either virus due to the highly cross-reactive nature of virus-specific antibodies, this has been poorly investigated. Therefore, we developed an ELISA to identify JEV-specific, DENV non cross-reactive antibody responses by identifying JEV-specific, highly conserved regions of the virus and proceeded to investigate if the presence of JEV-specific antibodies associates with dengue disease severity. 20 JEV-specific peptides were identified from highly conserved regions of the virus and the immunogenicity and specificity of these peptides were assessed. We found that seven peptides were highly immunogenic and specific to the JEV and we further evaluated the usefulness of an ELISA developed using these pools of peptides. We found that our in-house ELISA was found to be significantly more sensitive some of the existing commercial assays. As this assay appears to be highly sensitive and specific for detection of JEV-specific antibody responses, it would be an important tool to determine how JEV seropositivity modulate dengue immunity and disease severity when undertaking dengue vaccine trials.

scholarly journals Vaccine-Elicited Mucosal and Systemic Antibody Responses Are Associated with Reduced Simian Immunodeficiency Viremia in Infant Rhesus Macaques

2016 ◽  
Vol 90 (16) ◽  
pp. 7285-7302 ◽  
Author(s):  
Kara Jensen ◽  
Rafiq Nabi ◽  
Koen K. A. Van Rompay ◽  
Spencer Robichaux ◽  
Jeffrey D. Lifson ◽  
...  
Keyword(s):  
Breast Milk ◽  
Immune Responses ◽  
Viral Replication ◽  
Antibody Responses ◽  
Limiting Factor ◽  
High Avidity ◽  
Significant Progress ◽  
Content Type ◽  
Immunodeficiency Virus ◽  
Specific Igg

ABSTRACTDespite significant progress in reducing peripartum mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) with antiretroviral therapy (ART), continued access to ART throughout the breastfeeding period is still a limiting factor, and breast milk exposure to HIV accounts for up to 44% of MTCT. As abstinence from breastfeeding is not recommended, alternative means are needed to prevent MTCT of HIV. We have previously shown that oral vaccination at birth with live attenuatedMycobacterium tuberculosisstrains expressing simian immunodeficiency virus (SIV) genes safely induces persistent SIV-specific cellular and humoral immune responses both systemically and at the oral and intestinal mucosa. Here, we tested the ability of oralM. tuberculosisvaccine strains expressing SIV Env and Gag proteins, followed by systemic heterologous (MVA-SIV Env/Gag/Pol) boosting, to protect neonatal macaques against oral SIV challenge. While vaccination did not protect infant macaques against oral SIV acquisition, a subset of immunized animals had significantly lower peak viremia which inversely correlated with prechallenge SIV Env-specific salivary and intestinal IgA responses and higher-avidity SIV Env-specific IgG in plasma. These controller animals also maintained CD4+T cell populations better and showed reduced tissue pathology compared to noncontroller animals. We show that infants vaccinated at birth can develop vaccine-induced SIV-specific IgA and IgG antibodies and cellular immune responses within weeks of life. Our data further suggest that affinity maturation of vaccine-induced plasma antibodies and induction of mucosal IgA responses at potential SIV entry sites are associated with better control of viral replication, thereby likely reducing SIV morbidity.IMPORTANCEDespite significant progress in reducing peripartum MTCT of HIV with ART, continued access to ART throughout the breastfeeding period is still a limiting factor. Breast milk exposure to HIV accounts for up to 44% of MTCT. Alternative measures, in addition to ART, are needed to achieve the goal of an AIDS-free generation. Pediatric HIV vaccines constitute a core component of such efforts. The results of our pediatric vaccine study highlight the potential importance of vaccine-elicited mucosal Env-specific IgA responses in combination with high-avidity systemic Env-specific IgG in protection against oral SIV transmission and control of viral replication in infant macaques. The induction of potent mucosal IgA antibodies by our vaccine is remarkable considering the age-dependent development of mucosal IgA responses postbirth. A deeper understanding of postnatal immune development may inform the design of improved vaccine strategies to enhance systemic and mucosal SIV/HIV antibody responses.

scholarly journals The role of the tumour microenvironment in the angiogenesis of pituitary tumours

Endocrine ◽  
2020 ◽  
Vol 70 (3) ◽  
pp. 593-606
Author(s):  
Pedro Marques ◽  
Sayka Barry ◽  
Eivind Carlsen ◽  
David Collier ◽  
Amy Ronaldson ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
Immune Cells ◽  
Microvessel Density ◽  
Tumour Microenvironment ◽  
Vascular Morphology ◽  
Hla Dr ◽  
M1 Macrophage ◽  
Culture Supernatants

Abstract Purpose Angiogenesis has been studied in pituitary neuroendocrine tumours (PitNETs), but the role of the tumour microenvironment (TME) in regulating PitNET angiogenesis remains unknown. We aimed to characterise the role of TME components in determining the angiogenetic PitNET profile, focusing on immune cells and tumour-derived cytokines. Methods Immune cells were studied by immunohistochemistry in 24 human PitNETs (16 non-functioning-PitNETs (NF-PitNETs) and 8 somatotrophinomas): macrophages (CD68, CD163, HLA-DR), cytotoxic (CD8) and T helper (CD4) lymphocytes, regulatory T cells (FOXP3), B cells (CD20) and neutrophils (neutrophil elastase); endothelial cells were assessed with CD31. Five normal pituitaries (NP) were included for comparison. Microvessel density and vascular morphology were estimated with ImageJ. The cytokine secretome from these PitNETs were assessed on culture supernatants using a multiplex immunoassay panel. Results Microvessel density/area was higher in NP than PitNETs, which also had rounder and more regular vessels. NF-PitNETs had vessels of increased calibre compared to somatotrophinomas. The M2:M1 macrophage ratio correlated with microvessel area. PitNETs with more CD4+ T cells had higher microvessel area, while tumours with more FOXP3+ cells were associated with lower microvessel density. PitNETs with more B cells had rounder vessels. Of the 42 PitNET-derived cytokines studied, CCL2, CXCL10 and CX3CL1 correlated with microvessel density and vessel architecture parameters. Conclusions M2 macrophages appear to play a role in PitNET neovascularisation, while B, CD4+ and FOXP3+ lymphocytes, as well as non-cellular TME elements such as CCL2, CXCL10 and CX3CL1, may also modulate the angiogenesis of PitNETs.

scholarly journals Regulatory roles of IL-10–producing human follicular T cells

2019 ◽  
Vol 216 (8) ◽  
pp. 1843-1856 ◽  
Author(s):  
Pablo F. Cañete ◽  
Rebecca A. Sweet ◽  
Paula Gonzalez-Figueroa ◽  
Ilenia Papa ◽  
Naganari Ohkura ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
B Cell ◽  
Foxp3 Expression ◽  
Antibody Responses ◽  
T Cell Proliferation ◽  
Lymphoid Tissues ◽  
Human Tonsil ◽  
Follicular Helper ◽  
Cell Class

Mucosal lymphoid tissues such as human tonsil are colonized by bacteria and exposed to ingested and inhaled antigens, requiring tight regulation of immune responses. Antibody responses are regulated by follicular helper T (TFH) cells and FOXP3+ follicular regulatory T (TFR) cells. Here we describe a subset of human tonsillar follicular T cells identified by expression of TFH markers and CD25 that are the main source of follicular T (TF) cell–derived IL-10. Despite lack of FOXP3 expression, CD25+ TF cells resemble T reg cells in high CTLA4 expression, low IL-2 production, and their ability to repress T cell proliferation. CD25+ TF cell–derived IL-10 dampens induction of B cell class-switching to IgE. In children, circulating total IgE titers were inversely correlated with the frequencies of tonsil CD25+ TF cells and IL-10–producing TF cells but not with total T reg cells, TFR, or IL-10–producing T cells. Thus, CD25+ TF cells emerge as a subset with unique T and B cell regulatory activities that may help prevent atopy.

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