Immunofluorescence test with antigen-loaded erythrocytes: Detection of influenza virus specific IgG, IgA, and IgM antibodies

While SARS-CoV-2 specific neutralizing antibodies have been developed for therapeutic purposes, the specific viral triggers that drive the generation of SARS-CoV-2 specific IgG and IgM antibodies remain only partially characterized. Moreover, it is unknown whether endogenously derived antibodies drive viral clearance that might result in mitigation of clinical severity during natural infection. We developed a series of non-linear mathematical models to investigate whether SARS-CoV-2 viral and antibody kinetics are coupled or governed by separate processes. Patients with severe disease had a higher production rate of IgG but not IgM antibodies. Maximal levels of both isotypes were governed by their production rate rather than different saturation levels between people. Our results suggest that an exponential surge in IgG levels occurs approximately 5–10 days after symptom onset with no requirement for continual antigenic stimulation. SARS-CoV-2 specific IgG antibodies appear to have limited to no effect on viral dynamics but may enhance viral clearance late during primary infection resulting from the binding effect of antibody to virus, rather than neutralization. In conclusion, SARS-CoV-2 specific IgG antibodies may play only a limited role in clearing infection from the nasal passages despite providing long-term immunity against infection following vaccination or prior infection.

Download Full-text

Lectins for the detection of IgM antibodies to T. gondii in the diagnosis of acute toxoplasmosis by immunofluorescence test

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46651987000600004 ◽

1987 ◽

Vol 29 (6) ◽

pp. 354-360

Author(s):

I. T. I. Nojimoto ◽

S. Hoshino-Shimizu ◽

T. K. Nagasse-Sugahara ◽

M. E. Camargo

Keyword(s):

Relative Efficiency ◽

Healthy Subjects ◽

Lens Culinaris ◽

Test Results ◽

Immunofluorescence Test ◽

Igm Antibodies ◽

Acute Toxoplasmosis

Lectins were labeled with fluorescein and tried as conjugates in the immunofluorescence (IP) test for the detection of IgM antibodies to T. gondii, in the diagnosis of acute toxoplasmosis. This approach was an attempt to find alternative reagents for anti-human IgM fluorescent conjugates (AHIgMFC), which contain quite frequently anaibcdies to toxoplasma, as contaminants, due to natural T. gondii infections among animals used for imunization. Lentil (Lens culinaris) lectin fluorescence conjugates (LcFC) provided most satisfactory results. The evaluation of LcFC carried out in a total of 179 sera from patients with acute and chronic toxoplasmosis, with non-related infections or healthy subjects, gave high values of relative efficiency, co-positivity and co-negativity indices, respectively 0.989, 0.969 and 1.000, in reference to the conventional AHIgMFC. Moreover, three batches of LcFC successively prepared gave reproducible test results. The advantage of LcFC as an alternative reagent for the serodiagnosis of acute toxoplasmosis is supported by practical aspects of its preparation.

Download Full-text

Better Response to Influenza Virus Vaccination in Physically Trained Older Adults Is Associated With Reductions of Cytomegalovirus-Specific Immunoglobulins as Well as Improvements in the Inflammatory and CD8+ T-Cell Profiles

Frontiers in Immunology ◽

10.3389/fimmu.2021.713763 ◽

2021 ◽

Vol 12 ◽

Author(s):

Eduardo S. Felismino ◽

Juliana M. B. Santos ◽

Marcelo Rossi ◽

Carlos A. F. Santos ◽

Edison L. Durigon ◽

...

Keyword(s):

Older Adults ◽

T Cells ◽

Influenza Virus ◽

Exercise Training ◽

Serum Levels ◽

Specific Antibody Response ◽

Post Vaccination ◽

Specific Immunoglobulin ◽

Specific Igg ◽

Regular Practice

Chronic cytomegalovirus (CMV) infection is a trigger factor for the development of immunosenescence and negatively impacts the immune response to influenza virus vaccination (IVV) in older adults. However, the role of physical exercise training in this context is unknown. Thus, the aim of this study was to investigate whether the regular practice of combined exercise training can improve the specific antibody response to IVV in CMV-seropositive older adults. Eighty older adults were distributed into two groups—non-practitioners (NP, n = 31, age = 74.06 ± 6.4 years) and practitioners of combined exercise training (CET, n = 49, age = 71.7 ± 5.8 years)—for at least 12 months. Both volunteer groups were submitted to IVV and blood samples were collected before (pre) and 30 days after (post) the vaccination. Concerning the specific antibody response to IVV, higher serum levels of specific immunoglobulin A (IgA) were found in the CET group post- than pre-vaccination (p < 0.01), whereas higher levels of specific immunoglobulin M (IgM) were observed both in the NP (p < 0.05) and CET (p < 0.001) groups post-vaccination as compared to the pre-vaccination values. Serum levels of specific immunoglobulin G (IgG) for IVV and CMV, as well as interleukin 6 (IL-6) and IL-10, were similar between the time points evaluated. However, the IL-10/IL-6 ratio post-vaccination was higher (p < 0.05) in the CET group than that before vaccination. Negative correlations were observed between the specific IgG levels for IVV and CMV only in the CET group, both pre- and post-vaccination. In addition, negative correlations were found between IL-10 and specific IgG for CMV in all volunteer groups pre- and post-vaccination, whereas a positive correlation between IL-10 and specific-IgG for IVV pre- and post-vaccination was observed in the CET group. In addition, with the hemagglutination inhibition (HAI) assay, it was found that 32.2% of the NP group and 32.6% of the CET group were responders to IVV and displayed reductions in the CMV serostatus (p < 0.05 and p < 0.001, respectively) and increases in naive and effector CD8+ T cells post-vaccination (p < 0.01). However, only the responders from the CET group showed significant reductions in the ratio of effector to naive CD8+ T cells (p < 0.05) and increased IL-10 levels post-vaccination (p < 0.001). In summary, this study demonstrates that the improvement in the response to IVV in CMV-seropositive older adults was related to an anti-inflammatory status and enhancement of naive CD8+ T cells, particularly associated with regular practice of CET.

Download Full-text

Diagnosis of rubella virus infections. I. A comparison between Vero and BHK-21 cells for the detection of specific IgG and IgM antibodies by immunofluorescence

Canadian Journal of Microbiology ◽

10.1139/m75-041 ◽

1975 ◽

Vol 21 (3) ◽

pp. 289-292 ◽

Cited By ~ 2

Author(s):

Pierre Payment ◽

Lucille Roy ◽

Jean-Claude Gilker ◽

André Chagnon

Keyword(s):

Rubella Virus ◽

Vero Cells ◽

Virus Infections ◽

Igm Antibodies ◽

Specific Igg

Vero cells were more suitable then BHK-21 cells for the detection of rubella-specific 1gG antibodies because the nonspecific fluorescence was minimal. However, BHK-21 cells were found more sensitive than Vero cells for the detection of rubella-specific IgM antibodies.

Download Full-text

Protection against Influenza Virus Infection of Mice Fed Bifidobacterium breve YIT4064

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.6.2.186-192.1999 ◽

1999 ◽

Vol 6 (2) ◽

pp. 186-192 ◽

Cited By ~ 62

Author(s):

Hisako Yasui ◽

Junko Kiyoshima ◽

Tetuji Hori ◽

Kan Shida

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Oral Administration ◽

Lower Respiratory Tract ◽

Influenza Virus Infection ◽

Oral Immunization ◽

Igg Antibodies ◽

Virus Infections ◽

Bifidobacterium Breve ◽

Specific Igg

ABSTRACT Mice fed Bifidobacterium breve YIT4064 and immunized orally with influenza virus were more strongly protected against influenza virus infection of the lower respiratory tract than ones immunized with influenza virus only. The number of mice with enhanced anti-influenza virus immunoglobulin G (IgG) in serum upon oral administration of B. breve YIT4064 and oral immunization with influenza virus was significantly greater than that upon oral immunization with influenza virus only. These findings demonstrated that the oral administration of B. breve YIT4064 increased anti-influenza virus IgG antibodies in serum and protected against influenza virus infection. The oral administration of B. breve YIT4064 may enhance antigen-specific IgG against various pathogenic antigens taken orally and induce protection against various virus infections.

Download Full-text

Pseudothrombocytopenia: an immunologic study on platelet antibodies dependent on ethylene diamine tetra-acetate

Blood ◽

10.1182/blood.v59.1.157.157 ◽

1982 ◽

Vol 59 (1) ◽

pp. 157-161 ◽

Cited By ~ 105

Author(s):

JG Pegels ◽

EC Bruynes ◽

CP Engelfriet ◽

AE von dem Borne

Keyword(s):

Ethylene Diamine ◽

Igg Antibodies ◽

Immunofluorescence Test ◽

Igm Antibodies ◽

Platelet Antibodies ◽

Group Specificity ◽

Iga Antibodies ◽

Ethylene Diamine Tetra Acetate

Abstract Antibodies specifically reacting with platelets only in the presence of EDTA, by the platelet immunofluorescence test, were found in the serum of 20 patients with pseudothrombocytopenia due to in vitro EDTA- dependent platelet agglutination. These antibodies reacted optimally at 0–4 degree C. In 19 patients, IgG antibodies were detected; in 8 patients, IgM or IgA antibodies were also found. In one patient, only IgM antibodies were found. In 14 patients, the IgG antibodies were IgG1, but IgG2, IgG3, and IgG4 antibodies were also seen in 7 patients. The reaction of platelets with the antibodies was detectable in the presence of Na2EDTA, the K, Ca, and Mg salts of EDTA, and K2EGTA. F(ab')2 or F(ab') fragments of the IgG antibodies reached as strongly as the intact antibodies, indicating that the reaction is dependent on the antibody-combining site. The EDTA-dependent antibodies did not show platelet-group specificity. However, platelets from patients with Glanzmann disease did not react with the antibodies.

Download Full-text