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Virus-induced transient bone marrow aplasia: major role of interferon-alpha/beta during acute infection with the noncytopathic lymphocytic choriomeningitis virus.

Binder D, Fehr J, Hengartner H, Zinkernagel RM - J. Exp. Med. (1997)

Bottom Line: Within a given genetic background, the extent of the blood cell abnormalities did not correlate with the virulence of the LCMV isolate but variations were detected between different mouse strains: they were found to depend on their IFN-alpha/beta responder phenotype.In parallel, the bone marrow (BM) cellularity, the pluripotential and committed progenitor compartments were up to 30-fold reduced in wild type and IFN-gamma R0/0, but remained unchanged in IFN-alpha/beta R0/0 mice.Thus, the reversible depression of hematopoiesis during early LCMV infection was not mediated by LCMV-WE-specific cytotoxic T lymphocyte, cytolysis, or secreted IFN-gamma from virally induced NK cells but was a direct effect of IFN-alpha/beta.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University Hospital of Zurich, Switzerland.

ABSTRACT
The hematologic consequences of infection with the noncytopathic lymphocytic choriomeningitis virus (LCMV) were studied in wild-type mice with inherent variations in their interferon (IFN)-alpha/beta responder ability and in mutant mice lacking alpha/beta (IFN-alpha/beta R0/0) or gamma IFN (IFN-gamma R0/0) receptors. During the first week of infection, wild type mice demonstrated a transient pancytopenia. Within a given genetic background, the extent of the blood cell abnormalities did not correlate with the virulence of the LCMV isolate but variations were detected between different mouse strains: they were found to depend on their IFN-alpha/beta responder phenotype. Whereas IFN-gamma R0/0 mice were comparable to wild-type mice, IFN-alpha/beta R0/0 mice exhibited unchanged peripheral blood values during acute LCMV infection. In parallel, the bone marrow (BM) cellularity, the pluripotential and committed progenitor compartments were up to 30-fold reduced in wild type and IFN-gamma R0/0, but remained unchanged in IFN-alpha/beta R0/0 mice. Viral titers in BM 3 d after LCMV infection were similar in these mice, but antigen localization was different. Viral antigen was predominantly confined to stromal BM in normal mice and IFN-gamma R0/0 knockouts, whereas, in IFN-alpha/beta R0/0 mice, LCMV was detected in > 90% of megakaryocytes and 10-15% of myeloid precursors, but not in erythroblasts Although IFN-alpha/beta efficiently prevented viral replication in potentially susceptible hematopoietic cells, even in overwhelming LCMV infection, unlimited virus multiplication in platelet and myeloid precursors in IFN-alpha/beta R0/0 mice did not interfere with the number of circulating blood cells. Natural killer (NK) cell expansion and activity in the BM was comparable on day 3 after infection in mutant and control mice. Adaptive immune responses did not play a major role because comparable kinetics of LCMV-induced pancytopenia and transient depletion of the pluripotential and committed progenitor compartments were observed in CD8(0/0) and CD4(0/0) mice, in mice depleted of NK cells, in lpr mice, and in perforin-deficient (P0/0) mice lacking lytic NK cells. Thus, the reversible depression of hematopoiesis during early LCMV infection was not mediated by LCMV-WE-specific cytotoxic T lymphocyte, cytolysis, or secreted IFN-gamma from virally induced NK cells but was a direct effect of IFN-alpha/beta.

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(A) Infection of stromal cells in wild-type and IFN-γ R0/0  mice versus blood precursor cells in IFN-α/β R0/0 mice. Viral protein in  differentiated BM cells was detected by immunocytochemical staining 1 d  (A–C) and 3 d (D–F) after infection with 2 × 106 PFU LCMV-WE. BM  smears were stained with a LCMV-specific mAb followed by a peroxidase-labeled goat anti–rat Ig and by an alkaline phosphatase–labeled donkey anti–goat Ig. LCMV-WE–infected cells are colored red and uninfected cells appear blue due to counterstaining with Meyer's hemalum.  Note the intense staining of viral antigen in megakaryoctes and, to a lesser  extent, in myeloid precursors and stromal cells in IFN-α/β R0/0 mice (B, E).  In wild-type and IFN-γ R0/0 mice, LCMV-WE is detected in substantial  amounts exclusively in stromal fibroblast and endothelial cells (A, D, C, F).  Original magnification, (A–C) ×500; (D–F) ×1,000. (B) Differential quantification of LCMV-infected BM cells. Fixed BM smears of mice of the  indicated genotypes were stained with a LCMV-specific mAb at different  timepoints after infection with LCMV-WE. The frequency of infected cells was determined microscopically by counting 200 cells per individual mouse.  Bars represent the mean ± SD of the percentage of WE-positive BM cells of 2–3 individual mice per group.
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Figure 5: (A) Infection of stromal cells in wild-type and IFN-γ R0/0 mice versus blood precursor cells in IFN-α/β R0/0 mice. Viral protein in differentiated BM cells was detected by immunocytochemical staining 1 d (A–C) and 3 d (D–F) after infection with 2 × 106 PFU LCMV-WE. BM smears were stained with a LCMV-specific mAb followed by a peroxidase-labeled goat anti–rat Ig and by an alkaline phosphatase–labeled donkey anti–goat Ig. LCMV-WE–infected cells are colored red and uninfected cells appear blue due to counterstaining with Meyer's hemalum. Note the intense staining of viral antigen in megakaryoctes and, to a lesser extent, in myeloid precursors and stromal cells in IFN-α/β R0/0 mice (B, E). In wild-type and IFN-γ R0/0 mice, LCMV-WE is detected in substantial amounts exclusively in stromal fibroblast and endothelial cells (A, D, C, F). Original magnification, (A–C) ×500; (D–F) ×1,000. (B) Differential quantification of LCMV-infected BM cells. Fixed BM smears of mice of the indicated genotypes were stained with a LCMV-specific mAb at different timepoints after infection with LCMV-WE. The frequency of infected cells was determined microscopically by counting 200 cells per individual mouse. Bars represent the mean ± SD of the percentage of WE-positive BM cells of 2–3 individual mice per group.

Mentions: In vivo susceptibility to LCMV infection of wild-type and IFN R-deficient hematopoietic BM cells was evaluated for a high-dose (2 × 106 PFU) challenge with LCMV-WE. Wild-type and IFN-γ R0/0 mice showed a similar kinetics of LCMV replication with slightly higher titers in IFN-γ R0/0 mice 7 d after infection (Fig. 4). In contrast, IFN-α/β R0/0 mice exhibited an enhanced initial replication, i.e., the highest titer in the BM was reached already on day 1. All three groups showed a comparable maximal viral load of ∼5.6 log10 PFU/femur 3 d after virus inoculation. Thus, under high-dose conditions, absence of the IFN-α/β R favored uncontrolled viral replication maximally in the initial phase of infection, but overall maximal viral loads in BM were not affected by the expression of IFN receptors (note that IFN-α/β R0/0 mice become persistently infected with LCMV but titers are 1–2 log10 lower in the chronic state than the peak virus titer measured on day 3 [21, 41]). The kind of BM cell permissive for LCMV replication was characterized in wild-type, IFN-α/β R0/0, and IFN-γ R0/0 mice at different timepoints after infection (Fig. 5 A). Viral antigen was detected by an LCMV-WE–specific mAb on BM smears; in parallel, the type of infected hematopoietic cell was identified microscopically by cytomorphologic criteria by counterstaining with Meyer's hemalum. The prevalence of LCMVWE–positive morphologically differentiated hematopoietic cells in wild-type and IFN-γ R0/0 mice was low and did not exceed 20% of megakaryocytes and 0.5% of granulocytes at any timepoint of infection (Fig. 5 B). Virtually all detectable LCMV-specific antigen in wild-type and IFN-γ R0/0 mice was confined to stromal BM cells also on day 3, at times when highest LCMV titers were recovered. In contrast, in IFN-α/β R0/0 mice >90% of megakaryocytes were positive for viral antigen 1 d after virus inoculation, ∼60% stained positively on day 3 and ⩽50% of all megakaryocytes remained infected during the following week. In addition, ∼12% predominantly immature myeloid precursors (promyelocytes, myelocytes) of IFN-α/β R0/0 BM exhibited viral antigen peaking on day 3 after LCMV-WE infection (Fig. 5, A and B). In comparison to wild-type and IFN-γ R0/0 mice, stromal BM cells of IFN-α/β R0/0 mice were infected to a comparable extent. Interestingly, erythroblasts were resistant to LCMV-WE infection in all three mouse strains tested, i.e., the frequency of LCMV-positive erythroblasts in IFN-α/β R0/0 mice was less than 1:800.


Virus-induced transient bone marrow aplasia: major role of interferon-alpha/beta during acute infection with the noncytopathic lymphocytic choriomeningitis virus.

Binder D, Fehr J, Hengartner H, Zinkernagel RM - J. Exp. Med. (1997)

(A) Infection of stromal cells in wild-type and IFN-γ R0/0  mice versus blood precursor cells in IFN-α/β R0/0 mice. Viral protein in  differentiated BM cells was detected by immunocytochemical staining 1 d  (A–C) and 3 d (D–F) after infection with 2 × 106 PFU LCMV-WE. BM  smears were stained with a LCMV-specific mAb followed by a peroxidase-labeled goat anti–rat Ig and by an alkaline phosphatase–labeled donkey anti–goat Ig. LCMV-WE–infected cells are colored red and uninfected cells appear blue due to counterstaining with Meyer's hemalum.  Note the intense staining of viral antigen in megakaryoctes and, to a lesser  extent, in myeloid precursors and stromal cells in IFN-α/β R0/0 mice (B, E).  In wild-type and IFN-γ R0/0 mice, LCMV-WE is detected in substantial  amounts exclusively in stromal fibroblast and endothelial cells (A, D, C, F).  Original magnification, (A–C) ×500; (D–F) ×1,000. (B) Differential quantification of LCMV-infected BM cells. Fixed BM smears of mice of the  indicated genotypes were stained with a LCMV-specific mAb at different  timepoints after infection with LCMV-WE. The frequency of infected cells was determined microscopically by counting 200 cells per individual mouse.  Bars represent the mean ± SD of the percentage of WE-positive BM cells of 2–3 individual mice per group.
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Figure 5: (A) Infection of stromal cells in wild-type and IFN-γ R0/0 mice versus blood precursor cells in IFN-α/β R0/0 mice. Viral protein in differentiated BM cells was detected by immunocytochemical staining 1 d (A–C) and 3 d (D–F) after infection with 2 × 106 PFU LCMV-WE. BM smears were stained with a LCMV-specific mAb followed by a peroxidase-labeled goat anti–rat Ig and by an alkaline phosphatase–labeled donkey anti–goat Ig. LCMV-WE–infected cells are colored red and uninfected cells appear blue due to counterstaining with Meyer's hemalum. Note the intense staining of viral antigen in megakaryoctes and, to a lesser extent, in myeloid precursors and stromal cells in IFN-α/β R0/0 mice (B, E). In wild-type and IFN-γ R0/0 mice, LCMV-WE is detected in substantial amounts exclusively in stromal fibroblast and endothelial cells (A, D, C, F). Original magnification, (A–C) ×500; (D–F) ×1,000. (B) Differential quantification of LCMV-infected BM cells. Fixed BM smears of mice of the indicated genotypes were stained with a LCMV-specific mAb at different timepoints after infection with LCMV-WE. The frequency of infected cells was determined microscopically by counting 200 cells per individual mouse. Bars represent the mean ± SD of the percentage of WE-positive BM cells of 2–3 individual mice per group.
Mentions: In vivo susceptibility to LCMV infection of wild-type and IFN R-deficient hematopoietic BM cells was evaluated for a high-dose (2 × 106 PFU) challenge with LCMV-WE. Wild-type and IFN-γ R0/0 mice showed a similar kinetics of LCMV replication with slightly higher titers in IFN-γ R0/0 mice 7 d after infection (Fig. 4). In contrast, IFN-α/β R0/0 mice exhibited an enhanced initial replication, i.e., the highest titer in the BM was reached already on day 1. All three groups showed a comparable maximal viral load of ∼5.6 log10 PFU/femur 3 d after virus inoculation. Thus, under high-dose conditions, absence of the IFN-α/β R favored uncontrolled viral replication maximally in the initial phase of infection, but overall maximal viral loads in BM were not affected by the expression of IFN receptors (note that IFN-α/β R0/0 mice become persistently infected with LCMV but titers are 1–2 log10 lower in the chronic state than the peak virus titer measured on day 3 [21, 41]). The kind of BM cell permissive for LCMV replication was characterized in wild-type, IFN-α/β R0/0, and IFN-γ R0/0 mice at different timepoints after infection (Fig. 5 A). Viral antigen was detected by an LCMV-WE–specific mAb on BM smears; in parallel, the type of infected hematopoietic cell was identified microscopically by cytomorphologic criteria by counterstaining with Meyer's hemalum. The prevalence of LCMVWE–positive morphologically differentiated hematopoietic cells in wild-type and IFN-γ R0/0 mice was low and did not exceed 20% of megakaryocytes and 0.5% of granulocytes at any timepoint of infection (Fig. 5 B). Virtually all detectable LCMV-specific antigen in wild-type and IFN-γ R0/0 mice was confined to stromal BM cells also on day 3, at times when highest LCMV titers were recovered. In contrast, in IFN-α/β R0/0 mice >90% of megakaryocytes were positive for viral antigen 1 d after virus inoculation, ∼60% stained positively on day 3 and ⩽50% of all megakaryocytes remained infected during the following week. In addition, ∼12% predominantly immature myeloid precursors (promyelocytes, myelocytes) of IFN-α/β R0/0 BM exhibited viral antigen peaking on day 3 after LCMV-WE infection (Fig. 5, A and B). In comparison to wild-type and IFN-γ R0/0 mice, stromal BM cells of IFN-α/β R0/0 mice were infected to a comparable extent. Interestingly, erythroblasts were resistant to LCMV-WE infection in all three mouse strains tested, i.e., the frequency of LCMV-positive erythroblasts in IFN-α/β R0/0 mice was less than 1:800.

Bottom Line: Within a given genetic background, the extent of the blood cell abnormalities did not correlate with the virulence of the LCMV isolate but variations were detected between different mouse strains: they were found to depend on their IFN-alpha/beta responder phenotype.In parallel, the bone marrow (BM) cellularity, the pluripotential and committed progenitor compartments were up to 30-fold reduced in wild type and IFN-gamma R0/0, but remained unchanged in IFN-alpha/beta R0/0 mice.Thus, the reversible depression of hematopoiesis during early LCMV infection was not mediated by LCMV-WE-specific cytotoxic T lymphocyte, cytolysis, or secreted IFN-gamma from virally induced NK cells but was a direct effect of IFN-alpha/beta.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University Hospital of Zurich, Switzerland.

ABSTRACT
The hematologic consequences of infection with the noncytopathic lymphocytic choriomeningitis virus (LCMV) were studied in wild-type mice with inherent variations in their interferon (IFN)-alpha/beta responder ability and in mutant mice lacking alpha/beta (IFN-alpha/beta R0/0) or gamma IFN (IFN-gamma R0/0) receptors. During the first week of infection, wild type mice demonstrated a transient pancytopenia. Within a given genetic background, the extent of the blood cell abnormalities did not correlate with the virulence of the LCMV isolate but variations were detected between different mouse strains: they were found to depend on their IFN-alpha/beta responder phenotype. Whereas IFN-gamma R0/0 mice were comparable to wild-type mice, IFN-alpha/beta R0/0 mice exhibited unchanged peripheral blood values during acute LCMV infection. In parallel, the bone marrow (BM) cellularity, the pluripotential and committed progenitor compartments were up to 30-fold reduced in wild type and IFN-gamma R0/0, but remained unchanged in IFN-alpha/beta R0/0 mice. Viral titers in BM 3 d after LCMV infection were similar in these mice, but antigen localization was different. Viral antigen was predominantly confined to stromal BM in normal mice and IFN-gamma R0/0 knockouts, whereas, in IFN-alpha/beta R0/0 mice, LCMV was detected in > 90% of megakaryocytes and 10-15% of myeloid precursors, but not in erythroblasts Although IFN-alpha/beta efficiently prevented viral replication in potentially susceptible hematopoietic cells, even in overwhelming LCMV infection, unlimited virus multiplication in platelet and myeloid precursors in IFN-alpha/beta R0/0 mice did not interfere with the number of circulating blood cells. Natural killer (NK) cell expansion and activity in the BM was comparable on day 3 after infection in mutant and control mice. Adaptive immune responses did not play a major role because comparable kinetics of LCMV-induced pancytopenia and transient depletion of the pluripotential and committed progenitor compartments were observed in CD8(0/0) and CD4(0/0) mice, in mice depleted of NK cells, in lpr mice, and in perforin-deficient (P0/0) mice lacking lytic NK cells. Thus, the reversible depression of hematopoiesis during early LCMV infection was not mediated by LCMV-WE-specific cytotoxic T lymphocyte, cytolysis, or secreted IFN-gamma from virally induced NK cells but was a direct effect of IFN-alpha/beta.

Show MeSH
Related in: MedlinePlus