Melissa Herbst-Kralovetz
Associate Professor, BIO5 Institute
Associate Professor, Basic Medical Sciences
Associate Professor, Clinical Translational Sciences
Associate Professor, Obstetrics and Gynecology
Primary Department
Department Affiliations
(602) 827-2247
Research Interest
Melissa Herbst-Kralovetz, PhD is an Associate Professor in the Departments of Basic Medical Sciences and Obstetrics and Gynecology and is Director of the Women's Health Microbiome Initiative at the UA College of Medicine-Phoenix. The Herbst-Kralovetz research lab is broadly interested in understanding innate mucosal immune responses to resident bacteria, pathogens (e.g HSV-2), and microbial products at mucosal sites, including the female reproductive tract. The mucosa provides a major immune barrier (physical, biological, and chemical) to microbial insult and her lab is interested in studying the mucosal barrier function of the lower female reproductive tract and its role in host defense against infection and inflammation as well as maintaining mucosal homeostasis. Dr. Herbst-Kralovetz has a long-standing interest and background in studying infections/conditions that impact women’s health.


Velasquez, L. S., Shira, S., Berta, A. N., Kilbourne, J., Medi, B. M., Tizard, I., Ni, Y., Arntzen, C. J., & Herbst-Kralovetz, M. M. (2011). Intranasal delivery of Norwalk virus-like particles formulated in an in situ gelling, dry powder vaccine. Vaccine, 29(32).

The development of a vaccine to prevent norovirus infections has been focused on immunization at a mucosal surface, but has been limited by the low immunogenicity of self-assembling Norwalk virus-like particles (NV VLPs) delivered enterically or at nasal surfaces. Nasal immunization, which offers the advantage of ease of immunization, faces obstacles imposed by the normal process of mucociliary clearance, which limits residence time of applied antigens. Herein, we describe the use of a dry powder formulation (GelVac) of an inert in situ gelling polysaccharide (GelSite) extracted from Aloe vera for nasal delivery of NV VLP antigen. Powder formulations, with or without NV VLP antigen, were similar in structure in dry form or when rehydrated in simulated nasal fluids. Immunogenicity of the dry powder VLP formulation was compared to equivalent antigen/adjuvant liquid formulations in animals. For the GelVac powder, we observed superior NV-specific serum and mucosal (aerodigestive and reproductive tracts) antibody responses relative to liquid formulations. Incorporation of the TLR7 agonist gardiquimod in dry powder formulations did not enhance antibody responses, although its inclusion in liquid formulations did enhance VLP immunogenicity irrespective of the presence or absence of GelSite. We interpret these data as showing that GelSite-based dry powder formulations (1) stabilize the immunogenic structural properties of VLPs and (2) induce systemic and mucosal antibody titers which are equal or greater than those achieved by VLPs plus adjuvant in a liquid formulation. We conclude that in situ gelation of the GelVac dry powder formulation at nasal mucosal surfaces delays mucociliary clearance and thereby prolongs VLP antigen exposure to immune effector sites.

Herbst-Kralovetz, M. -., & Pyles, R. B. (2006). Toll-like Receptors, Innate Immunity and Herpes Simplex Virus Pathogenesis. Herpes, 37-41.
Łaniewski, P., Goulder, A., Barnes, D., Roe, D., Cui, H., Chase, D., & Herbst-Kralovetz, M. M. (2018). Linking cervicovaginal immune signatures, HPV and microbiota composition in cervical carcinogenesis in non-Hispanic and Hispanic women”. Scientific Reports.
Green, R., Herbst-Kralovetz, M. -., & Schountz, T. (2004). Genomic Organization of Deer Mouse (Peromyscus maniculatus) Tumor Necrosis Factor. Bios., 12-17.
Herbst-Kralovetz, M. M., Quayle, A. J., Ficarra, M., Greene, S., Rose, W. A., Chesson, R., Spagnuolo, R. A., & Pyles, R. B. (2008). Quantification and comparison of toll-like receptor expression and responsiveness in primary and immortalized human female lower genital tract epithelia. American journal of reproductive immunology (New York, N.Y. : 1989), 59(3).

To better understand innate immune responses to sexually-transmitted infection (STI) and the appropriateness of epithelial cell (EC) models of the vaginal and cervical mucosa, quantified toll-like receptor (TLR) expression from a population of women is needed.