Genocea Profiles T cell Responses to Identify Antigens Associated with Malaria Episodes
Findings reveal evidence of malaria in immune system years after clinical episodes
November 5, 2014
Genocea Biosciences, Inc., a company developing T cell-directed vaccines and immunotherapies, today presented study results identifying a cluster of antigens that may be a biomarker of disease. The findings, generated using Genocea’s proprietary ATLAS™ antigen discovery platform, revealed that malaria leaves a lasting imprint on the immune system. Genocea researchers found evidence that this T cell immunological memory can be detected many years after the previous clinical episode of malaria. The study was presented at the 63rd Annual Meeting of the American Society of Tropical Medicine and Hygiene in New Orleans, LA.
Malaria is caused by Plasmodium falciparum (Pf), a parasite that is transmitted through mosquito bites and rapidly travels to the liver, where it replicates in large numbers and is released into the bloodstream, causing illness. In the current study, the data were collected by analyzing samples from volunteers who recently immigrated to the United States from sub-Saharan Africa, a region where malaria is highly prevalent. Genocea researchers profiled CD8+ T cells from approximately 100 donors against 735 Pf proteins predicted to be expressed in the liver, where CD8+ T cells play a protective role against infection. Study results identified a cluster of 15 antigens that predicted clinical malaria, and may be a biomarker of disease after Pf exposure.
“This is one of the more unexpected findings coming out of our ATLAS™ antigen discovery platform, since immunity to the parasite is thought to be short-lived. Understanding the natural history of responses to diseases as complex as malaria is a necessary first step towards the development of immunotherapies that prevent and treat disease,” said Jessica Baker Flechtner, Ph.D., Genocea’s senior vice president of research. “This finding paves the way for the identification of novel biomarkers indicating Pf exposure, opens avenues for the development of new diagnostic tools, and advances Genocea’s efforts to identify antigens that could form the basis of a future preventative medicine.”
Genocea is collaborating with the Bill and Melinda Gates Foundation to advance the company’s vaccine program. In September 2014, Genocea received a $1.2 million grant from the Gates Foundation for the identification of protective T cell antigens for malaria vaccines, extending the collaboration through 2015.
The poster presented at the meeting (LB-3350) was titled “Profiling of T cell Responses in Recent African Immigrants Identifies a Cluster of Antigens Associated with Clinical Malaria Episodes.”
About Genocea’s Malaria Program
Malaria is one of the deadliest infectious diseases in the world. In 2012, more than 600 million cases of malaria were reported by the World Health Organization (WHO), claiming over 600,000 lives, many of them children and largely in developing countries. There is no licensed vaccine to prevent malaria, an infection caused by Plasmodium parasites transmitted by mosquitoes. When the parasite is injected through the bite of an infected mosquito, it rapidly travels to the liver where it replicates in large numbers and is released into the bloodstream causing sickness. T cells in the liver could potentially kill the cells in which the parasite is hiding before the parasite is able break out into the bloodstream. Genocea’s T cell target discovery platform, ATLAS, is currently being applied to identify which components of the Plasmodium could act as T cell targets and become part of novel vaccine candidates.
Genocea is harnessing the power of T cell immunity to develop life-changing vaccines and immunotherapies. T cells are increasingly recognized as a critical element of protective immune responses to a wide range of diseases, but traditional discovery methods have proven unable to identify the targets of such protective immune response. Using ATLAS™, its proprietary technology platform, Genocea identifies these targets to potentially enable the rapid development of medicines to address critical patient needs. Genocea’s pipeline of novel clinical stage T cell-enabled product candidates includes GEN-003 for HSV-2 therapy, GEN-004 to prevent infections caused by pneumococcus, and earlier-stage programs in chlamydia, HSV-2 prophylaxis, malaria and cancer immunotherapy. For more information, visit www.genocea.com.