Assessment Of Humoral Immune Responses Research Articles

LIPOSOMAL DELIVERY OF IMMUNOMODULATORY ANTIGEN OF B. MALAYI: ISOLATION, PREPARATION, CHARACTERIZATION, AND IMMUNE RESPONSES ASSESSMENT

Objective: The present study was aimed on developing and characterizing liposomal delivery system loaded with antigen of filaria parasite Brugia malayi extracted protein for assessment of humoral immune responses of antigen. Methods: Liposomes were prepared by reverse-phase evaporation method with slight modification using molar ratio of Soya PC: PE:Cholesterol in different molar concentrations. Results: The levels of F6 specific immunoglobulin (Ig) G1, IgG2a and IgG2b antibodies were found to be elevated in immunized animals over non-immunized controls. Analysis of IgG-subclasses revealed that all the subclasses at (1:25dilution) increased several folds over the controls with IgG1 showing the greatest increase (25.0-fold) followed by IgG2b (3.0-fold). Antibodies titers showed the many fold increment of titers on liposomized antigen groups (Gr.I; without booster dose and Gr.IV; with booster dose). IgG showed about 2.2 fold increment in Gr.IV than control group (Gr.V). IgG1 after booster dose showed about 25-fold increment followed by IgG2b than IgG2a. Conclusion: These results suggest that the liposomal antigen delivery system shows 25-fold IG-G responses in comparison to plain administrated antigen.

Long-Term Assessment of Antibody Response to COVID-19 Vaccination in People with Cystic Fibrosis and Solid Organ Transplantation.

With the worldwide spread of SARS-CoV-2 disease, people with cystic fibrosis (CF), especially solid organ transplant recipients, have quickly been identified as a risk group for severe disease. Studies have shown low antibody response to SARS-CoV-2 vaccines in recipients of solid organ transplant compared to the healthy population. Information on immune response in CF patients with solid organ transplantation is limited, especially regarding long-term efficacy. The aim of this real-world study was a long-term assessment of humoral immune response induced by three and four doses of the SARS-CoV-2 mRNA vaccine. S1RBD and IgG antibodies were measured every 12 weeks over a period of 27 months in twelve CF patients (five liver and seven lung transplantation recipients). A total of 83.3% of our patients showed a positive antibody response after three doses of the SARS-CoV-2 mRNA vaccine. A sustained immune response was observed in both groups over the observation period, with liver transplant recipients showing higher levels than lung transplant recipients. This study is among the first to show long-term data with constantly elevated or even increasing antibody levels. We conclude that this effect is most likely associated with repeated boostering in terms of infections and booster vaccinations.

Immunogenicity and real-world effectiveness of COVID-19 vaccines in Lebanon: Insights from primary and booster schemes, variants, infections, and hospitalization.

In this study, we conducted a case-control investigation to assess the immunogenicity and effectiveness of primary and first booster homologous and heterologous COVID-19 vaccination regimens against infection and hospitalization, targeting variants circulating in Lebanon during 2021-2022. The study population comprised active Lebanese military personnel between February 2021 and September 2022. Vaccine effectiveness (VE) against laboratory-confirmed SARS-CoV-2 infection and associated hospitalization was retrospectively determined during different variant-predominant periods using a case-control study design. Vaccines developed by Sinopharm, Pfizer, and AstraZeneca as well as Sputnik V were analyzed. Prospective assessment of humoral immune response, which was measured based on the SARS-CoV-2 antispike receptor binding domain IgG titer, was performed post vaccination at various time points, focusing on Sinopharm and Pfizer vaccines. Statistical analyses were performed using IBM SPSS and GraphPad Prism. COVID-19 VE remained consistently high before the emergence of the Omicron variant, with lower estimates during the Delta wave than those during the Alpha wave for primary vaccination schemes. However, vaccines continued to offer significant protection against infection. VE estimates consistently decreased for the Omicron variant across post-vaccination timeframes and schemes. VE against hospitalization declined over time and was influenced by the variant. No breakthrough infections progressed to critical or fatal COVID-19. Immunogenicity analysis revealed that the homologous Pfizer regimen elicited a stronger humoral response than Sinopharm, while a heterologous Sinopharm/Pfizer regimen yielded comparable results to the Pfizer regimen. Over time, both Sinopharm's and Pfizer's primary vaccination schemes exhibited decreased humoral immunity titers, with Pfizer being a more effective booster than Sinopharm. This study, focusing on healthy young adults, provides insights into VE during different pandemic waves. Continuous research and monitoring are essential for understanding vaccine-mediated immune responses under evolving circumstances.

Assessment of humoral immune response to different COVID-19 vaccines in patients undergoing maintenance hemodialysis

RESUMO Introdução: A resposta imune a diferentes vacinas contra a doença do coronavírus 2019 (COVID-19) é pouco investigada em pacientes com doença renal em estágio terminal (DRET), especialmente no Oriente Médio e norte da África. Realizamos esta pesquisa para estimar a eficácia da imunização contra a COVID-19 em pacientes com DRET em hemodiálise regular (HD). Métodos: Nesse estudo observacional prospectivo, inscrevemos 60 pacientes com DRET em HD regular que haviam concluído o esquema de vacinação contra a COVID-19 e 30 participantes saudáveis vacinados. Os níveis séricos de imunoglobulina G da síndrome respiratória aguda grave do coronavírus 2 (SARS-COV2 IgG) foram quantificados um mês após a conclusão do esquema vacinal, e todos os participantes foram acompanhados de outubro de 2021 a março de 2022. As vacinas utilizadas no estudo eram da Pfizer-BioNTech, AstraZeneca e Sinopharm. Resultados: O nível mediano de SARS-COV2 IgG foi menor em pacientes em HD do que em participantes saudáveis (p < 0,001). Com relação ao tipo de vacinação contra a COVID-19, não houve diferença estatística nos níveis de SARS-COV2 IgG entre pacientes em HD. Durante o período de observação, nenhum dos pacientes em HD teve COVID-19. Conclusão: A vacinação contra a COVID-19 pareceu ser eficaz na proteção de pacientes em HD por 6 meses e os efeitos colaterais das vacinas foram toleráveis.

Follow-up of humoral immune response after HPV vaccination using first-void urine: A longitudinal cohort study.

Assessment of humoral immune responses following human papillomavirus (HPV) vaccination currently relies on invasive blood sampling. This longitudinal cohort study explores the usability of first-void urine as a noninvasive alternative sample for antibody detection. In this study, 58 women receiving three doses of the 9vHPV vaccine within a Gardasil9 (9vHPV) Phase III randomized controlled trial were included. Participants provided paired first-void urine and blood samples before vaccination (M0), 1 month after the third dose (M7), and ~3 years after the third dose (M43). Type-specific antibody responses to the 9vHPV types were analyzed in 174 first-void urine and 172 serum samples using a virus-like particle-based IgG multiplex enzyme-linked immunosorbent assay. Additionally, total human IgG concentrations were determined using the BioPlex assay. At M7, 1 month after complete 9vHPV vaccination, 95%-100% of first-void urine and 100% of serum samples had detectable concentrations, varying by HPV type. At M43, 84%-100% of first-void urine and 98%-100% of serum samples had HPV-specific antibody concentrations. Results show significant Spearman rank correlations between type-specific HPV-antibody concentrations for paired first-void urine and serum at all time points. This study confirms the potential feasibility of utilizing first-void urine as a noninvasive immunological sample within HPV vaccine trials.

Assessment of Humoral Immune Responses to Repeated Influenza Vaccination in a Multiyear Cohort: A 5-Year Follow-up.

The long-term effects of host factors on vaccine-elicited immune responses have not been well studied, and the interactions of host factors with annual influenza vaccinations are yet to be explored. We analyzed data from a cohort of 386 individuals who received the standard-dose influenza vaccine and enrolled in ≥2 seasons from 2016 to 2020. Our analyses indicated disparate vaccine-elicited immune responses between males and females in adults when they were repeatedly vaccinated for at least 2 seasons. Notably, we found interactive effects between age and body mass index (BMI) on overall immune responses, and between sex at birth and BMI in adults.

Assessment of Humoral Immune Response in Pre- and Post-Vaccinated Cattle Against Lumpy Skin Disease.

Lumpy skin disease (LSD) is viral disease affecting cattle production and productivity in Ethiopia. As a prevention method, vaccinations have been used for a long period with a questionable output due to the existence of LSD outbreaks in vaccinated herds in different parts of Ethiopia. A longitudinal study was performed from October 2019 to April 2020 with the objective of assessing the humoral immune response of cattle with a serum neutralization test (SNT) from different management systems in central Ethiopia. In this study, theserum was collected from 113 cattle (extensive (60/113) and intensive (53/113) management systems) before and after vaccination. From collected sera, a limited number of cattle had seroconversion before vaccination (7.08%). On the other hand, it is obvious the seroconversion rises post vaccination. Accordingly, seroconversion starts to increase after a week (8.85% at 7 dpv) post-vaccination which proceeds to significantly increase at 30 days post vaccination (dpv) (41.65% (25/60)). Furthermore, the risk factor study before and after vaccination showed intensively managed cattle with significantly higher levels of antibody titer at 7 dpv (OR = 1.17; 95% CI = 0.22, 6.2; p = 0.016) and 30 dpv (OR = 3.67; 95% CI = 1.1, 12.29; p = 0.035) compared with that of extensively managed cattle. The other animal-related risk factor that showed a significant difference was breeds and a specific age group ([4½, 7] years) at 15 dpv (OR = 6.69; 95% CI = 2.02, 22.08; p = 0.002) and 30 dpv (OR = 4.24; 95% CI = 1.22, 14.71; p = 0.023); respectively. This study showed an overall lower antibody detection across the study, posing a question on the current LSD-vaccine efficacy. Therefore, a circulating strain of LSDV should be cross-checked with the vaccine strain and adaptations should be made from it.

Assessment of Humoral Immune Response to SARS CoV-2 Virus among Work Staff

Целью статьи является определение наличия антител (IgG+IgM) к нуклео- капсидному (N) белку вируса SARS CoV-2 у обследованных 89 сотрудников коллектива отдельно взятой организации города Еревана. Вместе с этим отмечается, что соотношение обследованных женщин и мужчин составило 44 (47,7%) и 45 (46,7%) соответственно, а средний возраст составил 44,3 года (наивысший возраст 73 года, наименьший 24 года). Авторы приходят к выводу, что общая серопревалентность (наличие комбинированных антител IgG + IgM) к антигенам SARS CoV-2 у обследованных сотрудников составила 47,2% (95% ДИ 45,6-48,8), в то время как антитела отсутствовали у 47 сотрудников 52,8% (95% ДИ 52,2- 53,4). На основании изучения наличия антител к вирусу SARS CoV-2 в разных возрастных группах установлено, что самые высокие уровни антител обнаружены среди возрастных групп 30-39 лет (23,8%) и 40-49 лет (21,4%), наименьший – в группе лиц старше 70 лет (2,4%). В качестве исследовательской задачи авторами выяснена зависимость инфицированности лиц от группы крови. Известны были группы крови 77 из 89 сотрудников организации (42 женщины и 35 мужчин). В результате исследования выяснено, что по группам крови распределение уровня антител имеет следующее соотношение: 0(I), А(II), В(III), АВ(IV) – 15,7; 44,7; 21,2; 18,4% соответственно. Авторы приходят к выводу, что у лиц с группой крови А(II) инфицированность COVID-19 была выше, более чем в 2 раза, а наименьшая инфицированность отмечена у лиц с 0(I) группой крови, что коррелирует с результатами исследований зарубежных коллег. Հոդվածի նպատակն է պարզել Երևան քաղաքի կազմակերպություններից մեկում հետազոտված 89 աշխատակիցների SARS CoV-2 վիրուսի նուկլեոկապսիդ (N) սպիտակուցի նկատմամբ հակամարմինների (IgG+IgM) առկայությունը։ Հետազոտված տղամարդկանց և կանանց հարաբերակցությունը կազմել է համապատասխանաբար՝ 47,7% (44 տղամարդ ) և 46,7% (45 կին), իսկ միջին տարիքը՝ 44,3 տարեկան (առավելագույնը՝ 73 տարեկան, նվազագույնը՝ 24 տարեկան): Իրականացված ուսումնասիրության արդյունքները վկայում են, որ զննված աշխատակիցների ընդհանուր հակածինների SARS CoV-2 նկատմամբ համակցված IgG + IgM հակամարմիններ առկա են հետազոտվածների 47,2%- ում (95% ՀԳ 45,6-48,8): Ավելին, հակամարմինների ամենաբարձր մակարդակ դիտվել է 30-39 և 40-49 տարիքային խմբերում՝ համապատասխանաբար 23,8% և 21,4%, իսկ ամենացածր մակարդակ՝ 70 տարեկանից բարձր մարդկանց խմբում՝ 2,4%։ Մեր խմբի գիտական հետաքրքրությունների շրջանակում է եղել նաև վերլուծել արյան խմբերի և հակամարմինների մակարդակների միջև առկա կապը արյան խմբերի պատկանելությունը հայտնի 77 (42 կին և 35 տղամարդ) աշխատակիցների դեպքում: Հետազոտության արդյունքում պարզվել է, որ հակամարմինների մա- կարդակի բաշխումը, ըստ արյան խմբերի, ունի հետևյալ հարաբերակ- ցությունը՝ 0(I), A(II), B(III), AB(IV) խմբերում համապատասխանաբար՝ 15,7; 44,7; 21,2; 18,4%: Կատարված վերլուծության արդյունքները փաստում են, որ արյան A(II) խումբ ունեցող մարդկանց COVID-19-ով վարակվածությունը այլ արյան խմբերի համեմատ եղել է ավելի քան 2 անգամ բարձր: Ամենացածր վարակվածություն գրանցվել է 0(I) արյան խումբ ունեցող աշխատակիցների շրջանում, ինչն էլ հարաբերակցվում է միջազգային գիտական գրականության մեջ բերված օտարերկրյա հետազոտողների կողմից իրականացված ուսում- նասիրությունների արդյունքների հետ:

Assessment of humoral immune response to two mRNA SARS-CoV-2 vaccines (Moderna and Pfizer) in healthcare workers fully vaccinated with and without a history of previous infection.

AimsPresence of anti‐S1 region of SARS‐CoV‐2 spike protein was analysed, at two and eight months, in 477 immunocompetent healthcare workers in Zaragoza, Spain, vaccinated with mRNA‐1273 (Moderna) or BNT162b2 (Pfizer).Methods and resultsAntibody analysis was performed with Alinity i System (Abbott). At 2 months, 100% of vaccinated had anti‐S1 IgG (mean = 13,285 AU ml−1). This value was significantly higher with Moderna (18,192 AU ml−1) than with Pfizer (10,441 AU ml−1). The mean value of anti‐S1 IgG after vaccination was significantly higher in patients with than without previous infection (18,539 vs. 7919 AU ml−1); in both groups was significantly higher with Moderna than with Pfizer (21,881 vs. 15,733 AU ml−1 and 11,949 vs. 6387 AU ml−1), respectively. At 8 months, 100% of patients were IgG positive, with higher levels with Moderna than with Pfizer. Nevertheless, in ensemble of cases, a mean decrease of antibody levels of 11,025 AU ml−1 was observed.ConclusionAt 2 and 8 months after vaccination, IgG response persists with both vaccines but with important decrease which suggests the need for revaccination.Significance and impact of studyThe study contributes to know the immune status after vaccination with two of more used anti‐SARS‐CoV‐2 vaccines. This knowledge is important for establishing the best vaccination strategy

Proteomic assessment of humoral immune responses in smallpox vaccine recipients

The availability of effective smallpox vaccines was a critical element of the successful eradication of smallpox in 1980. Antibody responses play a primary role in protective immunity and neutralizing antibody is an established correlate of protection against smallpox. In this study we used a poxvirus proteome array to assess the antibody response to individual viral proteins in a cohort of 1,037 smallpox vaccine recipients. Several statistically significant differences were observed in the antibody response to immunodominant proteins between men and women, including B5R—a major target of neutralizing antibody in vaccinia immune globulin, and the membrane proteins D8L and A27L, both of which have been used as vaccine antigens providing protection in animal models. We also noted differences across racial/ethnic groups. In this cohort, which consisted of both ACAM2000 and Dryvax recipients, we noted minute differences in the antibody responses to a restricted number of viral proteins, providing additional support for the use of ACAM2000 as a replacement smallpox vaccine. Furthermore, our data indicate that poxvirus proteome microarrays can be valuable for screening and monitoring smallpox vaccine-induced humoral immune responses in large-scale serologic surveillance studies and prove useful in the guidance of developing novel smallpox candidate vaccines.

Longitudinal analysis of humoral immunity against SARS-CoV-2 Spike in convalescent individuals up to 8 months post-symptom onset

SummaryWith the recent approval of highly effective coronavirus disease 2019 (COVID-19) vaccines, functional and lasting immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently under investigation as antibody levels in plasma were shown to decline during convalescence. Since the absence of antibodies does not equate to absence of immune memory, we evaluate the presence of SARS-CoV-2-specific memory B cells in convalescent individuals. Here, we report a longitudinal assessment of humoral immune responses on 32 donors up to 8 months post-symptom onset. Our observations indicate that anti-Spike and anti-receptor binding domain (RBD) immunoglobulin M (IgM) in plasma decay rapidly, whereas the reduction of IgG is less prominent. Neutralizing activity also declines rapidly when compared to Fc-effector functions. Concomitantly, the frequencies of RBD-specific IgM+ B cells wane significantly when compared to RBD-specific IgG+ B cells, which remain stable. Our results add to the current understanding of immune memory following SARS-CoV-2 infection, which is critical for secondary infection prevention and vaccine efficacy.

Comparative assessment of humoral immune responses of aluminum hydroxide and oil-emulsion adjuvants in Influenza (H9N2) and Newcastle inactive vaccines to chickens

Context Adjuvants are compounds used in the preparation of inactive vaccines to enhance the immune response. Aluminum hydroxide (alum) is one of the first compounds approved by the Food and Drug Administration, which is used as adjuvants in vaccine products for humans. Montanide ISA 70 is an oil-emulsion adjuvant and is used in poultry inactive vaccines. Objective In this study, the effects of alum adjuvant on the efficiency and induction of immune response in inactive vaccines of Influenza and Newcastle are compared with those of ISA 70. Materials and methods Six groups of 7-d-old specific-pathogen-free chickens were inoculated with 0.3 ml of the prepared vaccines via the subcutaneous route in the neck. Immune response in each group after 7, 14, 21, 31, 41, and 45 d was evaluated using the technique of hemagglutination inhibition. Results The results were compared using SPSS software. Results showed that vaccines containing adjuvant ISA 70 depicted a higher increase in the immune response and adjuvant of 20% alum is similar to adjuvant of ISA 70 in boosting the immune system. There was no statistically significant difference between 10% and 20% alum, but these adjuvants are visibly different from ISA 70. Conclusion In conclusion, alum can be used as an easily accessible, harmless, and effective adjuvant; however, to increase the immune period using the inactive vaccines for poultry, more research would be necessary.

Assessment of humoral immune response of a Cytomegalovirus DNA-vaccine candidate in BALB/c mice

Introduction: Glycoprotein B (gB) is the major antigen for induction of humoral responses against human cytomegalovirus (HCMV) making it an attractive candidate for immune prophylaxis. In the present study, the humoral immune response of BALB/c mice to a truncated HCMV gB protein fused with GFP was evaluated.:The truncated gB coding sequence was synthesized and cloned in pEGFPN1 eukaryotic expression vector and expr essed in HEK 293T cell line. After optimization, expression of the recombinant truncated HCMV gB was verified using HRP - conjugated polyclonal antibody specific for HCMV gB.The level of humoral immune responses was assessed in mice using DNA/DNA, peptide/peptide, and DNA/ peptide (prime -boost) immunization strategies. Results:Cloning of the truncated gB coding sequence in the pEGFPN1 was verified by restriction enzyme analysis and sequencing. After optimizing the transfection procedure the number of the GFP positive cells reached 32%. Western blot analysis confirmed theinvitroexpression of the truncated HCMV gB protein with an appa rent molecular weight of approximately 70 kDa.In vivoprime-boost immunization using HCMV gB DNA/peptide regimen showed significantly higher humoral immune responses compared to the control groups. Conclusion:This study demonstrated that thepEGFPN1 eukaryotic expression vector could be usedto optimize and evaluate the expression of this truncated protein.The results also showed that the DNA/peptide vaccination could induce a significant antibody response in animal model.

Assessment of humoral immune responses of sheep immunized with affinity purified excretory / secretory antigen of Haemonchus contortus

Assessment of humoral immune responses of sheep immunized with affinity purified excretory / secretory antigen of Haemonchus contortus

Assessment of humoral immune responses in malaria vaccine trials

Clinical trials for new vaccine candidates evaluate safety and tolerability of future vaccines. In some studies immunogenicity is an additional exploratory aim. For this purpose immunological assays have to be established and further developed for future multicentre studies. The implementation of immunological assays and the different logistic conditions worldwide display new challenges for scientists working in this field. This article shows this process on a recently conducted phase Ia clinical trial at the Institute of Tropical Medicine in Tübingen, Germany, to evaluate the safety and immunogenicity of a new malaria vaccine candidate. The group for clinical trials and immunology is the interphase for the establishment of immunological assays and their implementation in clinical trials.

Immunotoxicity and biodistribution analysis of arsenic trioxide in C57Bl/6 mice following a 2-week inhalation exposure

In these studies the immunotoxicity of arsenic trioxide (ATO, As 2O 3) was evaluated in mice following 14 days of inhalation exposures (nose only, 3 h per day) at concentrations of 50 μg/m 3 and 1 mg/m 3. A biodistribution analysis performed immediately after inhalation exposures revealed highest levels of arsenic in the kidneys, bladder, liver, and lung. Spleen cell levels were comparable to those found in the blood, with the highest concentration of arsenic detected in the spleen being 150 μg/g tissue following the 1 mg/m 3 exposures. No spleen cell cytotoxicity was observed at either of the two exposure levels. There were no changes in spleen cell surface marker expression for B cells, T cells, macrophages, and natural killer (NK) cells. There were also no changes detected in the B cell (LPS-stimulated) and T cell (Con A-stimulated) proliferative responses of spleen cells, and no changes were found in the NK-mediated lysis of Yac-1 target cells. The primary T-dependent antibody response was, however, found to be highly susceptible to ATO suppression. Both the 50 μg/m 3 and 1 mg/m 3 exposures produced greater than 70% suppression of the humoral immune response to sheep red blood cells. Thus, the primary finding of this study is that the T-dependent humoral immune response is extremely sensitive to suppression by ATO and assessment of humoral immune responses should be considered in evaluating the health effects of arsenic containing agents.

Novel antibody specificities targeting glycoprotein B of cytomegalovirus identified by molecular library technology

Antibodies provide some protection against cytomegalovirus-mediated disease. All aspects of antibody recognition of important viral antigens are, however, not fully appreciated. Glycoprotein B (gB), a key protein in the viral membrane, participates in viral infection and it is a component of prototype vaccines. By using combinatorial antibody library and selection technology, novel antibody specificities targeting gB have now been isolated. We define a monoclonal antibody fragment able to recognize site I of antigenic domain (AD) 2, a poorly immunogenic epitope targeted by potent virus-neutralizing antibodies, in a way that is different from the binding of antibodies induced by infection but similar to those induced by vaccination. We also describe the existence of a novel epitope overlapping site I of AD-2 and AD-1, the immunodominant epitope of gB. These specificities, derived by molecular engineering, will be useful for the future assessment of humoral immune responses against this opportunistic viral infection.

Assessment of humoral immune response in mink (Mustela vison): antibody production and detection.

A method for investigating the humoral immune response in mink (Mustela vison) was developed between October 1993 and March 1994. Protein A, 1:8000 dilution, had a high affinity for mink immunoglobulin, while anti-ferret (Mustela putorius) antibody, 1:200 dilution, had a weaker affinity. Four adult mink were immunized with a hapten, dinitrophenol (DNP), conjugated to a large carrier protein, keyhole limpet hemocyanin (KLH), and received two boosters at 3-week intervals. This provoked a strong T-lymphocyte dependent humoral immune response. An indirect enzyme linked immunosorbent assay (ELISA) was used to quantify the antibody produced. All mink had undetectable anti-DNP-KLH antibody in the pre-immune sera, with antibody levels increasing post-immunization, and peaking after the first or second booster.

In vitro Assessment of Humoral Immunity Following Exposure to Heavy Metals

The immune system of animals and man is extremely complex. This report will discuss the effect metals has on one segment of the immune system; that is, humoral immunity. Humoral immunity is essentially the production of antibody in response to an antigen. The B-lymphocyte is the primary cell responsible for producing antibody. However, this cell is regulated by T-lymphocytes and macrophages. Many methods are available to assess humoral immune responses. A multitude of immunoassays have been developed for enumeration of serum antibody. Some of these are immunodiffusion, complement fixation, serum neutralization, hemagglutination, radioimmunoassay and enzyme-linked immunosorbent assay (ELISA). Detection of antibody-forming cells distinguishes between effect on antibody production compared to degradation of preformed antibody. Other available methods are measurement of surface receptor (Fc and complement) activity on B-cells. Mitogens (T-independent) have also been regarded as a measurement for humoral immunity. In our laboratory, we have developed an ELISA technique that is appropriate for general assessment of humoral immune responses resulting from chemical exposure. This technique is highly sensitive and can be mechanized. The assay can easily be incorporated into the drug and chemical efficacy testing programs of industry.

In vitro assessment of humoral immunity following exposure to heavy metals.

The immune system of animals and man is extremely complex. This report will discuss the effect metals has on one segment of the immune system; that is, humoral immunity. Humoral immunity is essentially the production of antibody in response to an antigen. The B-lymphocyte is the primary cell responsible for producing antibody. However, this cell is regulated by T-lymphocytes and macrophages. Many methods are available to assess humoral immune responses. A multitude of immunoassays have been developed for enumeration of serum antibody. Some of these are immunodiffusion, complement fixation, serum neutralization, hemagglutination, radioimmunoassay and enzyme-linked immunosorbent assay (ELISA). Detection of antibody-forming cells distinguishes between effect on antibody production compared to degradation of preformed antibody. Other available methods are measurement of surface receptor (Fc and complement) activity on B-cells. Mitogens (T-independent) have also been regarded as a measurement for humoral immunity. In our laboratory, we have developed an ELISA technique that is appropriate for general assessment of humoral immune responses resulting from chemical exposure. This technique is highly sensitive and can be mechanized. The assay can easily be incorporated into the drug and chemical efficacy testing programs of industry.