Abstract
Toxoplasma gondii, an obligate intracellular protozoan parasite, can establish a chronic infection in the brain by forming tissue cysts. This chronic infection is widespread in humans worldwide including developed countries, with up to one third of the population being estimated to be infected with this parasite. Diagnosis of this chronic infection is usually conducted by serological detection of IgG antibodies against this parasite. Since infected individuals remain positive for these antibodies for years, it has generally been considered that this infection is a lifelong infection. It is also often considered that this chronic infection is “latent” or “quiescent”. However, recent discovery of the capability of perforin-dependent, CD8+ T cell-mediated immune responses to eliminate T. gondii cysts in collaboration with phagocytes illustrated dynamic interplays between T. gondii cysts and host immune system during this chronic infection. Importantly, the cytotoxic T cell-mediated protective immunity is able to remove mature cysts of the parasite. It is now clear that chronic T. gondii infection is not “latent” or “quiescent”. Elucidating the mechanisms of the dynamic host-pathogen interactions between the anti-cyst protective immunity and T. gondii cysts and identifying the pathway to appropriately activate anti-cyst CD8+ cytotoxic T cells would be able to open a door for eradicating T. gondii cysts and curing chronic infection with this parasite.
| Original language | English |
|---|---|
| Article number | 102259 |
| Journal | Parasitology International |
| Volume | 81 |
| DOIs | |
| State | Published - Apr 2021 |
Bibliographical note
Publisher Copyright:© 2020 Elsevier B.V.
Funding
The studies described in this review article were supported, in part, by National Institutes of Health grants ( AI095032 , AI152597 , AI134323 , and AI136821 ). The author appreciates contributions from individuals in my laboratory who participated in the studies and numbers of collaborators who provided valuable assistance in our studies. Two postdoctoral scholars, Ashish Tiwari, Ph.D. and Jenny Lutshuma, Ph.D. contributed to many of our studies published in recent two publications [ 12 , 22 ]. The author also appreciates the service provided by Markey Shared Resource Facility at University of Kentucky supported by Natonal Institutes of Health grant P30CA177558 . The images in Fig. 1 A are rearranged from Figs. 2 and 3 of our previous publication, Tiwari, A, et al., Am. J. Pathol., volume 189: 1594-1607, 2019 [ 12 ] with permission from Elsevier. Fig. 1 B–D are adapted from Fig. 6 in in our recent publication, Lutshumba et al., mSystems, volume 5, 2020, e00189-20, DOI: https://doi.org/10.1128/mSystems00189-20 [ 22 ], Copyright © American Society for Microbiology. The studies described in this review article were supported, in part, by National Institutes of Health grants (AI095032, AI152597, AI134323, and AI136821). The author appreciates contributions from individuals in my laboratory who participated in the studies and numbers of collaborators who provided valuable assistance in our studies. Two postdoctoral scholars, Ashish Tiwari, Ph.D. and Jenny Lutshuma, Ph.D. contributed to many of our studies published in recent two publications [12,22]. The author also appreciates the service provided by Markey Shared Resource Facility at University of Kentucky supported by Natonal Institutes of Health grant P30CA177558. The images in Fig. 1A are rearranged from Figs. 2 and 3 of our previous publication, Tiwari, A, et al. Am. J. Pathol. volume 189: 1594-1607, 2019 [12] with permission from Elsevier. Fig. 1B–D are adapted from Fig. 6 in in our recent publication, Lutshumba et al. mSystems, volume 5, 2020, e00189-20, DOI: https://doi.org/10.1128/mSystems00189-20 [22], Copyright © American Society for Microbiology.
| Funders | Funder number |
|---|---|
| Jenny Lutshuma | 12,22 |
| National Institutes of Health (NIH) | P30CA177558, AI136821, AI095032, AI152597 |
| National Institute of Allergy and Infectious Diseases | R21AI134323 |
Keywords
- CD8 cytotoxic T cells
- Chronic infection
- Cyst
- Persistence
- The protective immunity
- Toxoplasma gondii
ASJC Scopus subject areas
- Parasitology
- Infectious Diseases
