Studies were conducted to determine if gamma delta T cells participate in the immune response to Toxoplasma gondii. Preferential expansion of human gamma delta T cells occurred when peripheral blood T cells from either T. gondii-seronegative or seropositive individuals were incubated with autologous PBMC infected with the parasite. That gamma delta T cells proliferated after incubation with infected cells was confirmed using purified of gamma delta T cells. These T. gondii-induced gamma delta T cell responses did not require prior exposure to the parasite since T cells obtained from umbilical cord blood from seronegative newborns also exhibited preferential expansion of gamma delta T cells. Cytofluorometric analysis of T cells obtained from either umbilical cord blood or peripheral blood from adults revealed that V gamma 9+ and V delta 2+ gamma delta T cells responded to stimulation with infected cells. Preferential expansion of gamma delta T cells was not restricted by polymorphic determinants of MHC molecules. PBMC that had internalized killed parasites but not PBMC incubated with T. gondii lysate antigens also stimulated preferential expansion and activation of gamma delta T cells as assessed by expression of CD25 and HLA-DR molecules. V gamma 9+V delta 2+ gamma delta T cells were cytotoxic for T. gondii-infected cells in an MHC-unrestricted manner, and produced IFN-gamma, IL-2, TNF-alpha, but not IL-4 when incubated with cells infected with the parasite. These results suggest that rapid induction of a remarkable primary gamma delta T cell response may be important in the early protective immune response to T. gondii.
C S Subauste, J Y Chung, D Do, A H Koniaris, C A Hunter, J G Montoya, S Porcelli, J S Remington
Usage data is cumulative from January 2021 through January 2022.
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.