Gene expression profile of microglia following traumatic brain injury and adoptive transfer of Tregs at acute and chronic timepoints
To investigate whether the immunomodulatory effects of nasal anti-CD3 on the microglial transcriptomic profile following TBI is dependent on Tregs, we employed adoptive transfer experiments. Overall design: For the first adoptive transfer experiment, splenic/cervical lymph nodes CD4+ FoxP3+ Tregs from isotype and anti-CD3 treated donor mice (CD45.2) and CD4+ FoxP3(GFP) negative population from anti-CD3 treated donor mice (CD45.2) at 7 days post-TBI were intraperitoneally transferred into injured but untreated recipient mice (CD45.1). Bulk RNA-sequencing analysis was performed on microglia isolated from the ipsilateral hemisphere of injured but untreated mice at 7 days post-TBI following adoptive transfer of CD4+Foxp3+ Tregs from TBI-Iso mice, CD4+Foxp3+ Tregs from TBI-aCD3 mice, and CD4+ T cells depleted of Tregs from TBI-aCD3 mice. For the second experiment to characterize the gene expression profile of microglia at the chronic phase of injury following adoptive transfer, total splenic CD4+ T cells from isotype and aCD3-treated donor mice (CD45.2) and CD4+ FoxP3 GFP negative population from aCD3-treated donor mice (CD45.2) at 7 days post-TBI were intraperitoneally transferred into untreated but TBI-injured recipient mice (CD45.1). Bulk RNA-sequencing analysis was performed on microglia isolated from the ipsilateral hemisphere of injured but untreated mice at 1 month post-TBI following adoptive transfer of total CD4+ T cells from TBI-Iso mice, total CD4+ T cells from TBI-aCD3 mice, and CD4+ T cells depleted of FoxP3+ cells from TBI-aCD3 mice.