Infectious sporozoite challenge modulates radiation attenuated sporozoite vaccine–induced memory CD8+ T cells for better survival characteristics. (15th December 2021)

• Record Type: Journal Article
• Authors: Yadav, Naveen; Parmar, Rajesh; Patel, Hardik; Patidar, Manoj; Dalai, Sarat K.
• Is Part Of: Microbiology and immunology. Volume 66:Number 2(2022)
• Page Start: 41
• Page End: 51
• Publication Date: 2021-12-15
• Subjects: Annexin‐V -- Bcl‐2 -- CX3CR1 -- Ki‐67 -- malaria -- memory CD8+ -- T cell -- Nur77 -- radiation attenuated sporozoite -- whole‐parasite vaccine approach; Microbiology -- Periodicals; Immunology -- Periodicals; Allergy and Immunology -- Periodicals; Microbiology -- Periodicals; Microbiologie -- Périodiques; Immunologie -- Périodiques; 579
• DOI: 10.1111/1348-0421.12948
• Languages: English
• ISSNs: 0385-5600

Abstract

Abstract: Radiation attenuated sporozoite (RAS), a whole‐parasite vaccine approach, provides sterile protection against malaria. However, RAS immunization does not confer protection for long, and that has been correlated with the waning parasite–induced memory CD8 + T‐cell responses. Interestingly, an intermittent infectious (wild type) sporozoite challenge to the RAS‐vaccinated mice lengthened the protection period from 6 to 18 months. Herein, we have studied the changes induced by the infectious sporozoites in RAS‐induced memory CD8 + T cells for conferring lengthened protection. We observed that the infectious sporozoite challenge boosted the frequency of foreign antigen–experienced memory CD8 + T cells. In those CD8 + T cells, it has reduced the Annexin‐V reactivity, raised Bcl‐2 expression, and also more cells undergo homeostatic proliferation (Ki‐67 + ). It has also scaled down the frequency of Nur77 and CX3CR1 high expressing cells in those memory CD8 + T‐cell populations which we further correlated with better survival signals.