Features | Partner Sites | Information | LinkXpress
Sign In
PZ HTL SA
GLOBETECH PUBLISHING LLC
GLOBETECH PUBLISHING LLC

Antitoxin Vaccine Protects Laboratory Animals Against Staphylococcus Infection

By BiotechDaily International staff writers
Posted on 31 Dec 2013
Image: Scanning electron micrograph (SEM) showing numerous clumps of methicillin-resistant Staphylococcus aureus (MRSA) magnified 4,780x (Photo courtesy of the CDC - Centers for Disease Control and Prevention).
Image: Scanning electron micrograph (SEM) showing numerous clumps of methicillin-resistant Staphylococcus aureus (MRSA) magnified 4,780x (Photo courtesy of the CDC - Centers for Disease Control and Prevention).
A vaccine comprising a cocktail of superantigens and cytolysins protected rabbits challenged with virulent strains of Staphylococcus aureus while vaccines based on bacterial surface antigens failed to protect the animals or actually increased the severity of the infection.

Superantigens (SAgs) are a class of antigens that cause nonspecific activation of T-cells resulting in polyclonal T-cell activation and massive cytokine release. SAgs are produced by pathogenic microbes (including viruses, mycoplasma, and bacteria) as a defense mechanism against the immune system. Compared to a normal antigen-induced T-cell response where 0.0001–0.001% of the body’s T-cells are activated, SAgs are capable of activating up to 25% of the body’s T-cells.

Previous attempts to vaccinate laboratory animals with bacterial cell-surface proteins failed to protect them and, in some cases, actually increased the severity of the infection.

Using a different approach, investigators at the University of Iowa (Iowa City, USA) vaccinated rabbits with a cocktail of wild-type toxins or toxoids produced and secreted by S. aureus, which was made up of combinations of superantigens (toxic shock syndrome toxin-1, enterotoxins B and C, and enterotoxin-like X) and cytolysins (alpha, beta, and gamma-toxins). Other rabbits were passively vaccinated with hyperimmune serum taken from some of the actively vaccinated animals. The rabbits were challenged with multiple strains of S. aureus, both methicillin-sensitive and methicillin-resistant (MRSA).

Results published in the December 19, 2013, online edition of the Journal of Infectious Disease revealed that vaccination against secreted superantigens and cytolysins resulted in protection of 86/88 rabbits when challenged intrapulmonary with nine different S. aureus strains, compared to only 1/88 nonvaccinated animals.

Not only did the vaccine protect the animals from dying but also seven days after vaccination pathogenic bacteria could not be detected in the animals' lungs.

Passive immunization studies demonstrated that production of neutralizing antibodies was critically involved in the protective mechanism.

"Our study suggests that vaccination against these toxins may provide protection against all strains of Staphylococcus," said senior author Dr. Patrick Schlievert, professor of microbiology at the University of Iowa. "If we can translate this finding into an effective vaccine for people it could potentially prevent millions of cases of serious and milder skin and soft tissue infections yearly."

Related Links:

University of Iowa



comments powered by Disqus

Channels

Drug Discovery

view channel
Image: Disruption and removal of malaria parasites by the experimental drug (+)-SJ733 (Photo courtesy of the University of California, San Francisco).

Experimental Antimalaria Drug Induces the Immune System to Destroy Infected Red Blood Cells

An experimental drug for the treatment of malaria was found to induce morphological changes in infected erythrocytes that enabled the immune system to recognize and eliminate them. Investigators at... Read more

Biochemistry

view channel

Blocking Enzyme Switch Turns Off Tumor Growth in T-Cell Acute Lymphoblastic Leukemia

Researchers recently reported that blocking the action of an enzyme “switch” needed to activate tumor growth is emerging as a practical strategy for treating T-cell acute lymphoblastic leukemia. An estimated 25% of the 500 US adolescents and young adults diagnosed yearly with this aggressive disease fail to respond to... Read more

Business

view channel

R&D Partnership Initiated to Reduce Development Time for New Drugs

nanoPET Pharma, GmbH (Berlin, Germany) signed an open-ended framework contract with the international pharmaceutical company Boehringer Ingelheim (Ridgefield, CT, USA). By developing customized contrast agents for research in both basic and preclinical studies, nanoPET Pharma will contribute to the enhancement of Boehringer... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.