Toxoplasma: Immunity and Pathogenesis

Abstract

Purpose of Review

Toxoplasmosis is an apicomplexan parasite that can be found in all countries, which causes an infection of the central nervous system. This review outlines some of the recent immunological advances that have been made against this chronic infection that poses a major problem for the immunocompromised individuals.

Recent Findings

Recent studies have demonstrated that in a mouse model of chronic toxoplasmosis, the infection leads to T cell dysfunctionality. The exhaustion that is observed in both CD4 and CD8 T cells is manifested by increased expression of co-inhibitory molecules like PD-1 and leads to reactivation of latent infection. Blockade of PD-1-PDL-1 interaction reverses the exhaustion and prevents reactivation of latent infection in the host.

Summary

Prevention of loss of CD4 T cell function can be important therapeutic strategy for controlling chronic toxoplasmosis and preventing reactivation of latent infection.

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Funding

This work was supported by the NIH grant AI33325 awarded to IAK.

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Correspondence to Imtiaz A Khan.

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Khan, I.A., Ouellette, C., Chen, K. et al. Toxoplasma: Immunity and Pathogenesis. Curr Clin Micro Rpt 6, 44–50 (2019). https://doi.org/10.1007/s40588-019-0114-5

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Keywords

  • Toxoplasma
  • CD8 T cells
  • CD4 T cells
  • IL-12
  • IL-21
  • Exhaustion