The focus of my research is to examine endocrine-immune interactions and determine how these relationships alter and are altered by microbial infection. Specifically, I consider how immunological, hormonal, and genetic differences between males and females affect sex differences in susceptibility to infection.

To examine sex differences in infection, I am currently work with hantaviruses and influenza viruses. In each case, males and females are differentially susceptible. Current studies in my laboratory address how hormones, specifically androgens in males and estrogens in females, affect response to infection in rodents. We hypothesize that hormones influence the sexual dimorphism in infection through several mechanistic pathways, including: 1) effects on immune responses against infection; 2) behaviors that increase the likelihood of becoming infected (e.g., aggression); and 3) effects on the expression of genes that influence susceptibility to infection.

Molecular Microbiology and Immunology, Animal Behavior, Endocrine Disruption, Endocrine-Immune Interactions, Hantaviruses, Hormones, Neuroendocrinology, Immunology, Infectious Diseases, Influenza, Phytoestrogens, Pregnancy, Reproduction, Sex Differences, Stress

Easterbrook, J. D., & Klein, S. L. 2008. Immunological mechanisms mediating hantavirus persistence in rodent reservoirs. PLoS Pathogens, 4, e1000172. doi: 10.1371/journal.ppat.1000172.

Easterbrook, J. D., & Klein, S. L. 2008. Corticosteroids affect Seoul virus infection, regulatory T cell responses, and matrix metalloprotease 9 expression in male, but not female, Norway rats. Journal of General Virology, 89, 2723-2730.

Easterbrook, J. D., & Klein, S. L. 2008. Seoul virus enhances regulatory and reduces proinflammatory responses in male Norway rats. Journal of Medical Virology, 80, 1308-1318.

Siracusa, M. C., Overstreet, M. G., Housseau, F., Scott, A. L., & Klein, S. L. 2008. 17ß-estradiol alters the activity of conventional and interferon-producing killer dendritic cells. Journal of Immunology, 180, 1423-1431.

Hannah, M. F., Bajic, V. B., & Klein, S. L. 2008. Sex differences in the recognition of and antiviral responses to Seoul virus in Norway rats. Brain, Behavior, and Immunity, 22, 503-516.

Easterbrook, J. D., Zink, M. C., & Klein, S. L. 2007. Regulatory T cells enhance persistence of the zoonotic pathogen Seoul virus in its reservoir host. Proceedings of the National Academy of Sciences USA, 104, 15502-15507.

Klein, S. L., & Calisher, C. H. 2007. Emergence and persistence of hantaviruses. Current Topics in Microbiology and Immunology, 315, 217-252.

Easterbrook, J. D., Kaplan, J., Glass, G. E., Pletnikov, M. V., & Klein, S. L. 2007. Elevated testosterone and reduced 5-HIAA concentrations are associated with wounding and hantavirus infection in male Norway rats. Hormones and Behavior, 52, 474-481.

Cernetich, A., Garver, L. S., Jedlicka, A. E., Klein, P. W., Kumar, N., Scott, A. L., & Klein, S. L. 2006. Involvement of gonadal steroids and gamma interferon in sex differences in response to blood-stage malaria infection. Infection and Immunity, 74, 3190-3203.

Klein, S. L. 2004. Hormonal and immunological mechanisms mediating sex differences in parasite infection. Parasite Immunology, 26, 247-264.

Klein, S. L., Cernetich, A., Hilmer, S., Hoffman, E., Scott, A. L., & Glass, G. E. 2004. Differential expression of immunoregulatory genes in male and female Norway rats following infection with Seoul virus. Journal of Medical Virology, 74, 180-190.

Klein, S. L., Zink, M. C., & Glass, G. E. 2004. Seoul virus increases aggressive behaviour in male Norway rats. Animal Behaviour, 67, 421-429.

Klein, S. L. 2003. Parasite manipulation of the central mechanisms that mediate social behavior in vertebrates. Physiology & Behavior, 79, 441-449.

Klein, S. L., Marson, A., Scott, A., Ketner, G. & Glass, G. E. 2002. Neonatal sex steroids alter antibody responses but not Seoul virus replication in Norway rats. Brain, Behavior, and Immunity, 16, 736-746.

Klein, S. L., Bird, B. H., & Glass, G. E. 2001. Sex differences in immune responses and viral shedding following Seoul virus infection in Norway rats. American Journal of Tropical Medicine and Hygiene, 65, 57-63.

Klein, S. L., Bird, B. H, & Glass, G. E. 2000. Sex differences in Seoul virus infection are not related to adult sex steroid concentrations in Norway rats. Journal of Virology,74, 8213-8217.

Klein, S. L. 2000. The effects of hormones on sex differences in infection: from genes to behavior. Neuroscience and Biobehavioral Reviews, 24, 627-638.