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Full-Text Articles in Immunology of Infectious Disease

Assessing The Durability Of The Immune Response Induced By Rivax®, A Ricin Subunit Vaccine, Hayley Lynn Novak May 2021

Assessing The Durability Of The Immune Response Induced By Rivax®, A Ricin Subunit Vaccine, Hayley Lynn Novak

Legacy Theses & Dissertations (2009 - 2024)

Assessing the performance and durability of the antibody response in animal models can assist in the development of biodefense vaccines. Ricin is one of the most toxic biological agents known and has been a public health issue for years. Since ricin is easily manufactured and a deadly toxin, rational vaccine design and immunotherapeutic optimization have been explored. RiVax® is a candidate subunit vaccine with a modified A-chain of ricin toxin that was formulated to remove ricin's biological activity. It is thought that RiVax® could serve as a prophylactic that would induce humoral- and cell-mediated immunological responses that elicit protective antigens …


Intrabodies Reveal Critical Steps Involved In Ricin's Interactions With The Ribosome, Timothy Francis Czajka Jan 2021

Intrabodies Reveal Critical Steps Involved In Ricin's Interactions With The Ribosome, Timothy Francis Czajka

Legacy Theses & Dissertations (2009 - 2024)

Ricin is a highly lethal protein toxin derived from the seeds of the castor plant, Ricinus communis. It is a Type II ribosome inactivating protein (RIP), meaning it is a heterodimer with one subunit, ricin toxin B (RTB), that mediates cell surface attachment and intracellular trafficking and a second subunit, ricin toxin A (RTA), that irreversibly shuts down protein synthesis in the cytosol. During trafficking, RTA and RTB necessarily separate in the endoplasmic reticulum, wherein RTA unfolds and translocates into the cytosol where it refolds into an enzymatically active conformation. RTA is remarkably fast acting and efficient, with few molecules …


Extracellular And Intracellular Neutralization Of Ricin Toxin By Engineered Bispecific Antibodies, Cristina Herrera Jan 2016

Extracellular And Intracellular Neutralization Of Ricin Toxin By Engineered Bispecific Antibodies, Cristina Herrera

Legacy Theses & Dissertations (2009 - 2024)

Engineering anti-toxin antibodies (Ab) is of public health interest for biodefense counter measurements. Ricin toxin is one example of a major biothreat agent that has currently no antidote. Ricin is a glycoprotein from the castor bean plant, Ricinus communis, and belongs to the medically important A-B toxin family that also includes Shiga, anthrax and cholera toxins. Ricin’s enzymatic subunit (RTA) is an RNA N-glycosidase that inhibits protein synthesis by irreversibly depurinating the 28S rRNA of the eukaryotic 60S ribosomal subunit. RTB is a galactose-/N-acetylgalactosamine-specific lectin that has two important functions. First, RTB promotes binding and endocytosis of ricin into mammalian …


Role Of Antibody Isotypes In Providing Passive Protection Against Ricin Toxin, Ipneet Kaur Dhaliwal Jan 2015

Role Of Antibody Isotypes In Providing Passive Protection Against Ricin Toxin, Ipneet Kaur Dhaliwal

Legacy Theses & Dissertations (2009 - 2024)

Ricin toxin is a glycoprotein produced by the castor bean plant, Ricinus communis. Ricin is an extraordinarily potent inducer of cell death and inflammation, especially following inhalation. The toxin’s enzymatic subunit (RTA) is transported via retrograde transport into the cytoplasm of mammalian cells by the toxin’s B subunit (RTB). Once in the cytoplasm, RTA inactivates ribosomes through cleavage of ribosomal RNA. In this study, I characterized a ricin-specific monoclonal IgA antibody (mAb) known as 23D7. I confirmed that 23D7 reacts with RTA and is effective at neutralizing ricin in a Vero cell cytotoxicity assay in vitro. To localize the epitope …


Neutralizing Antibodies Against The Ricin Toxin Binding Subunit (Rtb), Anastasiya Yermakova Jan 2013

Neutralizing Antibodies Against The Ricin Toxin Binding Subunit (Rtb), Anastasiya Yermakova

Legacy Theses & Dissertations (2009 - 2024)

Ricin is a toxin that is naturally produced by the seeds of the castor bean plant Ricinus communis, and is part of a family of A-B toxins that includes Shiga, cholera, and anthrax toxins. The toxin consists of two subunits, RTA and RTB, which are linked by a disulfide bond. RTA is an RNA N-glycosidase that selectively targets and inactivates 28S ribosomal RNA, thereby arresting protein synthesis and leading to cell death. RTB is a galactose/ N-acetylgalactosamine-specific lectin that mediates attachment, entry, and intracellular trafficking of ricin in host cells. Currently, there is no approved vaccine or therapeutics available against …


Identification Of Epitopes On Ricin Toxin's Enzymatic Subunit (Rta) Critical For Eliciting Neutralizing Antibodies And Protective Immunity, Joanne Marie O'Hara Jan 2012

Identification Of Epitopes On Ricin Toxin's Enzymatic Subunit (Rta) Critical For Eliciting Neutralizing Antibodies And Protective Immunity, Joanne Marie O'Hara

Legacy Theses & Dissertations (2009 - 2024)

Ricin toxin's enzymatic subunit (RTA) is a 267 amino acid RNA N-glycosidase that selectively depurinates eukaryotic ribosomal RNA and arrests protein synthesis. The crystal structure of RTA revealed that the protein assumes three distinct folding domains (FD). Residues within FD1 and FD2 form RTA's active site pocket and are proposed to interface with ribosomal proteins, while FD3's primary function is to associate with ricin's B subunit (RTB). In this study I sought to identify the regions of RTA that are important in eliciting toxin-neutralizing antibodies (TNA), as this information is critical for current efforts to develop RTA-based subunit vaccines. I …