Comparable Long-Term Persistence of Anti-FVIII Antibodies in Hemophilic E17 Mice on Different Genetic Backgrounds Despite Significant Differences in the Amplitude of the Immune Responses.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1027-1027
Author(s):  
Natalie Bauer ◽  
Christina Hausl ◽  
Rafi U. Ahmad ◽  
Bernhard Baumgartner ◽  
Hans Peter Schwarz ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cells ◽  
Genetic Background ◽  
Neutralizing Antibodies ◽  
Plasma Cells ◽  
Memory B Cells ◽  
Mouse Strains ◽  
Igg Antibodies ◽  
Specific Memory

Abstract About 30% of patients with severe hemophilia A develop neutralizing antibodies against FVIII (FVIII inhibitors) following replacement therapy. The type of FVIII gene mutation as well as other predisposing genetic factors contribute to the inhibitor phenotype. Based on these findings, we asked if the genetic background modulates the long-term persistence of anti-FVIII antibodies and anti-FVIII antibody secreting plasma cells in the E17 murine hemophilia model. Furthermore, we asked if the recently described inhibition of memory-B-cell re-stimulation by high doses of FVIII is influenced by the genetic background of the murine model. E17 mice on two different genetic backgrounds (C57Bl/6J and Balb/c) were treated with four doses of 200 ng human FVIII at weekly intervals. Anti-FVIII antibodies and anti-FVIII antibody secreting plasma cells were followed up to 12 months after the last dose of FVIII. Antibody titers and subclasses of antibodies (IgM, IgG1, IgG2a, IgG2b, IgG3) were measured by ELISA. Antibody secreting plasma cells in spleen and bone marrow were detected by ELISPOT as described (Hausl et al., Thromb Haemost 2002). The re-stimulation of FVIII-specific memory B cells was studied as described recently (Hausl et al., Blood 2005). Anti-FVIII antibodies and anti-FVIII antibody secreting plasma cells were first detectable in E17 Balb/c mice. IgM antibodies in the circulation and IgM secreting plasma cells in the spleen were observed after the first dose of FVIII, IgG antibodies and IgG secreting plasma cells after the second dose. No anti-FVIII antibodies after the first dose of FVIII were observed in E17 C57BL/6J mice but both IgM and IgG antibodies as well as IgM and IgG producing plasma cells were detectable after the second dose of FVIII. The antibody response involved all IgG subclasses in both mouse strains. However, IgG1 was dominant in E17 Balb/c mice whereas IgG2a was dominant in E17 C57BL/6J mice. When the in vitro restimulation of FVIII-specific memory B cells was examined, similar patterns were observed for both mouse strains. Low concentrations of FVIII between 10 and 100 ng/ml FVIII restimulated memory B cells and induced their differentiation into antibody secreting plasma cells whereas high concentrations of FVIII between 1,000 and 20,000 ng/ml FVIII inhibited memory-B-cell-restimulation. These results indicate that the dose-dependent effect of FVIII on the restimulation of FVIII-specific memory B cells does not depend on the genetic background. The major difference between both hemophilic mouse strains was the amplitude of the anti-FVIII immune response. Peak titers of anti-FVIII antibodies and peak concentrations of anti-FVIII antibody secreting plasma cells in spleen and bone marrow were significantly higher in E17 C57BL/6J mice than in E17 Balb/c mice. Whether or not higher ELISA titers correlate with higher Bethesda titers of neutralizing antibodies is currently being investigated. Despite the substantial differences in the amplitude of the immune response, anti-FVIII antibodies and anti-FVIII antibody secreting plasma cells persisted for the whole observation period of 12 months after the last dose of FVIII in both mouse strains. We conclude that the amplitude of the anti-FVIII immune response in hemophilic mice is significantly different between E17 C57BL/6J and E17 Balb/c mice. However, the persistence of the immune response is comparable.

scholarly journals Antigen-Specific B Cell Memory

2000 ◽  
Vol 191 (7) ◽  
pp. 1149-1166 ◽  
Author(s):  
Louise J. McHeyzer-Williams ◽  
Melinda Cool ◽  
Michael G. McHeyzer-Williams
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Memory B Cells ◽  
Cell Memory ◽  
Specific Memory ◽  
B Cell Memory ◽  
Cellular Components

The mechanisms that regulate B cell memory and the rapid recall response to antigen remain poorly defined. This study focuses on the rapid expression of B cell memory upon antigen recall in vivo, and the replenishment of quiescent B cell memory that follows. Based on expression of CD138 and B220, we reveal a unique and major subtype of antigen-specific memory B cells (B220−CD138−) that are distinct from antibody-secreting B cells (B220+/−CD138+) and B220+CD138− memory B cells. These nonsecreting somatically mutated B220− memory responders rapidly dominate the splenic response and comprise >95% of antigen-specific memory B cells that migrate to the bone marrow. By day 42 after recall, the predominant quiescent memory B cell population in the spleen (75–85%) and the bone marrow (>95%) expresses the B220− phenotype. Upon adoptive transfer, B220− memory B cells proliferate to a lesser degree but produce greater amounts of antibody than their B220+ counterparts. The pattern of cellular differentiation after transfer indicates that B220− memory B cells act as stable self-replenishing intermediates that arise from B220+ memory B cells and produce antibody-secreting cells on rechallenge with antigen. Cell surface phenotype and Ig isotype expression divide the B220− compartment into two main subsets with distinct patterns of integrin and coreceptor expression. Thus, we identify new cellular components of B cell memory and propose a model for long-term protective immunity that is regulated by a complex balance of committed memory B cells with subspecialized immune function.

scholarly journals Göttingen Minipigs as a Model to Evaluate Longevity, Functionality, and Memory of Immune Response Induced by Pertussis Vaccines

2021 ◽  
Vol 12 ◽  
Author(s):  
Céline Vaure ◽  
Véronique Grégoire-Barou ◽  
Virginie Courtois ◽  
Emilie Chautard ◽  
Cyril Dégletagne ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cells ◽  
Vaccine Development ◽  
Vaccination Schedule ◽  
Memory B Cells ◽  
Immune Memory ◽  
Preclinical Model ◽  
Göttingen Minipig ◽  
Cellular Immune

Evaluation of the short-term and long-term immunological responses in a preclinical model that simulates the targeted age population with a relevant vaccination schedule is essential for human vaccine development. A Göttingen minipig model was assessed, using pertussis vaccines, to demonstrate that vaccine antigen-specific humoral and cellular responses, including IgG titers, functional antibodies, Th polarization and memory B cells can be assessed in a longitudinal study. A vaccination schedule of priming with a whole cell (DTwP) or an acellular (DTaP) pertussis vaccine was applied in neonatal and infant minipigs followed by boosting with a Tdap acellular vaccine. Single cell RNAsequencing was used to explore the long-term maintenance of immune memory cells and their functionality for the first time in this animal model. DTaP but not DTwP vaccination induced pertussis toxin (PT) neutralizing antibodies. The cellular immune response was also characterized by a distinct Th polarization, with a Th-2-biased response for DTaP and a Th-1/Th-17-biased response for DTwP. No difference in the maintenance of pertussis-specific memory B cells was observed in DTaP- or DTwP-primed animals 6 months post Tdap boost. However, an increase in pertussis-specific T cells was still observed in DTaP primed minipigs, together with up-regulation of genes involved in antigen presentation and interferon pathways. Overall, the minipig model reproduced the humoral and cellular immune responses induced in humans by DTwP vs. DTaP priming, followed by Tdap boosting. Our data suggest that the Göttingen minipig is an attractive preclinical model to predict the long-term immunogenicity of human vaccines against Bordetella pertussis and potentially also vaccines against other pathogens.

scholarly journals The BioNTech / Pfizer vaccine BNT162b2 induces class-switched SARS-CoV-2-specific plasma cells and potential memory B cells as well as IgG and IgA serum and IgG saliva antibodies upon the first immunization

2021 ◽  
Author(s):  
Anne S. Lixenfeld ◽  
Inga Künsting ◽  
Emily L. Martin ◽  
Vera von Kopylow ◽  
Selina Lehrian ◽  
...  
Keyword(s):  
B Cells ◽  
Respiratory Tract ◽  
Development Process ◽  
Plasma Cells ◽  
Memory B Cells ◽  
The Body ◽  
Cd4 T Cell ◽  
First Line ◽  
Underlying Mechanisms

AbstractTo treat the SARS-CoV-2 virus, that enters the body through the respiratory tract, different vaccines in particular against the SARS-CoV-2 spike (S)-protein have been developed or are in the development process. For the BioNTech / Pfizer mRNA vaccine BNT162b2, which is injected twice, protection against COVID-19 has been described for the first weeks after the second vaccination. The underlying mechanisms of defense and the long-term effectiveness of this vaccine against COVID-19 are currently under investigation.In addition to the induction of systemic antibodies (Abs), Ab responses in the respiratory tract would help to form a first line of defense against SARS-CoV-2. Furthermore, protection depends on Fab-part-dependent neutralizing capacities, however, Fc-part-mediated effector mechanisms might also be important. Long-term defense would be based on the induction of long-lived antibody-producing plasma cells (PCs) and memory B cells.Here, we established different assays to analyze anti-SARS-CoV-2-S IgG and IgA Abs in blood serum and saliva as well as SARS-CoV-2-S1-reactive IgG and IgA PCs and potential memory B cells in the blood of individuals upon their first immunization with BNT162b2.We show that the vaccine induces in particular anti-SARS-CoV-2-S IgG1 and IgG3 as well as IgA1 and in some individuals also IgG2 and IgA2 serum Abs. In the saliva, we found no anti-SARS-CoV-2-S IgA, but instead IgG Abs. Furthermore, we found SARS-CoV-2-S reactive IgG+ blood PCs and potential memory B cells as well as SARS-CoV-2-S reactive IgA+ PCs and/or potential memory B cells in some individuals.Our data suggest that the vaccine induces a promising CD4+ T cell-dependent systemic IgG1 and IgG3 Ab response with IgG+ PCs and potential memory B cells. In addition to the systemic IgG response, the systemic IgA and saliva IgG response might help to improve a first line of defense in the respiratory tract against SARS-CoV-2 and its mutants.

scholarly journals Case Report: Persistent Hypogammaglobulinemia More Than 10 Years After Rituximab Given Post-HSCT

2021 ◽  
Vol 12 ◽  
Author(s):  
Fanny Luterbacher ◽  
Fanette Bernard ◽  
Frédéric Baleydier ◽  
Emmanuelle Ranza ◽  
Peter Jandus ◽  
...  
Keyword(s):  
B Cells ◽  
Plasma Cells ◽  
Memory B Cells ◽  
Virus Reactivation ◽  
Normal Numbers ◽  
Cell Stage ◽  
Hematopoietic Stem ◽  
Barr Virus ◽  
Anti Cd20

Rituximab (RTX) is an anti-CD20 monoclonal antibody that targets B cells—from the immature pre-B-cell stage in the bone marrow to mature circulating B cells—while preserving stem cells and plasma cells. It is used to treat autoimmune diseases, hematological malignancies, or complications after hematopoietic stem cell transplantation (HSCT). Its safety profile is acceptable; however, a subset of patients can develop persistent hypogammaglobulinemia and associated severe complications, especially in pediatric populations. We report the unrelated cases of two young men aged 17 and 22, presenting with persistent hypogammaglobulinemia more than 7 and 10 years after treatment with RTX, respectively, and administered after HSCT for hemolytic anemia and Epstein–Barr virus reactivation, respectively. Both patients’ immunological workups showed low levels of total immunoglobulin, vaccine antibodies, and class switched-memory B cells but an increase in naive B cells, which can also be observed in primary immunodeficiencies such as those making up common variable immunodeficiency. Whole exome sequencing for one of the patients failed to detect a pathogenic variant causing a Mendelian immunological disorder. Annual assessments involving interruption of immunoglobulin replacement therapy each summer failed to demonstrate the recovery of endogenous immunoglobulin production or normal numbers of class switched-memory B cells 7 and 10 years after the patients’ respective treatments with RTX. Although the factors that may lead to prolonged hypogammaglobulinemia after rituximab treatment (if necessary) remain unclear, a comprehensive immunological workup before treatment and long-term follow-up are mandatory to assess long-term complications, especially in children.

Tracking Factor VIII-Specific Memory B Cells in Hemophilia A Patients with Factor VIII Inhibitors.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1016-1016 ◽  
Author(s):  
Irene Lang ◽  
Jerzy Windyga ◽  
Anna Klukowska ◽  
Josenato Ilas ◽  
Hans Peter Schwarz ◽  
...  
Keyword(s):  
B Cells ◽  
Tetanus Toxin ◽  
Plasma Cells ◽  
Hemophilia A ◽  
Positive Control ◽  
Negative Control ◽  
Memory B Cells ◽  
Healthy Individuals ◽  
Specific Memory

Abstract The development of neutralizing anti-FVIII antibodies (FVIII inhibitors) in about 30% of patients with severe hemophilia A is the most serious complication in the treatment of hemophilia patients with FVIII products. Little information is available on the immunological mechanisms that regulate the development and maintenance of FVIII inhibitors. Memory B cells are a central component of humoral immunity. They drive the rapid anamnestic antibody response that occurs after re-exposure to antigen and seem to be important for replenishing the pool of long-lived plasma cells to maintain long-term antibody levels in the absence of antigen. Nothing is known about the dynamics of FVIII-specific memory B cells in patients with hemophilia A who develop FVIII inhibitors. Recently, Crotty et al. (J Immunol Methods, 2004) described an in vitro assay to quantify antigen-specific memory B cells in human blood. This assay utilizes a 6-day polyclonal stimulation of peripheral blood mononuclear cells (PBMC) followed by an antigen-specific ELISPOT for the detection of memory B cells that have differentiated into antibody-secreting plasma cells in vitro. We adapted this assay to human FVIII and used it to track FVIII-specific memory B cells in the blood of hemophilia A patients with and without FVIII inhibitors. Human serum albumin was used as a negative control and tetanus toxin as a positive control. The numbers of FVIII-specific, tetanus toxin-specific (positive control) and albumin-specific (negative control) memory B cells were calculated as percentage of total IgG memory B cells. So far, we have analyzed 14 patients with hemophilia A (age: 6–65 years). 8 were positive and 6 were negative for FVIII inhibitors. For comparison, we have analyzed 20 healthy individuals (age: 19–48 years). 2 out of 8 patients with inhibitors had detectable FVIII-specific memory B cells in their peripheral blood cells. However, none of the patients without inhibitors and none of the healthy individuals had any detectable FVIII-specific memory B cells in their circulation. The detection limit for FVIII-specific memory B cells in patients with inhibitors was about 0.2 % (percent of total IgG memory B cells). Current activities focus on further advancing the method with the aim to improve the detection limit for the detection of FVIII-specific memory B cells. All samples analyzed (including patients and healthy individuals) were negative for human serum albumin-specific memory B cells (negative control). Tetanus toxin-specific memory B cells (positive control) were found in both patients and healthy blood donors. The percentage of tetanus toxin-specific memory B cells in individuals who were vaccinated with tetanus toxoid was in the range of 0.25 – 0.58 % (percent of total IgG memory B cells). We conclude that the method described is suitable to track FVIII-specific memory B cells in the circulation. We are currently asking the question whether the presence of FVIII-specific memory B cells in the circulation correlates with the persistence of FVIII inhibitors. Furthermore, we will monitor patients with inhibitors during ITI therapy in order to find out whether the disappearance of FVIII-specific memory B cells in the circulation could be an early predictor of a successful ITI outcome.

Memory B Cells Protect from CMV Infection in the Absence of T Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 619-619 ◽  
Author(s):  
Thomas H. Winkler ◽  
Florian Weisel ◽  
Karin Klenovsek ◽  
Michael Mach
Keyword(s):  
Bone Marrow ◽  
Immune Response ◽  
T Cell ◽  
B Cells ◽  
Memory B Cells ◽  
Primary Immune Response ◽  
Immunodeficient Mice ◽  
Virus Dissemination ◽  
Specific Memory ◽  
T Cell Help

Abstract Infections with cytomegalovirus are still a major clinical problem in immunosuppressed patients e.g. after bone marrow or stem cell transplantation. To prevent clinical overt disease resulting from disseminated virus infection, immunoprophylaxis and/or -therapy are considered a major goal. The humoral immune response contributes to immune protection against CMV by providing neutralizing antibodies. However, in the early phase after transplantation a primary immune response is not possible. Humoral anti-CMV immune effector functions can only be provided by memory B cells. The activation requirements for resting memory B cells are unclear. Using non-infectious hCMV particles in mice we have recently shown that activation of virus-specific memory B cells to secrete IgG is independent of cognate or bystander T cell help. To analyze whether transfer of memory B cells into immunodeficient mice can protect from lethal infection we switched to an infectious animal model using mCMV. When memory B cells from mCMV-infected mice were adoptively transferred into RAG-1−/− mice, a strong IgG anti-mCMV titer developed within 4–6 days after infection with mCMV. Virus dissemination and subsequent disease was inhibited. A 100–1000 fold decrease of virus titers and a 1.000–10.000 fold decrease of viral DNA load in spleen and lung was observed in mice that received mCMV specific memory B cells. Even in an established mCMV infection virus dissemination and subsequent disease could be prevented by means of adoptive memory B cell transfer. In further experiments we also used a virus mutant that cannot be controlled by NK cells in C57Bl/6 mice. Even in this experimental system we could demonstrate that adoptive transfer of memory B cells in the absence CD4 and CD8 cells is sufficient to protect from viral dissemination and rapid lethality. Our results show that memory B cells can mediate protection against mCMV in the absence of cognate or bystander T cell help. Similar regimens might be a therapeutic option for CMV reactivation after bone marrow transplantation in patients.

scholarly journals Loss of HIV-specific memory B-cells as a potential mechanism for the dysfunction of the humoral immune response against HIV

Virology ◽  
2010 ◽  
Vol 397 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Bianca M. Bussmann ◽  
Sven Reiche ◽  
Bernhard Bieniek ◽  
Ivanka Krznaric ◽  
Frank Ackermann ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cells ◽  
Humoral Immune Response ◽  
Memory B Cells ◽  
Potential Mechanism ◽  
Humoral Immune ◽  
Specific Memory

scholarly journals Serotype-Specific and Age-Dependent Generation of Pneumococcal Polysaccharide-Specific Memory B-Cell and Antibody Responses to Immunization with a Pneumococcal Conjugate Vaccine

2007 ◽  
Vol 15 (2) ◽  
pp. 182-193 ◽  
Author(s):  
Elizabeth A. Clutterbuck ◽  
Sarah Oh ◽  
Mainga Hamaluba ◽  
Sharon Westcar ◽  
Peter C. L. Beverley ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Conjugate Vaccine ◽  
Pneumococcal Conjugate Vaccine ◽  
Plasma Cells ◽  
Memory B Cells ◽  
Antibody Responses ◽  
Memory B Cell ◽  
Cell Responses ◽  
Specific Memory

ABSTRACT Glycoconjugate vaccines have dramatically reduced the incidence of encapsulated bacterial diseases in toddlers under 2 years of age, but vaccine-induced antibody levels in this age group wane rapidly. We immunized adults and 12-month-old toddlers with heptavalent pneumococcal conjugate vaccine to determine differences in B-cell and antibody responses. The adults and 12-month-old toddlers received a pneumococcal conjugate vaccine. The toddlers received a second dose at 14 months of age. The frequencies of diphtheria toxoid and serotype 4, 14, and 23F polysaccharide-specific plasma cells and memory B cells were determined by enzyme-linked immunospot assay. The toddlers had no preexisting polysaccharide-specific memory B cells or serum immunoglobulin G (IgG) antibody but had good diphtheria toxoid-specific memory responses. The frequencies of plasma cells and memory B cells increased by day 7 (P < 0.0001) in the adults and the toddlers following a single dose of conjugate, but the polysaccharide responses were significantly lower in the toddlers than in the adults (P = 0.009 to <0.001). IgM dominated the toddler antibody responses, and class switching to the IgG was serotype dependent. A second dose of vaccine enhanced the antibody and memory B-cell responses in the toddlers but not the ex vivo plasma cell responses. Two doses of pneumococcal conjugate vaccine are required in toddlers to generate memory B-cell frequencies and antibody class switching for each pneumococcal polysaccharide equivalent to that seen in adults.

scholarly journals Activation of Virus-specific Memory B Cells in the Absence of T Cell Help

2004 ◽  
Vol 199 (4) ◽  
pp. 593-602 ◽  
Author(s):  
Barbara J. Hebeis ◽  
Karin Klenovsek ◽  
Peter Rohwer ◽  
Uwe Ritter ◽  
Andrea Schneider ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Plasma Cells ◽  
Human Herpesvirus ◽  
Memory B Cells ◽  
Specific Memory ◽  
T Cell Help

Humoral immunity is maintained by long-lived plasma cells, constitutively secreting antibodies, and nonsecreting resting memory B cells that are rapidly reactivated upon antigen encounter. The activation requirements for resting memory B cells, particularly the role of T helper cells, are unclear. To analyze the activation of memory B cells, mice were immunized with human cytomegalovirus, a complex human herpesvirus, and tick-born encephalitis virus, and a simple flavivirus. B cell populations devoid of Ig-secreting plasma cells were adoptively transferred into T and B cell–deficient RAG-1−/− mice. Antigenic stimulation 4–6 d after transfer of B cells resulted in rapid IgG production. The response was long lasting and strictly antigen specific, excluding polyclonal B cell activation. CD4+ T cells were not involved since (a) further depletion of CD4+ T cells in the recipient mice did not alter the antibody response and (b) recipient mice contained no detectable CD4+ T cells 90 d posttransfer. Memory B cells could not be activated by a soluble viral protein without T cell help. Transfer of memory B cells into immunocompetent animals indicated that presence of helper T cells did not enhance the memory B cell response. Therefore, our results indicate that activation of virus-specific memory B cells to secrete IgG is independent of cognate or bystander T cell help.

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