scholarly journals The analysis of the monoclonal immune response to influenza virus. II. The antigenicity of the viral hemagglutinin.

1976 ◽  
Vol 144 (4) ◽  
pp. 985-995 ◽  
Author(s):  
W Gerhard

The antigenicity of the hemagglutinins (HA) of five influenza viruses of the A0 and A1 subtypes has been analyzed by means of monoclonal antibodies of murine origin produced in vitro. Secondary monoclonal anti-HA(PR8) antibodies were able to differentiate 14 antigenic determinants (or groups of determinants) on the HA of five influenza virus strains of the A0 and A1 subtypes. Taking into account that certain pairs of determinants delineated on heterologous HA may reflect the heterogeneity of the humoral immune response to a single homologous determinant, the presence of at least eight determinants (host cell-derived determinants not included) on the homologous HA of PR8 and probably on the HA of influenza viruses in general is postulated. Three types of HA-determinants of A0 and A1 influenza virus strains could be distinguished: strain-specific, partially shared, and determinant(s) common to all five virus strains tested. Roughly 40, 55, and 5%, respectively, of the secondary anti-PR8 antibodies of BALB/c mice were directed against determinants belonging to either of the three types.

2019 ◽  
Vol 64 (3) ◽  
pp. 125-131 ◽  
Author(s):  
I. T. Fediakina ◽  
M. V. Konopleva ◽  
E. S. Proshina ◽  
E. V. Linnik ◽  
N. I. Nikitina

Introduction. Active circulation of pandemic influenza and new variants of influenza H3N2 strains requires monitoring of antiviral efficacy of drugs permitted for influenza therapy in the Russian Federation. Purpose. Assessment of antiviral efficacy of «Kagocel» substance against influenza viruses H1N1, H1N1pdm09 and H3N2 in vitro. Material and methods. Cytotoxic effect of «Kagocel» substance on MDCK cells had been determined by stained with MTS. Antiviral efficacy of «Kagocel» substance against influenza infection has been studied in vitro in the culture of MDCK cells infected with influenza virus strains: A/Puerto Rico/8/34 (H1N1), А/California/7/2009 (H1N1)pdm09, А/Hong Kong/1/68 (H3N2) and А/Hong Kong/4801/2014 (H3N2). The antiviral activity of «Kagocel» substance was tested by its effect on the infectious titer of the influenza viruses and on its impact on the expression level of viral antigens in the enzyme immunoassay test system. Results. «Kagocel» substance had low toxicity for MDCK cells. «Kagocel» inhibited the infection titer of influenza virus strains A/Puerto Rico/8/34 (H1N1), А/California/7/2009 (H1N1)pdm09, А/Hong Kong/1/68 (H3N2) and А/ Hong Kong /4801/2014 (H3N2) in the MDCK cell culture with equal efficacy. Study of the impact of «Kagocel» substance on the expression level of viral antigens by ELISA also revealed its antiviral efficacy for all tested strains. Dose dependence was observed from concentration of substance and from infective dose of virus. Discussion. Effective suppression of the reproduction of influenza virus strains A(H1N1), A(Н1N1)pdm09 and A(H3N2) in the different sublines of MDCK cells with «Kagocel» was shown by the different methods. These results give the possibility to suggest that along with the ability to induce interferons, «Kagocel» can impact on the reproduction of influenza virus, but the further research is needed. Conclusion. «Kagocel» substance effectively inhibits the reproduction of influenza virus strains A(H1N1), A(Н1N1)pdm09 and A(H3N2) in vitro. At the same time, the selectivity index is quite high.


2021 ◽  
Author(s):  
Jenna J. Guthmiller ◽  
Henry A. Utset ◽  
Carole Henry ◽  
Lei Li ◽  
Nai-Ying Zheng ◽  
...  

Influenza viruses grown in eggs for the purposes of vaccine generation often acquire mutations during egg adaptation or possess differential glycosylation patterns than viruses circulating amongst humans. Here, we report that seasonal influenza virus vaccines possess an egg-derived sulfated N-acetyllactosamine (LacNAc) that is an antigenic decoy. Half of subjects that received an egg-grown vaccine mounted an antibody response against this egg-derived antigen. Egg-binding monoclonal antibodies specifically bind viruses grown in eggs, but not viruses grown in other chicken derived cells, suggesting only egg-grown vaccines can induce anti-LacNAc antibodies. Notably, antibodies against the sulfated LacNAc utilized a restricted antibody repertoire and possessed features of natural antibodies, as most antibodies were IgM and have simple heavy chain complementarity determining region 3. By analyzing a public dataset of influenza virus vaccine induced plasmablasts, we discovered egg-binding public clonotypes that were shared across studies. Together, this study shows that egg-grown vaccines can induce antibodies against an egg-associated glycan, which may divert the host immune response away from protective epitopes.


1987 ◽  
Vol 165 (2) ◽  
pp. 359-367 ◽  
Author(s):  
F W Klotz ◽  
D E Hudson ◽  
H G Coon ◽  
L H Miller

Immunity to 143/140 kD schizont antigens of a monkey malaria, Plasmodium knowlesi, provides partial protection to lethal malaria infection in rhesus monkeys challenged with uncloned parasites. To determine the capacity of a cloned parasite to generate variants of the 143/140 kD antigens, immunized monkeys were challenged with a clone of P. knowlesi. Parasites recovered 8 d after inoculation with a cloned parasite retained the 143/140 kD antigens. Parasites recovered 30 d after challenge had undergone changes in the 143/140 kD antigens. Antibodies that block erythrocyte invasion in vitro of the inoculum parasites did not inhibit invasion of erythrocytes by two isolates recovered from the immunized monkeys. An isolate from one monkey recovered on day 30 contained clones expressing new 76/72 kD antigens reactive with rabbit antiserum against the 143/140 kD proteins, and other clones expressing no antigens crossreactive with antisera against the 143/140 kD proteins. An isolate from another monkey obtained 59 d after challenge expressed new antigens of 160/155, 115/113, and 87/85 kD. Using monoclonal antibodies, we found that epitopes were lost from the variant proteins, but we were unable to determine whether new epitopes had appeared. We conclude that clones of P. knowlesi can rapidly vary antigenic determinants on the 143/140 kD proteins in animals immunized with these antigens.


1982 ◽  
Vol 28 (7) ◽  
pp. 809-814 ◽  
Author(s):  
P. Diaz-Rodriguez ◽  
A. Boudreault

As reported previously, attenuated stable inhibitor-resistant influenza viruses can be screened by a 50% ciliary activity inhibition test in ferret tracheal organ cultures. This test was further applied to 5 attenuated cold-adapted influenza strains and to 11 strains with known a percentage of RNA–RNA hybridization with the parental A/PR/8/34 (H0N1) virus strain. Again, with one exception, attenuated strains could be clearly differentiated from virulent ones. It was concluded that virulence of influenza strains for man can be detected using this test regardless of the techniques used to prepare attenuated variants. A preliminary screening of attenuated candidates for live influenza vaccines can be achieved with confidence on ferret tracheal organ cultures.


Blood ◽  
1985 ◽  
Vol 66 (4) ◽  
pp. 824-829
Author(s):  
BS Wilson ◽  
JL Platt ◽  
NE Kay

Several mouse monoclonal IgG antibodies (AB1, AB2, AB3, and AB5) were developed that reacted with a 140,000 mol wt glycoprotein on the surface of cultured RAJI B lymphoid cells. The antibodies reacted with purified normal human peripheral blood B cells and CLL Ig+ B cells and showed specific germinal center and mantle zone staining in tissue sections of secondary lymphoid organs. Immunodepletion studies using 125I surface-labeled Raji cell membrane antigens demonstrated that the antigen identified by AB5 is the same 140,000 mol wt glycoprotein detected by anti-B2 that has recently been shown to react with the C3d fragment or CR2 receptor. (Iida et al: J Exp Med 158:1021, 1983). Addition of the AB series and anti-B2 monoclonal antibodies to cultures of purified human peripheral blood B cells resulted in the uptake of 3H- thymidine at two to six times background control levels provided that irradiated autologous T cells were added to the culture. Stimulation was not evoked by other monoclonal antibodies to B cell surface molecules (ie, B1, BA-1, BA-2, and HLA-DR). Pepsin-generated F(ab')2 fragments of anti-CR2 antibodies were essentially as effective as the intact IgG molecule in stimulating B cells. Induction of B cell proliferation by antibody binding to CR2 suggests that the C3d receptor may have an integral role in regulation of humoral immune response.


Blood ◽  
1984 ◽  
Vol 63 (6) ◽  
pp. 1376-1384 ◽  
Author(s):  
T Yokochi ◽  
M Brice ◽  
PS Rabinovitch ◽  
T Papayannopoulou ◽  
G Stamatoyannopoulos

Two new cell surface antigens specific for the erythroid lineage were defined with cytotoxic IgM monoclonal antibodies (McAb) (EP-1; EP-2) that were produced using BFU-E-derived colonies as immunogens. These two antigens are expressed on in vivo and in vitro derived adult and fetal erythroblasts, but not on erythrocytes. They are not detectable on resting lymphocytes, concanavalin-A (Con-A) activated lymphoblasts, granulocytes, and monocytes or granulocytic cells or macrophages present in peripheral blood or harvested from CFU-GM cultures. Cell line and tissue distributions distinguish McAb EP-1 and EP-2 from all previously described monoclonal antibodies. McAb EP-1 (for erythropoietic antigen-1) inhibits the formation of BFU-E and CFU-E, but not CFU-GM, colonies in complement-dependent cytotoxicity assays. By cell sorting analysis, about 90% of erythroid progenitors (CFU-E, BFU-E) were recovered in the antigen-positive fraction. Seven percent of the cells in this fraction were progenitors (versus 0.1% in the negative fraction). The expression of EP-1 antigen is greatly enhanced in K562 cells, using inducers of hemoglobin synthesis. McAb EP-2 fails to inhibit BFU-E and CFU-E colony formation in complement-dependent cytotoxicity assays. EP-2 antigen is predominantly expressed on in vitro derived immature erythroblasts, and it is weakly expressed on mature erythroblasts. The findings with McAb EP-1 provide evidence that erythroid progenitors (BFU-E and CFU-E) express determinants that fail to be expressed on other progenitor cells and hence appear to be unique to the erythroid lineage. McAb EP-1 and EP-2 are potentially useful for studies of erythroid differentiation and progenitor cell isolation.


2020 ◽  
Author(s):  
Sophia Michelchen ◽  
Burkhard Micheel ◽  
Katja Hanack

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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chengchao Ding ◽  
Jun He ◽  
Xiangyu Zhang ◽  
Chengcheng Jiang ◽  
Yong Sun ◽  
...  

Small number of SARS-CoV-2 epidemic lineages did not efficiently exhibit a neutralization profile, while single amino acid mutation in the spike protein has not been confirmed in altering viral antigenicity resulting in immune escape. To identify crucial mutations in spike protein that escape humoral immune response, we evaluated the cross-neutralization of convalescent plasmas and RBD-specific monoclonal antibodies (mAbs) against various spike protein-based pseudoviruses. Three of 24 SARS-CoV-2 pseudoviruses containing different mutations in spike protein, including D614G, A475V, and E484Q, consistently showed an altered sensitivity to neutralization by convalescent plasmas. A475V and E484Q mutants are highly resistant to neutralization by mAb B38 and 2-4, suggesting that some crucial mutations in spike protein might evolve SARS-CoV-2 variants capable of escaping humoral immune response.


2000 ◽  
Vol 192 (7) ◽  
pp. 953-964 ◽  
Author(s):  
Richard K.G. Do ◽  
Eunice Hatada ◽  
Hayyoung Lee ◽  
Michelle R. Tourigny ◽  
David Hilbert ◽  
...  

B lymphocyte stimulator (BLyS) is a newly identified monocyte-specific TNF family cytokine. It has been implicated in the development of autoimmunity, and functions as a potent costimulator with antiimmunoglobulin M in B cell proliferation in vitro. Here we demonstrate that BLyS prominently enhances the humoral responses to both T cell–independent and T cell–dependent antigens, primarily by attenuation of apoptosis as evidenced by the prolonged survival of antigen-activated B cells in vivo and in vitro. BLyS acts on primary splenic B cells autonomously, and directly cooperates with CD40 ligand (CD40L) in B cell activation in vitro by protecting replicating B cells from apoptosis. Moreover, although BLyS alone cannot activate the cell cycle, it is sufficient to prolong the survival of naive resting B cells in vitro. Attenuation of apoptosis by BLyS correlates with changes in the ratios between Bcl-2 family proteins in favor of cell survival, predominantly by reducing the proapoptotic Bak and increasing its prosurvival partners, Bcl-2 and Bcl-xL. In either resting or CD40L-activated B cells, the NF-κB transcription factors RelB and p50 are specifically activated, suggesting that they may mediate BLyS signals for B cell survival. Together, these results provide direct evidence for BLyS enhancement of both T cell–independent and T cell–dependent humoral immune responses, and imply a role for BLyS in the conservation of the B cell repertoire. The ability of BLyS to increase B cell survival indiscriminately, at either a resting or activated state, and to cooperate with CD40L, further suggests that attenuation of apoptosis underlies BLyS enhancement of polyclonal autoimmunity as well as the physiologic humoral immune response.


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