Harlan D. Caldwell, Ph.D.

Chlamydial Diseases Section

Harlan D. Caldwell, Ph.D.

Chief, Chlamydial Diseases Section

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Harlan D. Caldwell, Ph.D.

Major Areas of Research

  • Pathogenesis of chlamydial infection
  • Immunity to chlamydial infection
  • Chlamydia vaccine development

Program Description

Chlamydia are important human pathogens that cause blinding trachoma and sexually transmitted disease for which vaccines are needed. The focus of our research is to identify chlamydial virulence factors that function in the pathobiology of chlamydial host-cell interactions and evasion of host immunity. We use in vitro and in vivo models of chlamydial infection together with comparative genomics, transcriptomics, proteomics, modern cell biology, and immunology to accomplish these goals. This information is being used to design novel subunit and live-attenuated vaccines for the prevention of human chlamydial diseases.



Ph.D., 1976, University of Washington

Dr. Caldwell received his Ph.D. in pathobiology from the University of Washington in 1976. After completing a senior research fellowship in the Department of Medicine at the University of Washington in 1978, Dr. Caldwell joined the faculty of the University of California, San Francisco, as an assistant professor of microbiology and immunology. In 1980, he was recruited to the National Institutes of Health (NIH) as a tenure-track investigator in the Laboratory of Microbial Structure and Function. He became a tenured investigator in 1986 and chief of the Laboratory of Intracellular Parasites in 1990. He is a recipient of the NIH Director’s Award, NIH Merit Award, and PHS Superior Service Award. He was appointed to the NIH Senior Biomedical Research Service in 1997. Dr. Caldwell is a member of the editorial board of Infection and Immunity and a fellow of the American Academy of Microbiology. He is an internationally recognized leader in the fields of chlamydial pathogenesis and immunology.

Selected Publications

Yang C, Briones M, Chiou J, Lei L, Patton MJ, Ma L, McClarty G, Caldwell HD. Chlamydia trachomatis Lipopolysaccharide Evades the Canonical and Noncanonical Inflammatory Pathways To Subvert Innate Immunity. MBio. 2019 Apr 23;10(2).

Patton MJ, McCorrister S, Grant C, Westmacott G, Fariss R, Hu P, Zhao K, Blake M, Whitmire B, Yang C, Caldwell HD, McClarty G. Chlamydial Protease-Like Activity Factor and Type III Secreted Effectors Cooperate in Inhibition of p65 Nuclear Translocation. MBio. 2016 Sep 27;7(5). 

Porcella SF, Carlson JH, Sturdevant DE, Sturdevant GL, Kanababandi K, Virtaneva K, Wilder H, Whitmire WM, Song L, Caldwell HD. Transcriptional profiling of human epithelial cells infected with plasmid-bearing and plasmid-deficient Chlamydia trachomatis. Infect Immun. 2015 Feb;83(2):534-43.

Olivares-Zavaleta N, Whitmire WM, Kari L, Sturdevant GL, Caldwell HD. CD8+ T cells define an unexpected role in live-attenuated vaccine protective immunity against Chlamydia trachomatis infection in macaques. Immunol. 2014 May 15;192(10):4648-54.

Song L, Carlson J, Whitmire WM, Kari L, Virtaneva K, Sturdevant DE, Watkins H, Zhou B, Sturdevant GL, Porcella SF, McClarty G, Caldwell HD. Chlamydia trachomatis plasmid-encoded Pgp4 is a transcriptional regulator of virulence-associated genes. Infect Immun. 2013 Mar;81(3):636-44. 

Kari L, Whitmire WM, Olivares-Zavaleta N, Goheen MM, Taylor LD, Carlson JH, Sturdevant GL, Lu C, Bakios LE, Randall LB, Parnell MJ, Zhong G, Caldwell HD. A live-attenuated chlamydial vaccine protects against trachoma in nonhuman primates. J Exp Med. 2011 Oct 24;208(11):2217-23.

Visit PubMed for a complete publication listing.

Research Group

  • Yang Chunfu, Ph.D., staff scientist
  • Saba Firdous, post-baccalaureate IRTA
  • Lei Lei, postdoctoral fellow
  • Li Ma, research assistant
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