Monocyte inflammatory protein-1
facilitates priming of CD8+ T cell responses to exogenous viral antigen
Inge E. A. Flesch,
Detlef Stober,
Reinhold Schirmbeck and
Jörg Reimann
Department of Medical Microbiology and Immunology, University of Ulm, Helmholtzstrasse 8/1, 89081 Ulm, Germany
Correspondence to:
J. Reimann
 |
Abstract
|
---|
Dendritic cells (DC) derived from bone marrow precursors of BALB/c or C57BL/6 mice in low-serum cultures supplemented with granulocyte macrophage colony stimulating factor and Flt3 ligand were pulsed in vitro with hepatitis B surface antigen (HBsAg) particles. DC processed exogenous HBsAg and presented its MHC class I-binding epitopes to cytotoxic T lymphocytes (CTL). This specific and restricted interaction of DC with CTL stimulated release of IFN-
and macrophage inflammatory protein (MIP)-1
from the responding CTL. MIP-1
enhanced the survival of DC in vitro but did not induce proliferation. Furthermore, co-delivery of MIP-1
facilitated CTL priming in vivo to exogenous HBsAg in low responder C57BL/6 (H-2b) mice: a single injection of a low dose of HBsAg particles (without further adjuvants) successfully primed Kb-restricted CTL responses to HBsAg only when the exogenous antigen was co-delivered with 100 ng MIP-1
. These in vitro and in vivo data point to an important role of MIP-1
in the DC-dependent priming of CTL to exogenous viral antigens.
Keywords: chemokines, cytotoxic T lymphocyte priming, dendritic cells
 |
Introduction
|
---|
Host factors rather than viral factors seem to be decisive in establishing chronic hepatitis B virus (HBV) infection. The magnitude, polyclonality and/or specialized effector functions of HBV-specific T cell responses seem to determine if the elicited immunity is either protective or allows HBV persistence. It is therefore of interest to study T cell priming by HBV-proteins. Dendritic cells (DC) are the most potent antigen-presenting cells (APC) that prime T cell responses (1). Immature DC take up antigen, undergo maturation and migrate to secondary lymphoid organs where they prime naive T cells (26). Different subsets of DC have been described in man and mouse that seem to originate from different developmental lineages and to home to different areas of lymphoid and non-lymphoid tissues (7,8). Myeloid CD8
DC preferentially home to cortical T cell areas of lymph nodes where they prime naive T cells or re-stimulate T memory cells. Lymphoid CD8
+ DC home to extra-lymphoid tissues and may play a role in the regulation of immune responses or the induction of tolerance (9,10).
Chemokines are small, pro-inflammatory proteins that stimulate chemotaxis of leukocytes (11,12). DC produce and respond to chemokines. The production of chemokines by DC is not a random event but a specific phenomenon that regulates recruitment, maturation, migration and activation of these potent APC. Recruitment of DC from the blood into inflamed tissues and their migration to T cell areas in lymph nodes or spleen depends on their regulated expression of chemokine receptors (2,1315). Mature DC produce large amounts of chemokines that attract immature DC, monocytes, T cells and B cells, and thereby increase the efficiency of an immune response (1618). Chemokines thus play a role in the initiation of immune responses and more specifically may have adjuvant properties. CD8+ cytotoxic T lymphocytes (CTL) specifically stimulated by MHC class Ipeptide complexes are another source of chemokines (19,20). Since viral epitopes are recognized in association with MHC class I molecules by CD8+ CTL on most cell types of the body, the chemokine response of CD8+ CTL can induce accumulation of leukocyte subsets at sites of infection (12,20).
In the experiments described below, DC were generated in vitro from BALB/c or C57BL/6 bone marrow precursors (BMDC) in the presence of granulocyte macrophage colony stimulating factor (GM-CSF) and Flt3 ligand (FL). These DC processed exogenous, particulate hepatitis B surface antigen (HBsAg) for MHC-class I restricted presentation of antigenic peptides to CD8+ CTL. This specific and restricted stimulation of CTL by DC triggered IFN-
and macrophage inflammatory protein (MIP)-1
release by CTL. MIP-1
enhanced the survival of DC in vitro. In vivo, MIP-1
facilitated priming of CTL from low responder C57BL/6 mice to exogenous HBsAg. These data point to a role of MIP-1
in anti-viral CTL responses to exogenous antigens.
BALB/cJ (H-2d) and C57BL/6 (H-2b) were bred under standard pathogen-free conditions in the animal colony of the University of Ulm. Human rFL, murine GM-CSF, recombinant monocyte chemoattractant protein-1 (rMCP-1), rMIP-2 and rRANTES were obtained from PeproTech (cat. nos 300-12, 315-03, 250-10, 250-15 and 250-07; Rocky Hill, NJ). Murine rIFN-
was obtained from Genzyme (cat. no. MG-IFN; Cambridge, MA). Murine rMIP-1
and murine rKC were purchased from R & D Systems (cat. nos 450-11A and 453-KC-010; Wiesbaden, Germany). HBsAg particles produced in CHO cells were kindly provided by Drs N. Lerner and M. Gorecki, Bio-Technology General (Kiryat Weizmann, Rehovot, Israel) (21). The Ld-binding 12mer S2839 peptide (22) and the Kb-binding peptide S208215 of HBsAg were synthesized in an Applied Biosystems peptide synthesizer model 431A and purified by reverse-phase HPLC. Peptides were dissolved in DMSO at 10 mg/ml, and diluted with culture medium before use. Murine BMDC were generated as described (23) with some modifications. Briefly, bone marrow cells were depleted of lymphocytes and MHC class II+ cells by a MACS following the manufacturer's instructions. Then, 1x106 cells/ml were cultured at 3 ml/well in six-well plates (Nunc, Wiesbaden, Germany) in UltraCulture medium supplemented with 5 ng/ml GM-CSF, 10 ng/ml FL, 0.5% (v/v) FCS, 2 mM glutamine and antibiotics. Cultures were incubated at 37°C in humidified air supplemented with 5% CO2. On days 3, 5 and 7, cells were fed by medium exchange. From this cell population CD11c+ cells were purified by MACS separation. CTL were derived from BALB/c (H-2d) or C57BL/6 (H-2b) mice immunized with HBsAg-encoding expression plasmid DNA as described previously (2426). The CTL used had the CD3+CD4CD8+ phenotype and recognized either the S2839 epitope of HBsAg in the context of Ld (22) or the S208215 epitope of HBsAg in the context of Kb. DC (1x106/ml), resuspended in UltraCulture medium with 0.5% (v/v) FCS and 1 ng/ml GM-CSF, were incubated for 2 h at 37°C with the indicated amounts of HBsAg particles or antigenic peptide. DC were washed and co-cultured (5x104/well) with titrated numbers of CTL in a final volume of 200 µl/well. Supernatants were harvested after 24 h and MIP-1
was determined by ELISA as described previously (27). For determination of IFN-
, the mAb R4-6A2 (cat. no. 18181D; PharMingen) was used for coating and the biotinylated mAb XMG1.2 (cat. no. 18112D; PharMingen) was employed for detection. C57BL/6 (H-2b) mice were injected i.m. (into the tibialis anterior muscle) with 10 µg HBsAg particles in 50 µl PBS as described (28). In some experimental groups, HBsAg was co-administered with 100 ng rMIP-1
. All mice received only one injection. Spleens were removed from mice 1025 days post-vaccination. Single-cell suspensions were prepared in
-MEM tissue culture medium supplemented with 10 mM HEPES buffer, 5x105 M 2-mercaptoethanol, antibiotics and 10% v/v FCS (Gibco/BRL, Eggenstein, Germany). A selected batch of concanavalin A-stimulated rat spleen cell supernatant was added to the culture medium (2% v/v). Then, 3x107 responder cells were co-cultured with 1x106 irradiated, HBsAg-pulsed P815 or RBL5 cells. Co-culture was performed in 10 ml medium in upright 25 cm2 tissue culture flasks in a humidified atmosphere supplemented with 5% CO2 at 37°C. After 5 days of culture, cells were harvested, washed and used as effector cells in the cytotoxicity assay. Specific cytolytic activity of CTL was tested in a standard 51Cr-release assays. Serial dilutions of CTL were co-cultured at 37°C with 2x103 51Cr-labeled, HBsAg-pulsed targets in 200 µl round-bottom plates. After 4 h, 100 µl supernatant were collected for
-radiation counting. Percent specific lysis was calculated as [(experimental release spontaneous release)/(total release spontaneous release)]x100. Total counts were measured by resuspending target cells. Spontaneous released counts were always <10% of the total counts.
DC were derived from murine BM precursors in low serum cultures supplemented with GM-CSF and FL. On day 79 of culture, CD11c+ cells were purified by MACS separation. These cells expressed intermediate levels of MHC class I and class II molecules, CD11b, CD80 (B7.1), CD86 (B7.2), CD54 (ICAM-1), CD40 and DEC-205 (NLDC-145). DC were devoid of the macrophage marker F4/80. Upon stimulation with lipopolysaccharide (LPS) for 24 h, DC released the chemokines MIP-1
, MIP-2 and MCP-1 but no IL-12 (Table 1
, data not shown). These DC have been described to display an intermediate differentiation phenotype (29).
CTL are important mediators of antiviral immunity. Effector mechanisms of CTL are lysis of infected target cells, and release of cytokines such as IFN-
, IL-2 and tumor necrosis factor (TNF) (30). Although both DC and macrophages can prime murine CTL responses to HBsAg in vivo, DC are the more potent APC in this system (31). To elucidate the mechanism(s) underlying the potency of CTL priming by DC, we analyzed the cytokines/chemokines involved in DCCTL interactions and the cytolytic activity of BALB/c- or C57BL/6-derived CTL towards HBsAg-presenting DC. We generated CTL from vaccinated BALB/c or C57BL/6 mice that recognized the immunodominant MHC class I-binding HBsAg epitopes. DC were pulsed for 2 h with titrated amounts of either native HBsAg particles or the antigenic HBsAg peptide, washed and co-cultured with syngeneic, HBsAg-specific CD8+ CTL. The 24 h supernatants of these co-cultures were analyzed by ELISA for IFN-
, IL-12, MIP-1
, MIP-2 and MCP-1. A dose-dependent release of IFN-
and MIP-1
(but not of IL-12, MIP-2 and MCP-1) into the supernatant of these co-cultures was detectable (Fig. 1A and D
; and data not shown). Similar data were obtained using BALB/c- and C57BL/6-derived DC and CTL (data not shown). Neither IFN-
nor MIP-1
were detected in supernatants of CTL cultured either with non-pulsed DC or without DC (data not shown). Although the HBsAg-specific CTL efficiently lysed HBsAg particle-pulsed tumor cell targets, their specific cytolytic reactivity against HBsAg particle- or HBsAg peptide-pulsed DC was low or undetectable (data not shown).
We tested if CTL or DC are the source of IFN-
and MIP-1
. Either CTL or HBsAg-pulsed DC were fixed with 1% paraformaldehyde prior to the co-culture with HBsAg-presenting BMDC. When fixed CTLL were co-cultured with HBsAg-pulsed, non-fixed DC, neither IFN-
nor MIP-1
appeared in the supernatant (Fig. 1B and E
). In contrast, when DC were pulsed with HBsAg particles or peptide, fixed with 1% paraformaldehyde and co-cultured with CTLL, release of IFN-
and MIP-1
was detectable in the supernatant (Fig. 1C and F
) although the quantities of IFN-
and MIP-1
were lower than those in supernatants of co-cultures of non-fixed CTL with non-fixed DC. Thus, CTL that recognize the immunodominant HBsAg peptides in the context of MHC class I produce IFN-
and MIP-1
in response to exogenous viral antigen processed and presented by DC. Although DC produce MIP-1
when stimulated with LPS, IL-4 or TNF-
(Table 1
), they apparently do not release MIP-1
in a specific and restricted interaction with CD8+ T cells.
Since the MIP-1
receptors CCR1 and CCR5 are expressed on immature but not on mature DC (12,32,33), we tested the effect of MIP-1
on survival and proliferation of DC in vitro. DC were harvested on day 7 and cultured for 3 days either in medium alone, or with GM-CSF, or with rMIP-1
. The viability of DC was determined daily by Trypan blue exclusion and the proliferation by [3H]thymidine incorporation. As shown in Fig. 2
, addition of rMIP-1
induced survival but, in contrast to GM-CSF, not proliferation of DC. In addition, rMIP-1
had no influence on the expression of co-stimulatory molecules by DC (data not shown). From other chemokines tested, MIP-2 and RANTES but not MCP-1 and KC maintained viability of DC (Fig. 2A
). In summary, these data show that MIP-1
released by CTL during antigen recognition acts as a survival factor but not as a proliferation factor for DC.
We further tested the adjuvant effect of rMIP-1
on CTL priming in vivo in a system that allows priming of CTL to Kb-binding peptides generated by processing exogenous (but not endogenous) HBsAg in low responder mice (28,34). HBsAg-specific CTL responses were inducible in H-2b mice by DNA-based vaccination, but not by injecting non-adjuvanted HBsAg particles; in contrast, injection of exogenous HBsAg lipoprotein particles without adjuvants efficiently primed Ld-restricted CTL responses in H-2d mice. C57BL/6 (H-2b) mice were injected i.m. with 10 µg HBsAg particles/mouse either alone or in combination with 100 ng murine rMIP-1
. Splenocytes were obtained 24 weeks post-vaccination and specifically re-stimulated in vitro with syngeneic, HBsAg-pulsed RBL5 cells. No evidence for priming a HBsAg-specific cytolytic response was found when HBsAg was delivered without adjuvants (Fig. 3A
), but a specific, Kb-restricted CTL reactivity was successfully primed when HBsAg was co-delivered with rMIP-1
as an adjuvant (Fig. 3B
). Boiling of the rMIP-1
prior to co-delivering it with HBsAg to mice destroyed its adjuvant effect (data not shown); this excludes contaminating, heat-resistant bacterial DNA or LPS as active adjuvants in this system.
A role of CD8+ T lymphocyte-derived MIP-1
in priming cellular immune responses has been shown. In adoptive transfer experiments, CD8+ T cells from MIP-1
/ knockout donor mice primed with Listeria monocytogenes were less effective in protecting mice against a lethal infection with L. monocytogenes than CD8+ T cells from MIP-1
+/+ wild-type mice (35). Furthermore, MIP-1
is an important mediator of virus-induced inflammation. MIP-1
/ mice infected with Coxsackie virus are resistant to the development of myocarditis that develops in all wild-type mice infected with this virus. Influenza virus-infected MIP-1
/ mice develop only a mild pneumonitis but show delayed clearance of the virus while wild-type mice develop a severe pneumonitis but rapidly clear this virus (36). CTL are considered the main mediators of anti-viral immunity in these experimental systems. Thus, MIP-1
is a regulator of CTL priming in different murine systems.
Our results define an important role for the chemokine MIP-1
in an anti-viral CTL response. First, MIP-1
released by CTL upon recognition of HBsAg on DC can prolong the functional life span of the APC. Second, MIP-1
has an adjuvant effect on CTL priming in low responder mice.
 |
Acknowledgments
|
---|
We thank Drs N. Lerner and M. Gorecki, Bio-Technology General (Kiryat Weizmann, Rehovot, Israel) for purified, CHO-derived HBsAg particles. The work was supported by the grants Schi505/1-3 to R. S. from the Deutsche Forschungsgemeinschaft, PL 970002 (EC) and 01 GE9611 (Federal Ministry for research) to R. S. and J. R.
 |
Abbreviations
|
---|
APC antigen-presenting cells |
BMDC bone marrow-derived DC |
CTL cytotoxic T lymphocyte |
CTLL CTL line |
DC dendritic cells |
FL Flt3 ligand |
GM-CSF granulocyte macrophage colony stimulating factor |
HBsAg hepatitis B surface antigen |
HBV hepatitis B virus |
LPS lipopolysaccharide |
MCP macrophage chemoattractant protein |
MIP macrophage inflammatory protein |
TNF tumor necrosis factor |
 |
Notes
|
---|
Transmitting editor: T. Hünig
Received 16 February 2000,
accepted 22 May 2000.
 |
References
|
---|
-
Banchereau, J. and Steinman, R. M. 1998. Dendritic cells and the control of immunity. Nature 392:245.[ISI][Medline]
-
Cella, M., Sallusto, F. and Lanzavecchia, A. 1997. Origin, maturation and antigen presenting function of dendritic cells. Curr. Opin. Immunol. 9:10.[ISI][Medline]
-
Hart, D. N. 1997. Dendritic cells: unique leukocyte populations which control the primary immune response. Blood 90:3245.[Free Full Text]
-
Reis, S. A. and Kaye, P. 1999. The role of dendritic cells in the induction and regulation of immunity to microbial infection. Curr. Opin. Immunol. 11:392.[ISI][Medline]
-
Lane, P. J. and Brocker, T. 1999. Developmental regulation of dendritic cell function. Curr. Opin. Immunol. 11:308.[ISI][Medline]
-
Sallusto, F. and Lanzavecchia, A. 1999. Mobilizing dendritic cells for tolerance, priming, and chronic inflammation. J. Exp. Med. 189:611.[Free Full Text]
-
Pulendran, B., Lingappa, J., Kennedy, M. K., Smith, J., Teepe, M., Rudensky, A., Maliszewski, C. R. and Maraskovsky, E. 1997. Developmental pathways of dendritic cells in vivo: distinct function, phenotype, and localization of dendritic cell subsets in FLT3 ligand-treated mice. J. Immunol. 159:2222.[Abstract]
-
Vremec, D. and Shortman, K. 1997. Dendritic cell subtypes in mouse lymphoid organs: cross-correlation of surface markers, changes with incubation, and differences among thymus, spleen, and lymph nodes. J. Immunol. 159:565.[Abstract]
-
Kronin, V., Winkel, K., Suss, G., Kelso, A., Heath, W. R., Kirberg, J., von Boehmer, H. and Shortman, K. 1996. A subclass of dendritic cells regulates the response of naive CD8 T cells by limiting their IL-2 production. J. Immunol. 157:3819.[Abstract]
-
Crowley, M. T., Reilly, C. and Lo, D. 1999. Influence of lymphocytes on the presence and organization of dendritic cell subsets in the spleen. J. Immunol. 163:4894.[Abstract/Free Full Text]
-
Schluger, N. W. and Rom, W. N. 1997. Early responses to infection: chemokines as mediators of inflammation. Curr. Opin. Immunol. 9:504.[ISI][Medline]
-
Baggiolini, M., Dewald, B. and Moser, B. 1997. Human chemokines: an update. Annu. Rev. Immunol. 15:675.[ISI][Medline]
-
Sallusto, F., Lanzavecchia, A. and Mackay, C. R. 1998. Chemokines and chemokine receptors in T-cell priming and Th1/Th2-mediated responses. Immunol. Today 19:568.[ISI][Medline]
-
Sallusto, F., Palermo, B., Hoy, A. and Lanzavecchia, A. 1999. The role of chemokine receptors in directing traffic of naive, type 1 and type 2 T cells. Curr. Top. Microbiol. Immunol. 246:123.[ISI][Medline]
-
Cyster, J. G. 1999. Chemokines and the homing of dendritic cells to the T cell areas of lymphoid organs. J. Exp. Med. 189:447.[Free Full Text]
-
Ngo, V. N., Tang, H. L. and Cyster, J. G. 1998. EpsteinBarr virus-induced molecule 1 ligand chemokine is expressed by dendritic cells in lymphoid tissues and strongly attracts naive T cells and activated B cells. J. Exp. Med. 188:181.[Abstract/Free Full Text]
-
Schaniel, C., Pardali, E., Sallusto, F., Speletas, M., Ruedl, C., Shimizu, T., Seidl, T., Andersson, J., Melchers, F., Rolink, A. G. and Sideras, P. 1998. Activated murine B lymphocytes and dendritic cells produce a novel CC chemokine which acts selectively on activated T cells. J. Exp. Med. 188:451.[Abstract/Free Full Text]
-
Sallusto, F., Palermo, B., Lenig, D., Miettinen, M., Matikainen, S., Julkunen, I., Forster, R., Burgstahler, R., Lipp, M. and Lanzavecchia, A. 1999. Distinct patterns and kinetics of chemokine production regulate dendritic cell function. Eur. J. Immunol. 29:1617.[ISI][Medline]
-
Conlon, K., Lloyd, A., Chattopadhyay, U., Lukacs, N., Kunkel, S., Schall, T., Taub, D., Morimoto, C., Osborne, J., Oppenheim, J., Young, H., Kelvin, D. and Ortaldo, J. 1995. CD8+ and CD45RA+ human peripheral blood lymphocytes are potent sources of macrophage inflammatory protein 1
, interleukin-8 and RANTES. Eur. J. Immunol. 25:751.[ISI][Medline]
-
Price, D. A., Klenerman, P., Booth, B. L., Phillips, R. E. and Sewell, A. K. 1999. Cytotoxic T lymphocytes, chemokines and antiviral immunity. Immunol. Today 20:212.[ISI][Medline]
-
Diminsky, D., Schirmbeck, R., Reimann, J. and Barenholz, Y. 1997. Comparison between surface antigen (HBsAg) particles derived from mammalian cells (CHO) and yeast cells (Hansenula polymorpha): composition, structure and immunogenicity. Vaccine 15:637.[ISI][Medline]
-
Ishikawa, T., Kono, D. H., Fowler, P., Theofilopoulos, A. N., Kakumu, S. and Chisari, F. V. 1998. Polyclonality and multispecificity of the CTL response to a single viral epitope. J. Immunol. 161:5842.[Abstract/Free Full Text]
-
Inaba, K., Inaba, M., Romani, N., Aya, H., Deguchi, M., Ikehara, S., Muramatsu, S. and Steinman, R. M. 1992. Generation of large numbers of dendritic cells from mouse bone marrow cultures supplemented with granulocyte/macrophage colony- stimulating factor. J. Exp. Med. 176:1693.[Abstract]
-
Davis, H. L., Schirmbeck, R., Reimann, J. and Whalen, R. G. 1995. DNA-mediated immunization in mice induces a potent MHC class I-restricted cytotoxic T lymphocyte response to Hepatitis B virus surface antigen. Hum. Gene Ther. 6:1447.[ISI][Medline]
-
Schirmbeck, R., Böhm, W., Ando, K.-I., Chisari, F. V. and Reimann, J. 1995. Nucleic acid vaccination primes hepatitis B surface antigen-specific cytotoxic T lymphocytes in nonresponder mice. J. Virol. 69:5929.[Abstract]
-
Böhm, W., Mertens, T., Schirmbeck, R. and Reimann, J. 1998. Routes of plasmid DNA vaccination that prime murine humoral and cellular immune responses. Vaccine 16:949.[ISI][Medline]
-
Flesch, I. E., Barsig, J. and Kaufmann, S. H. 1998. Differential chemokine response of murine macrophages stimulated with cytokines and infected with Listeria monocytogenes. Int. Immunol. 10:757.[Abstract]
-
Schirmbeck, R., Melber, K. and Reimann, J. 1999. Adjuvants that enhance priming of cytotoxic T cells to a Kb-restricted epitope processed from exogenous but not endogenous hepatitis B surface antigen. Int. Immunol. 11:1093.[Abstract/Free Full Text]
-
Labeur, M. S., Roters, B., Pers, B., Mehling, A., Luger, T. A., Schwarz, T. and Grabbe, S. 1999. Generation of tumor immunity by bone marrow-derived dendritic cells correlates with dendritic cell maturation stage. J. Immunol. 162:168.[Abstract/Free Full Text]
-
Kaegi, D., Ledermann, B., Burki, K., Zinkernagel, R. M. and Hengartner, H. 1996. Molecular mechanisms of lymphocyte-mediated cytotoxicity and their role in immunological protection and pathogenesis in vivo. Annu. Rev. Immunol. 14:207.[ISI][Medline]
-
Böhm, W., Schirmbeck, R., Elbe, A., Melber, K., Diminsky, D., Kraal, G., Van Rooijen, N., Barenholz, Y. and Reimann, J. 1995. Exogenous hepatitis B surface antigen particles processed by dendritic cells or macrophages prime murine MHC class I-restricted cytotoxic T lymphocytes in vivo. J. Immunol. 155:3313.[Abstract]
-
Sallusto, F., Schaerli, P., Loetscher, P., Schaniel, C., Lenig, D., Mackay, C. R., Qin, S. and Lanzavecchia, A. 1998. Rapid and coordinated switch in chemokine receptor expression during dendritic cell maturation. Eur. J. Immunol. 28:2760.[ISI][Medline]
-
Sozzani, S., Allavena, P., D'Amico, G., Luini, W., Bianchi, G., Kataura, M., Imai, T., Yoshie, O., Bonecchi, R. and Mantovani, A. 1998. Differential regulation of chemokine receptors during dendritic cell maturation: a model for their trafficking properties. J. Immunol. 161:1083.[Abstract/Free Full Text]
-
Schirmbeck, R., Wild, J. and Reimann, J. 1998. Similar as well as distinct MHC-I-binding peptides are generated by exogenous and endogenous processing of hepatitis B virus surface antigen (HBsAg). Eur. J. Immunol. 28:4149.[ISI][Medline]
-
Cook, D. N., Smithies, O., Strieter, R. M., Frelinger, J. A. and Serody, J. S. 1999. CD8+ T cells are a biologically relevant source of macrophage inflammatory protein-1
in vivo. J. Immunol. 162:5423.[Abstract/Free Full Text]
-
Cook, D. N., Beck, M. A., Coffman, T. M., Kirby, S. L., Sheridan, J. F., Pragnell, I. B. and Smithies, O. 1995. Requirement of MIP-1
for an inflammatory response to viral infection. Science 269:1583.[ISI][Medline]