J. Russell Hayman

J. Russell Hayman, Ph.D.

Contact Information:

J. Russell Hayman, Ph.D.
Associate Professor
Department of Biomedical Sciences
Quillen College of Medicine, ETSU
Johnson City, TN 37614

Phone: 423-439-6313
FAX: 423-439-8044
Email:
Office Location: VA#1, Rm 1-36A
Laboratory Location: VA#119, Rm 3-15


Cory Leonard

Cory Leonard
Graduate Assistant

Education and Professional Experience:

B.S. Biology,

May 1987

Mississippi College

Ph.D. Microbiology,

May 1995

University of Mississippi Medical Center

Postdoctoral Fellow,

1995-1998

Laboratory of Immunology, NIAID / NIH

Postdoctoral Fellow,

1998-2000

Laboratory of Parasitology, NIAID / NIH

Research Fellow,

2000-2002

Laboratory of Parasitology, NIAID / NIH

Associate Professor,

2002-Present

East Tennessee State University, JHQ College of Medicine

Research Interest:

My laboratory research focuses on the molecular aspects of propagation and viability of the obligate intracellular parasite microsporidia.  Microsporidia are opportunistic organisms that infect a wide variety of animals ranging from insects and fish to mammals, including humans.  First identified in the 19th century as a parasite of silkworms, the unicellular organisms now include more than 1000 species.  Microsporidiosis is a significant problem for arthropods and aquaculture based industries and can cause major economic losses.  Although microsporidiosis in humans was first characterized more than 40 years ago, it was thought of as a rare disease.  However, with the insurgence of the AIDS epidemic, many pathogens including microsporidia have emerged.  Microsporidia seem to flourish in immunocompromised individuals, however, numerous reports of immunocompetent persons contracting the disease have shown that microsporidiosis is not limited to the immunocompromised.  The most common species to infect humans is Enterocytozoon bieneusi and Encephalitozoon intestinalis .  Since no effective long-term culture system has been developed for E. bieneusi , my laboratory studies are based on E. intestinalis , which can easily be cultured in vitro .

Microsporidium is a water-borne pathogen and is transmitted orally via an environmentally resistant spore.  It is the spore wall that maintains the spore rigidity and affords the environmental protection.  My initial studies of E. intestinalis involved the identification of two spore wall proteins (SWP1 and 2).  Both proteins are glycosylated and are immunogenic in mouse infection models.  While EM studies show that SWP1 and 2 are differentially expressed on the surface of the spore during spore development, western blot analyses show that SWP1 and 2 form a protein complex on mature spores.  SWP1 and 2 are almost completely identical in the N-terminal region, but differ significantly in the C-terminal region.  SWP2 contains a unique 12 or 15 amino acid motif that is tandemly repeated fifty times.  The function of this motif is under investigation. 

                Another ongoing project involves the examination of spore adherence to host cells.  When spores are incubated with host cells, they will attach to the host cell surface and cannot be removed by extensive washing.  This adherence occurs spontaneously and is easily observed by light microscopy.  An adherence assay has been developed to measure the rate of spore adherence to host cells.  In addition, several inhibitors have been identified that will significantly reduce the number of attached spores.  The relationship of spore adherence to infectivity is also under investigation.  The working hypothesis is that specific spore adherence mechanisms exist that result in close approximation of E. intestinalis spores to host cells thereby increasing the chance of infection by enhancing successful penetration of the polar filament into the host cells.

Confocal Image of Developing Intracellular Microsporidial Spores from Encephalitozoonintestinalis using a Mononclonal Antibody to SWP2.
Confocal Image of Developing Intracellular Microsporidial Spores from Encephalitozoon intestinalis using a Mononclonal Antibody to SWP2.
Immunoelectron micrograph of E. intestinalis infected host cell showing the developing microsporidial spores and the expression of SWP1.   Immunoelectron micrograph of E. intestinalis infected host cell showing the developing microsporidial spores and the expression of SWP2.

Immunoelectron micrograph of E. intestinalis infected host cell showing the developing microsporidial spores and the expression of SWP1.

 

Immunoelectron micrograph of E. intestinalis infected host cell showing the developing microsporidial spores and the expression of SWP2.

Publications:

Maratz, C., J.R. Hayman, H. Gu, and J.H. Kehrl.  2003.  Rgs1 deficiency leads to abnormal B-lymphocyte migration and the disruption of the tissue architecture of the Spleen and Peyer's patches.  In press.  Journal of Experimental Medicine.

Hayman, J.R., and T.E. Nash.  2001.  Developmental Expression of Two Spore Wall Proteins During Maturation of the Microsporidian, Encephalitozoon intestinalis . Infection and Immunity69( 11):  7057-7066.

Hayman, J.R., and C.J. Lobb.  2000.  Heavy Chain Diversity Region Segments of the Channel Catfish: Structure, Organization, Expression, and Phylogenetic Implications. Journal of Immunology.   164( 4): 1916-1924.

Hayman, J.R., and T.E. Nash.  1999.  Isolating Expressed Microsporidial Genes Using a cDNA Subtractive Hybridization Approach.  Journal Eukaryotic Microbiology.  46( 5): 21S-24S.

Yang, X., J.J. Letterio, R.J. Lechleider, L. Chen, J.R. Hayman, H. Gu, A.B. Roberts and C. Deng .  1999.  Targeted disruption of SMAD3 results in impaired mucosal immunity and diminished T cell responsiveness to TGF-b.  EMBO Journal.  18( 5): 1280-1291.

Hayman, J.R., S.H. Ghaffari and C.J. Lobb. 1993. Heavy chain joining region segments of the channel catfish: Genomic organization and phylogenetic implications. Journal of Immunology. 151( 7): 3587-3596.

Hayman, J.R and C.J. Lobb. 1993. Immunoglobulin in the eggs of the channel catfish ( Ictalurus punctatus ). Developmental and Comparative Immunology. 17:241-248.

Lobb, C.J., S.H. Ghaffari, J.R. Hayman and D.T. Thompson. 1993. Plasmid and serological differences between Edwardsiella ictaluri strains. Applied and Environmental Microbiology. 59( 9): 2830-2836.

Hayman, J.R, J.E. Bly, R.P. Levine and C.J. Lobb. 1992. Complement deficiencies in channel catfish ( Ictalurus punctatus ) associated with temperature and seasonal mortality. Fish and Shellfish Immunology. 2:183-192. 

Lobb, C.J. and J.R. Hayman. 1989. Activation of complement by different immunoglobulin heavy chain isotypes of the channel catfish ( Ictalurus punctatus ). Molecular Immunology. 26:457-465.