Background Effective antiviral therapy against the severe acute respiratory syndrome virus 2 (SARS-CoV-2) remains elusive. Convalescent plasma is an anti-viral approach currently under investigation. We aimed to assess the laboratory and clinical parameters of patients with COVID-19 pneumonia treated with convalescent plasma containing high levels of neutralizing anti-SARS-CoV-2 antibodies.
The increasing use of nuclear energy sources inevitably raises the risk of accidental or deliberate radiation exposure and associated immune dysfunction. However, the extent to which radiation exposure impacts memory CD8 T cells, potent mediators of immunity to recurring intracellular infections and malignancies, remains understudied. Using P14 CD8 T cell chimeric mice (P14 chimeras) with an lymphocytic choriomeningitis virus (LCMV) infection model, we observed that sublethal (5Gy) whole-body irradiation (WBI) induced a rapid decline in the number of naive (T
N
) and P14 circulating memory CD8 T cells (T
CIRCM
), with the former being more susceptible to radiation-induced numeric loss. While T
N
cell numbers rapidly recovered, as previously described, the number of P14 T
CIRCM
cells remained low at least 9 mo after radiation exposure. Additionally, the remaining P14 T
CIRCM
in irradiated hosts exhibited an inefficient transition to a central memory (CD62L
+
) phenotype compared to nonirradiated P14 chimeras. WBI also resulted in long-lasting T cell intrinsic deficits in memory CD8 T cells, including diminished cytokine and chemokine production along with impaired secondary expansion upon cognate Ag reencounter. Irradiated P14 chimeras displayed significantly higher bacterial burden after challenge with
Listeria monocytogenes
expressing the LCMV GP
33-41
epitope relative to nonirradiated controls, likely due to radiation-induced numerical and functional impairments. Taken together, our findings suggest that sublethal radiation exposure caused a long-term numerical, impaired differentiation, and functional dysregulation in preexisting T
CIRCM
, rendering previously protected hosts susceptible to reinfection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.