scholarly journals Redirecting the Humoral Immune Response against Streptococcus mutans Antigen P1 with Monoclonal Antibodies

2004 ◽  
Vol 72 (12) ◽  
pp. 6951-6960 ◽  
Author(s):  
Monika W. Oli ◽  
Nikki Rhodin ◽  
William P. McArthur ◽  
L. Jeannine Brady

ABSTRACT The adhesin P1 of Streptococcus mutans has been studied as an anticaries vaccine antigen. An anti-P1 monoclonal antibody (MAb) bound to S. mutans prior to mucosal immunization of mice was shown previously to alter the amount, specificity, isotype, and biological activity of anti-P1 antibodies. The present study was undertaken to screen this and four additional anti-P1 MAbs for immunomodulatory activity when complexed with S. mutans and administered by a systemic route and to evaluate sera from immunized mice for the ability to inhibit adherence of S. mutans to immobilized human salivary agglutinin. All five MAbs tested influenced murine anti-P1 serum antibody responses in terms of subclass distribution and/or specificity. The effects varied depending on which MAb was used and its coating concentration. Two MAbs promoted a more effective, and two others a less effective, adherence inhibition response. An inverse relationship was observed between the ability of the MAbs themselves to inhibit adherence and the ability of antibodies elicited following immunization with immune complexes to inhibit adherence. Statistically significant correlations were demonstrated between the levels of anti-P1 serum immunoglobulin G2a (IgG2a) and IgG2b, but not of IgG1 or IgG3, and the ability of sera from immunized animals to inhibit bacterial adherence. These results indicate that multiple anti-P1 MAbs can mediate changes in the immune response and that certain alterations are potentially more biologically relevant than others. Immunomodulation by anti-P1 MAbs represents a useful strategy to improve the beneficial immune response against S. mutans.

Gut ◽  
1999 ◽  
Vol 45 (3) ◽  
pp. 335-340 ◽  
Author(s):  
P Sutton ◽  
J Wilson ◽  
R Genta ◽  
D Torrey ◽  
A Savinainen ◽  
...  

BACKGROUNDThe importance of host factors in helicobacter induced gastritis has been shown in animal models. Infection of most mouse strains withHelicobacter felis results in a functional atrophic gastritis, while other strains remain gastritis free.AIMSTo investigate these host factors further by using genetic crosses of responder and non-responder mice.METHODSF1 hybrids of the non-responder CBA/Ca strain and three strains of mice known to develop H felis induced gastritis were infected for three months with H felis. Gastritis was assessed by histopathology and serum antibody responses by ELISA.RESULTSInfection of CBA/Ca mice and F1 hybrids induced little or no gastritis. Analyses of the antibody responses in these mice revealed virtually undetectable anti-helicobacter antibody levels despite colonisation with high numbers of H felis. In contrast, infection of H felis responsive strains induced gastritis and a significant humoral immune response.CONCLUSIONSThe non-responsiveness of CBA/Ca mice to H felis infection is dominantly inherited. The lack of gastritis in CBA mice and their offspring is probably due to active suppression of the immune response normally mounted against H felis. Investigation of these mechanisms will provide important insights relevant to induction of gastric atrophy and cancer in humans.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ernesta Cavalcanti ◽  
Maria Antonietta Isgrò ◽  
Domenica Rea ◽  
Lucia Di Capua ◽  
Giusy Trillò ◽  
...  

Abstract Background Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and the resulting disease, coronavirus disease 2019 (COVID-19), have spread to millions of people globally, requiring the development of billions of different vaccine doses. The SARS-CoV-2 spike mRNA vaccine (named BNT162b2/Pfizer), authorized by the FDA, has shown high efficacy in preventing SARS-CoV-2 infection after administration of two doses in individuals 16 years of age and older. In the present study, we retrospectively evaluated the differences in the SARS-CoV-2 humoral immune response after vaccine administration in the two different cohorts of workers at the INT - IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy): previously infected to SARS-CoV-2 subjects and not infected to SARS-CoV-2 subjects. Methods We determined specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 by Roche Elecsys Anti-SARS-CoV-2 S immunoassay in serum samples of 35 healthcare workers with a previous documented history of SARS-CoV-2 infection and 158 healthcare workers without, after 1 and 2 doses of vaccine, respectively. Moreover, geometric mean titers and relative fold changes (FC) were calculated. Results Both previously infected and not infected to SARS-CoV-2 subjects developed significant immune responses to SARS-CoV-2 after the administration of 1 and 2 doses of vaccine, respectively. Anti-S antibody responses to the first dose of vaccine were significantly higher in previously SARS-CoV-2-infected subjects in comparison to titers of not infected subjects after the first as well as the second dose of vaccine. Fold changes for subjects previously infected to SARS-CoV-2 was very modest, given the high basal antibody titer, as well as the upper limit of 2500.0 BAU/mL imposed by the Roche methods. Conversely, for naïve subjects, mean fold change following the first dose was low ($$ \overline{x} $$ x ¯ =1.6), reaching 3.8 FC in 72 subjects (45.6%) following the second dose. Conclusions The results showed that, as early as the first dose, SARS-CoV-2-infected individuals developed a remarkable and statistically significant immune response in comparison to those who did not contract the virus previously, suggesting the possibility of administering only one dose in previously SARS-CoV-2-infected subjects. FC for previously infected subjects should not be taken into account for the generally high pre-vaccination values. Conversely, FC for not infected subjects, after the second dose, were = 3.8 in > 45.0% of vaccinees, and ≤ 3.1 in 19.0%, the latter showing a potential susceptibility to further SARS-CoV-2 infection.


2006 ◽  
Vol 2 (4) ◽  
pp. 573-576 ◽  
Author(s):  
Jane M Reid ◽  
Peter Arcese ◽  
Lukas F Keller ◽  
Dennis Hasselquist

Knowledge of the causes of variation in host immunity to parasitic infection and the time-scales over which variation persists, is integral to predicting the evolutionary and epidemiological consequences of host–parasite interactions. It is clear that offspring immunity can be influenced by parental immune experience, for example, reflecting transfer of antibodies from mothers to young offspring. However, it is less clear whether such parental effects persist or have functional consequences over longer time-scales, linking a parent's previous immune experience to future immune responsiveness in fully grown offspring. We used free-living song sparrows ( Melospiza melodia ) to quantify long-term effects of parental immune experience on offspring immune response. We experimentally vaccinated parents with a novel antigen and tested whether parental vaccination influenced the humoral antibody response mounted by fully grown offspring hatched the following year. Parental vaccination did not influence offspring baseline antibody titres. However, offspring of vaccinated mothers mounted substantially stronger antibody responses than offspring of unvaccinated mothers. Antibody responses did not differ between offspring of vaccinated and unvaccinated fathers. These data demonstrate substantial long-term effects of maternal immune experience on the humoral immune response of fully grown offspring in free-living birds.


Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 23 ◽  
Author(s):  
Stefano Petrini ◽  
Carmen Iscaro ◽  
Cecilia Righi

To date, in countries where infectious bovine rhinotracheitis (IBR) is widespread, its control is associated with deleted marker vaccines. These products lack one or more genes responsible for the synthesis of glycoproteins or enzymes. In Europe, the most widely used marker vaccine is one in which glycoprotein E (gE−) is deleted, and it is marketed in a killed or modified-live form. Using this type of immunization, it is possible to differentiate vaccinated animals (gE−) from those infected or injected with non-deleted (gE+) products using diagnostic tests specific for gE. The disadvantage of using modified-live gE-products is that they may remain latent in immunized animals and be reactivated or excreted following an immunosuppressive stimulus. For this reason, in the last few years, a new marker vaccine became commercially available containing a double deletion related to genes coding for gE and the synthesis of the thymidine-kinase (tk) enzyme, the latter being associated with the reduction of the neurotropism, latency, and reactivation of the vaccine virus. Intramuscularly and intranasally administered marker products induce a humoral immune response; however, the mother-to-calf antibody kinetics after vaccination with marker vaccines is poorly understood. This review discusses several published articles on this topic.


1977 ◽  
Vol 145 (6) ◽  
pp. 1602-1606 ◽  
Author(s):  
M Zaleski ◽  
J Klein

Mouse thymus, thymus-derived lymphocytes, and brain share an antigen determined by gene at the Thy-1 locus in chromosome 9 (1). Two alleles have been identified at this locus: Thy-1(a), coding for antigen Thy-1.1 (or θ-AKR) present in AKR and seven other strains; and Thy-1(b), coding for antigen Thy-1.2 (or{teta}-C3H) and present in C3H and all the remaining inbred strains. Injection of AKR thymocytes into inbred mice carrying the Thy-1(b) allele results in an immune response that can be measured either serologically by determining the level of antibodies in the recipients serum (1) or by counting plaque- forming cells (PFC) detectable in spleens of the recipients by means of an assay, with AKR thymocytes as target cells(2). The magnitude of PFC and serum antibody responses after a single thymocyte injection depends on the genetic make-up of the recipient. Three genes controlling the PFC response to the Thy- 1.1 antigen have been identified: Ir-Thy-1A and Ir-Thy-1B, which are closely linked to the major histocompatibility complex (H-2) of the mouse (3-6), and Ir-5, which is located at a distance of 17 cm to the right of the H-2 complex on chromosome 17 (6). Previous genetic mapping with H-2 recombinant strains has indicated that the two Ir-Thy-1 loci are located to the left of the IC subregion (7). Further experiments strongly suggested that either one or both Ir-Thy-1 loci map to the K rather than the I region of the H-2 complex (8). In this report, the study of an H- 2 mutant, CBA-H-2(ka) (M523) (9), and its parental strain, CBA/LacStoY (CBA) provided further evidence that one of these loci apparently resides in the K region and might even be identical with the H-2K locus in that region.


1999 ◽  
Vol 67 (5) ◽  
pp. 2643-2648 ◽  
Author(s):  
Benoît Baras ◽  
Marie-Ange Benoit ◽  
Loïc Dupré ◽  
Odile Poulain-Godefroy ◽  
Anne-Marie Schacht ◽  
...  

ABSTRACT The purpose of this work was to assess the immunogenicity of a single nasal or oral administration of recombinant 28-kDa glutathioneS-transferase of Schistosoma mansoni (rSm28GST) entrapped by poly(lactide-co-glycolide) (PLG)- or polycaprolactone (PCL)-biodegradable microparticles. Whatever the polymer and the route of administration used, the equivalent of 100 μg of entrapped rSm28GST induced a long-lasting and stable antigen-specific serum antibody response, with a peak at 9 to 10 weeks following immunization. Isotype profiles were comparable, with immunoglobulin G1 being the predominant isotype produced. The abilities of specific antisera to neutralize the rSm28GST enzymatic activity have been used as criteria of immune response quality. Pooled 10-week sera from mice receiving PLG microparticles by the nasal or oral route neutralized the rSm28GST enzymatic activity, whereas sera of mice receiving either PCL microparticles, free rSm28GST, or empty microparticles inefficiently neutralized this enzymatic activity. Finally, this study shows that a single administration of these microparticles could provide distinct and timely release pulses of microencapsulated antigen, which might greatly facilitate future vaccine development.


2018 ◽  
Author(s):  
Jinhee Yi ◽  
Mukoma F. Simpanya ◽  
Erik W. Settles ◽  
Austin B. Shannon ◽  
Karen Hernandez ◽  
...  

AbstractBurkholderia pseudomalleicauses melioidosis, a common source of pneumonia and sepsis in Southeast Asia and Northern Australia, that results in high mortality rates. A caprine melioidosis model of aerosol infection that leads to a systemic infection has the potential to characterize the humoral immune response. This could help identify immunogenic proteins for new diagnostics and vaccine candidates. Outbred goats may more accurately mimic human infection, in contrast to the inbred mouse models used to date.B. pseudomalleiinfection was delivered as an intratracheal aerosol. Antigenic protein profiling was generated from the infecting strain MSHR511. Humoral immune responses were analyzed by ELISA and western blot, and the antigenic proteins were identified by mass spectrometry. Throughout the course of the infection the assay results demonstrated a much greater humoral response with IgG antibodies, in both breadth and quantity, compared to IgM antibodies. Pre-infection sera showed multiple immunogenic proteins already reactive for IgG (7-20) and IgM (0-12) in most of the goats despite no previous exposure toB. pseudomallei. After infection, the number of IgG reactive proteins showed a marked increase as the disease progressed. Early stage infection (day 7) showed immune reaction to chaperone proteins (GroEL, EF-Tu, and DnaK). These three proteins were detected in all serum samples after infection, with GroEL immunogenically dominant. Seven common reactive antigens were selected for further analysis using ELISA. The heat shock protein GroEL1 elicited the strongest goat antibody immune response compared to the other six antigens. Most of the six antigens showed the peak IgM reactivity at day 14, whereas the IgG reactivity increased further as the disease progressed. An overall MSHR511 proteomic comparison between the goat model and human sera showed that many immune reactive proteins are common between humans and goats with melioidosis.Author SummaryB. pseudomalleiinfection, the causative agent of melioidosis, results in severe disseminated or localized infections. A systemic study of the humoral immune response toB. pseudomalleiinfection using theB. pseudomalleiaerosol caprine model would help understand the detectable antigenic proteins as the infection progresses. To study the immune response, IgG and IgM antibody responses to whole cell lysate proteins were identified and analyzed. Antigenic carbohydrates were also studied. From the results, this study suggests that the caprine humoral immune response to aerosolizedB. pseudomalleihas similarities to human melioidosis and may facilitate the analysis of the temporal antibody responses. In addition, commonly detected immunogenic proteins may be used as biomarkers for the future point of care (POC) diagnostics.


2021 ◽  
Author(s):  
S Jake Gonzales ◽  
Kathleen N Clarke ◽  
Gayani Batugedara ◽  
Ashley E Braddom ◽  
Rolando Garza ◽  
...  

Memory B cells (MBCs) and plasma antibodies against Plasmodium falciparum merozoite antigens are important components of the protective immune response against malaria. To gain understanding of how responses against P. falciparum develop in these two arms of the humoral immune system, we evaluated MBC and antibody responses against the most abundant merozoite antigen, merozoite surface protein 1 (MSP1), in individuals from a region in Uganda with high P. falciparum transmission. Our results showed that MSP1-specific B cells in adults with immunological protection against malaria were predominantly IgG+ classical MBCs, while children with incomplete protection mainly harbored IgM+ MSP1-specific classical MBCs. In contrast, anti-MSP1 plasma IgM reactivity was minimal in both children and adults. Instead, both groups showed high plasma IgG reactivity against MSP1 and whole merozoites, with broadening of the response against non-3D7 strains in adults. The antibodies encoded by MSP1-specific IgG+ MBCs carried high levels of amino acid substitutions and recognized relatively conserved epitopes on the highly variable MSP1 protein. Proteomics analysis of MSP119-specific IgG in plasma of an adult revealed a limited repertoire of anti-MSP1 antibodies, most of which were IgG1 or IgG3. Similar to MSP1-specific MBCs, anti-MSP1 IgGs had relatively high levels of amino acid substitutions and their sequences were predominantly found in classical MBCs, not atypical MBCs. Collectively, these results showed evolution of the MSP1-specific humoral immune response with cumulative P. falciparum exposure, with a shift from IgM+ to IgG+ B cell memory, diversification of B cells from germline, and stronger recognition of MSP1 variants by the plasma IgG repertoire.


2021 ◽  
Author(s):  
Ernesta Cavalcanti ◽  
Maria Antonietta Isgrò ◽  
Domenica Rea ◽  
Lucia Di Capua ◽  
Giusy Trillò ◽  
...  

Abstract Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and the resulting disease, coronavirus disease 2019 (COVID-19), have spread to millions of people globally, requiring the development of billions of different vaccine doses. The SARS-CoV-2 spike mRNA vaccine (named BNT162b2/Pfizer), authorized by the FDA, has shown high efficacy in preventing SARS-CoV-2 infection after administration of two doses in individuals 16 years of age and older. In the present study, we retrospectively evaluated the differences in the SARS-CoV-2 humoral immune response after vaccine administration in the two different cohorts of workers at the INT - IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy): previously exposed to SARS-CoV-2 subjects and not exposed to SARS-CoV-2 subjects.Methods: We determined specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 by Roche Elecsys Anti-SARS-CoV-2 S immunoassay in serum samples of 35 healthcare workers with a previous documented history of SARS-CoV-2 infection and 158 healthcare workers without, after 1 and 2 doses of vaccine, respectively. Moreover, geometric mean titers and relative fold changes (FC) were calculated.Results: Both previously exposed and not exposed to SARS-CoV-2 subjects developed significant immune responses to SARS-CoV-2 after the administration of 1 and 2 doses of vaccine, respectively. Anti-S antibody responses to the first dose of vaccine were significantly higher in previously SARS-CoV-2-exposed subjects in comparison to titers of not exposed subjects after the first as well as the second dose of vaccine. Fold changes for subjects previously exposed to SARS-CoV-2 was very modest, given the high basal antibody titer, as well as the upper limit of 2500.0 BAU/mL imposed by the Roche methods. Conversely, for naïve subjects, mean fold change following the first dose was low ( =1.6), reaching 3.8 FC in 72 subjects (45.6%) following the second dose.Conclusions: The results showed that, as early as the first dose, SARS-CoV-2-exposed individuals developed a remarkable and statistically significant immune response in comparison to those who did not contract the virus previously, suggesting the possibility of administering only one dose in previously SARS-CoV-2-exposed subjects. FC for previously exposed subjects should not be taken into account for the generally high pre-vaccination values. Conversely, FC for not exposed subjects, after the second dose, were = 3.8 in >45.0% of vaccinees, and ≤3.1 in 19.0%, the latter showing a potential susceptibility to further SARS-CoV-2 infection.


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