Vaccination against Trichinella spiralis in mice using antigens from different isolates

Parasitology ◽  
1993 ◽  
Vol 107 (3) ◽  
pp. 311-317 ◽  
Author(s):  
P. K. Goyal ◽  
D. Wakelin

SummaryAntigen preparations from three isolates of Trichinella spiralis (sensu-stricto) have been tested for their ability to immunize mice against homologous and heterologous challenge infections. Immunization was measured by accelerated expulsion of adult worms, reduction in female worm fecundity, stunting of growth, and level of antibody responses before and after challenge. Antigens of two isolates, from London (L) and Poland (P), immunized effectively against homologous challenge, adult worm recoveries being reduced by 64% and 51% respectively within 6 days. Antigen from a Spanish(S) isolate gave no homologous protection in terms of worm recovery at day 6 and only 43% reduction at day 8. L- and P-isolate antigens immunized well against heterologous challenge (day 6 worm recoveries reduced by 66% and 59%) but similar protection against S-isolate challenge was not seen until day 8. Immunization with S antigen gave better protection at day 6 against L-isolate challenge (77%) than against challenge with P-isolate (37%). These results imply considerable, but not complete, antigen cross-reactivity between the isolates and this was reflected in antibody responses. These variations in immunogenicity and immunization potential are discussed in terms of constraints on the use of vaccines against parasites that are widely distributed geographically.

Parasitology ◽  
1996 ◽  
Vol 113 (4) ◽  
pp. 367-375 ◽  
Author(s):  
M. V. Johansen ◽  
Y. Fillié ◽  
J. Monrad ◽  
N. Ø. Christensen ◽  
A. Deelder

SUMMARYCirculating antigen levels and antibody responses in Schistosoma bovis-infected West African Dwarf goats were evaluated during infection and following treatment with praziquantel (60 mg/kg) 13 weeks post-infection. One day, 1 week and 4 weeks post-treatment, subgroups of goats were sacrificed and perfused for worm recovery. For comparison, parasite-free control animals were included. Blood and faecal samples were collected biweekly. Two gut-associated schistosome antigens, circulating cathodic and circulating anodic antigen (CCA and CAA) and 3 specific antibody responses (total Ig, IgG and IgM) were measured. For specific antibody detection, crude S. bovis adult worm and egg homogenates were used. The level of CCA in the infected groups was significantly elevated from the time of onset of egg excretion onwards. However, following treatment, the CCA litres dropped to control levels within 1 week post-treatment. Strong positive correlations were found between CCA levels and worm counts and faecal egg counts during peak egg excretion. The correlations of CAA and specific antibody litres to egg and worm counts were poor. The antibody responses were all significantly elevated in the infected goats during patency, but only marginally affected by the treatment. Hence, CCA proved to be superior by correlating strongly to the level of infection and by being a sensitive indicator of the effect of treatment.


mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Ellen E. Higginson ◽  
Girish Ramachandran ◽  
Tracy H. Hazen ◽  
Dane A. Kania ◽  
David A. Rasko ◽  
...  

ABSTRACT Enteric fever is caused by three Salmonella enterica serovars: Typhi, Paratyphi A, and Paratyphi B sensu stricto. Although vaccines against two of these serovars are licensed (Typhi) or in clinical development (Paratyphi A), as yet there are no candidates for S. Paratyphi B. To gain genomic insight into these serovars, we sequenced 38 enteric fever-associated strains from Chile and compared these with reference genomes. Each of the serovars was separated genomically based on the core genome. Genomic comparisons identified loci that were aberrant between serovars Paratyphi B sensu stricto and Paratyphi B Java, which is typically associated with gastroenteritis; however, the majority of these were annotated as hypothetical or phage related and thus were not ideal vaccine candidates. With the genomic information in hand, we engineered a live attenuated S. Paratyphi B sensu stricto vaccine strain, CVD 2005, which was capable of protecting mice from both homologous challenge and heterologous challenge with S. Paratyphi B Java. These findings extend our understanding of S. Paratyphi B and provide a viable vaccine option for inclusion in a trivalent live attenuated enteric fever vaccine formulation. IMPORTANCE We developed a live attenuated Salmonella enterica serovar Paratyphi B vaccine that conferred protection in mice against challenge with S. Paratyphi B sensu stricto and S. Paratyphi B Java, which are the causes of enteric fever and gastroenteritis, respectively. Currently, the incidence of invasive S. Paratyphi B sensu stricto infections is low; however, the development of new conjugate vaccines against other enteric fever serovars could lead to the emergence of S. Paratyphi B to fill the niche left by these other pathogens. As such, an effective S. Paratyphi B vaccine would be a useful tool in the armamentarium against Salmonella infections. Comparative genomics confirmed the serovar-specific groupings of these isolates and revealed that there are a limited number of genetic differences between the sensu stricto and Java strains, which are mostly hypothetical and phage-encoded proteins. The observed level of genomic similarity likely explains why we observe some cross-protection.


Parasitology ◽  
1993 ◽  
Vol 106 (4) ◽  
pp. 371-378 ◽  
Author(s):  
P. K. Goyal ◽  
D. Wakelin

SUMMARYVariation in the immunogenicity of 3 isolates ofTrichinella spiraliswas assessed by the parameters of adult worm recovery, mast cell, eosinophil and antibody responses in mice of defined response phenotype. The levels of the protective, inflammatory and immune responses induced by infection differed between the isolates. Isolates showed considerable variation in the capacity to elicit mast cell and eosinophil responses. All induced increases in parasite-specific antibody, levels of total (IgGAM) antibody and of IgM and IgG isotypes rose steadily after infection, but there were significant differences in levels of response. The IgGAM response was correlated with the number of worms present, i.e. the greatest response was seen in low responder (C57BL/10) mice infected with the longest-surviving isolates. All isolates elicited specific IgG1 and IgG2a antibodies after infection, although, again, there were isolate-specific differences in the levels and kinetics of response. Levels of these isotypes were always higher, although not significantly so, in high-responder NIH mice. Low-responder mice showed higher IgE serum levels than high-responder mice after infection, one isolate giving much higher IgE values than the other two.


2021 ◽  
Author(s):  
Catherine Jacob-Dolan ◽  
Jared Feldman ◽  
Katherine McMahan ◽  
Jingyou Yu ◽  
Roland Zahn ◽  
...  

Vaccines are being rapidly developed with the goal of ending the SARS-CoV-2 pandemic. However, the extent to which SARS-CoV-2 vaccination induces serum responses that cross-react with other coronaviruses remains poorly studied. Here we define serum profiles in rhesus macaques after vaccination with DNA or Ad26 based vaccines expressing SARS-CoV-2 Spike protein followed by SARS-CoV-2 challenge, or SARS-CoV-2 infection alone. Analysis of serum responses showed robust reactivity to the SARS-CoV-2 full-length Spike protein and receptor binding domain (RBD), both included in the vaccine. However, serum cross-reactivity to the closely related sarbecovirus SARS-CoV-1 Spike and RBD, was reduced. Reactivity was also measured to the distantly related common cold alpha-coronavirus, 229E and NL63, and beta-coronavirus, OC43 and HKU1, Spike proteins. Using SARS-COV-2 and SARS-CoV-1 lentivirus based pseudoviruses, we show that neutralizing antibody responses were predominantly SARS-CoV-2 specific. These data define patterns of cross-reactive binding and neutralizing serum responses induced by SARS-CoV-2 infection and vaccination in rhesus macaques. Our observations have important implications for understanding polyclonal responses to SARS-CoV-2 Spike, which will facilitate future CoV vaccine assessment and development. Importance The rapid development and deployment of SARS-CoV-2 vaccines has been unprecedented. In this study, we explore the cross-reactivity of SARS-CoV-2 specific antibody responses to other coronaviruses. By analyzing responses from NHPs both before and after immunization with DNA or Ad26 vectored vaccines, we find patterns of cross reactivity that mirror those induced by SARS-CoV-2 infection. These data highlight the similarities between infection and vaccine induced humoral immunity for SARS-CoV-2 and cross-reactivity of these responses to other CoVs.


Infection ◽  
2021 ◽  
Author(s):  
Ali Hamady ◽  
JinJu Lee ◽  
Zuzanna A. Loboda

Abstract Objectives The coronavirus disease 2019 (COVID-19), caused by the novel betacoronavirus severe acute respiratory syndrome 2 (SARS-CoV-2), was declared a pandemic in March 2020. Due to the continuing surge in incidence and mortality globally, determining whether protective, long-term immunity develops after initial infection or vaccination has become critical. Methods/Results In this narrative review, we evaluate the latest understanding of antibody-mediated immunity to SARS-CoV-2 and to other coronaviruses (SARS-CoV, Middle East respiratory syndrome coronavirus and the four endemic human coronaviruses) in order to predict the consequences of antibody waning on long-term immunity against SARS-CoV-2. We summarise their antibody dynamics, including the potential effects of cross-reactivity and antibody waning on vaccination and other public health strategies. At present, based on our comparison with other coronaviruses we estimate that natural antibody-mediated protection for SARS-CoV-2 is likely to last for 1–2 years and therefore, if vaccine-induced antibodies follow a similar course, booster doses may be required. However, other factors such as memory B- and T-cells and new viral strains will also affect the duration of both natural and vaccine-mediated immunity. Conclusion Overall, antibody titres required for protection are yet to be established and inaccuracies of serological methods may be affecting this. We expect that with standardisation of serological testing and studies with longer follow-up, the implications of antibody waning will become clearer.


1977 ◽  
Vol 6 (3) ◽  
pp. 274-279
Author(s):  
Omar O. Barriga

Six diethylaminoethyl-cellulose fractions of a larval Trichinella spiralis extract, an Ascaris suum extract, and a nonrelated protein were used for cutaneous tests in guinea pigs with 8-, 14-, and 73-day-old T. spiralis infections, in guinea pigs with 13-day-old A. suum infections, and in normal guinea pigs. A selected T. spiralis fraction was used in hemagglutination (HA) tests with sera of 8 T. spiralis -infected rabbits, 41 sera of trichinellosis patients positive by bentonite agglutination tests, and 50 sera of clinically healthy persons. Immediate-type cutaneous reactions revealed extensive cross-reactivity between both parasites, although the establishment of conventional limits for considering a reaction positive allowed the specific diagnosis of acute or chronic trichinellosis with different fractions. Delayed-type reactions were specific with all fractions except one, and different fractions reacted during either the acute or the chronic phase of trichinellosis. HA detected anti- Trichinella antibodies in all the rabbits 9 to 10 days postinfection, in all trichinellosis patients, and in none of the healthy people. Correlation between HA and bentonite agglutination titers and other considerations suggest that HA with the selected fraction detects early antibodies. HA inhibition tests with A. suum extract suggest lack of HA cross-reactivity between the A. suum - and T. spiralis -selected fractions. The use of different fractions in diverse tests for clinical or epidemiological studies is suggested.


Allergy ◽  
2011 ◽  
Vol 66 (12) ◽  
pp. 1513-1521 ◽  
Author(s):  
B. A. Sin ◽  
M. Akdis ◽  
J. Zumkehr ◽  
S. Bezzine ◽  
C. Bekpen ◽  
...  

2020 ◽  
Vol 5 (52) ◽  
pp. eabe0367 ◽  
Author(s):  
Anita S. Iyer ◽  
Forrest K. Jones ◽  
Ariana Nodoushani ◽  
Meagan Kelly ◽  
Margaret Becker ◽  
...  

We measured plasma and/or serum antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in 343 North American patients infected with SARS-CoV-2 (of which 93% required hospitalization) up to 122 days after symptom onset and compared them to responses in 1548 individuals whose blood samples were obtained prior to the pandemic. After setting seropositivity thresholds for perfect specificity (100%), we estimated sensitivities of 95% for IgG, 90% for IgA, and 81% for IgM for detecting infected individuals between 15 and 28 days after symptom onset. While the median time to seroconversion was nearly 12 days across all three isotypes tested, IgA and IgM antibodies against RBD were short-lived with median times to seroreversion of 71 and 49 days after symptom onset. In contrast, anti-RBD IgG responses decayed slowly through 90 days with only 3 seropositive individuals seroreverting within this time period. IgG antibodies to SARS-CoV-2 RBD were strongly correlated with anti-S neutralizing antibody titers, which demonstrated little to no decrease over 75 days since symptom onset. We observed no cross-reactivity of the SARS-CoV-2 RBD-targeted antibodies with other widely circulating coronaviruses (HKU1, 229 E, OC43, NL63). These data suggest that RBD-targeted antibodies are excellent markers of previous and recent infection, that differential isotype measurements can help distinguish between recent and older infections, and that IgG responses persist over the first few months after infection and are highly correlated with neutralizing antibodies.


2020 ◽  
Vol 117 (36) ◽  
pp. 22341-22350 ◽  
Author(s):  
Deborah L. Burnett ◽  
Peter Schofield ◽  
David B. Langley ◽  
Jennifer Jackson ◽  
Katherine Bourne ◽  
...  

Conformational diversity and self-cross-reactivity of antigens have been correlated with evasion from neutralizing antibody responses. We utilized single cell B cell sequencing, biolayer interferometry and X-ray crystallography to trace mutation selection pathways where the antibody response must resolve cross-reactivity between foreign and self-proteins bearing near-identical contact surfaces, but differing in conformational flexibility. Recurring antibody mutation trajectories mediate long-range rearrangements of framework (FW) and complementarity determining regions (CDRs) that increase binding site conformational diversity. These antibody mutations decrease affinity for self-antigen 19-fold and increase foreign affinity 67-fold, to yield a more than 1,250-fold increase in binding discrimination. These results demonstrate how conformational diversity in antigen and antibody does not act as a barrier, as previously suggested, but rather facilitates high affinity and high discrimination between foreign and self.


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