| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
*
Pulmonary Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109; and
Department of Molecular Genetics and Microbiology and Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
, lack of anticryptococcal
delayed-type hypersensitivity, and high levels of serum IgE. These
results demonstrate that expression of CCR2 is required for the
development of a T1-type response to C. neoformans
infection and lack of CCR2 results in a switch to a T2-type response.
Thus, CCR2 plays a critical role in promoting the development of T1-
over T2-type immune responses in the lung following cryptococcus
infection. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
(2); a substantial influx of macrophages, lymphocytes, and
neutrophils into the lungs; and (3) the development of
Ag-specific delayed-type hypersensitivity (DTH) to C.
neoformans (1). The T1-type response requires
CD4+ and CD8+ T cells in
addition to the production of the cytokines TNF-
, IL-12, and IFN-
(1). Passive immunization of C.
neoformans-infected mice with anti-capsular Abs also requires
CD4+ T cells and IFN- for clearance of the
infection (2). Leukocyte recruitment into the lungs during a protective T1 response to pulmonary C. neoformans infection is not only T cell dependent, but also requires monocyte chemoattractant protein-1 (MCP-1) (3). MCP-1 is a C-C chemokine that can be produced by most cell types when stimulated by microbial products or certain cytokines and is chemotactic for monocytes and T lymphocytes (4, 5). Intratracheal inoculation with C. neoformans has been shown to stimulate production of MCP-1 in the lungs (3). Neutralization of MCP-1 after immunity develops results in a 95% reduction in macrophage recruitment and abrogation of cryptococcal clearance (3). Thus, MCP-1 plays a critical role in the effector phase of T1-type CMI to pulmonary C. neoformans infection.
The primary receptor for MCP-1 is CCR2 (6). CCR2 is expressed by monocytes, activated T cells, B cells, and NK cells (7). CCR2 knockout mice have severe deficits in macrophage recruitment in response to either antigenic or nonantigenic challenge (8, 9, 10). In addition, there is evidence to suggest that the T1-type cytokine response may be impaired (8). Our objective was to determine the role of CCR2 in leukocyte recruitment and development of T1-type CMI during pulmonary C. neoformans infection.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CCR2+/+ mice (B6129F2/J; The Jackson Laboratory, Bar Harbor, ME) and CCR2-/- mice (129B6F2-Cmkbr2tm1Kuz (10); University of Michigan breeding colony) were housed under specific pathogen-free conditions in enclosed filter top cages. Clean food and water were given ad libitum. The mice were handled and maintained using microisolator techniques with daily veterinarian monitoring. Bedding from the mice was transferred weekly to cages of uninfected sentinel mice that were subsequently bled at weekly intervals and found to be negative for Abs to mouse hepatitis virus, Sendai virus, and Mycoplasma pulmonis. Mice were 8–16 wk of age at the time of infection and there were no age-related differences in the responses of these mice to C. neoformans infection.
C. neoformans
C. neoformans strain 52D was obtained from the American Type Culture Collection (no. 24067-E; Manassas, VA). For infection, yeast were grown to stationary phase (48–72 h) at 37°C in Sabouraud dextrose broth (1% neopeptone and 2% dextrose; Difco, Detroit, MI) on a shaker. The cultures were then washed in nonpyrogenic saline, counted on a hemocytometer, and diluted to 3.3 x 105 CFU/ml in sterile nonpyrogenic saline.
Surgical intratracheal inoculation
Mice were anesthetized by i.p. injection of pentobarbital (0.074 mg/g weight of mouse) and restrained on a small surgical board. A small incision was made through the skin over the trachea and the underlying tissue was separated. A 30-gauge needle was bent and attached to a tuberculin syringe filled with diluted C. neoformans culture. The needle was inserted into the trachea, and 30 µl of inoculum (104 CFU) was dispensed into the lungs. The needle was removed and the skin closed with cyanoacrylate adhesive. The mice recovered with minimal visible trauma.
CFU assay
For lung CFU, small aliquots were collected from lung digests (described below). For brain and spleen CFU, the organs were excised, placed in 2 ml sterile water, and homogenized. Ten-microliter aliquots of the lungs, brain, and spleen were plated out on Sabouraud dextrose agar plates in duplicate 10-fold dilutions and incubated at room temperature. C. neoformans colonies were counted 2 to 3 days later, and the number of CFU was calculated on a per organ basis.
Lung leukocyte isolation
Individual lungs were excised, minced, and enzymatically digested for 30 min in 15 ml of digestion buffer (RPMI, 5% FCS, antibiotics, 1 mg/ml collagenase, and 30 µg/ml DNase). The cell suspension and undigested fragments were further dispersed by drawing up and down through the bore of a 10-ml syringe. The total cell suspension was then pelleted, and the erythrocytes were lysed by resuspending them in ice-cold NH4Cl buffer (0.83% NH4Cl, 0.1% KHCO3, and 0.037% Na2EDTA, pH 7.4). Tenfold excess of media was added to return the solution to isotonicity. The isolated leukocytes were repelleted and resuspended in complete media. Total lung leukocyte numbers were assessed in the presence of trypan blue using a hemocytometer; viability was >85%. Subsets of isolated leukocytes (neutrophils, eosinophils, macrophages, and total lymphocytes) were determined by Wright-Giemsa staining of samples cytospun onto slides.
Flow-cytometric analysis of lymphocyte subsets
Leukocytes (5 x 105) were incubated for 30 min on ice with staining buffer (FA buffer, 0.1% NaN3, 1% FCS; Difco). Each sample was incubated with 1) 0.12 µg of Cy-Chrome-labeled anti-CD45 (30-F11; PharMingen, San Diego, CA) and either 2) 0.25 µg each of FITC-labeled anti-CD4 (RM4-5) and PE-labeled anti-CD8 (53-6.7) or 3) 0.25 µg of FITC-labeled anti-B220 (RA3-6B2). The samples were washed in staining buffer and fixed in 2.5% paraformaldehyde in buffered saline. Stained samples were stored in the dark at 4°C until analyzed by flow cytometry (Coulter Elite ESP, Palo Alto, CA). Samples were gated for CD45-positive cells and then analyzed for staining by the specific FITC- and PE-labeled antilymphocyte markers.
Histology
Following euthanasia and before removal, the lungs were fixed by inflation with 1 ml of 10% neutral buffered Formalin. The fixed lung specimens were stored in 10% neutral buffered Formalin until dehydrated in 70% ethanol and paraffin embedded. Sections (5 µm) were cut, deparaffinized, stained with hematoxylin and eosin, and viewed by light microscopy.
Lung leukocyte culture and cytokine production
Isolated leukocytes (15 x 106) were
cultured in six-well plates with 3 ml of compete medium at 37°C and
5% CO2 without any additional stimulus.
Supernatants were harvested at 24 h and assayed for IL-4, IL-5,
and IFN- production by sandwich ELISA using the manufacturer’s
instructions supplied with the cytokine-specific kits (OptEIA;
PharMingen).
DTH response assay
Mice were tested for the development of DTH-mediating T cell immunity using a modification of a previously described footpad DTH assay (11). The Ag preparation for the assay, C. neoformans filtrate Ag, was prepared by concentrating and dialyzing the supernatant from a C. neoformans asparagine broth culture. The major protein in this preparation is a mannoprotein that cross-reacts with all strains and serotypes of C. neoformans. For each mouse tested, the hind right footpad was injected with 20 µl of C. neoformans filtrate Ag and the hind left footpad injected with 20 µl of dialyzed asparagine broth/2% BSA. After 48 h, the thickness of each footpad was measured using a micrometer. The swelling in the right footpad will be determined by subtracting the measurement of the right footpad from the measurement of the left. Uninfected mice were also challenged as a negative control for the assay.
Bronchoalveolar lavage (BAL)
Mice were lavaged after cannulation of the trachea with polyethylene tubing (PE50), which was attached to a 25-gauge needle on a tuberculin syringe. The lungs were lavaged twice with 0.8 ml of PBS containing 5 mM EDTA. The recovered fluid (1.3–1.4 ml total) was spun at 1500 rpm, and the supernatant was removed and stored at -20°C until analyzed for MCP-1 by ELISA (OptEIA; PharMingen).
Statistics
Statistical significance was calculated using a t test with significance being p < 0.05 for a single comparison. All values are reported as mean ± SE.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The role of CCR2 in protective immunity against pulmonary C.
neoformans infection was initially determined by assessing
pulmonary clearance and extrapulmonary dissemination after
intratracheal inoculation of C. neoformans strain 52D. By
week 1 postinfection, the pulmonary cryptococcal burden increased
350-fold and remained elevated through week 2 in both
CCR2+/+ and CCR2-/- mice
(Fig. 1
). CCR2-expressing mice began to
clear the infection at about week 3 and, by week 6, lung CFU had
decreased by over 300-fold. In contrast, CCR2-deficient mice failed to
control the infection between weeks 3–6, and lung CFU were 5000-fold
greater in CCR2-/- mice compared with
CCR2+/+ mice at week 6. These data show that CCR2
expression is required for clearance of a pulmonary C.
neoformans infection between weeks 3 and 6 postinfection.
|
). Over the
first 3 wk of infection, CCR2+/+ and
CCR2-/- mice had similar numbers of C.
neoformans in the spleen and brain. However, by week 6,
disseminated growth of C. neoformans in the spleens and
brains of CCR2-/- mice was significantly
greater (160- and 800-fold higher CFU per organ, respectively) than in
CCR2+/+ mice. Thus, CCR2 is also required to
control disseminated growth of C. neoformans in
extrapulmonary organs. MCP-1 is produced in the lungs of CCR2-deficient mice
Because MCP-1 is important in the clearance of a pulmonary
C. neoformans infection, our next objective was to determine
whether the absence of CCR2 diminished the production of MCP-1 in the
lung. MCP-1 production by pulmonary leukocytes was assayed in vitro
following isolation by mincing and enzymatic digestion. Leukocytes were
isolated from infected lungs and cultured for 24 h without
additional stimulus. Culture supernatants were harvested and tested for
MCP-1 production by ELISA. Leukocytes from both
CCR2+/+ and CCR2-/- mice
had comparable MCP-1 production at week 1 that was 6- to 10-fold
greater than MCP-1 production by leukocytes from uninfected mice (Fig. 2A). MCP-1 production in
leukocytes from CCR2+/+ mice then declined to
levels 2- to 3-fold higher than basal levels during weeks 2 through 6.
Interestingly, MCP-1 production by leukocytes from
CCR2-/- mice tended to remain elevated through
the course of infection. To assess MCP-1 production in vivo and take
into account that cells other than leukocytes most likely produce
MCP-1, BAL was done at 1 wk postinfection, and the recovered fluid was
analyzed for MCP-1 by ELISA (Fig. 2B). Both
CCR2+/+ and CCR2-/- mice
showed significant increases in MCP-1 within the alveolar space after
infection; however, the increase was 3-fold greater in
CCR2-/- mice. These results show that lack of
cryptococcal clearance in CCR2-/- mice is not
due to decreased levels of the CCR2 ligand, MCP-1.
|
The next objective was to determine whether pulmonary leukocyte
recruitment was diminished in the absence of CCR2, thereby contributing
to the decreased clearance of C. neoformans. Leukocyte
recruitment was determined by quantifying leukocyte numbers and by
assessing the phenotypes of the leukocytes involved in the response. A
small, early influx of leukocytes (week 1) was observed in
CCR2+/+ mice, but was absent in
CCR2-/- mice (Fig. 3). However, there was a dramatic
increase in lung leukocyte numbers in both
CCR2+/+ and CCR2-/- mice
at 2 wk postinfection. By week 6, total lung leukocyte numbers had
declined in CCR2+/+ mice, correlating with
resolution of the infection. In contrast, lung leukocyte numbers
remained elevated in CCR2-/- mice. Thus, the
absence of CCR2 does not result in an overall defect in lung leukocyte
recruitment in response to pulmonary C. neoformans
infection.
|
Although both CCR2+/+ and
CCR2-/- mice responded to infection by
developing a vigorous inflammatory response, cytological analysis
revealed differences in the leukocyte subsets recruited (Fig. 4). Infected
CCR2+/+ mice showed dramatic increases in
pulmonary macrophage numbers over the first 3 wk of infection. In
contrast, macrophage recruitment was minimal through week 3 in the
lungs of CCR2-/- mice, although macrophage
numbers did increase between weeks 3 and 6. The significant difference
in total lung leukocytes between CCR2+/+ and
CCR2-/- mice at week 1 (Fig. 3) could be
attributed to the reduced macrophage recruitment exhibited by
CCR2-/- mice. Another considerable difference
between CCR2+/+ and
CCR2-/- mice was the recruitment of eosinophils
into infected lungs. Beginning at week 2, and continuing through week
6, CCR2-/- mice had significant numbers of
pulmonary eosinophils (up to 41% of total lung leukocytes), whereas
eosinophils made up less than 5% of total leukocytes in
CCR2+/+ mice aside from a transient increase at
week 2 (13%). There were no significant differences between
CCR2+/+ and CCR2-/- mice
in terms of neutrophil and total lymphocyte recruitment. Lack
of CCR2 expression results in defective macrophage recruitment and
development of chronic eosinophilia in response to pulmonary C.
neoformans infection.
|
,
A and B, respectively). High power examination of
CCR2+/+ mouse lungs revealed that the localized
infiltrate was mainly mononuclear (Fig. 5C), whereas
affected areas in CCR2-/- mouse lungs contained
numerous cryptococci, eosinophils, and crystalline deposits (Fig. 5D). These crystals are derived from eosinophil
degranulation following interaction with C. neoformans
during a T2-type response (12). The complex granular
structure of the eosinophil lends itself to identification by flow
cytometry by causing increased side light scatter. Fig. 5, E
and F, illustrates the difference in eosinophils numbers, as
represented by high side scatter and low forward scatter (small size),
between CCR2+/+- and
CCR2-/--infected mice at 6 wk, respectively.
The pronounced pulmonary eosinophilia and crystals present in infected
CCR2-/- mice are suggestive of a T2-type immune
response.
|
Analysis of pulmonary lymphocytes by flow cytometry revealed
changes in lymphocyte subsets even though total lymphocyte numbers were
not different between infected CCR2+/+ and
CCR2-/- mice. Pulmonary
CD8+ T cells were reduced in
CCR2-/- mice at weeks 1 and 2 compared with
CCR2+/+ mice (reductions of 48% and 32%,
respectively) (Fig. 6). By week 3, there
was no difference and, by week 6, CCR2-/- mice
had twice the number of CD8+ T cells in the lung
compared with CCR2+/+ mice. There were no
significant differences in pulmonary CD4+ T cells
and B220+ B cells throughout the course of
infection, although there was a trend toward higher numbers of B cells
in the lungs of CCR2-/- mice by week 6. Thus,
CCR2 is involved in early recruitment of CD8 T cells into the lung
during pulmonary C. neoformans infection.
|
The possibility that C. neoformans-infected
CCR2-deficient mice produce a polarized T2-type immune response was
further investigated by examining cytokine production, anticryptococcal
DTH, and serum IgE. Leukocytes were isolated from infected lungs and
cultured for 24 h without additional stimulus. Culture
supernatants were harvested and tested for IL-4, IL-5, and IFN-
production by ELISA. Analysis of cytokine production profiles revealed
a distinct difference between CCR2+/+ and
CCR2-/- mice (Fig. 7). Leukocytes from
CCR2+/+ mice produced significant amounts of the
type 1 cytokine IFN- beginning at week 1 and continuing through week
3, while production of the type 2 cytokines IL-4 and IL-5 remained
minimal. Inversely, leukocytes from CCR2-/-
mice showed marked production of IL-4 and IL-5 beginning at week 2 with
no production of IFN-. A similar T1/T2 polarization pattern was seen
when infected mice were tested for the development of DTH (T1) and
production of IgE (T2) (Fig. 8). Footpad
injection of C. neoformans filtrate Ag produced a
characteristic DTH response in CCR2+/+ mice, but
not in CCR2-/- mice. Although the lack of a DTH
response is consistent with a T2-type response in
CCR2-/- mice, it is possible that reduced DTH
in these mice could be attributed to a reduction in CCR2-dependent
macrophage recruitment. IgE levels remained at uninfected levels in
CCR2+/+ mice, but were dramatically increased in
the serum of infected CCR2-/- mice at 3 and 6
wk. These results demonstrate that expression of CCR2 is required for
the development of a T1 response to C. neoformans infection
and lack of CCR2 results in a T2-type response.
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
, and
increased serum IgE. These results demonstrate that expression of CCR2
is required for the development of a T1-type response to C.
neoformans infection and lack of CCR2 results in a switch to a
T2-type response.
These results demonstrate a novel role for CCR2 in mediating T1 vs T2
switching to an infectious agent. Chemokines might promote immune
response polarization by directing selective migration of either Th1 or
Th2 cells to the site of infection (13). This idea is
based on the distinct expression of certain chemokine receptors, such
as CXCR3/CCR5 for Th1 cells and CCR3/CCR4 for Th2 cells
(13). However, Th1 and Th2 cells both express CCR2
(13), and CCR2-/- mice are
defective in their ability to develop T1- or T2-mediated lung
granulomas elicited by embolization of Ag-coated beads (8, 14). Chemokines may also promote immune response polarization by
modulating Th1 vs Th2 lymphocyte differentiation (15, 16).
Neutralization of CCR2 ligand MCP-1 decreased IL-4 and increased
IFN- production by CD4+ T cells cocultured
with lung fibroblasts or splenic macrophages (15).
Similarly, OVA-specific TCR transgenic T cells stimulated through the
TCR and treated with MCP-1 had enhanced IL-4 production
(16). However, splenocytes from CCR2 or MCP-1 knockout
mice are also defective in their ability to produce IFN- (8, 17). Our earlier work with C. neoformans infection
showed that MCP-1 is required for the efferent phase of the T1-type
response against this pathogen (3). Our present results
are consistent with this earlier observation and show further that in
the absence of CCR2, the primary MCP-1 receptor, there is a switch in
Th polarization.
CCR2-/- mice have defects in the ability to control a C. neoformans infection. Could this inability to control the infection lead to a Th2 response? Infectious burden or Ag levels can be a determinant in T1 vs T2 responses (18). However, there is no difference in organism burden through week 2 in the lungs, spleen, or brain between CCR2+/+ and CCR2-/- mice. Therefore, the mechanism of T1 to T2 switching in CCR2-/- mice is not due to a difference in early infectious burden.
Defective macrophage and CD8+ T cell
recruitment/activation in CCR2-deficient mice is a possible mechanism
that could drive a T1 to T2 switch in the immune response to C.
neoformans. We have previously shown that depletion of
CD8+ T cells during C. neoformans
infection results in the production of predominantly T2-type cytokines
by CD4+ T cells (4). Therefore,
IFN- production by CD8+ T cells is most likely
important for the development of Th1-type CD4+ T
cell immunity to C. neoformans. It remains to be determined
whether the CD8+ T cell defect observed in the
lungs of CCR2-/- mice is also observed in the
lung-associated lymph nodes, the likely site of T1/T2 differentiation
during pulmonary C. neoformans infection (19).
Activated macrophages are an important source of cytokines, such as
IL-12, that influence a developing T1 response in the lungs and lymph
nodes. IL-12 has been shown to induce IFN--dependent increases in
both mononuclear cell infiltration and MCP-1 production, resulting in a
protective response to pulmonary C. neoformans infection
(20, 21). Because monocytes and macrophages express CCR2
(14) and lack of CCR2 expression prevents
monocyte/macrophage recruitment into the lungs following C.
neoformans infection, it is possible that there are
recruitment/activation defects of these cells and other APC in the
lymph nodes. Thus, our data suggest that there may also be changes in
the lymph nodes of CCR2-/- that account for
T2-type response to C. neoformans in these mice.
The lack of IFN- production in the lungs of C.
neoformans-infected CCR2-deficient mice is likely to contribute to
the switch to a T2 response. Previous studies using cryptococcal
infection models have demonstrated the importance of IFN- production
during the development of protective T1-type immune response (19, 22, 23, 24, 25). Induction of IFN- in CCR2+/+
mice (week 1) precedes the induction of IL-4 in
CCR2-/- mice (week 2), suggesting that
production of IFN- during a C. neoformans infection
down-regulates induction of IL-4 and prevents a T2 response. However,
preliminary studies in our lab have demonstrated that there are factors
in addition to IFN- involved in driving the T1-type response.
Neutralization of IFN- at the onset of a pulmonary C.
neoformans infection in CCR2+/+ mice did not
duplicate the phenotype exhibited by infected
CCR2-/- mice (data not shown). At 2 wk
postinfection, anti-IFN--treated mice had reduced cryptococcal
clearance, increased eosinophil recruitment, and a trend toward greater
leukocyte IL-5 production similar to that seen in infected
CCR2-deficient mice (data not shown). However, early IFN-
neutralization did not decrease macrophage or
CD8+ T cell recruitment, nor did it increase IL-4
production (data not shown). Therefore, the switch to a T2 response in
CCR2-deficient mice cannot be attributed solely to a defect in IFN-
production.
Lack of cryptococcal clearance in CCR2-deficient mice is not due to
decreased production of the CCR2 ligand, MCP-1. Infected CCR2-deficient
mice had 3-fold greater levels of MCP-1 in BAL fluid at 1-wk
postinfection and increased MCP-1 production by cultured leukocytes
compared with control mice. In addition, analysis of whole lung
homogenates for MCP-1 production in uninfected mice revealed that basal
MCP-1 production was 4-fold greater in CCR2-/-
mice (
250 and 1218 pg/lung for CCR2+/+ and
CCR2-/-, respectively, unpublished
observations). Increases in lung mRNA have been observed for the CCR2
agonists MCP-1, MCP-3, and MCP-5 during schistosomal Ag-elicited
pulmonary granuloma formation (14). The finding that MCP-1
production is greater in the absence of CCR2 suggests that CCR2 is
involved in a negative feedback loop responsible for attenuating both
basal and stimulated MCP-1 production.
The high levels of MCP-1 in C. neoformans-infected CCR2-deficient mice could be a factor in the switch to a T2-type immune response. MCP-1 transgenic mice are more susceptible to infection by intracellular pathogens, and it was suggested that high levels of MCP-1 stimulated a Th2-dominant response (4). Furthermore, MCP-1 plays an important role in the generation of a T2-type response in models such as schistosome egg Ag-induced lung granuloma (14) and experimental autoimmune encephalomyelitis (26, 27, 28). Therefore, in the absence of CCR2, it is possible that the high levels of MCP-1 seen during C. neoformans infection might stimulate a T2 response via a second receptor, such as CCR9 (29) or an as yet unidentified receptor for MCP-1 (30).
Fungal infections can elicit protective T1- or nonprotective T2-type
immune responses. Our data indicate that the absence of CCR2 results in
a strong T2-type response to the fungus C. neoformans that
fails to clear the infection. In addition, CCR2 is required for
macrophage and CD8+ T cell recruitment to the
site of infection. Thus, CCR2 expression, along with induction of the
cytokines TNF-, IL-12, and IFN-, is critical for the development
of T1- over T2-type antifungal immunity.
|
Acknowledgments |
|---|
. |
Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. Gary B. Huffnagle, Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, 6301 MSRB III, Box 0642, University of Michigan Medical Center, Ann Arbor, MI 48109-0642. E-mail address:
3 Abbreviations used in this paper: CMI, cell-mediated immunity; BAL, bronchoalveolar lavage; DTH, delayed-type hypersensitivity; MCP, monocyte chemoattractant protein.
Received for publication September 9, 1999. Accepted for publication December 3, 1999.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
receptors: evidence for two closely linked C-C chemokine receptors on chromosome 9. J. Biol. Chem. 271:7551. are required for initiating the protective Th1 response to pulmonary cryptococcosis in resistant C.B-17 mice. Am. J. Respir. Cell Mol. Biol. 17:733. (IFN-)-dependent protection and synthesis of chemoattractants for mononuclear leukocytes caused by IL-12 in the lungs of mice infected with Cryptococcus neoformans. Clin. Exp. Immunol. 117:113.[Medline]
interferon in acquired resistance to Cryptococcus neoformans in the central nervous system of mice. Infect. Immun. 63:1725.[Abstract]
interferon-induced nitric oxide in pulmonary clearance of Cryptococcus neoformans. Am. J. Respir. Cell Mol. Biol. 13:116.[Abstract]
and MCP-1 differentially regulate acute and relapsing autoimmune encephalomyelitis as well as Th1/Th2 lymphocyte differentiation. J. Leukocyte Biol. 62:681.[Abstract]
This article has been cited by other articles:
|
|
 |
|
  A. V. Jain, Y. Zhang, W. B. Fields, D. A. McNamara, M. Y. Choe, G.-h. Chen, J. Erb-Downward, J. J. Osterholzer, G. B. Toews, G. B. Huffnagle, et al. Th2 but Not Th1 Immune Bias Results in Altered Lung Functions in a Murine Model of Pulmonary Cryptococcus neoformans Infection Infect. Immun., December 1, 2009; 77(12): 5389 - 5399. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Osterholzer, J. E. Milam, G.-H. Chen, G. B. Toews, G. B. Huffnagle, and M. A. Olszewski Role of Dendritic Cells and Alveolar Macrophages in Regulating Early Host Defense against Pulmonary Infection with Cryptococcus neoformans Infect. Immun., September 1, 2009; 77(9): 3749 - 3758. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. Crane, K. L. Hokeness-Antonelli, and T. P. Salazar-Mather Regulation of Inflammatory Monocyte/Macrophage Recruitment from the Bone Marrow during Murine Cytomegalovirus Infection: Role for Type I Interferons in Localized Induction of CCR2 Ligands J. Immunol., August 15, 2009; 183(4): 2810 - 2817. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. A. Szymczak and G. S. Deepe Jr The CCL7-CCL2-CCR2 Axis Regulates IL-4 Production in Lungs and Fungal Immunity J. Immunol., August 1, 2009; 183(3): 1964 - 1974. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. G. Pamer Tipping the balance in favor of protective immunity during influenza virus infection PNAS, March 31, 2009; 106(13): 4961 - 4962. [Full Text] [PDF]
|
|
|
|
 |
|
 J. J. Osterholzer, R. Surana, J. E. Milam, G. T. Montano, G.-H. Chen, J. Sonstein, J. L. Curtis, G. B. Huffnagle, G. B. Toews, and M. A. Olszewski Cryptococcal Urease Promotes the Accumulation of Immature Dendritic Cells and a Non-Protective T2 Immune Response within the Lung Am. J. Pathol., March 1, 2009; 174(3): 932 - 943. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Flaishon, G. Hart, E. Zelman, C. Moussion, V. Grabovsky, G. Lapidot Tal, S. Feigelson, R. Margalit, A. Harmelin, T. Avin-Wittenberg, et al. Anti-inflammatory effects of an inflammatory chemokine: CCL2 inhibits lymphocyte homing by modulation of CCL21-triggered integrin-mediated adhesions Blood, December 15, 2008; 112(13): 5016 - 5025. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Guillot, S. F. Carroll, R. Homer, and S. T. Qureshi Enhanced Innate Immune Responsiveness to Pulmonary Cryptococcus neoformans Infection Is Associated with Resistance to Progressive Infection Infect. Immun., October 1, 2008; 76(10): 4745 - 4756. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Guerrero and B. C. Fries Phenotypic Switching in Cryptococcus neoformans Contributes to Virulence by Changing the Immunological Host Response Infect. Immun., September 1, 2008; 76(9): 4322 - 4331. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Osterholzer, J. L. Curtis, T. Polak, T. Ames, G.-H. Chen, R. McDonald, G. B. Huffnagle, and G. B. Toews CCR2 Mediates Conventional Dendritic Cell Recruitment and the Formation of Bronchovascular Mononuclear Cell Infiltrates in the Lungs of Mice Infected with Cryptococcus neoformans J. Immunol., July 1, 2008; 181(1): 610 - 620. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G.-h. Chen, D. A. McNamara, Y. Hernandez, G. B. Huffnagle, G. B. Toews, and M. A. Olszewski Inheritance of Immune Polarization Patterns Is Linked to Resistance versus Susceptibility to Cryptococcus neoformans in a Mouse Model Infect. Immun., June 1, 2008; 76(6): 2379 - 2391. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. L. Lin, Y. Suzuki, H. Nakano, E. Ramsburg, and M. D. Gunn CCR2+ Monocyte-Derived Dendritic Cells and Exudate Macrophages Produce Influenza-Induced Pulmonary Immune Pathology and Mortality J. Immunol., February 15, 2008; 180(4): 2562 - 2572. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. D. Wareing, A. Lyon, C. Inglis, F. Giannoni, I. Charo, and S. R. Sarawar Chemokine regulation of the inflammatory response to a low-dose influenza infection in CCR2-/- mice J. Leukoc. Biol., March 1, 2007; 81(3): 793 - 801. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. R. Montgomery, C. J. Booth, X. Wang, V. A. Blaho, S. E. Malawista, and C. R. Brown Recruitment of Macrophages and Polymorphonuclear Leukocytes in Lyme Carditis Infect. Immun., February 1, 2007; 75(2): 613 - 620. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. C. Iannuzzi and B. A. Rybicki Genetics of Sarcoidosis: Candidate Genes and Genome Scans Proceedings of the ATS, January 1, 2007; 4(1): 108 - 116. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. I. Khan, Y. Motomura, H. Wang, R. T. El-Sharkawy, E. F. Verdu, M. Verma-Gandhu, B. J. Rollins, and S. M. Collins Critical role of MCP-1 in the pathogenesis of experimental colitis in the context of immune and enterochromaffin cells Am J Physiol Gastrointest Liver Physiol, November 1, 2006; 291(5): G803 - G811. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. K. Henke, C. G. Pearce, D. M. Moaveni, A. J. Moore, E. M. Lynch, C. Longo, M. Varma, N. A. Dewyer, K. B. Deatrick, G. R. Upchurch Jr, et al. Targeted Deletion of CCR2 Impairs Deep Vein Thombosis Resolution in a Mouse Model. J. Immunol., September 1, 2006; 177(5): 3388 - 3397. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Heesen, R. Renckens, A. F. de Vos, D. Kunz, and T. van der Poll Human Endotoxemia Induces Down-Regulation of Monocyte CC Chemokine Receptor 2 Clin. Vaccine Immunol., January 1, 2006; 13(1): 156 - 159. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. P. de Lema, H. Maier, T. J. Franz, M. Escribese, S. Chilla, S. Segerer, N. Camarasa, H. Schmid, B. Banas, S. Kalaydjiev, et al. Chemokine Receptor Ccr2 Deficiency Reduces Renal Disease and Prolongs Survival in MRL/lpr Lupus-Prone Mice J. Am. Soc. Nephrol., December 1, 2005; 16(12): 3592 - 3601. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. M. Robben, M. LaRegina, W. A. Kuziel, and L. D. Sibley Recruitment of Gr-1+ monocytes is essential for control of acute toxoplasmosis J. Exp. Med., June 6, 2005; 201(11): 1761 - 1769. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Arora, Y. Hernandez, J. R. Erb-Downward, R. A. McDonald, G. B. Toews, and G. B. Huffnagle Role of IFN-{gamma} in Regulating T2 Immunity and the Development of Alternatively Activated Macrophages during Allergic Bronchopulmonary Mycosis J. Immunol., May 15, 2005; 174(10): 6346 - 6356. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G.-H. Chen, R. A. McDonald, J. C. Wells, G. B. Huffnagle, N. W. Lukacs, and G. B. Toews The Gamma Interferon Receptor Is Required for the Protective Pulmonary Inflammatory Response to Cryptococcus neoformans Infect. Immun., March 1, 2005; 73(3): 1788 - 1796. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. L. Hokeness, W. A. Kuziel, C. A. Biron, and T. P. Salazar-Mather Monocyte Chemoattractant Protein-1 and CCR2 Interactions Are Required for IFN-{alpha}/{beta}-Induced Inflammatory Responses and Antiviral Defense in Liver J. Immunol., February 1, 2005; 174(3): 1549 - 1556. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Hernandez, S. Arora, J. R. Erb-Downward, R. A. McDonald, G. B. Toews, and G. B. Huffnagle Distinct Roles for IL-4 and IL-10 in Regulating T2 Immunity during Allergic Bronchopulmonary Mycosis J. Immunol., January 15, 2005; 174(2): 1027 - 1036. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B.-C. Chiu, C. M. Freeman, V. R. Stolberg, J. S. Hu, K. Zeibecoglou, B. Lu, C. Gerard, I. F. Charo, S. A. Lira, and S. W. Chensue Impaired Lung Dendritic Cell Activation in CCR2 Knockout Mice Am. J. Pathol., October 1, 2004; 165(4): 1199 - 1209. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S J Connor, N Paraskevopoulos, R Newman, N Cuan, T Hampartzoumian, A R Lloyd, and M C Grimm CCR2 expressing CD4+ T lymphocytes are preferentially recruited to the ileum in Crohn's disease Gut, September 1, 2004; 53(9): 1287 - 1294. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Gyetko, D. Aizenberg, and L. Mayo-Bond Urokinase-deficient and urokinase receptor-deficient mice have impaired neutrophil antimicrobial activation in vitro J. Leukoc. Biol., September 1, 2004; 76(3): 648 - 656. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Flaishon, S. Becker-Herman, G. Hart, Y. Levo, W. A. Kuziel, and I. Shachar Expression of the chemokine receptor CCR2 on immature B cells negatively regulates their cytoskeletal rearrangement and migration Blood, August 15, 2004; 104(4): 933 - 941. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Olszewski, M. C. Noverr, G.-H. Chen, G. B. Toews, G. M. Cox, J. R. Perfect, and G. B. Huffnagle Urease Expression by Cryptococcus neoformans Promotes Microvascular Sequestration, Thereby Enhancing Central Nervous System Invasion Am. J. Pathol., May 1, 2004; 164(5): 1761 - 1771. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Pina, R. C. Valente-Ferreira, E. E. W. Molinari-Madlum, C. A. C. Vaz, A. C. Keller, and V. L. G. Calich Absence of Interleukin-4 Determines Less Severe Pulmonary Paracoccidioidomycosis Associated with Impaired Th2 Response Infect. Immun., April 1, 2004; 72(4): 2369 - 2378. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. K. Mansour, L. E. Yauch, J. B. Rottman, and S. M. Levitz Protective Efficacy of Antigenic Fractions in Mouse Models of Cryptococcosis Infect. Immun., March 1, 2004; 72(3): 1746 - 1754. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Gyetko, S. Sud, and S. W. Chensue Urokinase-Deficient Mice Fail To Generate a Type 2 Immune Response following Schistosomal Antigen Challenge Infect. Immun., January 1, 2004; 72(1): 461 - 467. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Lee, L. Wang, A. D. Wells, Q. Ye, R. Han, M. E. Dorf, W. A. Kuziel, B. J. Rollins, L. Chen, and W. W. Hancock Blocking the Monocyte Chemoattractant Protein-1/CCR2 Chemokine Pathway Induces Permanent Survival of Islet Allografts through a Programmed Death-1 Ligand-1-Dependent Mechanism J. Immunol., December 15, 2003; 171(12): 6929 - 6935. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Spagnolo, E. A. Renzoni, A. U. Wells, H. Sato, J. C. Grutters, P. Sestini, A. Abdallah, E. Gramiccioni, H. J. T. Ruven, R. M. du Bois, et al. C-C Chemokine Receptor 2 and Sarcoidosis: Association with Lofgren's Syndrome Am. J. Respir. Crit. Care Med., November 15, 2003; 168(10): 1162 - 1166. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Belnoue, F. T. M. Costa, A. M. Vigario, T. Voza, F. Gonnet, I. Landau, N. van Rooijen, M. Mack, W. A. Kuziel, and L. Renia Chemokine Receptor CCR2 Is Not Essential for the Development of Experimental Cerebral Malaria Infect. Immun., June 1, 2003; 71(6): 3648 - 3651. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. He, A. Casadevall, S. C. Lee, and D. L. Goldman Phagocytic Activity and Monocyte Chemotactic Protein Expression by Pulmonary Macrophages in Persistent Pulmonary Cryptococcosis Infect. Immun., February 1, 2003; 71(2): 930 - 936. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. M. Scott and J. L. Flynn Mycobacterium tuberculosis in Chemokine Receptor 2-Deficient Mice: Influence of Dose on Disease Progression Infect. Immun., November 1, 2002; 70(11): 5946 - 5954. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Omata, M. Yasutomi, A. Yamada, H. Iwasaki, M. Mayumi, and Y. Ohshima Monocyte Chemoattractant Protein-1 Selectively Inhibits the Acquisition of CD40 Ligand-Dependent IL-12-Producing Capacity of Monocyte-Derived Dendritic Cells and Modulates Th1 Immune Response J. Immunol., November 1, 2002; 169(9): 4861 - 4866. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. R. Traynor, A. C. Herring, M. E. Dorf, W. A. Kuziel, G. B. Toews, and G. B. Huffnagle Differential Roles of CC Chemokine Ligand 2/Monocyte Chemotactic Protein-1 and CCR2 in the Development of T1 Immunity J. Immunol., May 1, 2002; 168(9): 4659 - 4666. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Mancuso, A. Gottschalk, S. M. Phare, M. Peters-Golden, N. W. Lukacs, and G. B. Huffnagle Leptin-Deficient Mice Exhibit Impaired Host Defense in Gram-Negative Pneumonia J. Immunol., April 15, 2002; 168(8): 4018 - 4024. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Gyetko, S. Sud, G.-H. Chen, J. A. Fuller, S. W. Chensue, and G. B. Toews Urokinase-Type Plasminogen Activator Is Required for the Generation of a Type 1 Immune Response to Pulmonary Cryptococcus neoformans Infection J. Immunol., January 15, 2002; 168(2): 801 - 809. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Gyetko, S. Sud, J. Sonstein, T. Polak, A. Sud, and J. L. Curtis Cutting Edge: Antigen-Driven Lymphocyte Recruitment to the Lung Is Diminished in the Absence of Urokinase-Type Plasminogen Activator (uPA) Receptor, but Is Independent of uPA J. Immunol., November 15, 2001; 167(10): 5539 - 5542. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Martinelli, I. Sabroe, G. LaRosa, T. J. Williams, and J. E. Pease The CC Chemokine Eotaxin (CCL11) Is a Partial Agonist of CC Chemokine Receptor 2b J. Biol. Chem., November 9, 2001; 276(46): 42957 - 42964. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B.B. Moore, T.A. Moore, and G.B. Toews Role of T- and B-;lymphocytes in pulmonary host defences Eur. Respir. J., November 1, 2001; 18(5): 846 - 856. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. P. Chen, W. A. Kuziel, and T. E. Lane Lack of CCR2 Results in Increased Mortality and Impaired Leukocyte Activation and Trafficking Following Infection of the Central Nervous System with a Neurotropic Coronavirus J. Immunol., October 15, 2001; 167(8): 4585 - 4592. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Olszewski, G. B. Huffnagle, T. R. Traynor, R. A. McDonald, D. N. Cook, and G. B. Toews Regulatory Effects of Macrophage Inflammatory Protein 1{alpha}/CCL3 on the Development of Immunity to Cryptococcus neoformans Depend on Expression of Early Inflammatory Cytokines Infect. Immun., October 1, 2001; 69(10): 6256 - 6263. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Peters, H. M. Scott, H. F. Chambers, J. L. Flynn, I. F. Charo, and J. D. Ernst Chemokine receptor 2 serves an early and essential role in resistance to Mycobacterium tuberculosis PNAS, July 3, 2001; 98(14): 7958 - 7963. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Kim, S.-s. J. Sung, W. A. Kuziel, S. Feldman, S. M. Fu, and C. E. Rose Jr Enhanced Airway Th2 Response After Allergen Challenge in Mice Deficient in CC Chemokine Receptor-2 (CCR2) J. Immunol., April 15, 2001; 166(8): 5183 - 5192. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Mack, J. Cihak, C. Simonis, B. Luckow, A. E. I. Proudfoot, H. Bruhl, M. Frink, H.-J. Anders, V. Vielhauer, J. Pfirstinger, et al. Expression and Characterization of the Chemokine Receptors CCR2 and CCR5 in Mice J. Immunol., April 1, 2001; 166(7): 4697 - 4704. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Peters, M. Dupuis, and I. F. Charo A Mechanism for the Impaired IFN-{gamma} Production in C-C Chemokine Receptor 2 (CCR2) Knockout Mice: Role of CCR2 in Linking the Innate and Adaptive Immune Responses J. Immunol., December 15, 2000; 165(12): 7072 - 7077. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Olszewski, G. B. Huffnagle, R. A. McDonald, D. M. Lindell, B. B. Moore, D. N. Cook, and G. B. Toews The Role of Macrophage Inflammatory Protein-1{alpha}/CCL3 in Regulation of T Cell-Mediated Immunity to Cryptococcus neoformans Infection J. Immunol., December 1, 2000; 165(11): 6429 - 6436. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. MacLean, G. T. De Sanctis, K. G. Ackerman, J. M. Drazen, A. Sauty, E. DeHaan, F. H. Y. Green, I. F. Charo, and A. D. Luster CC Chemokine Receptor-2 Is Not Essential for the Development of Antigen-Induced Pulmonary Eosinophilia and Airway Hyperresponsiveness J. Immunol., December 1, 2000; 165(11): 6568 - 6575. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Izikson, R. S. Klein, I. F. Charo, H. L. Weiner, and A. D. Luster Resistance to Experimental Autoimmune Encephalomyelitis in Mice Lacking the Cc Chemokine Receptor (Ccr2) J. Exp. Med., October 2, 2000; 192(7): 1075 - 1080. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Unutmaz, W. Xiang, M. J. Sunshine, J. Campbell, E. Butcher, and D. R. Littman The Primate Lentiviral Receptor Bonzo/STRL33 Is Coordinately Regulated with CCR5 and Its Expression Pattern Is Conserved Between Human and Mouse J. Immunol., September 15, 2000; 165(6): 3284 - 3292. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
