Neonatal and adult recent thymic emigrants produce IL-8 and express complement receptors CR1 and CR2

“…Early studies on the pattern of CD21 expression reported that thymocytes were CD21 ϩ (63) and that anti-CD21 antibody blocked EBV infection of thymocytes (17). More recently, recent thymic immigrants were found to express CD21 (64), which would be consistent with our observations that CD21 was expressed on both naive CD4 ϩ and CD8 ϩ mature peripheral T cells. This suggests a model whereby EBV uses CD21 to infect both immature and mature T cells.…”

“…Finally, our data indicate that the complement receptor CD21, previously used to identify CD4 + RTE cells, can also identify CD8 + RTE cells when used together with markers identifying naive cells. This is consistent with Pekalski et al, who reported that CD21 + CD4 + cells have higher T-cell excision circle content than their CD21counterparts, and that the depletion of T cells is followed by an influx of CD21 + T cells, as would be expected for a RTE marker [38]. Thus, we were able to analyze the tissue distribution and age-related changes of both CD4 + and CD8 + RTE cells.…”

“…Recently, the complement receptor CD21 has been suggested to be a more accurate marker for RTE cells in both CD4 + and CD8 + subsets [38]. Supporting this, we observed a high frequency of CD21 + naive cells within the circulating CD4 + and CD8 + populations in the youngest children included in our study (Supporting Information Fig.…”

“…Depletion of FDCs could impair responses to infections. In mature αβ T cells, CD21 was expressed at very low density on only <10%, with the highest expression in naïve subsets, as described in the literature (37). Accordingly, anti-CD21 CAR-T cells were not affected by fratricide, and T cell aplasia is an unlikely consequence of therapy.…”

“…Early studies on the pattern of CD21 expression reported that thymocytes were CD21 ϩ (63) and that anti-CD21 antibody blocked EBV infection of thymocytes (17). More recently, recent thymic immigrants were found to express CD21 (64), which would be consistent with our observations that CD21 was expressed on both naive CD4 ϩ and CD8 ϩ mature peripheral T cells. This suggests a model whereby EBV uses CD21 to infect both immature and mature T cells.…”

“…Finally, our data indicate that the complement receptor CD21, previously used to identify CD4 + RTE cells, can also identify CD8 + RTE cells when used together with markers identifying naive cells. This is consistent with Pekalski et al, who reported that CD21 + CD4 + cells have higher T-cell excision circle content than their CD21counterparts, and that the depletion of T cells is followed by an influx of CD21 + T cells, as would be expected for a RTE marker [38]. Thus, we were able to analyze the tissue distribution and age-related changes of both CD4 + and CD8 + RTE cells.…”

“…Recently, the complement receptor CD21 has been suggested to be a more accurate marker for RTE cells in both CD4 + and CD8 + subsets [38]. Supporting this, we observed a high frequency of CD21 + naive cells within the circulating CD4 + and CD8 + populations in the youngest children included in our study (Supporting Information Fig.…”

“…Depletion of FDCs could impair responses to infections. In mature αβ T cells, CD21 was expressed at very low density on only <10%, with the highest expression in naïve subsets, as described in the literature (37). Accordingly, anti-CD21 CAR-T cells were not affected by fratricide, and T cell aplasia is an unlikely consequence of therapy.…”

“…Early studies on the pattern of CD21 expression reported that thymocytes were CD21 ϩ (63) and that anti-CD21 antibody blocked EBV infection of thymocytes (17). More recently, recent thymic immigrants were found to express CD21 (64), which would be consistent with our observations that CD21 was expressed on both naive CD4 ϩ and CD8 ϩ mature peripheral T cells. This suggests a model whereby EBV uses CD21 to infect both immature and mature T cells.…”

“…Finally, our data indicate that the complement receptor CD21, previously used to identify CD4 + RTE cells, can also identify CD8 + RTE cells when used together with markers identifying naive cells. This is consistent with Pekalski et al, who reported that CD21 + CD4 + cells have higher T-cell excision circle content than their CD21counterparts, and that the depletion of T cells is followed by an influx of CD21 + T cells, as would be expected for a RTE marker [38]. Thus, we were able to analyze the tissue distribution and age-related changes of both CD4 + and CD8 + RTE cells.…”

“…Recently, the complement receptor CD21 has been suggested to be a more accurate marker for RTE cells in both CD4 + and CD8 + subsets [38]. Supporting this, we observed a high frequency of CD21 + naive cells within the circulating CD4 + and CD8 + populations in the youngest children included in our study (Supporting Information Fig.…”

“…Depletion of FDCs could impair responses to infections. In mature αβ T cells, CD21 was expressed at very low density on only <10%, with the highest expression in naïve subsets, as described in the literature (37). Accordingly, anti-CD21 CAR-T cells were not affected by fratricide, and T cell aplasia is an unlikely consequence of therapy.…”