Effect of Inapparent Murine Hepatitis Virus Infections on ... - CiteSeerX

12 downloads 1327 Views 751KB Size Report
virus (MHV) altered host resistance to experimental infection with a second ..... MHV-free or. MHV-infected mice. The peritoneal. MO compartment was also.
Journal

of Leukocyte

Biolo

39:559-565

(1986)

Effect of Inapparent Murine Hepatitis Virus Infections on Macrophages and Host Resistance Walla

L. Dempsey,

Department Philadelphia Epidemiology Connecticut

Abigail

L. Smith,

and Page

S. Morahan

of Microbiology and Immunology, Medical College of Pennsylvania, (WL.D., P.S.M.); Section of Comparative Medicine and Department of and Public Health, Yale University School of Medicine, New Haven, (A.L.S.)

Inapparent infections of mice with murine hepatitis virus (MHV) altered host resistance to experimental infection with a second virus, encephalomyocarditis virus (EMC), reduced the protective effects of exogeneously administered interferon against EMC infections, and it altered macrophage ectoenzyme phenotypes in two macrophage populations. Resident peritoneal macrophages from mice experimentally infected with one of two strains of MHV also demonstrated altered ectoenzyme phenotypes. These data demonstrate that inapparent infections with MHV alter several host resistance and macrophage parameters and directly demonstrate that effects of inapparent MHV infection on macrophage parameters can be reproduced experimentally.

Key words:

viral infections, mononuclear derived macrophages

phagocytes,

ectoenzymes,

bone marrow

INTRODUCTION Inapparent viral infections pronounced impact on various although potential studies natural

the immunomodulatory effects of inapparent are not fully appreciated. infection of mice with

coronaviruses, phage (MO) onstrating

phenotypic with

Received

October

Reprint

requests:

Henry

Avenue,

1986

Alan

changes

rodents have been results [4,6,9,10,11,201.

reported

to have Nevertheless,

to a second We further

in murine

peritoneal

virus infection and changes substantiate these findings MO

after

experimental

macroby deminfection

MHV. 30, Walla

1985: accepted L.

Dempsey.

Philadelphia,

R. Liss,

Inc.

PA

a

effects of many viruses are well established, the viral infections on immunologic and host resistance In the present study, we document that inapparent murine hepatitis virus (MHV), a ubiquitous group of

alters host resistance biochemical parameters.

of mice

©

of laboratory experimental

December Department

19129.

20, 1985. of Anatomy.

Medical

College

of Pennsylvania.

3200

560

Dempsey,

MATERIALS

AND

Smith,

and

Morahan

METHODS

Mice The I (Charles

effects River

Gilmore, the date

of inapparent Breeding

CA). Specific of arrival, for

Biocon

Inc.

pathogen-free seroconversion

Rockville,

,

infections with Labs, Kingston,

MD).

specific pathogen-free ME). All mice were

MHV NY)

mice were monitored to MHV and Sendai

Experimental

4-wk-old maintained

were documented and B6C3 Fl

infections

female BALB/cByJ on a 12-hr light/dark

in female (Simonsen

routinely, viruses

of

MHV

CDLabs,

including on (Elisa methodwere

initiated

in

mice (Jackson Labs, Bar Harbor, cycle, provided food and water

ad libitum, and cared for according to National Institutes of Health (NIH) guidelines. Infected and control BALB/cByJ mice were housed in separate facilities within microisolator

cages

(Lab

biological

safety

Microbial

Infections

one

Groups of four

Mortality data tally

Products,

ofseven dilutions

was

monitored

daily,

and

strain

the

was

of Peritoneal

MO

peritoneal

cells

Resident

5 ml of heparinized

by visual

Preparation Bone

essential 929 cell

marrow

[21].

lation.

The

nuclei

after

Ectoenzyme

lized

opened

only

Marrow cells

All

number

in a class

II

lysis

of

MO

were

were

stained by

of the cells

with

cells

3%

pantropic

MHV-JHM

TClD0.

Successful

[5].

serology

of the

survival

peritoneal

cavity

phosphate-buffered

with saline,

cytocentrifuge

adherence

preparations

for

2 hr

as

of

previously

(BMDMO)

cultured

performed

the overall

infected experimenThe low passage,

l0

IL)

for

10% fetal bovine serum, as a source of colony

adherent

the

with VR129).

by mechanical counting with a ZBM FL), and differential cell counts were

isolated

Derived

assays

and

Chicago,

determined Hialeah,

were

isolated

from

mice were MHV-JHM).

by lavage

Labs,

of Dif-Quik

MO

medium containing conditioned medium

described

calculated

orally,

obtained

Abbott

examination

Resident

of Bone

was

Each mouse received immunofluorescence

were

(2 U/mI,

cells. [151.

LDo

inoculated

pH 7.2). The number of cells was Coulter counter (Coulter Instruments, peritoneal described

were

mice were injected intraperitoneally virus (EMC) (ATCC strain

.

MHV-RI

determined

which

procedure I 161 BALB/cByJ strains of MHV (MHV-RI or

strain was inoculated intranasally. infections were monitored by indirect Preparation

NJ),

to eight female CD-i of encephalomycarditis

by the Reed-Muench with one of two

enterotropic

Maywood,

cabinet.

on was

cetrimide

the

up

to

7 days

10% horse stimulating

resulting

determined

as reported

in alpha-minimal

serum, factor

adherent by

counting

by Stewart

and 10% Las previously

BMDMO the

popu-

number

of

[211.

Determination

Adherent cells cell membranes

were were

lysed with 0.05% Triton X-lOO and aliquots analyzed for protein content, 5’ nucleotidase

and alkaline phosphodiesterase-I cording to the BioRad procedure was determined by measuring

of the solubi(5’N) activity,

(APD-I) activity. Protein content was assayed ac(Bio-Rad Labs, Rockville Center, NY). S’N activity the hydrolysis of 3H-adenosine monophosphate, and

MHV, TABLE Activity

Macrophages,

1. Effect of Inapparent in BMDMO

MHV

Cells

Host

Resistance

Infection

BMDMO

7-day

BMDMO activity

a5,

cells).

The

in protein

the

0.05

expressed

specific

content

bRepresents