scholarly journals A Humoral Immune Response Confers Protection against Haemophilus ducreyi Infection

2003 ◽  
Vol 71 (12) ◽  
pp. 6971-6977 ◽  
Author(s):  
Leah E. Cole ◽  
Kristen L. Toffer ◽  
Robert A. Fulcher ◽  
Lani R. San Mateo ◽  
Paul E. Orndorff ◽  
...  

ABSTRACT Haemophilus ducreyi is the etiologic agent of the sexually transmitted genital ulcer disease chancroid. Neither naturally occurring chancroid nor experimental infection with H. ducreyi results in protective immunity. Likewise, a single inoculation of H. ducreyi does not protect pigs against subsequent infection. Accordingly, we used the swine model of chancroid infection to examine the impact of multiple inoculations on a host's immune response. After three successive inoculations with H. ducreyi, pigs developed a modestly protective immune response evidenced by the decreased recovery of viable bacteria from lesions. All lesions biopsied 2 days after the first and second inoculations contained viable H. ducreyi cells, yet only 55% of the lesions biopsied 2 days after the third inoculation did. Nearly 90% of the lesions biopsied 7 days after the first inoculation contained viable H. ducreyi cells, but this percentage dropped to only 16% after the third inoculation. Between the first and third inoculations, the average recovery of CFU from lesions decreased approximately 100-fold. The reduced recovery of bacteria corresponded directly with a fivefold increase in H. ducreyi-specific antibody titers and the emergence of bactericidal activity. These immune sera were protective when administered to naïve pigs prior to challenge with H. ducreyi. These data suggest that pigs mount an effective humoral immune response to H. ducreyi after multiple exposures to the organism.

2019 ◽  
Vol 7 (5) ◽  
pp. 125
Author(s):  
Ryan M. Moreno ◽  
Victor Jimenez ◽  
Fernando P. Monroy

Burkholderia pseudomallei, the causative agent of melioidosis can occur in healthy humans, yet binge alcohol use is progressively being recognized as a major risk factor. Currently, no experimental studies have investigated the effects of binge alcohol on the adaptive immune system during an active infection. In this study, we used B. thailandensis and B. vietnamiensis, to investigate the impact of a single binge alcohol episode on the humoral response during infection. Eight-week-old female C57BL/6 mice were administered alcohol comparable to human binge drinking (4.4 g/kg) or PBS intraperitoneally 30 min before intranasal infection. Mice infected with B. thailandensis had a 100% survival rate, while those infected with B. vietnamiensis had a 33% survivability rate when a binge alcohol dose was administered. B. thailandensis was detected in blood of mice administered alcohol at only 7 days post infection (PI), while those infected with B. vietnamiensis and receiving alcohol were found throughout the 28-day infection as well as in tissues at day 28 PI. Binge alcohol elevated IgM and delayed IgG specific to the whole cell lysate (WCL) of B. vietnamiensis but not B. thailandensis infections. Differences in immunogenicity of B. pseudomallei near-neighbors provide a framework for novel insights into the effects of binge alcohol’s suppression of the humoral immune response that can cause opportunistic infections in otherwise healthy hosts.


PLoS ONE ◽  
2008 ◽  
Vol 3 (1) ◽  
pp. e1481 ◽  
Author(s):  
M. Abid Hussain ◽  
Shaik A. Naveed ◽  
Leonardo A. Sechi ◽  
Sarita Ranjan ◽  
Ayesha Alvi ◽  
...  

1992 ◽  
Vol 18 (2) ◽  
pp. 309-314
Author(s):  
MICHELLE J. ALFA ◽  
NANCY OLSON ◽  
PAT DEGAGNE ◽  
LESLIE SLANEY ◽  
FRANK PLUMMER ◽  
...  

2012 ◽  
Vol 36 (0E) ◽  
pp. 84-88
Author(s):  
Ekram A. Al-Samarrae

Salmonella typhimurium and salmonella enteritidis were isolated from infected goat andprepared an antigens of whole cell sonicated antigen of S.typhimurium(WCS.Ag.S.typhimurium ),whole cell sonicated antigen of S.enteritidis (WCS.Ag.S.entertidis) and combination of whole cell sonicated antigen (Salmonella typhimurium andSalmonella enteritidis) (CWS.Ag) . Their efficacy was evaluated by using tube agglutinationtest and enzyme linked immune sorbent assay (ELISA). Twenty rabbits were randomlydivided into four groups; the 1st group was immunized by WCS. Ag - Salmonella enteritidis,2nd group immunized by (WCS Ags .typhimurium), 3rd group immunized by CWCS.Agcompound and 4th left as control group which injected by physiological buffer saline (pH7.2). The antibody titer was increased in after the day 12, first, second and third months ofimmunization by agglutination test. IgG concentration was done by ELISA at the same time;which were recorded a higher significant differences (p˂ 0.01) at the first month in the groupimmunized by CWS Ag (449.65 ±38.6 1ng/ml IgG and 952± 20.85 antibodies titer )compared with other immunized groups ( WCS – Ag – S. enteritidis andWCS.Ag.S.typhimurium ). Also, the IgG concentration and antibodies titer are still higher inthe second and the third months in the immunized group by CWCS.Ag. 218.90± 6.69ng/ml,528± 68.58 and 89.55± 2.63ng/ml, 280± 49.98 respectively with significant differences (p˂0.01) compared with the immunized groups (WCS.Ag.S. entertidis and WCS. Ag.S.typhimurium) and also, they are significant (p˂ 0.01) when compared with the control groupResearch


2013 ◽  
Vol 81 (12) ◽  
pp. 4443-4452 ◽  
Author(s):  
William G. Fusco ◽  
Christopher Elkins ◽  
Isabelle Leduc

ABSTRACTHaemophilus ducreyiis the etiologic agent of the sexually transmitted genital ulcer disease chancroid. In both natural and experimental chancroid,H. ducreyicolocalizes with fibrin at the base of the ulcer. Fibrin is obtained by cleavage of the serum glycoprotein fibrinogen (Fg) by thrombin to initiate formation of the blood clot. Fg binding proteins are critical virulence factors in medically important Gram-positive bacteria.H. ducreyihas previously been shown to bind Fg in an agglutination assay, and theH. ducreyiFg binding protein FgbA was identified in ligand blotting with denatured proteins. To better characterize the interaction ofH. ducreyiwith Fg, we examined Fg binding to intact, viableH. ducreyibacteria and identified a novel Fg binding protein.H. ducreyibound unlabeled Fg in a dose-dependent manner, as measured by two different methods. In ligand blotting with total denatured cellular proteins, digoxigenin (DIG)-Fg bound only twoH. ducreyiproteins, the trimeric autotransporter DsrA and the lectin DltA; however, only the isogenicdsrAmutant had significantly less cell-associated Fg than parental strains in Fg binding assays with intact bacteria. Furthermore, expression of DsrA, but not DltA or an empty vector, rendered the non-Fg-bindingH. influenzaestrain Rd capable of binding Fg. A 13-amino-acid sequence in the C-terminal section of the passenger domain of DsrA appears to be involved in Fg binding byH. ducreyi. Taken together, these data suggest that the trimeric autotransporter DsrA is a major determinant of Fg binding at the surface ofH. ducreyi.


2021 ◽  
pp. 135245852110493
Author(s):  
Gabriel Bsteh ◽  
Sophie Dürauer ◽  
Hamid Assar ◽  
Harald Hegen ◽  
Bettina Heschl ◽  
...  

Background: Knowledge on immunity after SARS-CoV-2 infection in patients with multiple sclerosis (pwMS) and the impact of disease-modifying treatment (DMT) is limited. Objective: To evaluate degree, duration and potential predictors of specific humoral immune response in pwMS with prior COVID-19. Methods: Anti-SARS-CoV-2 antibody testing was performed in pwMS with PCR-confirmed diagnosis of symptomatic COVID-19 from a nation-wide registry. Predictors of seropositivity were identified by multivariate regression models. Results: In 125 pwMS (mean age = 42.4 years (SD = 12.3 years), 70% female), anti-SARS-CoV-2 antibodies were detected in 76.0% after a median of 5.2 months from positive PCR. Seropositivity rate was significantly lower in patients on IS-DMT (61.4%, p = 0.001) than without DMT or immunomodulatory DMT (80.6%; 86.0%, respectively). In multivariate analysis, IS-DMT was associated with reduced probability of seropositivity (odds ratio (OR): 0.51; 95% confidence interval (95% CI): 0.17–0.82; p < 0.001). Predefined subgroup analyses showed marked reduction of seropositivity in pwMS on rituximab/ocrelizumab (OR 0.15; 95% CI: 0.05–0.56; p < 0.001). Rate of seropositivity did not change significantly over 6 months. Conclusions: Humoral immunity is stable after SARS-CoV-2 infection in MS, but is reduced by immunosuppressive DMT, particularly anti-CD20 monoclonal antibodies. This provides important evidence for advising pwMS as well as for planning and prioritizing vaccination.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 777-777
Author(s):  
Wen-Kai Weng ◽  
Debra Czerwinski ◽  
Ronald Levy

Abstract Recently, we found that anti-idiotype humoral immune response and FcγRIIIa 158 Valine/Valine (V/V) correlated with clinical outcome in follicular lymphoma patients receiving idiotype vaccination (JCO 22:4717). This result highlighted the importance of developing anti-tumor antibodies and hosting an efficient ADCC machinery. In the previous study, all 136 patients received induction chemotherapy and were in clinical remission at the time of idiotype vaccination. One important question is whether the outcome of these patients was correlated with their clinical response to induction chemotherapy. We, therefore, analyzed the impact of chemotherapy response on clinical outcome to determine if the better outcome associated with humoral immune response and V/V genotype applies to patients with different chemotherapy response. Induction cheomtherapies included chlorambucil, CVP, an adriamycin-containing regimen, or alternating CVP and fludarabine. Ninety patients (66%) achieved complete response or unconfirmed complete response (CR/CRu) and 46 patient (34%) achieved partial response (PR). The progression free survival at 4 years was 59% for CR/CRu patients and 41% for PR patients. The median time to progression (TTP) of 5.21 for CR/CRu patients was significantly longer than the 1.62 years for PR patients (p=0.004). Multi-variant analysis using the Cox Proportional Hazards Model showed that humoral IR, V/V genotype and CR/CRu were three independent positive predictors for progression free survival, while FcγRIIa genotype, FcγRIIb genotype, cellular IR, gender, age, B symptoms, time from diagnosis to therapy, use of adriamycin or use of fludarabine during induction chemotherapy had no impact. The relative benefit was 2.26 (95% CI, 1.36–3.76, p=0.0016) for humoral IR, 5.03 (95% CI, 2.06–12.25, p=0.0004) for V/V genotype and 2.01 (95% CI, 1.22–3.29, p=0.0057) for CR/CRu. The impact of humoral immune response and V/V genotype on CR/CRu or PR patients were then examined. In CR/CRu patients, the progression free survival at 4 years was 74% for patients with humoral immune response and/or V/V genotype while only 45% for patients without either, with median TTP not reached and of 3.46 years for the two groups, respectively (p=0.007). In PR patients, the benefit of having humoral immune response and/or V/V genotype was even more pronounced. The progression free survival at 4 years was 63% for patients with humoral immune response and/or V/V genotype and 21% for patients without either, with median TTP not reached after 8 years and of 1.31 years for the two groups, respectively (p=0.0004). This result suggests that having humoral immune response and/or V/V genotype was associated with longer TTP regardless of their response to induction chemotherapy. In fact, there is no difference in the TTP between CR/CRu and PR patients if they had humoral immune response and/or V/V genotype (TTP not reached in both groups, p=0.338). In contrast, in the group with neither humoral immune response nor V/V genotype, CR/CRu patients enjoyed much longer TTP than PR patients (TTP 3.46 year vs 1.31 years, p=0.0005). This result further confirms the strong association of clinical outcome with humoral immune response and with the functional activity of Fc receptor bearing cells in patients receiving idiotype vaccination. Our results also argue for the inclusion of PR as well as CR patients in idiotype vaccine trials, since the apparent benefit of immune response is even greater in PR patients.


PLoS ONE ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. e0122282 ◽  
Author(s):  
Iana H. Haralambieva ◽  
Scott D. Painter ◽  
Richard B. Kennedy ◽  
Inna G. Ovsyannikova ◽  
Nathaniel D. Lambert ◽  
...  

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1470
Author(s):  
Lutz Achtnichts ◽  
Barbara Jakopp ◽  
Michael Oberle ◽  
Krassen Nedeltchev ◽  
Christoph Andreas Fux ◽  
...  

CD20 depletion is a risk factor for unfavorable outcomes of COVID-19 in people with MS (pwMS). Evidence suggests that protective IgG response to mRNA-based vaccines in B cell-depleted individuals is limited. We studied the seroconversion after the third mRNA SARS-CoV-2 vaccine in B cell-depleted pwMS with limited or no IgG response after the standard immunization. Sixteen pwMS treated with ocrelizumab or rituximab received a third homologous SARS-CoV-2 mRNA vaccine, either the Moderna mRNA-1273 or Pfizer-BioNTech’s BNT162b2 vaccine. We quantified the response of IgG antibodies against the spike receptor-binding domain of SARS-CoV-2 four weeks later. An antibody titer of 100 AU/mL or more was considered clinically relevant. The median time between the last infusion of the anti-CD20 treatment and the third vaccination was 22.9 weeks (range 15.1–31.3). After the third vaccination, one out of 16 patients showed an IgG titer deemed clinically relevant. Only the seroconverted patient had measurable B-cell counts at the time of the third vaccination. The development of a humoral immune response remains rare in pwMS on anti-CD20 therapy, even after third dose of the homologous SARS-CoV-2 mRNA vaccine. It remains to be determined whether T-cell responses can compensate for the lack of seroconversion and provide sufficient protection against CoV-2 infections.


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