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Antigen-pulsed CD8alpha+ dendritic cells generate an immune response after subcutaneous injection without homing to the draining lymph node.

Smith AL, Fazekas de St Groth B - J. Exp. Med. (1999)

Bottom Line: In contrast to CD8alpha- dendritic cells, the CD8alpha+ fraction failed to traffic to the draining lymph node and did not generate responses to intravenous peptide.Such responses may have been initiated via transfer of peptide-major histocompatibility complex complexes to migratory host CD8alpha- dendritic cells after injection.These data suggest that correlation of T helper cell type 1 (Th1) and Th2 priming with injection of CD8alpha+ and CD8alpha- dendritic cells, respectively, may not result from direct T cell activation by lymphoid versus myeloid dendritic cells, but rather from indirect modification of the response to immunogenic CD8alpha- dendritic cells by CD8alpha+ dendritic cells.

View Article: PubMed Central - PubMed

Affiliation: Centenary Institute of Cancer Medicine and Cell Biology, Newtown, New South Wales, Australia, 2042.

ABSTRACT
Two subsets of murine splenic dendritic cells, derived from distinct precursors, can be distinguished by surface expression of CD8alpha homodimers. The functions of the two subsets remain controversial, although it has been suggested that the lymphoid-derived (CD8alpha+) subset induces tolerance, whereas the myeloid-derived (CD8alpha-) subset has been shown to prime naive T cells and to generate memory responses. To study their capacity to prime or tolerize naive CD4(+) T cells in vivo, purified CD8alpha+ or CD8alpha- dendritic cells were injected subcutaneously into normal mice. In contrast to CD8alpha- dendritic cells, the CD8alpha+ fraction failed to traffic to the draining lymph node and did not generate responses to intravenous peptide. However, after in vitro pulsing with peptide, strong in vivo T cell responses to purified CD8alpha+ dendritic cells could be detected. Such responses may have been initiated via transfer of peptide-major histocompatibility complex complexes to migratory host CD8alpha- dendritic cells after injection. These data suggest that correlation of T helper cell type 1 (Th1) and Th2 priming with injection of CD8alpha+ and CD8alpha- dendritic cells, respectively, may not result from direct T cell activation by lymphoid versus myeloid dendritic cells, but rather from indirect modification of the response to immunogenic CD8alpha- dendritic cells by CD8alpha+ dendritic cells.

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Local response of  CFSE-labeled T cells to (A) intravenous peptide or (B) in  vitro–pulsed peptide, after subcutaneous inoculation of DCs  purifed using MACS® beads.  The total numbers of CD11c+  DCs in the inocula were 6 × 105  “CD8+” (3.0 × 105 CD8+ plus  3.0 × 105 CD8−), 6.5 × 105  CD8− (6.2 × 105 CD8− plus  0.3 × 105 CD8+), and 12.0 ×  105 CD8− (high dose; 11.4 ×  105 CD8− plus 0.6 × 105  CD8+). Popliteal LN cells were  gated for CD4+ propidium iodide (PI)− cells. The data are  presented as 10% probability  plots plus outliers. The histograms (B, bottom panels) show  CFSE division peaks within the  CD4+PI−Tgα+ T cell gate  (boxed). Note the different histogram scales, indicating significantly different responses in the  different groups.
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Figure 1: Local response of CFSE-labeled T cells to (A) intravenous peptide or (B) in vitro–pulsed peptide, after subcutaneous inoculation of DCs purifed using MACS® beads. The total numbers of CD11c+ DCs in the inocula were 6 × 105 “CD8+” (3.0 × 105 CD8+ plus 3.0 × 105 CD8−), 6.5 × 105 CD8− (6.2 × 105 CD8− plus 0.3 × 105 CD8+), and 12.0 × 105 CD8− (high dose; 11.4 × 105 CD8− plus 0.6 × 105 CD8+). Popliteal LN cells were gated for CD4+ propidium iodide (PI)− cells. The data are presented as 10% probability plots plus outliers. The histograms (B, bottom panels) show CFSE division peaks within the CD4+PI−Tgα+ T cell gate (boxed). Note the different histogram scales, indicating significantly different responses in the different groups.

Mentions: To test the capacity of subcutaneously injected DCs to migrate to the DLNs and act as APCs presenting intravenously administered peptide to naive T cells, CD8α− and CD8α+ DCs were purified from the spleens of 107-1 Tg donors by two-step positive magnetic bead selection, first for expression of CD11c and then for CD8α. This yielded two fractions, a CD8α− fraction containing <1% CD8α+ contaminants, and a “CD8α+” fraction containing 50% CD8α− cells and 50% CD8α− cells. An aliquot of each purified fraction was pulsed with peptide in vitro. The DCs were then injected into hind footpads of unirradiated 36-2 Tg mice reconstituted with CFSE-labeled T cells 2 d before. 12 h after DC injection, MCC87–103 peptide was administered intravenously to the animals that had received unpulsed DCs, and antigen-specific T cell responses were determined 3 d later in the popliteal LNs. The marked increase in effectiveness of in vitro versus in vivo peptide loading was apparent from comparison of responses in the two groups (Fig. 1, A vs. B). We have previously noted a difference of similar magnitude between in vitro and in vivo peptide loading of naive B cells (6). The size of the response to intravenous peptide correlated with the number of CD8α− DCs in the inoculum, being barely detectable in the group that received the “CD8α+” DCs consisting of a mixture of CD8α− and CD8α+ DCs, and highest in the animals receiving a high dose of pure CD8α− DCs (Fig. 1 A). The response to both fractions of peptide-pulsed DCs was high. Analysis of the CFSE division profiles indicated that the number of cells recruited into division was again proportional to the number of CD8α− cells in the inoculum (Fig. 1 B, bottom panels). As expected, all the T cell responses were localized to the DLNs, as indicated by the lack of response in the contralateral popliteal node.


Antigen-pulsed CD8alpha+ dendritic cells generate an immune response after subcutaneous injection without homing to the draining lymph node.

Smith AL, Fazekas de St Groth B - J. Exp. Med. (1999)

Local response of  CFSE-labeled T cells to (A) intravenous peptide or (B) in  vitro–pulsed peptide, after subcutaneous inoculation of DCs  purifed using MACS® beads.  The total numbers of CD11c+  DCs in the inocula were 6 × 105  “CD8+” (3.0 × 105 CD8+ plus  3.0 × 105 CD8−), 6.5 × 105  CD8− (6.2 × 105 CD8− plus  0.3 × 105 CD8+), and 12.0 ×  105 CD8− (high dose; 11.4 ×  105 CD8− plus 0.6 × 105  CD8+). Popliteal LN cells were  gated for CD4+ propidium iodide (PI)− cells. The data are  presented as 10% probability  plots plus outliers. The histograms (B, bottom panels) show  CFSE division peaks within the  CD4+PI−Tgα+ T cell gate  (boxed). Note the different histogram scales, indicating significantly different responses in the  different groups.
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Related In: Results  -  Collection

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Figure 1: Local response of CFSE-labeled T cells to (A) intravenous peptide or (B) in vitro–pulsed peptide, after subcutaneous inoculation of DCs purifed using MACS® beads. The total numbers of CD11c+ DCs in the inocula were 6 × 105 “CD8+” (3.0 × 105 CD8+ plus 3.0 × 105 CD8−), 6.5 × 105 CD8− (6.2 × 105 CD8− plus 0.3 × 105 CD8+), and 12.0 × 105 CD8− (high dose; 11.4 × 105 CD8− plus 0.6 × 105 CD8+). Popliteal LN cells were gated for CD4+ propidium iodide (PI)− cells. The data are presented as 10% probability plots plus outliers. The histograms (B, bottom panels) show CFSE division peaks within the CD4+PI−Tgα+ T cell gate (boxed). Note the different histogram scales, indicating significantly different responses in the different groups.
Mentions: To test the capacity of subcutaneously injected DCs to migrate to the DLNs and act as APCs presenting intravenously administered peptide to naive T cells, CD8α− and CD8α+ DCs were purified from the spleens of 107-1 Tg donors by two-step positive magnetic bead selection, first for expression of CD11c and then for CD8α. This yielded two fractions, a CD8α− fraction containing <1% CD8α+ contaminants, and a “CD8α+” fraction containing 50% CD8α− cells and 50% CD8α− cells. An aliquot of each purified fraction was pulsed with peptide in vitro. The DCs were then injected into hind footpads of unirradiated 36-2 Tg mice reconstituted with CFSE-labeled T cells 2 d before. 12 h after DC injection, MCC87–103 peptide was administered intravenously to the animals that had received unpulsed DCs, and antigen-specific T cell responses were determined 3 d later in the popliteal LNs. The marked increase in effectiveness of in vitro versus in vivo peptide loading was apparent from comparison of responses in the two groups (Fig. 1, A vs. B). We have previously noted a difference of similar magnitude between in vitro and in vivo peptide loading of naive B cells (6). The size of the response to intravenous peptide correlated with the number of CD8α− DCs in the inoculum, being barely detectable in the group that received the “CD8α+” DCs consisting of a mixture of CD8α− and CD8α+ DCs, and highest in the animals receiving a high dose of pure CD8α− DCs (Fig. 1 A). The response to both fractions of peptide-pulsed DCs was high. Analysis of the CFSE division profiles indicated that the number of cells recruited into division was again proportional to the number of CD8α− cells in the inoculum (Fig. 1 B, bottom panels). As expected, all the T cell responses were localized to the DLNs, as indicated by the lack of response in the contralateral popliteal node.

Bottom Line: In contrast to CD8alpha- dendritic cells, the CD8alpha+ fraction failed to traffic to the draining lymph node and did not generate responses to intravenous peptide.Such responses may have been initiated via transfer of peptide-major histocompatibility complex complexes to migratory host CD8alpha- dendritic cells after injection.These data suggest that correlation of T helper cell type 1 (Th1) and Th2 priming with injection of CD8alpha+ and CD8alpha- dendritic cells, respectively, may not result from direct T cell activation by lymphoid versus myeloid dendritic cells, but rather from indirect modification of the response to immunogenic CD8alpha- dendritic cells by CD8alpha+ dendritic cells.

View Article: PubMed Central - PubMed

Affiliation: Centenary Institute of Cancer Medicine and Cell Biology, Newtown, New South Wales, Australia, 2042.

ABSTRACT
Two subsets of murine splenic dendritic cells, derived from distinct precursors, can be distinguished by surface expression of CD8alpha homodimers. The functions of the two subsets remain controversial, although it has been suggested that the lymphoid-derived (CD8alpha+) subset induces tolerance, whereas the myeloid-derived (CD8alpha-) subset has been shown to prime naive T cells and to generate memory responses. To study their capacity to prime or tolerize naive CD4(+) T cells in vivo, purified CD8alpha+ or CD8alpha- dendritic cells were injected subcutaneously into normal mice. In contrast to CD8alpha- dendritic cells, the CD8alpha+ fraction failed to traffic to the draining lymph node and did not generate responses to intravenous peptide. However, after in vitro pulsing with peptide, strong in vivo T cell responses to purified CD8alpha+ dendritic cells could be detected. Such responses may have been initiated via transfer of peptide-major histocompatibility complex complexes to migratory host CD8alpha- dendritic cells after injection. These data suggest that correlation of T helper cell type 1 (Th1) and Th2 priming with injection of CD8alpha+ and CD8alpha- dendritic cells, respectively, may not result from direct T cell activation by lymphoid versus myeloid dendritic cells, but rather from indirect modification of the response to immunogenic CD8alpha- dendritic cells by CD8alpha+ dendritic cells.

Show MeSH
Related in: MedlinePlus