AIDS RESEARCH AND HUMAN RETROVIRUSES Volume 30, Number 12, 2014 ª Mary Ann Liebert, Inc. DOI: 10.1089/aid.2014.0293
Depletion of Lamina Propria Innate Lymphoid Cells in Simian Immunodeficiency Virus Infection R. Keith Reeves,1,2 Guobin Kang,3 Haiying Li,2 and Qingsheng Li 3
FIG. 1. Identification of lamina propria NKp44 + CD3 - innate lymphoid cells (ILCs) in macaque colorectal tissue. Confocal microscopy on colorectal sections was performed using established methods.4 Tissue sections were stained with primary antibodies to NKp44 and CD3, and then secondary antibodies labeled with Alexa Fluor 555 (red) and Alexa Fluor 488 (green), respectively. Cell nuclei were counterstained blue with TOTO-3. Sequential images at wavelengths for each fluorophore were collected using a Bio-Rad MRC 1000 Confocal Microscope at · 60 and were processed in Adobe Photoshop 7.0. Representative samples from naive (left panel) and chronically SIVmac251-infected macaques (right panel) are shown.
D
uring infection, the gastrointestinal (GI) tract is a major site for HIV-1 and simian immunodeficiency virus (SIV) replication and dissemination. CD4 + T cells are rapidly depleted and the epithelial barrier is compromised, resulting in subsequent microbial translocation that drives
immune activation and disease progress. However, the full mechanisms of mucosal breakdown and dysfunction are poorly understood. In humans and mice, innate lymphoid cells (ILCs) are primarily mucosae restricted and increasing evidence indicates that ILCs maintain mucosae epithelial integrity and
1 Division of Immunology, New England Primate Research Center, Harvard Medical School, Southborough Campus, Southborough, Massachusetts. 2 Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts. 3 Nebraska Center for Virology and School of Biological Sciences, University of Nebraska–Lincoln, Lincoln, Nebraska.
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provide innate immunological defense against pathogens by producing interleukin (IL)-17 and IL-22. Others and we have recently identified the macaque counterpart of IL-17-producing NKp44 + type 3 ILCs, and also found that ILCs can be numerically and functionally impaired during SIV infection.1–3 We first identified NKp44 + CD3 - type 3 ILCs from rhesus macaque colorectal tissue by confocal microscopy (Fig. 1), validating previous efforts to phenotype these cells using polychromatic flow cytometry.1 Furthermore, Fig. 1 demonstrates that NKp44 + CD3 - type 3 ILCs are generally not intraepithelial, but rather are found in the lamina propria and are depleted in tissue from chronically SIVmac251-infected macaques compared to naive animals. Although the full role of ILCs in maintaining gut homeostasis in SIV/HIV infection is not yet entirely clear, development of such in situ methods to evaluate their proximity and cellular interactions in the gut microenvironment will be critical for future studies. Author Disclosure Statement
No competing financial interests exist. References
1. Reeves RK, Rajakumar PA, Evans TI, Connole M, Gillis J, Wong FE, et al.: Gut inflammation and indoleamine deox-
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ygenase inhibit IL-17 production and promote cytotoxic potential in NKp44 + mucosal NK cells during SIV infection. Blood 2011;118:3321–3330. 2. Xu H, Wang X, Liu DX, Moroney-Rasmussen T, Lackner AA, and Veazey RS: IL-17-producing innate lymphoid cells are restricted to mucosal tissues and are depleted in SIV-infected macaques. Mucosal Immunol 2012;5:658– 669. 3. Klatt NR, Estes JD, Sun X, Ortiz AM, Barber JS, Harris LD, et al.: Loss of mucosal CD103 + DCs and IL-17 + and IL22 + lymphocytes is associated with mucosal damage in SIV infection. Mucosal Immunol 2012;5:646–657. 4. Li Q, Duan L, Estes JD, Ma ZM, Rourke T, Wang Y, et al.: Peak SIV replication in resting memory CD4 + T cells depletes gut lamina propria CD4 + T cells. Nature 2005;434: 1148–1152.
Address correspondence to: R. Keith Reeves Center for Virology and Vaccine Research Beth Israel Deaconess Medical Center 3 Blackfan Circle Boston, Massachusetts 02215 E-mail: [email protected]
Depletion of Lamina Propria Innate Lymphoid Cells in Simian Immunodeficiency Virus Infection R. Keith Reeves,1,2 Guobin Kang,3 Haiying Li,2 and Qingsheng Li 3
FIG. 1. Identification of lamina propria NKp44 + CD3 - innate lymphoid cells (ILCs) in macaque colorectal tissue. Confocal microscopy on colorectal sections was performed using established methods.4 Tissue sections were stained with primary antibodies to NKp44 and CD3, and then secondary antibodies labeled with Alexa Fluor 555 (red) and Alexa Fluor 488 (green), respectively. Cell nuclei were counterstained blue with TOTO-3. Sequential images at wavelengths for each fluorophore were collected using a Bio-Rad MRC 1000 Confocal Microscope at · 60 and were processed in Adobe Photoshop 7.0. Representative samples from naive (left panel) and chronically SIVmac251-infected macaques (right panel) are shown.
D
uring infection, the gastrointestinal (GI) tract is a major site for HIV-1 and simian immunodeficiency virus (SIV) replication and dissemination. CD4 + T cells are rapidly depleted and the epithelial barrier is compromised, resulting in subsequent microbial translocation that drives
immune activation and disease progress. However, the full mechanisms of mucosal breakdown and dysfunction are poorly understood. In humans and mice, innate lymphoid cells (ILCs) are primarily mucosae restricted and increasing evidence indicates that ILCs maintain mucosae epithelial integrity and
1 Division of Immunology, New England Primate Research Center, Harvard Medical School, Southborough Campus, Southborough, Massachusetts. 2 Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts. 3 Nebraska Center for Virology and School of Biological Sciences, University of Nebraska–Lincoln, Lincoln, Nebraska.
1160
MUCOSAL ILC DEPLETION
provide innate immunological defense against pathogens by producing interleukin (IL)-17 and IL-22. Others and we have recently identified the macaque counterpart of IL-17-producing NKp44 + type 3 ILCs, and also found that ILCs can be numerically and functionally impaired during SIV infection.1–3 We first identified NKp44 + CD3 - type 3 ILCs from rhesus macaque colorectal tissue by confocal microscopy (Fig. 1), validating previous efforts to phenotype these cells using polychromatic flow cytometry.1 Furthermore, Fig. 1 demonstrates that NKp44 + CD3 - type 3 ILCs are generally not intraepithelial, but rather are found in the lamina propria and are depleted in tissue from chronically SIVmac251-infected macaques compared to naive animals. Although the full role of ILCs in maintaining gut homeostasis in SIV/HIV infection is not yet entirely clear, development of such in situ methods to evaluate their proximity and cellular interactions in the gut microenvironment will be critical for future studies. Author Disclosure Statement
No competing financial interests exist. References
1. Reeves RK, Rajakumar PA, Evans TI, Connole M, Gillis J, Wong FE, et al.: Gut inflammation and indoleamine deox-
1161
ygenase inhibit IL-17 production and promote cytotoxic potential in NKp44 + mucosal NK cells during SIV infection. Blood 2011;118:3321–3330. 2. Xu H, Wang X, Liu DX, Moroney-Rasmussen T, Lackner AA, and Veazey RS: IL-17-producing innate lymphoid cells are restricted to mucosal tissues and are depleted in SIV-infected macaques. Mucosal Immunol 2012;5:658– 669. 3. Klatt NR, Estes JD, Sun X, Ortiz AM, Barber JS, Harris LD, et al.: Loss of mucosal CD103 + DCs and IL-17 + and IL22 + lymphocytes is associated with mucosal damage in SIV infection. Mucosal Immunol 2012;5:646–657. 4. Li Q, Duan L, Estes JD, Ma ZM, Rourke T, Wang Y, et al.: Peak SIV replication in resting memory CD4 + T cells depletes gut lamina propria CD4 + T cells. Nature 2005;434: 1148–1152.
Address correspondence to: R. Keith Reeves Center for Virology and Vaccine Research Beth Israel Deaconess Medical Center 3 Blackfan Circle Boston, Massachusetts 02215 E-mail: [email protected]
