scholarly journals Immune complexes can trigger specific, T cell-dependent, autoanti-IgG antibody production in mice.

1985 ◽  
Vol 161 (1) ◽  
pp. 242-256 ◽  
Author(s):  
D A Nemazee
Keyword(s):  
Rheumatoid Factor ◽  
Antibody Production ◽  
Immune Complexes ◽  
B Lymphocyte ◽  
Active Form ◽  
Igg Antibody ◽  
Factor Production ◽  
Igg Isotypes ◽  
Igg2a Response

Immunization of mice with a combination of passively administered syngeneic IgG (anti-p-azophenylarsonate [anti-Ars]) antibody and a soluble, multivalent form of the antibody's corresponding antigen (Limulus polyphemus hemocyanin conjugated with Ars [Lph-Ars]) resulted in specific autoanti-IgG Fc (rheumatoid factor) production. The response was rapid and only anti-IgG of the IgM isotype is found. Because immunization with either the IgG antibody or the antigen alone did not result in rheumatoid antibody production, immune complexes appear to be the active form of the immunogens. Antibody/antigen ratios that resulted in maximal anti-IgG antibody responses were the same as those required for peak in vitro immunoprecipitation, i.e., equivalence. Previous exposure of the mice to the exogenously supplied antigen was not required for the response. The response to immune complexes is specific because mice immunized with IgG2a-containing complexes produced autoanti-IgG2a, while mice immunized with IgG1-containing complexes produced anti-IgG1 with little reactivity to other IgG isotypes. IgG2a blocked in its complement-fixing capacity was more effective in eliciting the anti-IgG2a response than native IgG2a, suggesting a possible role for the complement system in modulating the anti-IgG2a response. Induction of rheumatoid factor production by immune complexes could be induced in xid mice but not in nu/nu mice, indicating T lymphocyte dependence of the response. In contrast, the B lymphocyte activator lipopolysaccharide was able to elicit vigorous rheumatoid factor production in both nu/nu and normal mice, demonstrating that nu/nu mice contain B cells capable of making the response. Rheumatoid antibody produced in the immune complex- or LPS-induced responses is Fc specific and has relatively low affinity for IgG that is not bound to antigen.

scholarly journals In vitro immunization approach to generate specific murine monoclonal IgG antibodies

2020 ◽  
Author(s):  
Sophia Michelchen ◽  
Burkhard Micheel ◽  
Katja Hanack
Keyword(s):  
Monoclonal Antibodies ◽  
Legionella Pneumophila ◽  
B Lymphocyte ◽  
Laboratory Animals ◽  
Igg Antibody ◽  
Simplified Approach ◽  
Humoral Immune ◽  
Viral Coat

AbstractGenerating monoclonal antibodies to date is a time intense process requiring immunization of laboratory animals. The transfer of the humoral immune response into in vitro settings shortens this process and circumvents the necessity of animal immunization. However, orchestrating the complex interplay of immune cells in vitro is very challenging. We aimed for a simplified approach focusing on the protagonist of antibody production: the B lymphocyte. We activated purified murine B lymphocytes in vitro with combinations of antigen and stimuli. Within ten days of culture we induced specific IgM and IgG antibody responses against a viral coat protein. Permanently antibody-producing hybridomas were generated. Furthermore we used this method to induce a specific antibody response against Legionella pneumophila. We thus established an effective protocol to generate monoclonal antibodies in vitro. By overcoming the necessity of in vivo immunization it may be the first step towards a universal strategy to generate antibodies from various species.

scholarly journals Potentiating Antigen-Specific Antibody Production with Peptides Obtained from In Silico Screening for High-Affinity against MHC-II

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2949
Author(s):  
Yoshiro Hanyu ◽  
Yuto Komeiji ◽  
Mieko Kato
Keyword(s):  
Monoclonal Antibodies ◽  
Binding Affinity ◽  
Antibody Production ◽  
Specific Antibody ◽  
In Silico ◽  
Igg Antibody ◽  
Mhc Ii ◽  
High Affinity ◽  
Specific Antibody Production

Monoclonal antibodies with high affinity and specificity are essential for research and clinical purposes, yet remain difficult to produce. Agretope peptides that can potentiate antigen-specific antibody production have been reported recently. Here, we screened in silico for peptides with higher affinity against the agretope binding pocket in the MHC-II. The screening was based on the 3D crystal structure of a complex between MHC-II and a 14-mer peptide consisting of ovalbumin residues 323–339. Using this 14-mer peptide as template, we constructed a library of candidate peptides and screened for those that bound tightly to MHC-II. Peptide sequences that exhibited a higher binding affinity than the original ovalbumin peptide were identified. The peptide with the highest binding affinity was synthesized and its ability to boost antigen-specific antibody production in vivo and in vitro was assessed. In both cases, antigen-specific IgG antibody production was potentiated. Monoclonal antibodies were established by in vitro immunization using this peptide as immunostimulant, confirming the usefulness of such screened peptides for monoclonal antibody production.

scholarly journals Evaluation of Red and Green Colored Bell peppers for the Production of Polyclonal IgM and IgG Antibodies in Murine Spleen Cells

2021 ◽  
Vol 24 (1) ◽  
pp. 45-53
Author(s):  
Md Moklesur Rahman Sarker
Keyword(s):  
B Cells ◽  
Antibody Production ◽  
Bacterial Infections ◽  
Pharmaceutical Journal ◽  
Bell Pepper ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Green Pepper ◽  
Bell Peppers

Immunostimulants are greatly required for the upregulation of immunity to fight against viral and bacterial infections and cancers. Bell peppers (Capsicum annuum L.), eaten as vegetables, are rich sources of vitamin C and E, provitamin A, β-carotene, and numerous phenolic compounds. Antimicrobial, antioxidant, anti-mutagenic and anti-inflammatory properties of Bell peppers were reported. Our research group for the first time reported the immunomodulatory activities of Bell peppers. In this study, we evaluated the antibody production abilities of two different colored Bell peppers (red and green) in the culture of antibody producing splenic B cells of mice. Antibodies and the number of viable cells were determined by an ELISA and MTT assays, respectively. Red Bell pepper Extract (RBPE) at the doses of (0.375, 0.75, 1.5, and 2.25 mg/mL) significantly augmented the production of polyclonal IgM and IgG antibodies in-vitro. The highest amount of IgM antibody production was observed by the dose of 1.5 mg/kg which was 3 times higher than that of the untreated cells. Similarly, RBPE also enhanced the production of IgG antibody in the culture of murine splenic B cells. On the contrary, cultural treatment of murine splenic B cells with Green Bell pepper Extract (GBPE) could not stimulate the B cells, and hence, failed to produce neither IgM nor IgG antibody. Thus the current findings suggest that consumption of Red Bell Pepper extract or its vegetables, not green pepper, may be beneficial to strengthen humoral immune responses. Bangladesh Pharmaceutical Journal 24(1): 45-53, 2021

IgM rheumatoid factor amplifies the inflammatory response of macrophages induced by the rheumatoid arthritis-specific immune complexes containing anticitrullinated protein antibodies

2014 ◽  
Vol 74 (7) ◽  
pp. 1425-1431 ◽  
Author(s):  
Lætitia Laurent ◽  
Florence Anquetil ◽  
Cyril Clavel ◽  
Ndiémé Ndongo-Thiam ◽  
Géraldine Offer ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Rheumatoid Factor ◽  
Immune Complexes ◽  
Cytokine Response ◽  
Igm Rheumatoid Factor ◽  
Tnf Α ◽  
Vitro Model ◽  
Synovial Membranes ◽  
Anticitrullinated Protein Antibodies

ObjectivesAnticitrullinated protein antibodies (ACPA) are specifically associated with rheumatoid arthritis (RA) and produced in inflamed synovial membranes where citrullinated fibrin, their antigenic target, is abundant. We showed that immune complexes containing IgG ACPA (ACPA-IC) induce FcγR-mediated tumour necrosis factor (TNF)-α secretion in macrophages. Since IgM rheumatoid factor (RF), an autoantibody directed to the Fc fragment of IgG, is also produced and concentrated in the rheumatoid synovial tissue, we evaluated its influence on macrophage stimulation by ACPA-IC.MethodsWith monocyte-derived macrophages from more than 40 healthy individuals and different human IgM cryoglobulins with RF activity, using a previously developed human in vitro model, we evaluated the effect of the incorporation of IgM RF into ACPA-IC.ResultsIgM RF induced an important amplification of the TNF-α secretion. This effect was not observed in monocytes and depended on an increase in the number of IgG-engaged FcγR. It extended to the secretion of interleukin (IL)-1β and IL-6, was paralleled by IL-8 secretion and was not associated with overwhelming secretion of IL-10 or IL-1Ra. Moreover, the RF-induced increased proinflammatory bioactivity of the cytokine response to ACPA-IC was confirmed by an enhanced, not entirely TNF-dependent, capacity of the secreted cytokine cocktail to prompt IL-6 secretion by RA synoviocytes.ConclusionsBy showing that it can greatly enhance the proinflammatory cytokine response induced in macrophages by the RA-specific ACPA-IC, these results highlight a previously undescribed, FcγR-dependent strong proinflammatory potential of IgM RF. They clarify the pathophysiological link between the presence of ACPA and IgM RF, and RA severity.

scholarly journals Cytokine profile of macrophages in vitro stimulated by ACPA immune complexes in the presence or absence of IgM rheumatoid factor

2011 ◽  
Vol 70 (Suppl 2) ◽  
pp. A38-A38
Author(s):  
L. Laurent ◽  
C. Clavel ◽  
F. Anquetil ◽  
J.-L. Pasquali ◽  
M. Sebbag ◽  
...  
Keyword(s):  
Rheumatoid Factor ◽  
Immune Complexes ◽  
Cytokine Profile ◽  
Igm Rheumatoid Factor

Studies on the relationship between HLA DR4 and in vitro IgM rheumatoid factor production

1983 ◽  
Vol 27 (1) ◽  
pp. 96-109 ◽  
Author(s):  
Martin A. Rodriguez ◽  
Arthur D. Bankhurst ◽  
Ralph C. Williams ◽  
Gary M. Troup ◽  
Peter Stastny
Keyword(s):  
Rheumatoid Factor ◽  
Igm Rheumatoid Factor ◽  
Factor Production ◽  
The Relationship

scholarly journals PHAGOCYTOSIS OF IMMUNE COMPLEXES BY MACROPHAGES

1972 ◽  
Vol 135 (4) ◽  
pp. 780-792 ◽  
Author(s):  
B. Mantovani ◽  
M. Rabinovitch ◽  
V. Nussenzweig
Keyword(s):  
Immune Complexes ◽  
Rabbit Antiserum ◽  
Immune Serum ◽  
Mononuclear Phagocytes ◽  
Secondary Response ◽  
Primary Immune Response ◽  
Igg Antibody ◽  
Osmotic Lysis

Sheep red cells (E) sensitized with IgG antibody (EA) or with antibody and complement (EAC) interact in vitro with mouse peritoneal macrophage monolayers. The role of IgG and of C3 in the attachment and ingestion of the erythrocytes was examined by means of quantitative technique utilizing 51Cr-labeled E. Controlled osmotic lysis permitted the separate measurement of the radioactivity associated with bound or with ingested E. IgG-125I was used to estimate the number of IgG molecules bound per E as a function of the IgG concentration. Control experiments showed that iodination did not influence the extent of binding of IgG to E and that the binding of IgG prepared from immune serum could be essentially ascribed to its anti-E antibody content. Only between 103 and 104 rabbit anti-E IgG molecules per erythrocyte were needed for detectable attachment and ingestion of EA (a maximum number of 6 x 105 IgG antibody molecules could be accomodated on one erythrocyte). Evidence was obtained that C3 is primarily involved in particle attachment, whereas only IgG is able to markedly promote the ingestion of particles attached to macrophages: (a) Addition of complement to the EA substantially increased the binding to the macrophages, whereas ingestion was increased to a smaller extent. Both binding and ingestion of EAC were markedly inhibited by papain fragments of IgG obtained from a rabbit antiserum to mouse C3. (b) Low doses (2 µg/ml) of papain fragments of IgG from a rabbit antiserum to mouse IgG markedly reduced the ingestion of EAC, whereas attachment of EAC to macrophages was inhibited to a much smaller degree. The possible relevance of these findings for the in vivo fate of particulate immune complexes as they interact with macrophages is discussed. It is suggested that in the primary immune response, when the complexes are predominantly in the form of EA (IgM) or EA (IgM) C3, they would tend to remain on the surface of the macrophages and thus be in a position to stimulate immunocompetent cells. In the secondary response, when EA (IgG) or EA (IgG) C3 predominate, the complexes would tend to be more rapidly interiorized and degraded by the mononuclear phagocytes,

scholarly journals A mechanism for the induction of immunological tolerance by antigen feeding: antigen-antibody complexes.

1975 ◽  
Vol 142 (6) ◽  
pp. 1509-1519 ◽  
Author(s):  
C André ◽  
J F Heremans ◽  
J P Vaerman ◽  
C L Cambiaso
Keyword(s):  
Rheumatoid Factor ◽  
Immune Complexes ◽  
Immunological Tolerance ◽  
Antibody Activity ◽  
Previous Contact ◽  
Primary Type ◽  
A Site ◽  
Antigen Antibody

We have previously reported on the induction, in mice, of a systemic (splenic) immune response with IgA as the dominant antibody, as a result of a short (4 day) intragastric immunization course with foreign erythrocytes. This response was followed by a prolonged period of hyporesponsiveness to similarly administered antigen. Here it is shown that this hyporesponsiveness is also manifested towards antigen given intraperitoneally, and that one is therefore dealing with tolerance, not with failure to absorb antigen from the gut. In contrast, mice primed parenterally and then challenged intragastrically behaved as if never having any previous contact with the antigen, i.e., with a primary-type splenic response of predominant IgA character. This agrees with our former conclusion that splenic responses to enterically absorbed antigen reflect colonization of the spleen by cells sensitized locally in the gut wall, a site not readily primed by the parenteral route. Serum from intragastrically immunized mice contained a very active tolerogen. In vivo, it was capable of conferring tolerance to nonimmune recipient mice. In vitro, it paralyzed the activity of antibody-producing cells. Inhibitory sera has weak antibody activity, restricted to the IgA class, and contained immune complexes reacting with rheumatoid factor but not with C1q. Elimination of these complexes by means by insolubilized rheumatoid factor abolished the tolerogenic effect. In conclusion, the enterically induced tolerogen seems to consist of immune complexes with IgA as the antibody.

In vitro IgM and IgM rheumatoid factor production and response to remittive agents in rheumatoid arthritis

1985 ◽  
Vol 28 (3) ◽  
pp. 356-357 ◽  
Author(s):  
Graciela S. Alarcón ◽  
William J. Koopman ◽  
Ralph E. Schrohenloher
Keyword(s):  
Rheumatoid Arthritis ◽  
Rheumatoid Factor ◽  
Igm Rheumatoid Factor ◽  
Factor Production
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