Periarteriolar lymphoid sheaths

Periarteriolar lymphoid sheaths (or periarterial lymphatic sheaths, or PALS) are a portion of the white pulp of the spleen. They are populated largely by T cells and surround central arteries within the spleen; the PALS T-cells are presented with blood borne antigens via myeloid dendritic cells.

(This is in contrast to the lymphoid portions of the white pulp, where B cells predominate.)

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