Pascal Clayette - Academia.edu (original) (raw)
Papers by Pascal Clayette
Neurobiology of Disease
In multiple sclerosis (MS), the T-cell receptors (TCRS) of autoreactive T lymphocytes recognize v... more In multiple sclerosis (MS), the T-cell receptors (TCRS) of autoreactive T lymphocytes recognize various myelin components or derivatives including peptides of the myelin basic protein (MBP). Using the exhaustive immunoscope approach we showed that the T-cell repertoires of MS patients differ from those of healthy controls, with expansion of Vbeta13 cell clones in cerebrospinal fluid (CSF) and in peripheral blood lymphocytes (PBLs). Sequencing of the beta13(+) chains of T cells recovered from the CSF revealed high interindividual diversity, and no particular Vbeta13(+) rearrangements were shown to be myelin-autoreactive. Within the overall Vbeta13 repertoire in the CSF of patient MS3 at the onset of the disease, most of the overrepresented (N)Dbeta(N)Jbeta junctional regions were found to be associated with two or three different Vbeta13 segments. These rearrangements were most common in the PBLs of patient MS3. No such associations were detected in the Vbeta5 multigene family that was used as a control. Thus, Vbeta13 T cells infiltrating the CSF from patient MS3 may have been selected on the basis of both the Vbeta13 segments and the (N)Dbeta(N)Jbeta junctional CDR3 sequence.
AJP Cell Physiology
Cysteine is the limiting precursor for glutathione synthesis. Because of its low bioavailability,... more Cysteine is the limiting precursor for glutathione synthesis. Because of its low bioavailability, cysteine is generally produced from cystine, which may be taken up through two different transporters. The cystine/glutamate antiporter (x system) transports extracellular cystine in exchange for intracellular glutamate. The X(AG) transport system takes up extracellular cystine, glutamate, and aspartate. Both are sensitive to competition between cystine and glutamate, and excess extracellular glutamate thus inhibits glutathione synthesis, a nonexcitotoxic mechanism for glutamate toxicity. We demonstrated previously that human macrophages express the glutamate transporters excitatory amino acid transporter (EAAT)1 and EAAT2 (which do not transport cystine, X system) and overcome competition for the use of cystine transporters. We now show that macrophages take up cystine through the x and not the X(AG) system. We also found that glutamate, although competing with cystine uptake, dose-dependently increases glutathione synthesis. We used inhibitors to demonstrate that this increase is mediated by EAATs. EAAT expression in macrophages thus leads to glutamate-dependent enhancement of glutathione synthesis by providing intracellular glutamate for direct insertion in glutathione and also for fueling the intracellular pool of glutamate and trans-stimulating the cystine/glutamate antiporter.
Pathologie Biologie
Treatment of the human immunodeficiency virus (HIV) is restricted by therapeutic escape. The biol... more Treatment of the human immunodeficiency virus (HIV) is restricted by therapeutic escape. The biological mechanisms of this chemoresistance rely notably on the modulation of cell kinase and P-glycoprotein (P-gp) expression. In this study, we investigated, in cynomolgus macaques, the roles of SHIV89.6P infection and of HAART in the mRNA expression of these cell factors. SHIV infection, or associated pathophysiological disorders, increase both thymidine kinase and thymidylate kinase mRNA expression and decrease those of P-gp. On the other hand, the expression of other cell kinases is not modulated. In parallel, HAART accentuates the decrease of P-gp expression and attenuates the increase of kinase expression. On the whole, such metabolic disorders, evidenced herein an animal model of HIV infection, could be involved in HIV-infected patients.
Vaccine, 2015
We evaluated the immunogenicity of a prime/boost vaccine strategy combining 5 lipopeptides (HIV-L... more We evaluated the immunogenicity of a prime/boost vaccine strategy combining 5 lipopeptides (HIV-Lipo-5) and a recombinant modified vaccinia virus Ankara (rMVA-HIV) in cynomolgus macaques. Both of these vaccine components deliver HIV LAI Gag, Pol, and Nef antigens. Systemic and local safety was excellent in all groups. Immunization with HIV-Lipo-5 alone induced significant serum anti-HIV antibody titers which were not modified by rMVA-HIV immunization. However, induction of T-cell responses, as measured by IFNγ and IL-2 producing cells upon short-term stimulation with HIV peptide pools, required combined immunization with rMVA-HIV. Responses were preferentially observed against Gag antigen. Interestingly, HIV-Lipo-5 efficiently primed HIV induced T-cell responses upon the injection of rMVA-HIV, which may help to reduce the required number of vector injections. Our results provide a rationale for the use of a strategy involving HIV-Lipo-5 priming followed by rMVA-HIV booster immunization as a prophylactic or therapeutic vaccine approach against HIV infection and AIDS.
ChemInform, 2001
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
American journal of physiology. Cell physiology, 2001
Cysteine is the limiting precursor for glutathione synthesis. Because of its low bioavailability,... more Cysteine is the limiting precursor for glutathione synthesis. Because of its low bioavailability, cysteine is generally produced from cystine, which may be taken up through two different transporters. The cystine/glutamate antiporter (x system) transports extracellular cystine in exchange for intracellular glutamate. The X(AG) transport system takes up extracellular cystine, glutamate, and aspartate. Both are sensitive to competition between cystine and glutamate, and excess extracellular glutamate thus inhibits glutathione synthesis, a nonexcitotoxic mechanism for glutamate toxicity. We demonstrated previously that human macrophages express the glutamate transporters excitatory amino acid transporter (EAAT)1 and EAAT2 (which do not transport cystine, X system) and overcome competition for the use of cystine transporters. We now show that macrophages take up cystine through the x and not the X(AG) system. We also found that glutamate, although competing with cystine uptake, dose-dep...
Pathologie-biologie, 1999
Type I interferon (IFN) such as IFN-alpha have demonstrated relative efficiency in HIV-infected p... more Type I interferon (IFN) such as IFN-alpha have demonstrated relative efficiency in HIV-infected patients with Kaposi's sarcoma. Nevertheless, their clinical uses have been restricted by several major side effects. IFN-tau is a non-cytotoxic type I IFN. In the present manuscript, we described its in vitro effects towards HIV replication and its mode of action. IFN-tau is a potent antiviral molecule that interferes with an early step of HIV biological cycle. Moreover, it induces IL-6 synthesis by macrophages, and this cytokine favorises its antiviral efficacy, probably by amplifying the induction of 2', 5'OAS and RNase L. Altogether, these results confirm the interest of IFN-tau as adjuvant therapy in HIV infection, and more particularly in HIV/HCV-infected patients.
Antimicrobial agents and chemotherapy, 1997
Tumor necrosis factor alpha (TNF-alpha) is overexpressed during human immunodeficiency virus (HIV... more Tumor necrosis factor alpha (TNF-alpha) is overexpressed during human immunodeficiency virus (HIV) infection. RP 55778, a TNF-alpha synthesis inhibitor, decreases HIV replication in monocytes/macrophages. Therapeutic use of RP 55778 in vivo, like that of other biological response modifiers, would theoretically require association with dideoxynucleosides. We have evaluated here the combinatory effects of zidovudine (AZT) or dideoxyinosine (ddI) and RP 55778. This TNF-alpha inhibitor antagonizes the antiviral effects of both dideoxynucleosides, especially AZT. The more favorable anti-HIV activity of ddI in resting cells may explain these unequal degrees of antagonism.
Encyclopedia of Cancer, 2011
Encyclopedia of Cancer, 2011
Encyclopedia of Cancer, 2011
Encyclopedia of Cancer, 2011
Research in Virology, 1998
This study evaluates the consequences of antiretroviral treatment of the acute simian immunodefic... more This study evaluates the consequences of antiretroviral treatment of the acute simian immunodeficiency virus (SIV) primary infection on virus load and cytokine responses. Four cynomolgus macaques were inoculated intravenously with a pathogenic primary isolate (SIVmac251). Animals were pretreated with 10.8 mg/kg/day of dideoxyinosine (ddI) from 4 days before inoculation, and treatment was continued for 28 days. Proinflammatory (IL6, IL1 beta and TNF alpha) and antiinflammatory (IL10) cytokine and lymphokine (IL2, IL4 and IFN gamma) polymerase chain reaction (PCR) ratios were monitored in unmanipulated peripheral blood mononuclear cells (PBMCs) during acute infection by using a semiquantitative reverse transcription (RT)-PCR method. PBMC-associated virus loads were dramatically reduced compared to those of placebo-treated macaques. Nevertheless, a transient rise in IL6, IL1 beta, TNF alpha and IL10 mRNA expression was observed in PBMCs. IL2, IL4 and IFN gamma mRNAs were either undetectable or weakly detectable throughout the study, with no major changes. Despite a dramatic reduction in the acute viral loads in ddI-treated monkeys, early cytokine mRNA profiles were comparable to those of untreated SIVmac251-infected monkeys. Contrary to what was previously evidenced during primary infection with an attenuated SIV clone, no increase in IL2 and IL4 mRNA was detected in PBMCs of the ddI-treated monkeys, although these monkeys exhibited virus loads similar to those evidenced in macaques infected by attenuated SIV. These data indicate that differential lymphokine expression patterns found in pathogenic and Nef-truncated SIV-infected monkeys may not be strictly dependent on virus load levels.
ChemInform, 1999
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Vaccine, 2007
Intramuscular administration of aluminum-adjuvanted vaccines induces an infiltration of aluminum-... more Intramuscular administration of aluminum-adjuvanted vaccines induces an infiltration of aluminum-containing macrophages between muscle fibers. In vitro stimulation of human monocyte-derived macrophages with aluminum hydroxide (AlOOH) induces similar intracellular crystalline inclusions as well as phenotypical and functional modifications. We compared in this study the ability of other adjuvants to exert similar changes in macrophages in vitro. All mineral salts, i.e. aluminic (AlOOH, AlPO 4 ) and non-aluminic mineral adjuvants (CaPO 4 , FePO 4 ) but not emulsion were able to increase macrophages capacity to potentiate autologous memory T lymphocyte proliferation, while only aluminic adjuvants induced CD83 expression and increased CD86 on macrophages. All together, this suggests that aluminic and non-aluminic adjuvants exerted their immunoactivities by distinct mechanisms on macrophages.
Glycerolipidic prodrug is an interesting concept to enhance lymphatic absorption of polar drugs i... more Glycerolipidic prodrug is an interesting concept to enhance lymphatic absorption of polar drugs intended to oral delivery such as didanosine (ddI). In order to improve ddI bioavailability, two didanosine glycerolipidic prodrugs, the phosphorylated (ProddIP) and the non-phosphorylated derivatives (ProddINP) were synthesized to follow triglyceride metabolism. The biomimetism approach of these prodrugs has been studied in vitro at two steps. First, liposomal formulation of each prodrug was incubated with a lipolysis model based on pancreatin and analysed using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). These experiments evidenced that both didanosine prodrugs were recognized by the lipases; as expected, they were cleaved at both positions sn-1 and sn-3 of glycerol. ProddIP was metabolised twice more rapidly than ProddINP suggesting an implication of some phospholipases in ProddIP degradation. Secondly, the detection of dideoxyadenosine triphosphate (ddA-TP) into HIV-1 infected cells after their incubation with ProddINP loaded liposomes evidenced their ability to release ddI that could penetrate into the cells and be metabolised by intracellular kinases. These results confirmed that the synthesized glycerolipidic prodrugs of didanosine could be investigated for a biomimetic approach with final aiming of increasing the drug oral bioavailability by enhancing intestinal absorption.
Vaccine, 2004
Aluminum hydroxide (AlOOH) has been used for many years as a vaccine adjuvant, but little is know... more Aluminum hydroxide (AlOOH) has been used for many years as a vaccine adjuvant, but little is known about its mechanism of action. We investigated in this study the in vitro effect of aluminum hydroxide adjuvant on isolated macrophages. We showed that AlOOH-stimulated macrophages contain large and persistent intracellular crystalline inclusions, a characteristic property of muscle infiltrated macrophages described in animal models of vaccine injection, as well as in the recently described macrophagic myofasciitis (MMF) histological reaction in humans. AlOOH-loaded macrophages exhibited phenotypical and functional modifications, as they expressed the classical markers of myeloid dendritic cells (HLA-DR high /CD86 high /CD83 + /CD1a − /CD14 − ) and displayed potent ability to induce MHC-II-restricted antigen specific memory responses, but kept a macrophage morphology. This suggests a key role of macrophages, in the reaction to AlOOH-adjuvanted vaccines and these mature antigen-presenting macrophages may therefore be of particular importance in the establishment of memory responses and in vaccination mechanisms leading to long-lasting protection.
Vaccine, 2010
In the present work, the capacity of new pro-GSH molecules to increase the intra-macrophage thiol... more In the present work, the capacity of new pro-GSH molecules to increase the intra-macrophage thiol content in vitro and in vivo as well as to shift the immune response to Th1 in ovalbumin (Ova)-sensitized mice were examined. The molecules were the N-butanoyl GSH derivative, GSH-C4, and a pro-drug of N-acetylcysteine (NAC) and beta-mercaptoethylamine (MEA), I-152. In vitro, 2 h-incubation with both molecules was found to increase intra-macrophage thiol content; in vivo, Ova-sensitized mice pre-treated by intraperitoneal administration of the pro-GSH molecules showed an increase in plasma anti-Ova IgG2a and IgG2b, characterizing Th1 immune response, and a decrease in IgG1, typical of the Th2 response. Such findings were connected to a shift to a Th1 response also involving splenocyte IFN-␥ production as revealed by ELISPOT assay and higher levels of IL-12 in circulation. Although immune responses are in vivo mediated both by dendritic cells and macrophages, the data reported in this paper corroborate the suggestion that the pro-GSH molecules, increasing the intra-cellular thiol pool, modulate the Th1/Th2 balance favouring Th1-type responses and may be employed as Th1-directing adjuvants in new vaccination protocols and as immunomodulators in those diseases where Th1 response patterns are compromised in favour of Th2.
Trends in Neurosciences, 2001
Neurobiology of Disease
In multiple sclerosis (MS), the T-cell receptors (TCRS) of autoreactive T lymphocytes recognize v... more In multiple sclerosis (MS), the T-cell receptors (TCRS) of autoreactive T lymphocytes recognize various myelin components or derivatives including peptides of the myelin basic protein (MBP). Using the exhaustive immunoscope approach we showed that the T-cell repertoires of MS patients differ from those of healthy controls, with expansion of Vbeta13 cell clones in cerebrospinal fluid (CSF) and in peripheral blood lymphocytes (PBLs). Sequencing of the beta13(+) chains of T cells recovered from the CSF revealed high interindividual diversity, and no particular Vbeta13(+) rearrangements were shown to be myelin-autoreactive. Within the overall Vbeta13 repertoire in the CSF of patient MS3 at the onset of the disease, most of the overrepresented (N)Dbeta(N)Jbeta junctional regions were found to be associated with two or three different Vbeta13 segments. These rearrangements were most common in the PBLs of patient MS3. No such associations were detected in the Vbeta5 multigene family that was used as a control. Thus, Vbeta13 T cells infiltrating the CSF from patient MS3 may have been selected on the basis of both the Vbeta13 segments and the (N)Dbeta(N)Jbeta junctional CDR3 sequence.
AJP Cell Physiology
Cysteine is the limiting precursor for glutathione synthesis. Because of its low bioavailability,... more Cysteine is the limiting precursor for glutathione synthesis. Because of its low bioavailability, cysteine is generally produced from cystine, which may be taken up through two different transporters. The cystine/glutamate antiporter (x system) transports extracellular cystine in exchange for intracellular glutamate. The X(AG) transport system takes up extracellular cystine, glutamate, and aspartate. Both are sensitive to competition between cystine and glutamate, and excess extracellular glutamate thus inhibits glutathione synthesis, a nonexcitotoxic mechanism for glutamate toxicity. We demonstrated previously that human macrophages express the glutamate transporters excitatory amino acid transporter (EAAT)1 and EAAT2 (which do not transport cystine, X system) and overcome competition for the use of cystine transporters. We now show that macrophages take up cystine through the x and not the X(AG) system. We also found that glutamate, although competing with cystine uptake, dose-dependently increases glutathione synthesis. We used inhibitors to demonstrate that this increase is mediated by EAATs. EAAT expression in macrophages thus leads to glutamate-dependent enhancement of glutathione synthesis by providing intracellular glutamate for direct insertion in glutathione and also for fueling the intracellular pool of glutamate and trans-stimulating the cystine/glutamate antiporter.
Pathologie Biologie
Treatment of the human immunodeficiency virus (HIV) is restricted by therapeutic escape. The biol... more Treatment of the human immunodeficiency virus (HIV) is restricted by therapeutic escape. The biological mechanisms of this chemoresistance rely notably on the modulation of cell kinase and P-glycoprotein (P-gp) expression. In this study, we investigated, in cynomolgus macaques, the roles of SHIV89.6P infection and of HAART in the mRNA expression of these cell factors. SHIV infection, or associated pathophysiological disorders, increase both thymidine kinase and thymidylate kinase mRNA expression and decrease those of P-gp. On the other hand, the expression of other cell kinases is not modulated. In parallel, HAART accentuates the decrease of P-gp expression and attenuates the increase of kinase expression. On the whole, such metabolic disorders, evidenced herein an animal model of HIV infection, could be involved in HIV-infected patients.
Vaccine, 2015
We evaluated the immunogenicity of a prime/boost vaccine strategy combining 5 lipopeptides (HIV-L... more We evaluated the immunogenicity of a prime/boost vaccine strategy combining 5 lipopeptides (HIV-Lipo-5) and a recombinant modified vaccinia virus Ankara (rMVA-HIV) in cynomolgus macaques. Both of these vaccine components deliver HIV LAI Gag, Pol, and Nef antigens. Systemic and local safety was excellent in all groups. Immunization with HIV-Lipo-5 alone induced significant serum anti-HIV antibody titers which were not modified by rMVA-HIV immunization. However, induction of T-cell responses, as measured by IFNγ and IL-2 producing cells upon short-term stimulation with HIV peptide pools, required combined immunization with rMVA-HIV. Responses were preferentially observed against Gag antigen. Interestingly, HIV-Lipo-5 efficiently primed HIV induced T-cell responses upon the injection of rMVA-HIV, which may help to reduce the required number of vector injections. Our results provide a rationale for the use of a strategy involving HIV-Lipo-5 priming followed by rMVA-HIV booster immunization as a prophylactic or therapeutic vaccine approach against HIV infection and AIDS.
ChemInform, 2001
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
American journal of physiology. Cell physiology, 2001
Cysteine is the limiting precursor for glutathione synthesis. Because of its low bioavailability,... more Cysteine is the limiting precursor for glutathione synthesis. Because of its low bioavailability, cysteine is generally produced from cystine, which may be taken up through two different transporters. The cystine/glutamate antiporter (x system) transports extracellular cystine in exchange for intracellular glutamate. The X(AG) transport system takes up extracellular cystine, glutamate, and aspartate. Both are sensitive to competition between cystine and glutamate, and excess extracellular glutamate thus inhibits glutathione synthesis, a nonexcitotoxic mechanism for glutamate toxicity. We demonstrated previously that human macrophages express the glutamate transporters excitatory amino acid transporter (EAAT)1 and EAAT2 (which do not transport cystine, X system) and overcome competition for the use of cystine transporters. We now show that macrophages take up cystine through the x and not the X(AG) system. We also found that glutamate, although competing with cystine uptake, dose-dep...
Pathologie-biologie, 1999
Type I interferon (IFN) such as IFN-alpha have demonstrated relative efficiency in HIV-infected p... more Type I interferon (IFN) such as IFN-alpha have demonstrated relative efficiency in HIV-infected patients with Kaposi's sarcoma. Nevertheless, their clinical uses have been restricted by several major side effects. IFN-tau is a non-cytotoxic type I IFN. In the present manuscript, we described its in vitro effects towards HIV replication and its mode of action. IFN-tau is a potent antiviral molecule that interferes with an early step of HIV biological cycle. Moreover, it induces IL-6 synthesis by macrophages, and this cytokine favorises its antiviral efficacy, probably by amplifying the induction of 2', 5'OAS and RNase L. Altogether, these results confirm the interest of IFN-tau as adjuvant therapy in HIV infection, and more particularly in HIV/HCV-infected patients.
Antimicrobial agents and chemotherapy, 1997
Tumor necrosis factor alpha (TNF-alpha) is overexpressed during human immunodeficiency virus (HIV... more Tumor necrosis factor alpha (TNF-alpha) is overexpressed during human immunodeficiency virus (HIV) infection. RP 55778, a TNF-alpha synthesis inhibitor, decreases HIV replication in monocytes/macrophages. Therapeutic use of RP 55778 in vivo, like that of other biological response modifiers, would theoretically require association with dideoxynucleosides. We have evaluated here the combinatory effects of zidovudine (AZT) or dideoxyinosine (ddI) and RP 55778. This TNF-alpha inhibitor antagonizes the antiviral effects of both dideoxynucleosides, especially AZT. The more favorable anti-HIV activity of ddI in resting cells may explain these unequal degrees of antagonism.
Encyclopedia of Cancer, 2011
Encyclopedia of Cancer, 2011
Encyclopedia of Cancer, 2011
Encyclopedia of Cancer, 2011
Research in Virology, 1998
This study evaluates the consequences of antiretroviral treatment of the acute simian immunodefic... more This study evaluates the consequences of antiretroviral treatment of the acute simian immunodeficiency virus (SIV) primary infection on virus load and cytokine responses. Four cynomolgus macaques were inoculated intravenously with a pathogenic primary isolate (SIVmac251). Animals were pretreated with 10.8 mg/kg/day of dideoxyinosine (ddI) from 4 days before inoculation, and treatment was continued for 28 days. Proinflammatory (IL6, IL1 beta and TNF alpha) and antiinflammatory (IL10) cytokine and lymphokine (IL2, IL4 and IFN gamma) polymerase chain reaction (PCR) ratios were monitored in unmanipulated peripheral blood mononuclear cells (PBMCs) during acute infection by using a semiquantitative reverse transcription (RT)-PCR method. PBMC-associated virus loads were dramatically reduced compared to those of placebo-treated macaques. Nevertheless, a transient rise in IL6, IL1 beta, TNF alpha and IL10 mRNA expression was observed in PBMCs. IL2, IL4 and IFN gamma mRNAs were either undetectable or weakly detectable throughout the study, with no major changes. Despite a dramatic reduction in the acute viral loads in ddI-treated monkeys, early cytokine mRNA profiles were comparable to those of untreated SIVmac251-infected monkeys. Contrary to what was previously evidenced during primary infection with an attenuated SIV clone, no increase in IL2 and IL4 mRNA was detected in PBMCs of the ddI-treated monkeys, although these monkeys exhibited virus loads similar to those evidenced in macaques infected by attenuated SIV. These data indicate that differential lymphokine expression patterns found in pathogenic and Nef-truncated SIV-infected monkeys may not be strictly dependent on virus load levels.
ChemInform, 1999
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Vaccine, 2007
Intramuscular administration of aluminum-adjuvanted vaccines induces an infiltration of aluminum-... more Intramuscular administration of aluminum-adjuvanted vaccines induces an infiltration of aluminum-containing macrophages between muscle fibers. In vitro stimulation of human monocyte-derived macrophages with aluminum hydroxide (AlOOH) induces similar intracellular crystalline inclusions as well as phenotypical and functional modifications. We compared in this study the ability of other adjuvants to exert similar changes in macrophages in vitro. All mineral salts, i.e. aluminic (AlOOH, AlPO 4 ) and non-aluminic mineral adjuvants (CaPO 4 , FePO 4 ) but not emulsion were able to increase macrophages capacity to potentiate autologous memory T lymphocyte proliferation, while only aluminic adjuvants induced CD83 expression and increased CD86 on macrophages. All together, this suggests that aluminic and non-aluminic adjuvants exerted their immunoactivities by distinct mechanisms on macrophages.
Glycerolipidic prodrug is an interesting concept to enhance lymphatic absorption of polar drugs i... more Glycerolipidic prodrug is an interesting concept to enhance lymphatic absorption of polar drugs intended to oral delivery such as didanosine (ddI). In order to improve ddI bioavailability, two didanosine glycerolipidic prodrugs, the phosphorylated (ProddIP) and the non-phosphorylated derivatives (ProddINP) were synthesized to follow triglyceride metabolism. The biomimetism approach of these prodrugs has been studied in vitro at two steps. First, liposomal formulation of each prodrug was incubated with a lipolysis model based on pancreatin and analysed using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). These experiments evidenced that both didanosine prodrugs were recognized by the lipases; as expected, they were cleaved at both positions sn-1 and sn-3 of glycerol. ProddIP was metabolised twice more rapidly than ProddINP suggesting an implication of some phospholipases in ProddIP degradation. Secondly, the detection of dideoxyadenosine triphosphate (ddA-TP) into HIV-1 infected cells after their incubation with ProddINP loaded liposomes evidenced their ability to release ddI that could penetrate into the cells and be metabolised by intracellular kinases. These results confirmed that the synthesized glycerolipidic prodrugs of didanosine could be investigated for a biomimetic approach with final aiming of increasing the drug oral bioavailability by enhancing intestinal absorption.
Vaccine, 2004
Aluminum hydroxide (AlOOH) has been used for many years as a vaccine adjuvant, but little is know... more Aluminum hydroxide (AlOOH) has been used for many years as a vaccine adjuvant, but little is known about its mechanism of action. We investigated in this study the in vitro effect of aluminum hydroxide adjuvant on isolated macrophages. We showed that AlOOH-stimulated macrophages contain large and persistent intracellular crystalline inclusions, a characteristic property of muscle infiltrated macrophages described in animal models of vaccine injection, as well as in the recently described macrophagic myofasciitis (MMF) histological reaction in humans. AlOOH-loaded macrophages exhibited phenotypical and functional modifications, as they expressed the classical markers of myeloid dendritic cells (HLA-DR high /CD86 high /CD83 + /CD1a − /CD14 − ) and displayed potent ability to induce MHC-II-restricted antigen specific memory responses, but kept a macrophage morphology. This suggests a key role of macrophages, in the reaction to AlOOH-adjuvanted vaccines and these mature antigen-presenting macrophages may therefore be of particular importance in the establishment of memory responses and in vaccination mechanisms leading to long-lasting protection.
Vaccine, 2010
In the present work, the capacity of new pro-GSH molecules to increase the intra-macrophage thiol... more In the present work, the capacity of new pro-GSH molecules to increase the intra-macrophage thiol content in vitro and in vivo as well as to shift the immune response to Th1 in ovalbumin (Ova)-sensitized mice were examined. The molecules were the N-butanoyl GSH derivative, GSH-C4, and a pro-drug of N-acetylcysteine (NAC) and beta-mercaptoethylamine (MEA), I-152. In vitro, 2 h-incubation with both molecules was found to increase intra-macrophage thiol content; in vivo, Ova-sensitized mice pre-treated by intraperitoneal administration of the pro-GSH molecules showed an increase in plasma anti-Ova IgG2a and IgG2b, characterizing Th1 immune response, and a decrease in IgG1, typical of the Th2 response. Such findings were connected to a shift to a Th1 response also involving splenocyte IFN-␥ production as revealed by ELISPOT assay and higher levels of IL-12 in circulation. Although immune responses are in vivo mediated both by dendritic cells and macrophages, the data reported in this paper corroborate the suggestion that the pro-GSH molecules, increasing the intra-cellular thiol pool, modulate the Th1/Th2 balance favouring Th1-type responses and may be employed as Th1-directing adjuvants in new vaccination protocols and as immunomodulators in those diseases where Th1 response patterns are compromised in favour of Th2.
Trends in Neurosciences, 2001