Differences In Humoral Immune Response Research Articles

Humoral and Cellular Immune Response on COVID-19 Patients and Sinovac Vaccine Participants

Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 is a new SARS-CoV virus. A person who is infected with this virus will induce both humoral and cellular immune responses. Herd immunity can be achieved through vaccination. The purpose of vaccination is the formation of antibodies capable of neutralizing coronavirus against the receptor binding domain. This study aimed to determine the differences between humoral and cellular immune responses between confirmed COVID-19 patients and Sinovac vaccine participants. This observational analytic study with a prospective cohort approach was conducted between March to October 2021. Fifty subjects (25 officers who had received vaccinations for COVID-19 patients and 25 COVID-19 patients treated at the Dr. Moewardi General Hospital) and met the inclusion and exclusion criteria were enrolled. Different tests were carried out to see the difference between the levels of CD8+ T cells and anti-SARS-CoV-2 antibodies in the vaccine group and the COVID-19 patient group. There was no significant difference in humoral immune response (anti-SARS-CoV-2) between the vaccine group and COVID-19 patient group [33.93 (0.4–196.6) U/L vs. 101.28±158.59 U/L; p=0.409], but there was a significant difference in cellular immune response (CD8+) between the vaccine group and COVID-19 patient group [878.52±47368 cells/µL vs. 270.16±213.64 cells/µL; p=0.001]. CD8 assay can be used as a parameter to differentiate the cellular immune response between COVID-19 patients and COVID-19 vaccine recipients.

Association between sex hormones and anti-S/RBD antibody responses to COVID-19 vaccines in healthcare workers

ABSTRACT Healthcare workers (HCWs) are the target population for vaccination against coronavirus disease (COVID-19) as they are at a high risk of exposure and transmission of pathogens to patients. Neutralizing antibodies developed after COVID-19 vaccination decline within few months of vaccination. Several factors, including age and sex, can affect the intensity, efficacy, and duration of immune response to vaccines. However, sex-specific analyses of humoral responses to COVID-19 vaccines are lacking. This study aimed to evaluate sex-based differences in anti-S/RBD (Receptor Binding Domain) responses at three different time points after the second dose of mRNA COVID-19 vaccine in HCWs in relation to age, and to investigate the role of sex hormones as potential markers of response. Anti-S/RBD levels after two doses of the mRNA vaccine were collected from 521 HCWs naïve to COVID-19, working at two Italian Clinical Centers. Multiple regression analysis was applied to evaluate the association between anti-S levels and sex, age, and plasma levels of sex hormones. Significantly higher anti-S/RBD response to the COVID-19 vaccination was found in female HCWs, and a significant and more abrupt decline in response with time was observed in women than that in men. A novel, positive association of testosterone plasma levels and higher anti-S levels in male HCWs was found, suggesting its potential role as sex specific marker in males. In conclusion, understanding the sex-based differences in humoral immune responses to vaccines may potentially improve vaccination strategies and optimize surveillance programs for HCWs.

Adenovirus type D and type E infection in broiler chickens: the effect on CD4 and CD8 T cell response, cytokines expression and their immunopathology

ABSTRACT 1. A total of 150-day-old chicks were divided into three groups of 50 birds (G1-G3); G1 and G2 were orally inoculated at 1-day old with 0.5 ml of 107 TCID50/ml FAdV-D serotype 2 (MT386509.1) and FAdV-E serotype 8a (MW847902), respectively, and G3 was blank control group. 2. Cell-mediated immune response was evaluated by detection of CD4, CD8 T lymphocytes and the mRNA expression of IL6 and IL8 in the chicken spleen using q-PCR. Additionally, immunopathology was performed at 3, 5 and 7 day post infection (dpi) and weekly until the end of the experiment. 3. Results revealed that transcription of inflammatory cytokines (IL6, IL8) was up regulated in the spleen of FAdV type D and type E infected chickens at various time points relative to the control group. A marked decrease in the number of CD4 and CD8 T lymphocytes at 5 and 7 dpi in G1 of chickens infected with FAdV type D. Whereas, in chickens infected with FAdV type E, the CD4 and CD8 T lymphocytes were markedly decreased at 7 dpi. 4. In contrast, there were no significant differences in humoral immune responses against NDV vaccine in (G1 and G2) at different intervals post-vaccination compared to the control group. The histopathology of the bursa, thymus, and spleen in the infected groups showed lymphocytolysis with severe reticular cells hyperplasia and lymphoid depletion. 5. In conclusion, fowl adenovirus types D and E have an immunosuppressive effect in broilers which may be considered one of the main causes of the continuous co-infections with other viruses reported in the field during the last 10 years.

Response to BNT162b2 mRNA COVID-19 vaccine of ART-experienced people living with HIV: a prospective analysis from a single-center study in Rome, Italy.

We aimed to assess the immunologic response to BNT162b2 mRNA COVID-19 vaccine in ART-experienced people living with HIV (PLWH). Methods: In this pilot prospective study, we enrolled 20 PLWH (all on effective ART, 80% with CD4 cells count >500) and 52 immunocompetent health-care workers, as control. All subjects received two doses of vaccine 21 days apart. Serum samples were collected at different time points, immediately before first administration (BL) and 21 days after each dose (T1 and T2) and 45-50 days after second dose (T3). We evaluated the immune response in terms of frequency of responders and antibody titers against SARS-CoV-2 at each timepoint. The viro-immunological parameters of PLWH were also monitored. We found that the participants displayed an immune response after the first dose that increased markedly at T2. At T3 a significantly descending trend of IgG levels was observed in both groups. No difference in humoral immune response assessed in terms of percentage of responders after first and second dose and in terms of IgG titers over time and at each time point was found between groups. Any significant variation in terms of viremia and immunological parameters was observed in PLWH. BNT162b2 mRNA COVID-19 vaccine appears immunogenic in this setting of PLWH eliciting an immune response comparable to that of healthy donors.

Analysis of a German blood donor cohort reveals a high number of undetected SARS-CoV-2 infections and sex-specific differences in humoral immune response.

Seroprevalence studies can contribute to a better assessment of the actual incidence of infection. Since long-term data for Germany are lacking, we determined the seroprevalence of immunoglobulin G (IgG) antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in residual plasma samples of 3,759 German regular blood donors between July 2020 and June 2021. Over almost the entire study period, the incidences determined based on our data were higher than those officially reported by the Robert Koch Institute, the public health institute in Germany. Using our serological testing strategy, we retrospectively detected natural infection in 206/3,759 (5.48%; 95% confidence interval (CI): 4.77-6.25) individuals. The IgG seroprevalence ranked from 5.15% (95% CI: 3.73-6.89) in Lower Saxony to 5.62% (95% CI: 4.57-6.84) in North Rhine Westphalia. The analyses of follow-up samples of 88 seropositive blood donors revealed a comparable fast decay of binding and neutralizing anti-SARS-CoV-2 IgG antibodies. The antibody avidity remained at a low level throughout the whole follow-up period of up to 181 days. Interestingly, female donors seem to express a stronger and longer lasting humoral immunity against the new coronavirus when compared to males. Conclusion: Overall, our data emphasizes that seroprevalence measurements can and should be used to understand the true incidence of infection better. Further characterization of follow-up samples from seropositive donors indicated rapid antibody waning with sex-specific differences concerning the strength and persistence of humoral immune response.

Humoral immune response following a third SARS-CoV-2 mRNA vaccine dose in solid organ transplant recipients compared with matched controls.

Solid organ transplant (SOT) recipients have shown suboptimal antibody response following COVID-19 vaccination. Several risk factors for the diminished response have been identified including immunosuppression and older age, but the influence of different comorbidities is not fully elucidated. This case-control study consisted of 420 Danish adult SOT recipients and 840 sex- and age-matched controls, all vaccinated with a third homologous dose of either BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) vaccine. The primary outcome was differences in humoral immune response. The secondary outcome was breakthrough infections. Additionally, we looked for factors that could predict possible differences between the two groups. Response rate increased from 186/382 (49%) to 275/358 (77%) in SOT recipients and remained on 781/790 (99%) to 601/609 (99%) in controls following a third vaccine dose. SOT recipients had significantly lower median antibody concentrations after third dose compared to controls (332.6 BAU/ml vs 46,470.0 BAU/ml, p <0.001). Lowest median antibody concentrations were seen in SOT recipients with liver disease (10.3 BAU/ml, IQR 7.1-319) and diabetes (275.3 BAU/ml, IQR 7.3-957.4). Breakthrough infections occurred similarly frequent, 150 (40%) among cases and 301 (39%) among controls (p = 0.80). A third COVID-19 vaccine dose resulted in a significant increase in humoral immunogenicity in SOT recipients and maintained high response rate in controls. Furthermore, SOT recipients were less likely to produce antibodies with overall lower antibody concentrations and humoral immunity was highly influenced by the presence of liver disease and diabetes. The prevalence of breakthrough infections was similar in the two groups.

Vacina COVID-19: quanto valem os Anticorpos?

Introduction Since the appearance of the first cases of COVID-19, the pandemic has shown rapid growth with an impact on a global scale. The ability to generate immunity is a key factor for its control, which is why it has been a topic of exhaustive scientific investigation so far. However, despite the widespread administration of vaccines, several doubts remain as to their immunogenicity. The literature suggests that age, gender, and previous serological status influence the difference in humoral immune response. Seropositivity, young age and female gender seem to have a positive influence on antibody levels in most studies published so far. Objectives The aim of this study is to evaluate the humoral response to the Pfizer-BionNTech vaccine in healthcare professionals at a hospital. Methods Professionals with both positive and negative serology were inoculated with two doses. The influence of age, gender and previous serological status on antibody levels was analyzed over a period of six months. Antibodies were assayed using Abbott’s SARS-CoV-2 IgG chemiluminescence immunoassay (SARS-CoV-2 IgG II Quant®) in four stages: prior to the first vaccine inoculation, as well as on the first, third and sixth month after the second inoculation. The study included an initial sample of 1387 health professionals, but only 391 strictly complied with the 4 stages mentioned above. Of the final sample of 391 collaborators, 341 had negative serology prior to vaccination, and had no history of positive RT-PCR for COVID-19. The remaining 50 had positive serology (&gt;6.8 AU/mL). Results It is observed that there is a more robust response in previously seropositive individuals, having presented a higher quantitative value of IgG, but with a similar behaviour to seronegatives regarding sustainability. Antibodies peaked in the first month, especially in younger subjects, showing a progressive decline in the post-vaccination semester for both groups. In a population where the female sex is predominant, it was this one that had a more robust quantitative response to IgG. Finally, we found a marked decrease in the number of symptomatic infections by COVID-19 after immunization, which is transversal to all the current literature. Conclusion In summary, we conclude that previously infected individuals vaccinated with two doses have the same serological behavior regarding humoral immunity compared to uninfected individuals vaccinated with two doses. This result reinforces that the humoral immunity assay cannot be utilized as a clinical tool for the selection and prioritization of whom to vaccinate. KEYWORDS: SARS-CoV-2; BNT162 Vaccine; Immunity; Occupational Health; COVID 19.

Differences in Humoral Immune Response against the Type 2 Porcine Reproductive and Respiratory Syndrome Virus via Different Immune Pathways.

The intramuscular vaccine is the principal strategy to protect pigs from porcine reproductive and respiratory syndrome virus (PRRSV), However, it is still difficult to control PRRSV effectively. This study infected piglets with PRRSV through intramuscular and intranasal inoculation. Subsequently, viral loads, anti-PRRSV antibody levels, and neutralizing antibodies (NAs) titers in both serum and saliva were monitored for 43 days. Meanwhile, tissues were obtained through necropsy at 43 days post-inoculation (dpi) to detect viral loads. The results indicated that viremia lasted from 3 to 31 dpi in both the inoculation groups, but the viruses survived in the lungs and lymph nodes after viremia clearance. The antibody response was detected from 11 dpi, but the response of NAs was delayed until 3–4 weeks. Furthermore, intranasal inoculation induced lower viral load levels than injection inoculation. In addition, positive SIgA and NAs levels were produced early, with higher levels through intranasal inoculation. Therefore, our data indicated that a more robust antibody response and lower virus loads could be induced by intranasal inoculation, and mucosal inoculation could be a suitable pathway for PRRSV vaccines.

Differences in SARS-CoV-2-Specific Antibody Responses After the First, Second, and Third Doses of BNT162b2 in Naïve and Previously Infected Individuals: A 1-Year Observational Study in Healthcare Professionals.

BackgroundSafe and effective vaccines against COVID-19 are critical for preventing the spread of SARS-CoV-2, but little is known about the humoral immune response more than 9 months after vaccination. We aimed to assess the humoral immune response after the first, second, and third (booster) doses of BNT162b2 vaccine in SARS-CoV-2 naïve and previously infected healthcare professionals (HCP) and the humoral immune response after infection in vaccinated HCP.MethodsWe measured anti-spike (anti-S) and anti-nucleocapsid antibodies at different time points up to 12 months in the sera of 300 HCP who had received two or three doses of BNT162b2 vaccine. Mixed-model analyses were used to assess anti-S antibody dynamics and to determine their predictors (age, sex, BMI, and previous infection).ResultsNaïve individuals had statistically lower anti-S antibody concentrations after the first dose (median 253 BAU/ml) than previously infected individuals (median 3648 BAU/ml). After the second dose, anti-S antibody concentrations increased in naïve individuals (median 3216 BAU/ml), whereas the second dose did not significantly increase concentrations in previously infected individuals (median 4503 BAU/ml). The third dose resulted in an additional increase in concentrations (median 4844 BAU/ml in naïve and median 5845 BAU/ml in previously infected individuals). Anti-S antibody concentrations steadily decreased after the second dose and after the third dose in naïve and previously infected individuals. In addition, we found that age had an effect on the humoral immune response. Younger individuals had higher anti-S antibody concentrations after the first and second doses. After infection with the new variant Omicron, a further increase in anti-S antibody concentrations to a median value of 4794 BAU/ml was observed in three times vaccinated HCP whose anti-S antibody concentrations were relatively high before infection (median 2141 BAU/ml). Our study also showed that individuals with systemic adverse events achieved higher anti-S antibody concentrations.ConclusionIn this study, significant differences in humoral immune responses to BNT162b2 vaccine were observed between naïve and previously infected individuals, with age playing an important role, suggesting that a modified vaccination schedule should be practiced in previously infected individuals. In addition, we showed that the high anti-S antibodies were not protective against new variants of SARS-CoV-2.

Magnitude and diversity of immune response to vaccinia virus is dependent on route of administration

Historic observations suggest that survivors of smallpox maintained lifelong immunity and protection to subsequent infection compared to vaccinated individuals. Although protective immunity by vaccination using a related virus (vaccinia virus (VACV) strains) was the key for smallpox eradication, it does not uniformly provide long term, or lifelong protective immunity (Heiner et al., 1971). To determine differences in humoral immune responses, mice were inoculated with VACV either systemically, using intranasal inoculation (IN), or locally by an intradermal (ID) route. We hypothesized that sub-lethal IN infections may mimic systemic or naturally occurring infection and lead to an immunodominance reaction, in contrast to localized ID immunization. The results demonstrated systemic immunization through an IN route led to enhanced adaptive immunity to VACV-expressed protein targets both in magnitude and in diversity when compared to an ID route using a VACV protein microarray. In addition, cytokine responses, assessed using a Luminex® mouse cytokine multiplex kit, following IN infection was greater than that stemming from ID infection. Overall, the results suggest that the route of immunization (or infection) influences antibody responses. The greater magnitude and diversity of response in systemic infection provides indirect evidence for anecdotal observations made during the smallpox era that survivors maintain lifelong protection. These findings also suggest that systemic or disseminated host immune induction may result in a superior response, that may influence the magnitude of, as well as duration of protective responses.

Sex and life history shape the strength of cellular and humoral immune responses in a wing dimorphic cricket

Immune function is a complex collection of responses that often trade-off with one another and with other life history traits, because of the high costs of mounting and maintaining immune responses. Animals, even those from the same populations, may emphasize different aspects of immune function depending on their habitat and phenotype. For example, host population density mediates the threat from density-dependent parasites. Animals at high densities may emphasize fast-acting humoral responses, while those at low densities may favor slower, but more specific, cellular responses. However, these predictions may be dependent on other life history traits, like sex, which is associated with variation in many immune responses. We used wing dimorphic Gryllus firmus crickets to test humoral responses, measured by lysozyme and phenoloxidase activities, and cellular immune responses, measured by encapsulation, between morphs and sex. We found that both morphs and sexes differed in aspects of immune function. Long wing morphs had stronger encapsulation responses than short winged morphs. Additionally, females exhibited higher PO activity than males, and by contrast, males had higher lysozyme activity than females. Our study suggests that G. firmus morphs prioritize different immune responses that may reflect a balancing between the costs of immunity and differing pathogen threats. Male and female crickets exhibit differences in humoral immune responses that may reflect their different life history demands.

Differential miRNA expression in B cells is associated with inter-individual differences in humoral immune response to measles vaccination.

BackgroundMicroRNAs are important mediators of post-transcriptional regulation of gene expression through RNA degradation and translational repression, and are emerging biomarkers of immune system activation/response after vaccination.MethodsWe performed Next Generation Sequencing (mRNA-Seq) of intracellular miRNAs in measles virus-stimulated B and CD4+ T cells from high and low antibody responders to measles vaccine. Negative binomial generalized estimating equation (GEE) models were used for miRNA assessment and the DIANA tool was used for gene/target prediction and pathway enrichment analysis.ResultsWe identified a set of B cell-specific miRNAs (e.g., miR-151a-5p, miR-223, miR-29, miR-15a-5p, miR-199a-3p, miR-103a, and miR-15a/16 cluster) and biological processes/pathways, including regulation of adherens junction proteins, Fc-receptor signaling pathway, phosphatidylinositol-mediated signaling pathway, growth factor signaling pathway/pathways, transcriptional regulation, apoptosis and virus-related processes, significantly associated with neutralizing antibody titers after measles vaccination. No CD4+ T cell-specific miRNA expression differences between high and low antibody responders were found.ConclusionOur study demonstrates that miRNA expression directly or indirectly influences humoral immunity to measles vaccination and suggests that B cell-specific miRNAs may serve as useful predictive biomarkers of vaccine humoral immune response.

Differences in humoral immune response between patients with or without nasal carriage of Staphylococcus aureus.

The humoral immune response against 43 staphylococcal antigens was compared among hospitalized patients where none of them had any staphylococcal infection on the day of admission with or without nasal Staphylococcus aureus carriage. Fifty-nine carriers and 59 matched non-carriers were studied. The carriers harbored S. aureus of 35 different spa types, including three t037/ST239 methicillin-resistant S. aureus (MRSA) (5.1%). Among the 118 patients, 31 acquired S. aureus during hospitalization. In colonized and non-colonized patients, unique patterns of S. aureus-specific immune responses were observed. The mean fluorescence indices (MFIs) of antibodies against 36/43 (83.7%) antigens were seen to be elevated among carriers. The MFI among carriers with acquisition was significantly higher for staphylococcal superantigen-like protein 5 (SSL5, p = 0.028) when compared to carriers without acquisition. High antibody levels against staphylococcal enterotoxin A (SEA) among carriers illustrate its role as a superantigen in both infection and colonization. We also report a dynamic immune response in S. aureus-carrying patients against the recently reported formyl peptide receptor-like inhibitory (FLIPr)-like protein. In the current study, the dynamics of antibodies against staphylococcal antigens among carrier patients seem quite similar to non-carrier patients. To better understand the dynamic immunogenicity during S. aureus infection and colonization, artificial colonization studies and investigation of the changes in the levels of antibodies against other staphylococcal antigens are recommended.

Associations between race, sex and immune response variations to rubella vaccination in two independent cohorts

IntroductionImmune response variations after vaccination are influenced by host genetic factors and demographic variables, such as race, ethnicity and sex. The latter have not been systematically studied in regard to live rubella vaccine, but are of interest for developing next generation vaccines for diverse populations, for predicting immune responses after vaccination, and for better understanding the variables that impact immune response. MethodsWe assessed associations between demographic variables, including race, ethnicity and sex, and rubella-specific neutralizing antibody levels and secreted cytokines (IFNγ, IL-6) in two independent cohorts (1994 subjects), using linear and linear mixed models approaches, and genetically defined racial and ethnic categorizations. ResultsOur replicated findings in two independent, large, racially diverse cohorts indicate that individuals of African descent have significantly higher rubella-specific neutralizing antibody levels compared to individuals of European descent and/or Hispanic ethnicity (p<0.001). ConclusionOur study provides consistent evidence for racial/ethnic differences in humoral immune response following rubella vaccination.

Chronic psychosocial stress: does it modulate immunity to the influenza vaccine in Hong Kong Chinese elderly caregivers?

Previous studies evaluated the effects of psychosocial stress on influenza vaccine responses. However, there were methodological limitations. This study aims to determine whether chronic stress is associated with poorer influenza-specific immune responses to influenza vaccines in Hong Kong Chinese elderly people. This is a prospective study with a 12-week follow-up. Subjects were recruited from government general out-patient clinics, non-government organizations, and public housing estates in Hong Kong. Participants include 55 caregivers of spouses with chronic conditions that impaired their activities of daily living and 61 age- and sex-matched non-caregivers. A single-dose trivalent influenza vaccine was given to all subjects by intramuscular ingestion. Blood samples were collected before vaccination, at 6 weeks, and at 12 weeks after vaccination. Influenza vaccine strain-specific antibody titers were measured by the hemagglutination inhibition method. Lymphocyte subsets were analyzed for ratios and absolute counts, and cytokine concentration were measured by flow cytometry. Validated scales were used to assess psychological (depressive symptoms, perceived stress, and caregiver strain), social (multidimensional social support scale), and lifestyle factors (physical exercise, cigarette smoking, and alcohol consumption) at baseline prior to vaccination. Demographic and socioeconomic variables were also collected. Albumin levels were measured as an indicator for nutritional status in subjects. Caregivers had statistically significant (p < 0.05) lower cell-mediated immune responses to influenza vaccination at 12 weeks when compared with those of the controls. No differences in humoral immune response to vaccination were observed between caregivers and controls. Hong Kong Chinese elderly who experience chronic stress have a significantly lower cell-mediated immune response to influenza vaccination when compared with non-caregivers.

Human Leukocyte Antigen and Cytokine Receptor Gene Polymorphisms Associated With Heterogeneous Immune Responses to Mumps Viral Vaccine

Mumps outbreaks continue to occur throughout the world, including in highly vaccinated populations. Vaccination against mumps has been successful; however, humoral and cellular immune responses to mumps vaccines vary significantly from person to person. We set out to assess whether HLA and cytokine gene polymorphisms are associated with variations in the immune response to mumps viral vaccine. To identify genetic factors that might contribute to variations in mumps vaccine-induced immune responses, we performed HLA genotyping in a group of 346 healthy schoolchildren (12-18 years of age) who previously received 2 doses of live mumps vaccine. Single-nucleotide polymorphisms (minor allele frequency of >5%) in cytokine and cytokine receptor genes were genotyped for a subset of 118 children. Median values for mumps-specific antibody titers and lymphoproliferative stimulation indices were 729 IU/mL and 4.8, respectively. Girls demonstrated significantly higher mumps antibody titers than boys, indicating gender-linked genetic differences in humoral immune response. Significant associations were found between the HLA-DQB1*0303 alleles and lower mumps-specific antibody titers. An interesting finding was the association of several HLA class II alleles with mumps-specific lymphoproliferation. Alleles of the DRB1 (*0101, *0301, *0801, *1001, *1201, and *1302), DQA1 (*0101, *0105, *0401, and *0501), and DQB1 (*0201, *0402, and *0501) loci were associated with significant variations in lymphoproliferative immune responses to mumps vaccine. Additional associations were observed with single-nucleotide polymorphisms in the interleukin-10RA, interleukin-12RB1, and interleukin-12RB2 cytokine receptor genes. Minor alleles for 4 single-nucleotide polymorphisms within interleukin-10RA and interleukin-12RB genes were associated with variations in humoral and cellular immune responses to mumps vaccination. These data suggest the important role of HLA and immunoregulatory cytokine receptor gene polymorphisms in explaining variations in mumps vaccine-induced immune responses.

Age related differences in humoral immune response to respiratory syncytial virus infection in adults.

The humoral immune response to Respiratory Syncytial Virus (RSV) was investigated in old and young adults. RSV was identified by culture and/or reverse transcription polymerase chain reaction (RT-PCR) in 52 elderly (mean age 74 years) and 15 young adults (mean age 33 years) with respiratory illness. Preinfection serum neutralizing and binding antibody levels were similar in the two age groups, although older persons had significantly greater serum neutralizing responses to group A RSV (log(2) 2.8 increase vs. 1.7, P = 0.001) and group B RSV (log(2) 2.8 vs. 1.3, P = 0.0008). Older persons also had significantly increased responses to the RSV F (log(2) 2.9 vs. 1.1, P < 0.0001), Ga (log(2) 2.1 vs. 1.3, P = 0.0007), and Gb proteins (log(2) 2.7 vs. 1.4, P = 0.0004). The exuberant antibody response seen in older adults may be a reflection of greater viral load and antigenic stimulation and/or a shift from Th1 to Th2 dominant immune response with aging. The relationship of immune response to disease pathogenesis in older persons deserves further study.

Assessment of the association between measles vaccine response and asthma status

Rationale Both T-helper 1 cell (Th1) and T-helper 2 cells (Th2) play a role in determining humoral immune response. Asthmatics have been found to have a Th2 predominant milieu. However, it is not known whether there is a difference in humoral immune response between asthmatics and non-asthmatics. Thus, we determined whether humoral immune response in asthmatics differs from that in non-asthmatics. Methods Our previous study determined the seroprevalence of measles antibody at ages 5 to 12 years in a convenience sample of 876 schoolchildren in Rochester, MN, who had been immunized with MMR vaccine at 15 months of age. Circulating measles virus-specific IgG antibody levels in the subjects' sera were determined by an IgG whole virus-specific EIA (BioWhittaker, Walkersville, MD). For a group of 558 children from the original sample, we conducted medical record reviews to determine asthma status by applying pre-determined asthma criteria with documented reliability. The antibody levels were compared between asthmatics and non-asthmatics. Results There was no difference in humoral immune response between asthmatics (1.75 ± 0.85) and non-asthmatics (1.78 ± 0.73) (p=0.61). Conclusions We found that asthmatics had similar humoral immune response to non-asthmatics. Our data suggest no significant association between Th2 predominant milieu and humoral immune responses and reassure that asthmatics have normal humoral immunity.

Induced changes in total serum IgE concentration in the Brown Norway rat: potential for identification of chemical respiratory allergens.

A variety of chemicals can cause sensitization of the respiratory tract and occupational asthma that may be associated with IgE antibody production. Topical exposure to chemical respiratory allergens such as trimellitic anhydride (TMA) has been shown previously to induce increases in the total serum concentration of IgE in BALB/c strain mice. Contact allergens such as 2,4-dinitrochlorobenzene (DNCB), which apparently lack respiratory sensitizing potential, fail to provoke similar changes. However, it became apparent with time that there was some inter-animal variation in constitutive and inducible IgE levels. We have now examined the influence of topical exposure to TMA and DNCB on serum IgE levels in the Brown Norway (BN) rat. Such animals can be bled serially and thus it is possible to perform longitudinal analyses of changes in serum IgE concentration. The kinetics of IgE responses therefore can be followed on an individual animal basis, allowing discrimination between transient and sustained increases in serum IgE concentration. Rats (n = 5) were exposed on shaved flanks to 50% TMA, to 1% DNCB (concentrations that elicit comparable immune activation with respect to draining lymph node cellularity and proliferation) or to vehicle alone. Total IgE was measured by enzyme-linked immunosorbent assay in serum samples taken prior to and 14-42 days following initial exposure. Those animals having high pre-existing IgE levels (>1.0 microg ml(-1)) were excluded from subsequent analyses. The levels of serum IgE in the majority of rats exposed to DNCB or vehicle alone remained relatively stable throughout the duration of all the experiments conducted, although some animals displayed transient increases in serum IgE. Only TMA treatment was associated with a significant and sustained increase in the level of serum IgE in the majority of experiments. The elevated concentrations of IgE induced by topical exposure to TMA are persistent, the results reported here demonstrating that induced changes in IgE are maximal or near maximal at approximately 35 days, with a significant increase in IgE demonstrable for at least 42 days following the initiation of exposure. Interestingly, although TMA and DNCB at the test concentrations used were found to be of comparable overall immunogenicity with regard to lymph node activation and the induction of lymph node cell proliferation, there were apparent differences in humoral immune responses. Thus, not only did exposure to TMA stimulate increases in total serum IgE concentration and the production of specific IgE antibody, but also a more vigorous IgG antibody response was provoked by TMA compared with DNCB. These data suggest that the measurement of induced changes in serum IgE concentration in the BN strain of rat is able to differentiate between different classes of chemical allergen. Given the inter-animal variation in IgE production, it would be prudent to incorporate a concurrent assessment of responses induced by treatment with TMA as a positive control against which to assess the activity of other test materials.

Differences in immune responses to antibiotics in three guinea-pig strains.

The present experiments were undertaken to clarify the differences in humoral immune response to two beta-lactam antibiotics, benzylpenicillin potassium (PcG) and cephalothin sodium (CET), in guinea-pig strains. Guinea pigs of three different strains, Hartley, Strain 2 and Strain 13, were immunized subcutaneously with PcG (10 mg/body) 1 or 3 times a week, 10 times in total, or with CET (20 mg/body) 3 times a week, 12 times in total. Humoral immune responses to the two antibiotics were assessed by passive cutaneous anaphylaxis (PCA) and active systemic anaphylaxis (ASA) reactions. The relative intensities of the responses to PcG and CET detected by PCA reaction were Hartley > Strain 2 > Strain 13. On the other hand, Hartley and Strain 13 guinea pigs displayed high responses to the two antibiotics by ASA reaction, and Strain 2 exhibited a relatively low response. Based on these results, it was clarified that the Hartley strain, which is the most common strain used in ordinary allergenicity tests, showed the highest response to the two antibiotics tested in PCA and ASA reactions.