High Level EBV Persistence in the IgM+ IgD+ CD27+ B Cell Subset in Patients with X-Linked Lymphoproliferative Disease Lacking Isotype-Switched Memory B Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2276-2276
Author(s):  
Sridhar Chaganti ◽  
Cindy Ma ◽  
Andrew Bell ◽  
Debbie Croom-Carter ◽  
Andrew Hislop ◽  
...  

Abstract Epstein-Barr virus (EBV) infects >90% of population world wide and, in healthy virus carriers, establishes life long persistence in the immunoglobulin (Ig)Dneg, CD27+ (“class-switched”) memory B cell compartment normally produced by antigen stimulation and transit through germinal centres. Patients with the X-linked lymphoproliferative disease (XLP) cannot make such class-switched memory B cells due to an inherited mutation in the slam-associated protein (SAP) gene involved in the maturation of antibody responses. Interestingly, XLP patients are highly susceptible to severe primary EBV infection and develop a fulminant infectious mononucleosis (IM) which is often fatal and where the symptoms progress to resemble those of a different (non-familial) disease, EBV-associated haemophagocytosis syndrome (EBV-AHS), caused by virus entry into the NK or T cell system. Some XLP patients survive their primary infection, but the nature of EBV carriage in these individuals (lacking conventional memory B cells) remains unresolved. To investigate this further we obtained blood samples from 8 such XLP patients. EBV load in total peripheral blood mononuclear cells (PBMC), determined by quantitative PCR, occupied a broad range but on average was 2 to 3-fold fold higher than that of healthy controls. The virus was concentrated within the B cell (CD19+) compartment, as in healthy carriers, and not within T or NK cells, as typically seen in EBV-AHS. We then confirmed that these XLP patients indeed lacked conventional class-switched memory B cells but did carry a small population of IgM+, IgD+, CD27+ (“non-switched”) memory cells; however their circulating B cell pool was dominated by naïve (IgM+, IgD+, CD27neg) cells and by expanded numbers of immature “transitional” (CD10+ CD27neg) cells. In each of 4 cases studied by cell sorting, EBV was concentrated in this small subset of “non-switched” memory B cells. To see if the high virus load detected in these patients indicated true virus persistence as opposed to recent or recurrent infection, serial samples obtained over a 3 year period from two XLP patients were assayed. Virus load was stable and, in one case with the highest load, screening with markers of virus polymorphism detected the same resident strain over time. Our results in XLP patients make it clear that EBV can persist in the absence of a conventional class-switched memory B cell compartment. Instead, the virus is sequestered in a small population of “non-class-switched memory” cells with Ig gene mutations. The origin of such cells, which are also detectable in the blood of normal donors, is uncertain; however their existence in XLP patients suggests that such cells arise independently of germinal centre activity and hence that EBV may be able to colonise its host without exploiting germinal centre transit.

2015 ◽  
Vol 112 (38) ◽  
pp. E5281-E5289 ◽  
Author(s):  
Bettina Budeus ◽  
Stefanie Schweigle de Reynoso ◽  
Martina Przekopowitz ◽  
Daniel Hoffmann ◽  
Marc Seifert ◽  
...  

Our knowledge about the clonal composition and intraclonal diversity of the human memory B-cell compartment and the relationship between memory B-cell subsets is still limited, although these are central issues for our understanding of adaptive immunity. We performed a deep sequencing analysis of rearranged immunoglobulin (Ig) heavy chain genes from biological replicates, covering more than 100,000 memory B lymphocytes from two healthy adults. We reveal a highly similar B-cell receptor repertoire among the four main human IgM+ and IgG+ memory B-cell subsets. Strikingly, in both donors, 45% of sequences could be assigned to expanded clones, demonstrating that the human memory B-cell compartment is characterized by many, often very large, B-cell clones. Twenty percent of the clones consisted of class switched and IgM+(IgD+) members, a feature that correlated significantly with clone size. Hence, we provide strong evidence that the vast majority of Ig mutated B cells—including IgM+IgD+CD27+ B cells—are post-germinal center (GC) memory B cells. Clone members showed high intraclonal sequence diversity and high intraclonal versatility in Ig class and IgG subclass composition, with particular patterns of memory B-cell clone generation in GC reactions. In conclusion, GC produce amazingly large, complex, and diverse memory B-cell clones, equipping the human immune system with a versatile and highly diverse compartment of IgM+(IgD+) and class-switched memory B cells.


Parasitology ◽  
2020 ◽  
Vol 147 (9) ◽  
pp. 994-998 ◽  
Author(s):  
Halina M. Pietrzak ◽  
Lisa J. Ioannidis ◽  
Diana S. Hansen

AbstractEmerging evidence started to delineate multiple layers of memory B cells, with distinct effector functions during recall responses. Whereas most studies examining long-lived memory B cell responses have focussed on the IgG+ memory B cell compartment, IgM+ memory B cells have only recently started to receive attention. It has been proposed that unlike IgG+ memory B cells, which differentiate into antibody-secreting plasma cells upon antigen re-encounter, IgM+ memory B cells might have the additional capacity to establish secondary germinal centre (GC) responses. The precise function of IgM+ memory B cells in the humoral immune response to malaria has not been fully defined. Using a murine model of severe malaria infection and adoptive transfer strategies we found that IgM+ memory B cells induced in responses to P. berghei ANKA readily proliferate upon re-infection and adopt a GC B cell-like phenotype. The results suggest that that IgM+ memory B cells might play an important role in populating secondary GCs after re-infection with Plasmodium, thereby initiating the induction of B cell clones with enhanced affinity for antigen, at faster rates than naive B cells.


2007 ◽  
Vol 204 (9) ◽  
pp. 2103-2114 ◽  
Author(s):  
Shannon M. Anderson ◽  
Mary M. Tomayko ◽  
Anupama Ahuja ◽  
Ann M. Haberman ◽  
Mark J. Shlomchik

The study of murine memory B cells has been limited by small cell numbers and the lack of a definitive marker. We have addressed some of these difficulties with hapten-specific transgenic (Tg) mouse models that yield relatively large numbers of antigen-specific memory B cells upon immunization. Using these models, along with a 5-bromo-2′-deoxyuridine (BrdU) pulse-label strategy, we compared memory cells to their naive precursors in a comprehensive flow cytometric survey, thus revealing several new murine memory B cell markers. Most interestingly, memory cells were phenotypically heterogeneous. Particularly surprising was the finding of an unmutated memory B cell subset identified by the expression of CD80 and CD35. We confirmed these findings in an analogous V region knock-in mouse and/or in non-Tg mice. There also was anatomic heterogeneity, with BrdU+ memory cells residing not just in the marginal zone, as had been thought, but also in splenic follicles. These studies impact the current understanding of murine memory B cells by identifying new phenotypes and by challenging assumptions about the location and V region mutation status of memory cells. The apparent heterogeneity in the memory compartment implies either different origins and/or different functions, which we discuss.


Blood ◽  
2008 ◽  
Vol 112 (3) ◽  
pp. 672-679 ◽  
Author(s):  
Sridhar Chaganti ◽  
Cindy S. Ma ◽  
Andrew I. Bell ◽  
Debbie Croom-Carter ◽  
Andrew D. Hislop ◽  
...  

AbstractEpstein-Barr virus (EBV) persists in healthy virus carriers within the immunoglobulin (Ig)D−CD27+ (class-switched) memory B-cell compartment that normally arises through antigen stimulation and germinal center transit. Patients with X-linked lymphoproliferative disease (XLP) lack such class-switched memory B cells but are highly susceptible to EBV infection, often developing fatal symptoms resembling those seen in EBV-associated hemophagocytic syndrome (EBV-AHS), a disease caused by aberrant virus entry into the NK- or T-cell system. Here we show that XLP patients who survive primary EBV exposure carry relatively high virus loads in the B-cell, but not the NK- or T-cell, compartment. Interestingly, in the absence of conventional class-switched memory B cells, the circulating EBV load was concentrated within a small population of IgM+IgD+CD27+ (nonswitched) memory cells rather than within the numerically dominant naive (IgM+IgD+CD27−) or transitional (CD10+CD27−) subsets. In 2 prospectively studied patients, the circulating EBV load was stable and markers of virus polymorphism detected the same resident strain over time. These results provide the first definitive evidence that EBV can establish persistence in the B-cell system in the absence of fully functional germinal center activity and of a class-switched memory B-cell compartment.


2020 ◽  
Vol 218 (1) ◽  
Author(s):  
Takeshi Inoue ◽  
Ryo Shinnakasu ◽  
Chie Kawai ◽  
Wataru Ise ◽  
Eiryo Kawakami ◽  
...  

A still unanswered question is what drives the small fraction of activated germinal center (GC) B cells to become long-lived quiescent memory B cells. We found here that a small population of GC-derived CD38intBcl6hi/intEfnb1+ cells with lower mTORC1 activity favored the memory B cell fate. Constitutively high mTORC1 activity led to defects in formation of the CD38intBcl6hi/intEfnb1+ cells; conversely, decreasing mTORC1 activity resulted in relative enrichment of this memory-prone population over the recycling-prone one. Furthermore, the CD38intBcl6hi/intEfnb1+ cells had higher levels of Bcl2 and surface BCR that, in turn, contributed to their survival and development. We also found that downregulation of Bcl6 resulted in increased expression of both Bcl2 and BCR. Given the positive correlation between the strength of T cell help and mTORC1 activity, our data suggest a model in which weak help from T cells together with provision of an increased survival signal are key for GC B cells to adopt a memory B cell fate.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marco Vincenzo Lenti ◽  
Nicola Aronico ◽  
Ivan Pellegrino ◽  
Emanuela Boveri ◽  
Paolo Giuffrida ◽  
...  

AbstractImpaired immune responses have been hypothesised to be a possible trigger of unfavourable outcomes in coronavirus disease 2019 (COVID-19). We aimed to characterise IgM memory B cells in patients with COVID-19 admitted to an internal medicine ward in Northern Italy. Overall, 66 COVID-19 patients (mean age 74 ± 16.6 years; 29 females) were enrolled. Three patients (4.5%; 1 female) had been splenectomised and were excluded from further analyses. Fifty-five patients (87.3%) had IgM memory B cell depletion, and 18 (28.6%) died during hospitalisation (cumulative incidence rate 9.26/100 person-week; 5.8–14.7 95% CI). All patients who died had IgM memory B cell depletion. A superimposed infection was found in 6 patients (9.5%), all of them having IgM memory B cell depletion (cumulative incidence rate 3.08/100 person-week; 1.3–6.8 95% CI). At bivariable analyses, older age, sex, number of comorbidities, and peripheral blood lymphocyte count < 1500/µl were not correlated with IgM memory B cell depletion. A discrete-to-marked reduction of the B-cell compartment was also noticed in autoptic spleen specimens of two COVID-19 patients. We conclude that IgM memory B cells are commonly depleted in COVID-19 patients and this correlates with increased mortality and superimposed infections.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Kristian Assing ◽  
Christian Nielsen ◽  
Marianne Jakobsen ◽  
Charlotte B. Andersen ◽  
Kristin Skogstrand ◽  
...  

Abstract Background Germinal center derived memory B cells and plasma cells constitute, in health and during EBV reactivation, the largest functional EBV reservoir. Hence, by reducing germinal center derived formation of memory B cells and plasma cells, EBV loads may be reduced. Animal and in-vitro models have shown that IL-21 can support memory B and plasma cell formation and thereby potentially contribute to EBV persistence. However, IL-21 also displays anti-viral effects, as mice models have shown that CD4+ T cell produced IL-21 is critical for the differentiation, function and survival of anti-viral CD8+ T cells able to contain chronic virus infections. Case presentation We present immunological work-up (flow-cytometry, ELISA and genetics) related to a patient suffering from a condition resembling B cell chronic active EBV infection, albeit with moderately elevated EBV copy numbers. No mutations in genes associated with EBV disease, common variable immunodeficiency or pertaining to the IL-21 signaling pathway (including hypermorphic IL-21 mutations) were found. Increased (> 5-fold increase 7 days post-vaccination) CD4+ T cell produced (p < 0.01) and extracellular IL-21 levels characterized our patient and coexisted with: CD8+ lymphopenia, B lymphopenia, hypogammaglobulinemia, compromised memory B cell differentiation, absent induction of B-cell lymphoma 6 protein (Bcl-6) dependent peripheral follicular helper T cells (pTFH, p = 0.01), reduced frequencies of peripheral CD4+ Bcl-6+ T cells (p = 0.05), compromised plasmablast differentiation (reduced protein vaccine responses (p < 0.001) as well as reduced Treg frequencies. Supporting IL-21 mediated suppression of pTFH formation, pTFH and CD4+ IL-21+ frequencies were strongly inversely correlated, prior to and after vaccination, in the patient and in controls, Spearman’s rho: − 0.86, p < 0.001. Conclusions To the best of our knowledge, this is the first report of elevated CD4+ IL-21+ T cell frequencies in human EBV disease. IL-21 overproduction may, apart from driving T cell mediated anti-EBV responses, disrupt germinal center derived memory B cell and plasma cell formation, and thereby contribute to EBV disease control.


2019 ◽  
Vol 31 (12) ◽  
pp. 771-779 ◽  
Author(s):  
Sarah Leach ◽  
Ryo Shinnakasu ◽  
Yu Adachi ◽  
Masatoshi Momota ◽  
Chieko Makino-Okamura ◽  
...  

Memory B cells protect against heterologous influenza infection


2009 ◽  
Vol 182 (12) ◽  
pp. 7634-7643 ◽  
Author(s):  
Agata Matejuk ◽  
Michael Beardall ◽  
Yang Xu ◽  
Qi Tian ◽  
Daniel Phillips ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3248-3248
Author(s):  
Sridhar Chaganti ◽  
Noelia Begue Pastor ◽  
Mark T. Drayson ◽  
Andy I. Bell ◽  
Alan B. Rickinson

Abstract Somatic hypermutation of immunoglobulin (Ig) gene sequences in the germinal centres of lymphoid tissues is necessary for affinity maturation of B cell responses to antigen challenge. This process generates a few clones with improved affinity that are selected into B cell memory and many clones with other non favourable Ig mutations, including some cells with functionally inactivated Ig gene that normally die by apoptosis. It is postulated that infection with Epstein-Barr virus (EBV), a B lymphotropic agent linked to several types of B cell lymphoma, can rescue germinal centre cells with unfavourable mutations. This creates a pool of infected cells at greater risk of developing into lymphomas. In the present work, CD38+ germinal centre B cells were separated from tonsil by negative selection for IgD and CD39. Peripheral blood naïve and memory B cell subpopulations were FACS sorted as IgD+, CD27− and IgD−, CD27+ fractions respectively. These cells were infected with EBV (B95.8 strain) in vitro and seeded at limiting dilutions onto fibroblast feeders. EBV transformed lymphoblastoid cell lines (LCLs) from such cultures were analysed for surface Ig phenotype. Naïve B cell transformants were consistently IgM+, IgD+. Memory B cell transformants were IgM+ in some cases but more frequently IgG+ or IgA+. Germinal centre transformants showed the same spectrum of surface Ig phenotypes as memory cell transformants but in addition we identified six germinal centre derived LCLs which were consistently surface Ig negative. Sequencing from these lines confirmed that in at least three cases EBV had rescued cells with functionally inactivated Ig heavy chain gene.


Sign in / Sign up

Export Citation Format

Share Document