Cytokine-Independent Detection of Antigen-Specific Germinal Center T Follicular Helper Cells in Immunized Nonhuman Primates Using a Live Cell Activation-Induced Marker Technique

摘要: A range of current candidate AIDS vaccine regimens are focused on generating protective HIV-neutralizing Ab responses. Many these efforts rely the rhesus macaque animal model. Understanding how responses develop and to increase their efficacy both major knowledge gaps. Germinal centers (GCs) engines affinity maturation. GC T follicular helper (Tfh) CD4 cells required for GCs. Studying vaccine-specific Tfh after protein immunizations has been challenging, as Ag-specific difficult identify by conventional intracellular cytokine staining. Cytokine production may be intrinsically limited in comparison with other Th effector cells, biological role a cell is provide help individual B within GC, rather than secreting large amounts cytokines bathing tissue. To test this idea, we developed cytokine-independent method cells. RNA sequencing was performed using TCR-stimulated markers. Validation experiments determined CD25 (IL-2Rα) OX40 highly upregulated activation-induced markers (AIM) surface stimulation. In staining, AIM assay identified >10-fold more HIV Env protein-immunized macaques (BG505 SOSIP). blood were also studied. summary, demonstrates that stingy producers cytokines, which likely an essential part function.