scholarly journals Characterization of B1-cells during experimental leukomogenesis

2020 ◽  
Vol 65 (1) ◽  
pp. 35-40
Author(s):  
I. Yu. Ezdakova ◽  
O. V. Kapustina ◽  
M. I. Gulyukin ◽  
T. V. Stepanova
Keyword(s):  
Immune Response ◽  
B Cells ◽  
B Lymphocytes ◽  
Early Period ◽  
Primary Immune Response ◽  
Functional Difference ◽  
Infected Cattle ◽  
Primary Target ◽  
B1 Cells

Background. Bovine leukemia causes a significant polyclonal expansion of CD5+ , IgM+ B lymphocytes, known as persistent lymphocytosis (PL), in approximately 30% of infected cattle. However, it is not yet clear what happens to this subpopulation of B cells in the early period of infection of animals.Purpose. Quantitative characterization of IgM+ and CD5+ B cells during the immune response, which can provide important information on the mechanisms of lymphocyte priming in BLV infection.Material and methods. The experiment used BLV-negative calves of black-motley breed at the age of 8 months (n = 11). Animals (n = 8) were intravenously injected with blood of a BLV-positive cow. Control calves (n = 3) were injected with saline. Studies were performed before and after infection on days 5, 7, 14, 21, 28 and 65 of the immune response. The determination of the number of B-lymphocytes in the blood was carried out by the method of immunoperoxidase staining based on monoclonal antibodies to IgM, CD5.Results. As a result of the studies, it was found that the level of CD5+ B cells increases on the 14th day of the primary immune response, characterized by polyclonal proliferation of CD5+ B cells, which are the primary target for BLV. Our research data confirm that in the lymphocytes of experimentally infected cattle, surface aggregation of IgM and CD5 molecules on B-lymphocytes is absent.Discussion. It is known that the wave-like nature of IgM synthesis, which was shown in previous studies, depends on a subpopulation of B1 cells. After 7 days of the immune response, IgM+ and CD5+ cells do not correlate, which shows their functional difference. The increase in CD5+ cells is probably not associated with B cells, but with T cells differentiating under the influence of the virus.Conclusions. A subset of B1 cells is the primary target of cattle leukemia virus. The 65th day of the immune response is characterized by the expansion of IgM+ B cells, a decrease in the number of CD5+ cells and a uniform distribution of receptors around the perimeter of the cells.

scholarly journals In situ studies of the primary immune response to (4-hydroxy-3-nitrophenyl)acetyl. IV. Affinity-dependent, antigen-driven B cell apoptosis in germinal centers as a mechanism for maintaining self-tolerance.

1995 ◽  
Vol 182 (6) ◽  
pp. 1635-1644 ◽  
Author(s):  
S Han ◽  
B Zheng ◽  
J Dal Porto ◽  
G Kelsoe
Keyword(s):  
Immune Response ◽  
Cell Death ◽  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
Germinal Centers ◽  
Primary Immune Response ◽  
Soluble Antigen ◽  
High Affinity ◽  
Apoptotic Death

Germinal centers (GCs) are the sites of antigen-driven V(D)J gene hypermutation and selection necessary for the generation of high affinity memory B lymphocytes. Despite the antigen dependence of this reaction, injection of soluble antigen during an established primary immune response induces massive apoptotic death in GC B cells, but not in clonally related populations of nonfollicular B lymphoblasts and plasmacytes. Cell death in GCs occurs predominantly among light zone centrocytes, is antigen specific, and peaks within 4-8 h after injection. Antigen-induced programmed death does not involve cellular interactions mediated by CD40 ligand (CD40L) or Fas; disruption of GCs by antibody specific for CD40L was not driven by apoptosis and C57BL/6.lpr mice, though unable to express the Fas death trigger, remained fully susceptible to soluble antigen. Single injections of antigen did not significantly decrease GC numbers or average size, but repeated injections during an 18-h period resulted in fewer and substantially smaller GCs. As cell loss appeared most extensive in the light zone, decreased GC cellularity after prolonged exposure to soluble antigen implies that the Ig- centroblasts of the dark zone may require replenishment from light zone cells that have survived antigenic selection. GC cell death is avidity-dependent; oligovalent antigen induced relatively little apoptosis and GC B cells that survived long exposures to multivalent antigen expressed atypical VDJ rearrangements unlikely to encode high affinity antibody. Antigen-induced apoptotic death in GCs may represent a mechanism for the peripheral deletion of autoreactive B cell mutants much as the combinatorial repertoire of immature B lymphocytes is censored in the bone marrow.

scholarly journals Purinergic signalling in B cells

2018 ◽  
Vol 65 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Tomasz Przybyła ◽  
Monika Sakowicz-Burkiewicz ◽  
Tadeusz Pawełczyk
Keyword(s):  
Immune Response ◽  
Immune System ◽  
B Cells ◽  
B Lymphocytes ◽  
Atp Release ◽  
Primary Immune Response ◽  
Purinergic Signalling ◽  
Humoral Immune ◽  
Human B Cells ◽  
Subsequent Degradation

Adenosine and adenosine triphosphate are involved in purinergic signalling which plays important role in control of immune system. Much data have been obtained regarding impact of purinergic signalling on dendritic cells, macrophages, monocytes and T lymphocytes, however less attention has been paid to purinergic regulation of B cells. This review summarizes present knowledge about ATP- and Ado-dependant signalling in B lymphocytes. Human B cells have been shown to express A2A­-R and A­3-R and each subtype of P2 receptors. Surface of B cells exhibits two antagonistic ectoenzymatic pathways, one relays on constitutive secretion and resynthesis of ATP while the second one depends on degradation of adenosine nucleotides to nucleosides and their subsequent degradation. Inactivated B cells remain under suppressive impact of autocrine and paracrine Ado however activated B lymphocytes increase ATP release and production. ATP protects B cells from suppressive impact of Ado and exerts pro-inflammatory impact on target tissues, it is also involved in IgM release. Ado synthesis however is related with optimal development, implantation and maintenance of plasmocyte population in bone marrow during primary immune response. Moreover Ado plays important role in immunoglobulin class switching which is a key mechanism of humoral immune response. Disruption of purinergic signalling is related with severe clinical implications. Impairment of Ado production in environment of B cells is one of the factors responsible for common variable immunodeficiency. List of evidence suggests also that dysfunction of immune system observed during diabetes may in part depend on disrupted ATP and Ado metabolism in B cells.

scholarly journals Tracing the development of single memory-lineage B cells in a highly defined immune response.

1996 ◽  
Vol 183 (5) ◽  
pp. 2053-2063 ◽  
Author(s):  
A H Liu ◽  
P K Jena ◽  
L J Wysocki
Keyword(s):  
Immune Response ◽  
B Cells ◽  
B Lymphocyte ◽  
Clonal Selection ◽  
Germinal Centers ◽  
Primary Immune Response ◽  
Taq Polymerase ◽  
Predominant Component ◽  
V Genes ◽  
V Gene

To study the development of B lymphocyte memory, we identified and isolated splenic B cells expressing a highly defined antibody variable region that constitutes a reproducible and predominant component of the memory antibody response to p-azophenylarsonate (Ars). Isolation was achieved during the primary immune response by surface staining and flow cytometry using a specific anti-idiotypic antibody called E4, which recognizes this canonical V region, encoded by one set of V gene segments. The isolated E4+ cells displayed all of the phenotypic characteristics of germinal center centrocytes, including a low level of surface Ig, a lack of surface IgD, a high level of receptor for peanut agglutinin, and expression of mutated antibody V genes. E4+ B cells were first detected in the spleen 7-8 d after primary immunization, reached peak numbers from days 10-13, and waned by day 16. Surprisingly, at their peak, E4+ cells comprised only 40,000 of all splenocytes, and half of these failed to bind Ars. Using this number, we estimate the total number of Ars-specific memory-lineage cells in the spleen to be no more than 50,000 (0.1%) at any one time, and presumably far fewer that are committed to the memory pool. Chromosomal copies of rearranged V genes from single E4+ cells were amplified by nested PCR, and the amplified products were sequenced directly without cloning, using standardized conditions that disclose virtually no Taq polymerase errors. V gene sequence analyses of E4+ cells isolated from single mice confirmed their canonical nature and revealed that they were derived from few precursors. In the average mouse, the E4+ pool was derived from fewer than five canonical precursors. Somatic mutations were found within the V genes of almost all cell isolates. At day 13, a significant fraction of E4+ cells had mutations known to increase antibody affinity for Ars, suggesting they were products of at least one cycle of post-mutational antigen-driven selection. However, the lack of shared mutations by clonally related cells indicated that the selective expansion of mutant subclones typical of memory responses had not yet taken place. This was supported by the observation that half of the E4+ cells failed to bind Ars. Collectively, our results indicate that the memory compartment is a highly selected entity, even at relatively early stages of the primary immune response when somatic mutation and clonal selection are still in progress. If germinal centers are the source of memory B cells, our data suggest that B cell memory may be derived from only a small fraction of all germinal centers.

scholarly journals Antigen-initiated B-lymphocyte differentiation. VIII. Sedimentation velocity and buoyant density characterization of virgin antibody-forming cell progenitors in the adoptive immune response of unprimed CBA mice to 4-hydroxy-3-iodo-5-nitrophenylacetic acid-polymerized bacterial flagellin antigen.

1976 ◽  
Vol 143 (5) ◽  
pp. 1220-1238 ◽  
Author(s):  
J M Fidler ◽  
M C Howard ◽  
K Shortman
Keyword(s):  
B Cells ◽  
Physical Properties ◽  
B Cell ◽  
B Lymphocytes ◽  
Buoyant Density ◽  
Specific Antigen ◽  
Significant Proportion ◽  
Sedimentation Velocity ◽  
Cba Mice

The characteristics of antibody-forming cell (AFC) progenitors lacking previous contact with specific antigen (virgin AFC progenitors) has been studied using sedimentation velocity and buoyant density separation for the investigation of physically distinct B-cell subpopulations. Functional characterization of isolated subsets was made using a quantitative adoptive immune assay for the IgM AFC progenitors responding to the antigen 4-hydroxy-3-iodo-5-nitrophenylacetic acid conjugated polymerized bacterial flagellin. Extensive heterogeneity is present among B lymphocytes, only some subpopulations of which exhibit AFC progenitor function. In the spleen of adult conventional CBA mice, atypically fast sedimenting cells of low buoyant density are active, while typical small B lymphocytes do not appear to be progenitors of IgM AFC. Spleen of adult specific pathogen-free (SPF), germfree, and athymic nude mice give similar results, although a minor population of typical slowly sedimenting dense cells are active in the latter two sources. Adult conventional bone marrow cells are as physically and functionally heterogeneous as splenic B cells, and although a significant proportion of AFC progenitor activity is found among dense, slowly sedimenting cells, most of the activity is among low density, faster sedimenting cells. In contrast to this situation in adult animals, where most of the unprimed AFC progenitors are large, atypical B cells, the spleens of neonatal mice provide a site where virgin AFC progenitors with the physical properties of typical small B lymphocytes are found. While being present in conventional and SPF neonatal spleens, these virgin cells are predominant in 7-day-old germfree mouse spleen. These findings suggest that the newborn virgin B cell is a typical small lymphocyte. However, few cells of this type are found in the adult animal. The unprimed AFC-progenitor population in the adult consists of large, fast sedimenting, low buoyant density, adherent cells, the physical properties of which are characteristic of activated B lymphocytes. It is suggested that these atypical cells are derived from the small newborn virgin B cell by the nonspecific effects of environmental antigenic stimuli.

scholarly journals The VP6 Protein of Rotavirus Interacts with a Large Fraction of Human Naive B Cells via Surface Immunoglobulins

2004 ◽  
Vol 78 (22) ◽  
pp. 12489-12496 ◽  
Author(s):  
Nathalie Parez ◽  
Antoine Garbarg-Chenon ◽  
Cynthia Fourgeux ◽  
Françoise Le Deist ◽  
Annabelle Servant-Delmas ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cells ◽  
B Lymphocytes ◽  
B Lymphocyte ◽  
Large Fraction ◽  
Memory Cell ◽  
Viral Gastroenteritis ◽  
Human B Cells ◽  
Surface Immunoglobulins ◽  
The Individual

ABSTRACT Immunity to human group A rotavirus (RV), a major cause of viral gastroenteritis in infants, involves B lymphocytes that provide RV-specific antibodies. Additionally, some arguments suggest that naive B cells could be implicated in the first steps of the immune response against RV. The aim of our study was to analyze the interaction of VP6 and VP7 RV capsid proteins with human B cells depending on the immune status of the individual, i.e., naive or RV experienced. For this purpose, a two-color virus-like particle flow cytometry assay was devised to evaluate the blood B-lymphocyte reactivity to VP6 and VP7 proteins from healthy RV-exposed adults, recently infected infants, and neonates at birth. Both VP6 and VP7 interactions with B cells were mediated by surface immunoglobulins and probably by their Fab portions. VP7-reactive B lymphocytes were mainly detected from RV-experienced patients and almost exclusively in the CD27-positive memory cell fraction. Conversely, VP6-reactive B lymphocytes were detected at similar and high frequencies in adult, infant, and neonate samples. In adult samples, VP6 reacted with about 2% of the CD27-negative (CD27neg) naive B cells. These results demonstrated that the VP6 RV protein interacted with a large fraction of naive B lymphocytes from both adults and neonates. We propose that naive B cell-VP6 interaction might influence the strength and quality of the acquired immune response and should be considered for elaborating RV vaccine strategies.

scholarly journals The bcl-2 gene product inhibits clonal deletion of self-reactive B lymphocytes in the periphery but not in the bone marrow.

1993 ◽  
Vol 178 (4) ◽  
pp. 1247-1254 ◽  
Author(s):  
S Nisitani ◽  
T Tsubata ◽  
M Murakami ◽  
M Okamoto ◽  
T Honjo
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
Transgenic Mice ◽  
Gene Product ◽  
B Lymphocytes ◽  
Immunoglobulin Genes ◽  
Clonal Deletion ◽  
Immature B Cells ◽  
B1 Cells ◽  
Self Antigen

To test whether the product of the bcl-2 proto-oncogene blocks clonal deletion of self-reactive B cells, we have generated transgenic mice carrying the bcl-2 gene and the immunoglobulin genes for the anti-erythrocyte 4C8 antibody. In these transgenic mice, clonal deletion of self-reactive immature B cells in the bone marrow was not inhibited in spite of expression of the bcl-2 gene. In contrast, self-antigen-induced clonal deletion of mature self-reactive Ly-1 B (B1) cells in the peritoneal cavity was inhibited in the transgenic mice. These results indicate that the mechanism for clonal deletion of immature self-reactive B cells in the bone marrow differs from that of mature self-reactive B cells in the periphery.

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 Production of antibodies in egg whites of chickens

2021 ◽  
Author(s):  
Angel Justiz Vaillant ◽  
Belkis Ferrer-Cosme
Keyword(s):  
Immune Response ◽  
Affinity Chromatography ◽  
Bacterial Growth ◽  
Statistical Significance ◽  
Protein A ◽  
Egg White ◽  
Primary Immune Response ◽  
Enzyme Linked Immunosorbent Assay

AbstractBackgroundIgM, which participates in the primary immune response, is the primary antibody in egg whites. There is scant information about the production of antibodies in egg whites. This study describes the preparation of antibodies against bacterial antigens.MethodsEnzyme-linked immunosorbent assay (ELISA) was used to detect the presence of anti-egg white antibodies. The antibodies were purified using affinity chromatography. Statistical analyses were performed using SPSS version 22. Statistical significance was set at P<0.05.ResultsLarge amounts of anti-protein A antibodies were produced in chicken egg whites. The generation of anti-SpA antibodies was demonstrated by affinity chromatography from 9 d post-immunization egg white samples. Inhibition of agglutination was observed in samples containing anti-SpA antibodies, and agglutination at the bottom of the wells was observed in the negative samples.ConclusionAnti-protein A antibodies (IgM) were produced in the egg whites of the immunized hens. Bacterial growth in blood agar plates was observed only in specimens plated with egg whites from pre-immunized birds. Protein A-affinity chromatography was helpful for the characterization of anti-protein A antibodies. Inhibition of these antibodies was observed in vitro.

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