Dr. Catherine Brennan, Biology

Education and Professional Positions

Current Research Interests

Dr. Brennan’s research program investigates the mechanisms used by white blood cells to regulate the killing of bacteria that they have engulfed through the process of phagocytosis.  Phagocytosis is an ancient immune defense used throughout the animal kingdom, and is important not just for killing invaders, but also for initiating and co-ordinating immune responses, because white blood cells have mechanisms to probe the identity of any engulfed microbe, prior to destroying them.  However, very little is known about how white blood cells balance these two roles, for example, how they might delay or accelerate microbe destruction in order to optimize recognition vs killing.

In order to identify and characterize cellular mechanisms for regulating the rate of killing of engulfed microbes, Dr. Brennan’s lab takes a genetic approach in the model organism Drosophila.  By identifying mutants in which the destruction of engulfed bacteria is dysregulated, genes are identified that play key roles, thus leading to new insights into how white blood cells control the killing of engulfed invaders.  Dr. Brennan identified the first ever mutant in any organism that had defects in killing engulfed bacteria, and is continuing with this gene discovery and characterization approach.  In the Brennan lab, students learn a variety of research approaches to address these research questions, including molecular biology (PCR, cloning, qPCR, RNAi), cell culture, fluorescent microscopy, and genetics.  Students are well-supported in their research projects, and have the opportunity to present their findings at local and national conferences, as well as to publish in well-regarded scientific journals.

Selected Publications

  1. Brennan, C. A., Ibarrondo, F.J., Shih, R., Sugar, C.A., Detels, R., Rinaldo, C.R., Margolick, J.B., Phair, J., Jacobson, L., Yang, O.O., and Jamieson, B.D. (2012) Early HLA-B*57-restricted CD8+ T lymphocyte responses predict subsequent HIV-1 disease progression. J. Virol. 86:10505-16. (cover article)

  2. Brennan, C. A., Delaney, J.R., Schneider, D.S., and Anderson, K.V. (2007) Psidin is required in Drosophila blood cells for both phagocytic degradation and immune activation of the fat body. Curr. Biol. 17:67-72.
    • Research Highlight:  Ahmad, S. (2007) Insect immunity: the psidin adventure. Nature Rev. Immunol. 7:90.
    • Dispatch:  Hultmark, D. and Borge-Renberg, K. (2007) Drosophila immunity: Is antigen processing the first step? Curr Biol. 17: R22-R24.

  3. Brennan, C. A., Anderson, K. V. (2004) Drosophila: the genetics of innate immune recognition and response. Annu. Rev. Immunol. 22: 457-83. 

  4. Brennan, C. A., Li, T-R., Bender, M., Hsiung, F., Moses, K. (2001) Broad-complex, but not Ecdysone receptor,is required for progression of the morphogenetic furrow in the Drosophila eye. Development 128: 1-11.

  5. Brennan, C. A. and Moses, K. (2000) Determination of Drosophila photoreceptors: timing is everything. Cell. Mol. Life Sci. 57: 195-214.

Website

http://www.fullerton.edu/biology/People/faculty/brennanca.php