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Simian varicella virus infection of rhesus macaques recapitulates essential features of varicella zoster virus infection in humans.

Messaoudi I, Barron A, Wellish M, Engelmann F, Legasse A, Planer S, Gilden D, Nikolich-Zugich J, Mahalingam R - PLoS Pathog. (2009)

Bottom Line: Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP) resulted in persistent infection.More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted.Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation.

View Article: PubMed Central - PubMed

Affiliation: Vaccine and Gene Therapy, Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, Oregon, United States of America. messaoud@ohsu.edu

ABSTRACT
Simian varicella virus (SVV), the etiologic agent of naturally occurring varicella in primates, is genetically and antigenically closely related to human varicella zoster virus (VZV). Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP) resulted in persistent infection. More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted. Thus, previous NHP models were not ideally suited to analyze the immune response to SVV during acute infection and the transition to latency. Here, we show for the first time that intrabronchial inoculation of rhesus macaques with SVV closely mimics naturally occurring varicella (chickenpox) in humans. Infected monkeys developed varicella and viremia that resolved 21 days after infection. Months later, viral DNA was detected only in ganglia and not in non-ganglionic tissues. Like VZV latency in human ganglia, transcripts corresponding to SVV ORFs 21, 62, 63 and 66, but not ORF 40, were detected by RT-PCR. In addition, as described for VZV, SVV ORF 63 protein was detected in the cytoplasm of neurons in latently infected monkey ganglia by immunohistochemistry. We also present the first in depth analysis of the immune response to SVV. Infected animals produced a strong humoral and cell-mediated immune response to SVV, as assessed by immunohistology, serology and flow cytometry. Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation.

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SVV-induced T cell proliferation occurs earlier in BAL than in peripheral blood.In contrast to PBMCs, BAL revealed only CM and EM T cells subsets as illustrated by a profile of CD8 T cells from 24953 day 0 (A, left). T cell proliferation was measured as described in Figure 3. A representative example of Ki67 staining within CD8 EM T cells from monkey 24953 on 0 dpi (A, middle) and 14 dpi (A, right) is shown. Fold increases (relative to 0 dpi) in the percentages of Ki67+ CD4/CM, CD4/EM, CD8/CM and CD8/EM T cells subsets in BAL from all 4 monkeys indicate a robust proliferative response of all T cell subsets 7–14 dpi in all monkeys (B–E).
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ppat-1000657-g005: SVV-induced T cell proliferation occurs earlier in BAL than in peripheral blood.In contrast to PBMCs, BAL revealed only CM and EM T cells subsets as illustrated by a profile of CD8 T cells from 24953 day 0 (A, left). T cell proliferation was measured as described in Figure 3. A representative example of Ki67 staining within CD8 EM T cells from monkey 24953 on 0 dpi (A, middle) and 14 dpi (A, right) is shown. Fold increases (relative to 0 dpi) in the percentages of Ki67+ CD4/CM, CD4/EM, CD8/CM and CD8/EM T cells subsets in BAL from all 4 monkeys indicate a robust proliferative response of all T cell subsets 7–14 dpi in all monkeys (B–E).

Mentions: T cell proliferation in PBMCs (Figure 4) and BAL (Figure 5) was also determined by measuring the relative (fold) increase in the number (PBMC) or percentage (BAL) of Ki67+. At each time point, PBMCs and BAL cells were stained with antibodies directed against CD4, CD8, CD28 and CD95 (Figure 4A and 5A, left) to delineate naïve (CD28+CD95−), central memory (CD28+CD95+, CM) and effector memory (CD28−CD95+, EM) T cell subsets [34]. Cells were fixed, permeabilized and incubated with anti-Ki67 antibodies (Figures 4A and 5A, middle and right). Previous studies showed that naïve T cells identified using these markers were CCR7+. EM T cell were CCR7-, whereas CM T cells contained a transitional population that lacked CCR7 expression [32],[35]. Both naïve and memory T cells were detected in PBMCs (Figure 4A, left), whereas, as expected, only memory T cells were present in BAL cells (Figure 5A, left). SVV infection induced robust T cell proliferation as shown by an increase in Ki67+ CD8 EM T cells (Figures 4A and 5A, middle and right).


Simian varicella virus infection of rhesus macaques recapitulates essential features of varicella zoster virus infection in humans.

Messaoudi I, Barron A, Wellish M, Engelmann F, Legasse A, Planer S, Gilden D, Nikolich-Zugich J, Mahalingam R - PLoS Pathog. (2009)

SVV-induced T cell proliferation occurs earlier in BAL than in peripheral blood.In contrast to PBMCs, BAL revealed only CM and EM T cells subsets as illustrated by a profile of CD8 T cells from 24953 day 0 (A, left). T cell proliferation was measured as described in Figure 3. A representative example of Ki67 staining within CD8 EM T cells from monkey 24953 on 0 dpi (A, middle) and 14 dpi (A, right) is shown. Fold increases (relative to 0 dpi) in the percentages of Ki67+ CD4/CM, CD4/EM, CD8/CM and CD8/EM T cells subsets in BAL from all 4 monkeys indicate a robust proliferative response of all T cell subsets 7–14 dpi in all monkeys (B–E).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2770849&req=5

ppat-1000657-g005: SVV-induced T cell proliferation occurs earlier in BAL than in peripheral blood.In contrast to PBMCs, BAL revealed only CM and EM T cells subsets as illustrated by a profile of CD8 T cells from 24953 day 0 (A, left). T cell proliferation was measured as described in Figure 3. A representative example of Ki67 staining within CD8 EM T cells from monkey 24953 on 0 dpi (A, middle) and 14 dpi (A, right) is shown. Fold increases (relative to 0 dpi) in the percentages of Ki67+ CD4/CM, CD4/EM, CD8/CM and CD8/EM T cells subsets in BAL from all 4 monkeys indicate a robust proliferative response of all T cell subsets 7–14 dpi in all monkeys (B–E).
Mentions: T cell proliferation in PBMCs (Figure 4) and BAL (Figure 5) was also determined by measuring the relative (fold) increase in the number (PBMC) or percentage (BAL) of Ki67+. At each time point, PBMCs and BAL cells were stained with antibodies directed against CD4, CD8, CD28 and CD95 (Figure 4A and 5A, left) to delineate naïve (CD28+CD95−), central memory (CD28+CD95+, CM) and effector memory (CD28−CD95+, EM) T cell subsets [34]. Cells were fixed, permeabilized and incubated with anti-Ki67 antibodies (Figures 4A and 5A, middle and right). Previous studies showed that naïve T cells identified using these markers were CCR7+. EM T cell were CCR7-, whereas CM T cells contained a transitional population that lacked CCR7 expression [32],[35]. Both naïve and memory T cells were detected in PBMCs (Figure 4A, left), whereas, as expected, only memory T cells were present in BAL cells (Figure 5A, left). SVV infection induced robust T cell proliferation as shown by an increase in Ki67+ CD8 EM T cells (Figures 4A and 5A, middle and right).

Bottom Line: Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP) resulted in persistent infection.More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted.Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation.

View Article: PubMed Central - PubMed

Affiliation: Vaccine and Gene Therapy, Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, Oregon, United States of America. messaoud@ohsu.edu

ABSTRACT
Simian varicella virus (SVV), the etiologic agent of naturally occurring varicella in primates, is genetically and antigenically closely related to human varicella zoster virus (VZV). Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP) resulted in persistent infection. More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted. Thus, previous NHP models were not ideally suited to analyze the immune response to SVV during acute infection and the transition to latency. Here, we show for the first time that intrabronchial inoculation of rhesus macaques with SVV closely mimics naturally occurring varicella (chickenpox) in humans. Infected monkeys developed varicella and viremia that resolved 21 days after infection. Months later, viral DNA was detected only in ganglia and not in non-ganglionic tissues. Like VZV latency in human ganglia, transcripts corresponding to SVV ORFs 21, 62, 63 and 66, but not ORF 40, were detected by RT-PCR. In addition, as described for VZV, SVV ORF 63 protein was detected in the cytoplasm of neurons in latently infected monkey ganglia by immunohistochemistry. We also present the first in depth analysis of the immune response to SVV. Infected animals produced a strong humoral and cell-mediated immune response to SVV, as assessed by immunohistology, serology and flow cytometry. Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation.

Show MeSH
Related in: MedlinePlus