Authors' Affiliations

Cindy Barrett, Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN. Cheryl Moore, Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN. Dr. Hayman, Department of Biomedical Sciences and Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN.

Faculty Sponsor’s Department

Biomedical Sciences

Name of Project's Faculty Sponsor

Dr. James Hayman

Type

Poster: Competitive

Classification of First Author

Graduate Student-Doctoral

Project's Category

Microbiology

Abstract Text

Microsporidia are an obligate, intracellular fungal pathogen that can cause devastating, disseminating infections in the immunocompromised. Because of the limitations of current medications, microsporidia’s abundant presence in the environment, and an increasing number of at-risk populations, investigation into decreasing microsporidia infectivity is needed. As an intracellular pathogen, microspridial attachment is a vital first step to infection, and if attachment is reduced, previous work shows that infectivity is mitigated. An in silico analysis of Encephalitozoon intestinalis revealed a predicted protein similar in sequence to ADAM (A Disintegrin And Metalloproteinase) proteins. This predicted protein is termed microsporidia ADAM or MADAM. ADAM proteins contain an integrin binding region, which is well known to bind to integrin proteins. Integrins are important receptors for attachment and cell signaling, and several pathogens utilize host integrins as a receptor to aid in attachment during infection. Immunoelectron microscopy demonstrates that MADAM protein is found on the plasma membrane, anchoring disk, and polar tube of E. intestinalis spores. Our hypothesis is that MADAM is involved in the key role of host cell attachment. To this end, a 17 amino acid long section of the MADAM protein was generated that surrounded the integrin binding domain. During spore adherence assays, pretreating host cells with this small peptide protein, significantly decreased E. intestinalis spore attachment to host cells as compared to control samples. These results suggest E. intestinalis cleverly exploits host integrins as a means to bind to host cells before infection.

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MADAM Protein Decreases Microsporidia Attachment to Host Cells

Microsporidia are an obligate, intracellular fungal pathogen that can cause devastating, disseminating infections in the immunocompromised. Because of the limitations of current medications, microsporidia’s abundant presence in the environment, and an increasing number of at-risk populations, investigation into decreasing microsporidia infectivity is needed. As an intracellular pathogen, microspridial attachment is a vital first step to infection, and if attachment is reduced, previous work shows that infectivity is mitigated. An in silico analysis of Encephalitozoon intestinalis revealed a predicted protein similar in sequence to ADAM (A Disintegrin And Metalloproteinase) proteins. This predicted protein is termed microsporidia ADAM or MADAM. ADAM proteins contain an integrin binding region, which is well known to bind to integrin proteins. Integrins are important receptors for attachment and cell signaling, and several pathogens utilize host integrins as a receptor to aid in attachment during infection. Immunoelectron microscopy demonstrates that MADAM protein is found on the plasma membrane, anchoring disk, and polar tube of E. intestinalis spores. Our hypothesis is that MADAM is involved in the key role of host cell attachment. To this end, a 17 amino acid long section of the MADAM protein was generated that surrounded the integrin binding domain. During spore adherence assays, pretreating host cells with this small peptide protein, significantly decreased E. intestinalis spore attachment to host cells as compared to control samples. These results suggest E. intestinalis cleverly exploits host integrins as a means to bind to host cells before infection.