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bioRxiv · 10.1101/2024.02.05.578900

CD40 Expression by B cells is Required for Optimal Immunity to Murine Pneumocystis Infection

Sassi, M.·Curran, S. J.·Bishop, L. R.·Lin, Y.·Kovacs, J.
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Abstract

CD40-CD40L interactions are critical for controlling Pneumocystis infection. However, which CD40-expressing cell populations are important for this interaction have not been well-defined. We used a cohousing mouse model of Pneumocystis infection, combined with flow cytometry and qPCR, to examine the ability of different populations of cells from C57BL/6 mice to reconstitute immunity in CD40 knockout (KO) mice. Unfractionated splenocytes, as well as purified B cells, were able to control Pneumocystis infection, while B cell depleted splenocytes and unstimulated bone-marrow derived dendritic cells (BMDCs) were unable to control infection in CD40 KO mice. Pneumocystis antigen-pulsed BMDCs showed early, but limited, control of infection. Consistent with recent studies that have suggested a role for antigen presentation by B cells, using cells from immunized animals, B cells were able to present Pneumocystis antigens to induce proliferation of T cells. Thus, CD40 expression by B cells appears necessary for robust immunity to Pneumocystis.

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Sassi, M., Curran, S. J., Bishop, L. R., Lin, Y., Kovacs, J.. 2024-02-05. CD40 Expression by B cells is Required for Optimal Immunity to Murine Pneumocystis Infection. https://doi.org/10.1101/2024.02.05.578900

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