Genocea Announces New Research Identifying Potential Vaccine Candidates for Chlamydia

Genocea Announces New Research Identifying Potential Vaccine Candidates for Chlamydia

-- Study published in Vaccine demonstrates antigens capable of eliciting immune responses that provide protection against infection in preclinical model --

June 07, 2012

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Genocea Biosciences announced today the publication of a new study characterizing two protein antigens that may hold utility in the design of novel vaccines for Chlamydia trachomatis. The research, led by Jessica Baker Flechtner, Ph.D., Vice President of Research, appears in the current issue of Vaccine. The authors found that both antigens stimulated potent immune responses and long-lived protection against vaginal infection in preclinical models of Chlamydia, confirming the critical role that T cell responses can play in the control of this infection.

The antigens were identified using Genocea's revolutionary platform for the rapid discovery of antigens that induce T cell immunity, underscoring the potential of this platform in the discovery and development of next-generation vaccines to prevent and treat complex infectious diseases.

"These results provide a strong rationale for us to move forward with the design of a vaccine for Chlamydia, which is associated with serious health problems and significant costs to the medical system," Flechtner said. "This study provides further validation of our approach for identifying promising vaccine candidates capable of addressing a wide variety of complex pathogens."

Genocea has identified protective antigens from humans using the same technology, and is currently advancing vaccine development plans.

In addition to Chlamydia, Genocea is utilizing its AnTigen Lead Acquisition System (ATLAS™) technology to develop preventive and therapeutic vaccines for HSV-2, malaria, and Pneumococcus, each of which is in active development.

While there is a growing understanding of the importance of T cell immunity in protecting against infectious diseases, genetic diversity and limitations in screening technology have made it challenging to identify antigens that would produce a protective immune response across a broad population in Chlamydia and other complex illnesses. Genocea's technology enables high throughput screening and characterization of human T cell immune responses to reduce the trial-and-error traditionally associated with antigen selection. The result is a comprehensive and validated set of target antigens in a drastically reduced period of time, making it feasible to stimulate this vital arm of the immune system, which to date has been underutilized in the design of vaccines.

About the Study

A comprehensive proteomic screening technology was previously used to characterize T cell responses to Chlamydia trachomatis infection. The study demonstrated that T cells specific for protein antigens identified through this comprehensive technology home to the site of infection after mucosal challenge with C. trachomatis. In addition, T cell responses to these proteins were elicited in multiple genetic backgrounds. Two protein antigens, CT823 and CT144, were evaluated as vaccine candidates. When administered with AbISCO-100 adjuvant, these antigens stimulated potent CD8+ T cell responses, polyfunctional TH1-polarized CD4+ T cell responses, and high titer protein-specific TH1-skewed antibody responses. Vaccination with either antigen with AbISCO-100 provided long-lived protection against intravaginal challenge with C. trachomatis. Adoptive transfer of immune T cells also conferred protection in the challenge model whereas passive transfer of immune serum did not, indicating the critical role for T cell responses in control of this infection. The ability of these antigens to induce potent immune responses and provide long lived protection in response to challenge provides a basis for the rational design of a C. trachomatis subunit vaccine.

About Chlamydia

Chlamydia is the most frequently reported bacterial sexually transmitted disease in the United States, and results in two billion dollars in health care costs annually. A successful vaccine would prevent serious health problems that result from this disease, such as pelvic inflammatory disease, ectopic pregnancy, and infertility and help control the costs associated with these complications.

About Genocea Biosciences

Genocea Biosciences is harnessing the power of the T cell immunity to develop the next generation of vaccines. T cells are increasingly recognized as a critical element of a protective immune response to a wide range of infectious disease pathogens, but are difficult to target using traditional vaccine discovery methods. Genocea is uniquely able to identify and employ T cell antigens using its proprietary technology platform that mimics human immune response in the laboratory, potentially improving the effectiveness of vaccine candidates and drastically reducing the time needed to create them.

For more information, please visit the company's website at


Feinstein Kean Healthcare
Jessica Rowlands, 202-729-4089
[email protected]