Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
Add more filters











Publication year range
1.
Indian J Pharmacol ; 55(3): 149-154, 2023.
Article in English | MEDLINE | ID: mdl-37555408

ABSTRACT

OBJECTIVES: Carbamazepine (CBZ), an anti-seizure drug, is widely prescribed for the management of focal seizures. At a given therapeutic dose, CBZ exhibits marked interindividual variation in the plasma CBZ levels. The aim wasto study the influence of EPHX1 c.337 T>C and UGT2B7*2 genetic polymorphisms on plasma carbamazepine (CBZ) levels in persons with epilepsy (PWE) from South India. METHODS: 115 PWE belong to South India origin who are on carbamazepine monotherapy were recruited. Genotyping of the two variants weredone using RT-PCR method. PWE who had seizure freedom for one year and their last dose which was not changed for one year duration were included and their plasma levels of CBZ and its active metabolite CBZ 10,11 epoxide were analysed by reverse phase HPLC. RESULTS: In EPHX1 c. 337 (T>C) polymorphism, the PWE carrying CC had lower plasma CBZ levels when compared to CT genotype (2.45 µg/ml vs 3.15 µg/ml. In UGT2B7*2, PWE carrying homozygous mutant TT had higher levels when compared with CT (3.09 µg/ml vs 2.74 µg/ml) genotype but found no statistical significance. Mutant genotype of EPHX1 (CC) had higher metabolic ratio compared to TT genotype (1.33 vs 1.17) but not found to be statistically significant. Mutant genotype of UGT2B7*2 (TT) was found to be having lower metabolic ratio when compared with CC genotype (1.18 vs 1.35; p value =0.08). CONCLUSION: PWE carrying EPHX1 c.337 T>C (rs1051740) and UGT2B7*2 (rs7439366) genetic polymorphisms did not affect the plasma CBZ levels and metabolic ratio of PWE of South Indian origin. However, this finding should be confirmed in a larger sample size which may help in optimization and personalized CBZ therapy in South Indians.


Subject(s)
Anticonvulsants , Epilepsy , Humans , Epoxide Hydrolases/genetics , Epoxide Hydrolases/therapeutic use , Glucuronosyltransferase/genetics , Glucuronosyltransferase/therapeutic use , Cross-Sectional Studies , Polymorphism, Single Nucleotide , Epilepsy/drug therapy , Epilepsy/genetics , Carbamazepine , Benzodiazepines/therapeutic use , Genetic Association Studies , Uridine Diphosphate/therapeutic use
2.
Drug Metab Pers Ther ; 38(2): 191-197, 2023 06 01.
Article in English | MEDLINE | ID: mdl-36853909

ABSTRACT

OBJECTIVES: Carbamazepine (CBZ) is a first-line antiseizure drug used for focal onset seizures. It exhibits inter-individual variability in plasma carbamazepine levels and there are both genetic and non-genetic factors having a role in the requirement of CBZ maintenance dose. The aim was to study the influence of EPHX1 c.337 T>C and UGT2B7*2 genetic polymorphisms on CBZ maintenance dose requirement in persons with epilepsy. METHODS: Persons with epilepsy (PWE) of both gender of age 15-65 years on carbamazepine monotherapy who had been taking same maintenance dose for one year were eligible. Five milliliter of venous blood was collected in 10% EDTA under aseptic precautions. After centrifugation, the cellular component was used for DNA extraction and genotyping. For three genotypes of EPHX1 c.337 T>C and UGT2B7*2, the differences in mean carbamazepine dose were analyzed using Analysis of Variance (ANOVA). An unpaired t-test was used to draw a comparison between the genotypes and CBZ maintenance dose requirement for dominant and recessive models of EPHX1 c.337 T>C and UGT2B7*2. A value of p<0.05 was considered to be statistically significant. RESULTS: For UGT2B7*2 (rs 7439366), CT required a higher dose (CT 626 mg/day and TT 523 mg/day) but not found to be significant (p-value 0.167). PWE carrying CT genotype of EPHX1 c.337 T>C had 62 mg higher dose when compared to homozygous mutant CC (590 mg/day for CT and 528 mg/day for CC) but p-value was not found to be significant (p-value 0.835). CONCLUSIONS: The results of our study done in 115 PWE showed there was a lack of association between SNPs of EPHX1 c.337 T>C, UGT2B7*2 and CBZ maintenance dose requirement in Southern part of India and this finding has to be confirmed in a larger sample size.


Subject(s)
Anticonvulsants , Epilepsy , Humans , Adolescent , Young Adult , Adult , Middle Aged , Aged , Cross-Sectional Studies , Carbamazepine/therapeutic use , Epilepsy/drug therapy , Epilepsy/genetics , Polymorphism, Single Nucleotide/genetics , Benzodiazepines/therapeutic use , India , Genetic Association Studies , Glucuronosyltransferase/genetics , Epoxide Hydrolases/genetics , Epoxide Hydrolases/therapeutic use
3.
Front Immunol ; 13: 1056397, 2022.
Article in English | MEDLINE | ID: mdl-36618349

ABSTRACT

ICOS/ICOSL and CD28/B7-1/B7-2 are T cell co-stimulators and CTLA-4 is an immune checkpoint inhibitor that play critical roles in the pathogenesis of neoplasia. Chitinase 3-like-1 (CHI3L1) is induced in many cancers where it portends a poor prognosis and contributes to tumor metastasis. Here we demonstrate that CHI3L1 inhibits the expression of ICOS, ICOSL and CD28 while stimulating CTLA-4 and the B7 moieties in melanoma lung metastasis. We also demonstrate that RIG-like helicase innate immune activation augments T cell co-stimulation, inhibits CTLA-4 and suppresses pulmonary metastasis. At least additive antitumor responses were seen in melanoma lung metastasis treated with anti-CTLA-4 and anti-CHI3L1 antibodies in combination. Synergistic cytotoxic T cell-induced tumor cell death and the heightened induction of the tumor suppressor PTEN were seen in co-cultures of T and tumor cells treated with bispecific antibodies that target both CHI3L1 and CTLA-4. Thus, CHI3L1 contributes to pulmonary metastasis by inhibiting T cell co-stimulation and stimulating CTLA-4. The simultaneous targeting of CHI3L1 and the CTLA-4 axis with individual and, more powerfully with bispecific antibodies, represent promising therapeutic strategies for pulmonary metastasis.


Subject(s)
Antibodies, Bispecific , Lung Neoplasms , Melanoma , Humans , CD28 Antigens , Antigens, CD , Melanoma/metabolism , Chitinase-3-Like Protein 1
4.
Cancer Sci ; 113(1): 349-361, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34738707

ABSTRACT

CD28, one of the costimulatory molecules, has a pivotal role in T-cell activation, and its expression is strictly regulated in normal T cells. Gain-of-function genetic alterations involving CD28 have been frequently observed in adult T-cell leukemia/lymphoma (ATLL). These abnormalities, such as CD28 fusions and copy number variations, may not only confer continuous, prolonged, and enhanced CD28 signaling to downstream pathways but also induce overexpression of the CD28 protein. In this study, 120 ATLL cases were examined by immunohistochemistry for CD28 and its ligands CD80 and CD86, and their expression on tumor cells was semiquantitatively evaluated. CD28 was overexpressed in 55 (46%) cases, and CD80 or CD86 (CD80/CD86) was infrequently overexpressed in 12 (11%). Compared with non-overexpressers, CD28 overexpressers showed a higher frequency of CD28 genetic alterations and had an increased number of CD80/CD86-positive non-neoplastic cells infiltrating tumor microenvironment. In the entire ATLL patient cohort, CD28 overexpressers showed a significantly poorer overall survival (OS) compared with non-overexpressers (P = .001). The same was true for a subgroup who were treated with multidrug regimens with or without mogamulizumab. CD28 overexpression had no prognostic impact in the group who received allogeneic hematopoietic stem cell transplantation. In the multivariate analysis for OS, CD28 overexpression was selected as an independent risk factor. These results suggest ATLL patients with CD28 overexpression have more aggressive clinical course and are more refractory to treatment with multidrug chemotherapy. CD28 overexpression appears to be a novel unfavorable prognostic marker in ATLL patients, and further prospective studies are warranted to establish its prognostic significance.


Subject(s)
B7-1 Antigen/metabolism , B7-2 Antigen/metabolism , CD28 Antigens/genetics , CD28 Antigens/metabolism , Leukemia-Lymphoma, Adult T-Cell/mortality , Up-Regulation , Adult , Aged , Aged, 80 and over , DNA Copy Number Variations , Female , Gene Expression Regulation, Neoplastic , Humans , Leukemia-Lymphoma, Adult T-Cell/genetics , Leukemia-Lymphoma, Adult T-Cell/metabolism , Male , Middle Aged , Prognosis , Survival Analysis , Tumor Microenvironment
5.
Protein Sci ; 30(9): 1958-1973, 2021 09.
Article in English | MEDLINE | ID: mdl-34191384

ABSTRACT

T-cell co-stimulation through CD28/CTLA4:B7-1/B7-2 axis is one of the extensively studied pathways that resulted in the discovery of several FDA-approved drugs for autoimmunity and cancer. However, many aspects of the signaling mechanism remain elusive, including oligomeric association and clustering of B7-2 on the cell surface. Here, we describe the structure of the IgV domain of B7-2 and its cryptic association into 1D arrays that appear to represent the pre-signaling state of B7-2 on the cell membrane. Super-resolution microscopy experiments on heterologous cells expressing B7-2 and B7-1 suggest, B7-2 form relatively elongated and larger clusters compared to B7-1. The sequence and structural comparison of other B7 family members, B7-1:CTLA4 and B7-2:CTLA-4 complex structures, support our view that the observed B7-2 1D zipper array is physiologically important. This observed 1D zipper-like array also provides an explanation for its clustering, and upright orientation on the cell surface, and avoidance of spurious signaling.


Subject(s)
B7-1 Antigen/chemistry , B7-2 Antigen/chemistry , CD28 Antigens/chemistry , CTLA-4 Antigen/chemistry , Amino Acid Sequence , Animals , B7-1 Antigen/genetics , B7-1 Antigen/metabolism , B7-2 Antigen/genetics , B7-2 Antigen/metabolism , Binding Sites , CD28 Antigens/genetics , CD28 Antigens/metabolism , CTLA-4 Antigen/genetics , CTLA-4 Antigen/metabolism , Cell Line, Tumor , Gene Expression , Humans , Mice , Models, Molecular , Neurons/cytology , Neurons/metabolism , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Protein Multimerization , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Alignment , Sequence Homology, Amino Acid
6.
Front Immunol ; 10: 942, 2019.
Article in English | MEDLINE | ID: mdl-31114583

ABSTRACT

Staphylococcal and streptococcal superantigens are virulence factors that cause toxic shock by hyperinducing inflammatory cytokines. Effective T-cell activation requires interaction between the principal costimulatory receptor CD28 and its two coligands, B7-1 (CD80) and B7-2 (CD86). To elicit an inflammatory cytokine storm, bacterial superantigens must bind directly into the homodimer interfaces of CD28 and B7-2. Recent evidence revealed that by engaging CD28 and B7-2 directly at their dimer interface, staphylococcal enterotoxin B (SEB) potently enhances intercellular synapse formation mediated by B7-2 and CD28, resulting in T-cell hyperactivation. Here, we addressed the question, whether diverse bacterial superantigens share the property of triggering B7-2/CD28 receptor engagement and if so, whether they are capable of enhancing also the interaction between B7-1 and CD28, which occurs with an order-of-magnitude higher affinity. To this end, we compared the ability of distinct staphylococcal and streptococcal superantigens to enhance intercellular B7-2/CD28 engagement. Each of these diverse superantigens promoted B7-2/CD28 engagement to a comparable extent. Moreover, they were capable of triggering the intercellular B7-1/CD28 interaction, analyzed by flow cytometry of co-cultured cell populations transfected separately to express human CD28 or B7-1. Streptococcal mitogenic exotoxin Z (SMEZ), the most potent superantigen known, was as sensitive as SEB, SEA and toxic shock syndrome toxin-1 (TSST-1) to inhibition of inflammatory cytokine induction by CD28 and B7-2 dimer interface mimetic peptides. Thus, superantigens act not only by mediating unconventional interaction between MHC-II molecule and T-cell receptor but especially, by strongly promoting engagement of CD28 by its B7-2 and B7-1 coligands, a critical immune checkpoint, forcing the principal costimulatory axis to signal excessively. Our results show that the diverse superantigens use a common mechanism to subvert the inflammatory response, strongly enhancing B7-1/CD28 and B7-2/CD28 costimulatory receptor engagement.


Subject(s)
B7-1 Antigen/immunology , B7-2 Antigen/immunology , Bacterial Toxins/toxicity , CD28 Antigens/immunology , Staphylococcus aureus/immunology , Streptococcus pyogenes/immunology , Superantigens/toxicity , T-Lymphocytes/immunology , Bacterial Toxins/immunology , HEK293 Cells , Humans , Inflammation/chemically induced , Inflammation/immunology , Inflammation/pathology , Lymphocyte Activation/drug effects , Superantigens/immunology , T-Lymphocytes/pathology
7.
J Virol ; 93(11)2019 06 01.
Article in English | MEDLINE | ID: mdl-30918073

ABSTRACT

In this article we report that the M2 protein encoded by the vaccinia virus is secreted as a homo-oligomer by infected cells and binds two central costimulation molecules, CD80 (B7-1) and CD86 (B7-2). These interactions block the ligation of the two B7 proteins to both soluble CD28 and soluble cytotoxic T-lymphocyte associated protein 4 (CTLA4) but favor the binding of soluble PD-L1 to soluble CD80. M2L gene orthologues are found in several other poxviruses, and the B7-CD28/CTLA4 blocking activity has been identified for several culture supernatants of orthopoxvirus-infected cells and for a recombinant myxoma virus M2 protein homolog (i.e., Gp120-like protein, or Gp120LP). Overall, these data indicate that the M2 poxvirus family of proteins may be involved in immunosuppressive activities broader than the NF-κB inhibition already reported (R. Gedey, X. L. Jin, O. Hinthong, and J. L. Shisler, J Virol 80:8676-8685, 2006, https://doi.org/10.1128/JVI.00935-06). A Copenhagen vaccinia virus with a deletion of the nonessential M2L locus was generated and compared with its parental virus. This M2L-deleted vaccinia virus, unlike the parental virus, does not generate interference with the B7-CD28/CTLA4/PD-L1 interactions. Moreover, this deletion did not affect any key features of the virus (in vitro replication, oncolytic activities in vitro and in vivo, and intratumoral expression of a transgene in an immunocompetent murine model). Altogether, these first results suggest that the M2 protein has the potential to be used as a new immunosuppressive biotherapeutic and that the M2L-deleted vaccinia virus represents an attractive new oncolytic platform with an improved immunological profile.IMPORTANCE The vaccinia virus harbors in its genome several genes dedicated to the inhibition of the host immune response. Among them, M2L was reported to inhibit the intracellular NF-κB pathway. We report here several new putative immunosuppressive activities of M2 protein. M2 protein is secreted and binds cornerstone costimulatory molecules (CD80/CD86). M2 binding to CD80/CD86 blocks their interaction with soluble CD28/CTLA4 but also favors the soluble PD-L1-CD80 association. These findings open the way for new investigations deciphering the immune system effects of soluble M2 protein. Moreover, a vaccinia virus with a deletion of its M2L has been generated and characterized as a new oncolytic platform. The replication and oncolytic activities of the M2L-deleted vaccinia virus are indistinguishable from those of the parental virus. More investigations are needed to characterize in detail the immune response triggered against both the tumor and the virus by this M2-defective vaccinia virus.


Subject(s)
B7-1 Antigen/metabolism , B7-H1 Antigen/metabolism , Vaccinia virus/metabolism , Animals , Antigens, CD/metabolism , B7-1 Antigen/genetics , B7-2 Antigen/genetics , B7-2 Antigen/metabolism , CD28 Antigens/metabolism , CTLA-4 Antigen/metabolism , Cell Adhesion Molecules , Cell Line , Chick Embryo , Humans , Immunoconjugates , Interleukin-2/metabolism , Lymphocyte Activation/immunology , Membrane Glycoproteins/metabolism , Mice , NF-kappa B/metabolism , Vaccinia/genetics , Vaccinia/metabolism , Vaccinia virus/genetics , Viral Proteins/metabolism
8.
Chinese Journal of Immunology ; (12): 140-145, 2019.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-744622

ABSTRACT

Objective: To generate mouse B7-2 gene RNAi lentivirus and study its interference effects on B7-2 expression and T lymphocytes proliferation induced by dendritic cells. Methods: Three sequences specific targeting B7-2 gene and one non-specific sequence were respectively synthesized, and inserted into lentiviral vector, then the recombinant vectors were sequencing. 293 T cells were co-transfected with lentiviral expression plasmid and packaging plasmids to produce recombinant lentivirus which titre was checked according to the expression level of green fluorescent protein ( GFP). Bone marrow cells from C57 BL/6 mice were isolated to differentiate into DCs at the present of GM-CSF, IL-4 and LPS for 48 h, then morphology and phenotypic was identified. DCs were infected by recombinant RNAi lentivirus and then the efficiency of infection and the expression of B7-2 on the surface of DCs were detected by flow cytometry. Effects on the proliferation of T cells were detected by co-culturing with DCs which were infected by B7-2 RNAi lentivirus and murine spleen T cells in vitro. Results: DNA sequencing confirmed that three B7-2 RNAi and one non-specific recombinant lentiviral transfer plasmids were successfully constructed, the titer of recombinant lentivirus was ( 2-4) × 108 TU/ml. The recombinant lentivirus could effectively infect DC and inhibit the expression of B7-2. After the B7-2 recombinant lentivirus infection, the ability of DCs to stimulate the proliferation of T cells decreased obviously ( P<0. 05). Conclusion: The lentiviral B7-2 gene RNAi vector can effectively silence the expression of B7-2 on the surface of DCs and inhibit the proliferation effect of T cells induced by DCs.

9.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-746047

ABSTRACT

Objective To prepare a mouse anti-human B7-2 monoclonal antibody ( McAb) and to study its effect on the induction of death-related molecules on the surface of tumor cells. -ethods Trans-genic cells, L929-B7-2, were used as the immunogen to immunize BALB/c mice. Through cell fusion, mul-tiple screening by immunofluorescence labeling and continuous subcloning, the hybridoma secreting B7-2 McAb was obtained. Biological characteristics of the McAb were analyzed using Ig subclass identification test strip, antigenic site competition inhibition assay and specific cell membrane molecules binding test. McAb was prepared through inducing ascites in vivo and then purified by protein G affinity chromatography. The purified McAb was co-cultured with 8266 cells, naturally expressing B7-2 molecules, to observe the expres-sion of Fas and FasL on cell surface by flow cytometry ( FCM) . Results The prepared B7-2 McAb labeled as 12G4 was successfully obtained with a titer of 0. 1 μg/5×105 cells. Its heavy and light chains were IgG2b and κ, respectively. The concentration of the purified ascites-derived antibody was 1. 61 mg/ml. FCM re-sults showed that the 12G4 McAb recognized cell membrane molecules well with a positive binding rate of 89. 6% to 8266 cells. The mean value of the Fas molecule on the cell surface increased after incubating with 20 μg/ml of 12G4 McAb for 12 h and reached the peak of 62575. 8 at 48 h, which was significantly higher than the maximum value of 57135. 4 in the IgG control group (P<0. 05). After culturing the cells with 20μg/ml of 12G4 McAb for 12 h, the expression of FasL on the cell surface also increased and reached the maximum of 7. 98% at 48 h, which was significantly higher than the 1. 10% in the IgG control group ( P<0. 05). Conclusions B7-2 McAb was successfully prepared. It could be used to induce the expression of some death-related molecules on the surface of tumor cells.

10.
Toxins (Basel) ; 10(11)2018 Nov 06.
Article in English | MEDLINE | ID: mdl-30404186

ABSTRACT

During severe bacterial infections, death and disease are often caused by an overly strong immune response of the human host. Acute toxic shock is induced by superantigen toxins, a diverse set of proteins secreted by Gram-positive staphylococcal and streptococcal bacterial strains that overstimulate the inflammatory response by orders of magnitude. The need to protect from superantigen toxins led to our discovery that in addition to the well-known MHC class II and T cell receptors, the principal costimulatory receptor, CD28, and its constitutively expressed coligand, B7-2 (CD86), previously thought to have only costimulatory function, are actually critical superantigen receptors. Binding of the superantigen into the homodimer interfaces of these costimulatory receptors greatly enhances B7-2/CD28 engagement, leading to excessive pro-inflammatory signaling. This finding led to the design of short receptor dimer interface mimetic peptides that block the binding of superantigen and thus protect from death. It then turned out that such a peptide will protect also from Gram-negative bacterial infection and from polymicrobial sepsis. One such CD28 mimetic peptide is advancing in a Phase 3 clinical trial to protect from lethal wound infections by flesh-eating bacteria. These host-oriented therapeutics target the human immune system itself, rendering pathogens less likely to become resistant.


Subject(s)
Bacterial Toxins/immunology , CD28 Antigens/immunology , Drug Development , Superantigens/immunology , Animals , Humans
11.
Article in English | MEDLINE | ID: mdl-28286804

ABSTRACT

Formation of the costimulatory axis between the B7-2 and CD28 coreceptors is critical for T-cell activation. Superantigens, Gram-positive bacterial virulence factors, cause toxic shock and sepsis by hyperinducing inflammatory cytokines. We report a novel role for costimulatory receptors CD28 and B7-2 as obligatory receptors for superantigens, rendering them therapeutic targets. We show that by engaging not only CD28 but also its coligand B7-2 directly, superantigens potently enhance the interaction between B7-2 and CD28, inducing thereby T-cell hyperactivation. Using a conserved twelve amino-acid domain, superantigens engage both B7-2 and CD28 at their homodimer interfaces, sites far removed from where these receptors interact, implying that inflammatory signaling can be controlled through the receptor homodimer interfaces. Short B7-2 and CD28 dimer interface mimetic peptides bind diverse superantigens, prevent superantigen binding to cell-surface B7-2 or CD28, attenuate inflammatory cytokine overexpression, and protect mice from lethal superantigen challenge. Thus, superantigens induce a cytokine storm by mediating not only the interaction between MHC-II molecule and T-cell receptor but critically, by promoting B7-2/CD28 coreceptor engagement, forcing the principal costimulatory axis to signal excessively. Our findings highlight the B7/CD28 interaction as a bottleneck in signaling for expression of inflammatory cytokines. B7-2 and CD28 homodimer interface mimetic peptides prevent superantigen lethality by blocking the superantigen-host costimulatory receptor interaction.

12.
Proc Natl Acad Sci U S A ; 113(42): E6437-E6446, 2016 10 18.
Article in English | MEDLINE | ID: mdl-27708164

ABSTRACT

Full T-cell activation requires interaction between the costimulatory receptors B7-2 and CD28. By binding CD28, bacterial superantigens elicit harmful inflammatory cytokine overexpression through an unknown mechanism. We show that, by engaging not only CD28 but also its coligand B7-2 directly, superantigens potently enhance the avidity between B7-2 and CD28, inducing thereby T-cell hyperactivation. Using the same 12-aa ß-strand-hinge-α-helix domain, superantigens engage both B7-2 and CD28 at their homodimer interfaces, areas remote from where these coreceptors interact, implying that inflammatory signaling can be controlled through the receptor homodimer interfaces. Short B7-2 dimer interface mimetic peptides bind diverse superantigens, prevent superantigen binding to cell-surface B7-2 or CD28, attenuate inflammatory cytokine overexpression, and protect mice from lethal superantigen challenge. Thus, superantigens induce a cytokine storm not only by mediating the interaction between MHC-II molecule and T-cell receptor but also, critically, by promoting B7-2/CD28 coreceptor engagement, forcing the principal costimulatory axis to signal excessively. Our results reveal a role for B7-2 as obligatory receptor for superantigens. B7-2 homodimer interface mimotopes prevent superantigen lethality by blocking the superantigen-host costimulatory receptor interaction.


Subject(s)
B7-2 Antigen/metabolism , CD28 Antigens/metabolism , Cytokines/metabolism , Inflammation Mediators/metabolism , Superantigens/immunology , Amino Acid Sequence , Animals , B7-2 Antigen/chemistry , B7-2 Antigen/genetics , Cell Line, Tumor , Cytokines/genetics , Enterotoxins/chemistry , Enterotoxins/immunology , Female , Humans , Mice , Models, Molecular , Molecular Mimicry , Peptides/chemistry , Peptides/immunology , Peptides/metabolism , Protein Binding/immunology , Protein Conformation, alpha-Helical , Protein Interaction Domains and Motifs , Protein Multimerization , Recombinant Fusion Proteins , Signal Transduction , Superantigens/chemistry , Superantigens/metabolism
13.
Hum Vaccin Immunother ; 10(1): 184-91, 2014.
Article in English | MEDLINE | ID: mdl-24096573

ABSTRACT

Toxoplasma gondii infection occurs commonly in humans and other warm-blooded animals. Its serious impact on public health and livestock sectors makes the development of an effective vaccine particularly important. In the current study, we constructed a multiantigenic DNA vaccine expressing ROP16 and GRA7 of T. gondii and evaluated the protective efficacy of these two fragments with or without a plasmid encoding murine costimulatory molecule B7-2. These recombinant eukaryotic expression plasmids were termed pROP16, pGRA7, pROP16-GRA7 and pB7-2, respectively. After intramuscular immunization in Kunming mice, we assessed the immune response using cytokine and antibody determinations, T lymphocyte subsets analysis, and the survival times of mice post acute T. gondii challenge. The results showed that mice immunized with the multiantigenic DNA vaccine pROP16-GRA7 gained higher levels of IgG titers and IgG2a subclass titers, production of IFN-γ, percentage of CD8+ T cells and median survival times against the acute infection of T. gondii compared with those of mice administered with pROP16 or pGRA7 and those in control groups. Moreover, the adjuvant pB7-2 formulated with DNA vaccine boosted these humoral and cellular (Th1, CD8+ T cell) immune responses. Therefore, it might be a promising genetic adjuvant to DNA vaccine against T. gondii for further investigation.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Antigens, Protozoan/immunology , B7-2 Antigen/administration & dosage , Protein-Tyrosine Kinases/immunology , Protozoan Proteins/immunology , Protozoan Vaccines/immunology , Vaccines, DNA/immunology , Adjuvants, Immunologic/genetics , Animals , Antibodies, Protozoan/blood , Antigens, Protozoan/genetics , B7-2 Antigen/genetics , Cytokines/metabolism , Female , Leukocytes, Mononuclear/immunology , Protein-Tyrosine Kinases/genetics , Protozoan Proteins/genetics , Protozoan Vaccines/administration & dosage , Protozoan Vaccines/genetics , Survival Analysis , T-Lymphocyte Subsets/immunology , Vaccines, DNA/administration & dosage , Vaccines, DNA/genetics
14.
Article in English | MEDLINE | ID: mdl-23891730

ABSTRACT

Studies suggest that inflammation is involved in the neurodegenerative cascade of dementias. Immunological mechanisms may be part of the pathophysiological process in frontotemporal dementia (FTD), but up till now only vague evidence of such mechanisms has been presented. The B7- CD28/CTLA-4 pathway is an important immunological signaling pathway involved in modulation of T cell activation. The aim of this study was to compare the expression of molecules associated with co-stimulatory signaling in peripheral blood mononuclear cells (PBMC) of FTD to Alzheimer disease (AD) and control groups. Our results confirm the previous demonstrated increased expression of CD80 in CD14+ Alzheimer patients T cells but show, for the first time, a reduction in the expression of CTLA-4 in CD4+ FTD cells. As CTLA-4 is the most potent negative regulators of T-cell activation we speculated that peripheral T lymphocytes in FTD are more activated and this could be involved in the neurodegeneration observed in this dementia.


Subject(s)
Alzheimer Disease/pathology , CTLA-4 Antigen/metabolism , Frontotemporal Dementia/pathology , T-Lymphocytes/metabolism , Antigens, CD/metabolism , B-Lymphocytes/metabolism , Brazil , Female , HLA-DR Antigens/metabolism , Humans , Male
15.
Cell Immunol ; 285(1-2): 69-75, 2013.
Article in English | MEDLINE | ID: mdl-24099792

ABSTRACT

B7.1 and B7.2 are homologous costimulatory molecules expressed predominantly on antigen-presenting cells (APC). Interaction of these B7 molecules with CD28 and CTLA-4 expressed on T cells is a critical step in T cell activation. Previously, we reported that Mycobacterium tuberculosis infection in the combined absence of B7.1 and B7.2 resulted in impaired host resistance to the pathogen. Despite their structural similarities, the individual contribution of B7.1 and B7.2 to the development of pathogenic T cells in autoimmune diseases and protective T cells in infectious diseases is markedly distinct. In the current study, we therefore examined whether B7.1 and B7.2 have discrete, equivalent, or overlapping functions in mediating host resistance to M. tuberculosis. We found that the individual absence of either B7.1 or B7.2 had no effect on the ability of the host to contain bacterial load in the lungs, recruit immune cells to the lung, generate a Th1 response, or induce a pulmonary granulomatous response. These results indicate that B7.1 and B7.2 molecules have equal ability to mediate host resistance to M. tuberculosis, underscoring the therapeutic utility of individual B7.1 and B7.2 antagonists in treating inflammatory disorders.


Subject(s)
B7-1 Antigen/metabolism , B7-2 Antigen/metabolism , Lymphocyte Activation/immunology , Mycobacterium tuberculosis/immunology , Tuberculosis/immunology , Animals , Antigen-Presenting Cells/metabolism , B7-1 Antigen/deficiency , B7-1 Antigen/genetics , B7-2 Antigen/deficiency , B7-2 Antigen/genetics , CD28 Antigens/immunology , CTLA-4 Antigen/immunology , Cells, Cultured , Cytokines/biosynthesis , Cytokines/immunology , Female , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Tuberculosis/prevention & control
16.
J Autoimmun ; 45: 58-67, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23850635

ABSTRACT

The non-obese diabetic (NOD) mouse is susceptible to the development of autoimmune diabetes but also multiple other autoimmune diseases. Over twenty susceptibility loci linked to diabetes have been identified in NOD mice and progress has been made in the definition of candidate genes at many of these loci (termed Idd for insulin-dependent diabetes). The susceptibility to multiple autoimmune diseases in the NOD background is a unique opportunity to examine susceptibility genes that confer a general propensity for autoimmunity versus susceptibility genes that control individual autoimmune diseases. We previously showed that NOD mice deficient for the costimulatory molecule B7-2 (NOD-B7-2KO mice) were protected from diabetes but spontaneously developed an autoimmune peripheral neuropathy. Here, we took advantage of multiple NOD mouse strains congenic for Idd loci to test the role of these Idd loci the development of neuropathy and determine if B6 alleles at Idd loci that are protective for diabetes will also be for neuropathy. Thus, we generated NOD-B7-2KO strains congenic at Idd loci and examined the development of neuritis and clinical neuropathy. We found that the NOD-H-2(g7) MHC region is necessary for development of neuropathy in NOD-B7-2KO mice. In contrast, other Idd loci that significantly protect from diabetes did not affect neuropathy when considered individually. However, we found potent genetic interactions of some Idd loci that provided almost complete protection from neuritis and clinical neuropathy. In addition, defective immunoregulation by Tregs could supersede protection by some, but not other, Idd loci in a tissue-specific manner in a model where neuropathy and diabetes occurred concomitantly. Thus, our study helps identify Idd loci that control tissue-specific disease or confer general susceptibility to autoimmunity, and brings insight to the Treg-dependence of autoimmune processes influenced by given Idd region in the NOD background.


Subject(s)
Diabetes Mellitus, Type 1/genetics , Genetic Loci , Guillain-Barre Syndrome/genetics , T-Lymphocytes, Regulatory/immunology , Alleles , Animals , B7-2 Antigen/genetics , Cells, Cultured , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/immunology , Female , Genetic Loci/genetics , Genetic Predisposition to Disease/genetics , Guillain-Barre Syndrome/complications , Guillain-Barre Syndrome/immunology , Histocompatibility Antigens Class II/genetics , Interferon-gamma/metabolism , Male , Mice , Mice, Congenic , Mice, Inbred C57BL , Mice, Inbred NOD , Mice, Knockout , Organ Specificity , Sex Factors
17.
Mol Med Rep ; 6(6): 1301-4, 2012 12.
Article in English | MEDLINE | ID: mdl-22965188

ABSTRACT

The aim of this study was to investigate the role of the cell surface expression levels of HLA class I and II molecules, the costimulatory molecules CD80/B7-1 and CD86/B7-2, and the adhesion molecules CD54 and CD58 during cervical carcinogenesis. The expression levels of MHC class I and II molecules, the costimulatory molecules CD80/B7-1 and CD86/B7-2 and the adhesion molecules CD54 and CD58 on CD14+ peripheral blood monocytes (PBMs) from 21 cases of cervical intraepithelial neoplasia (CIN) II-III, 51 squamous cervical carcinomas (SCCs) and 18 healthy controls were analyzed using flow cytometry analysis. We found increased expression levels of HLA-DR (p=0.000), HLA-DQ (p=0.000), CD86/B7-2 (p=0.002) and CD58 (p=0.000) on PBMs from patients with SCC and CIN II-III, compared with healthy control subjects, whereas no significant difference existed in the expression levels of HLA class I antigens, HLA-DP CD80/B7-1 and CD54. Upregulated expression levels of HLA-DR, HLA-DQ, CD86/B7-2 and CD58 were associated with disease progression, indicating that an increased expression of HLA-DR, HLA-DQ, CD86/B7-2 and CD58 on PBMs may be correlated with the evolution of cervical cancer.


Subject(s)
Carcinoma, Squamous Cell/metabolism , Histocompatibility Antigens Class II/metabolism , Monocytes/metabolism , Uterine Cervical Dysplasia/metabolism , Uterine Cervical Neoplasms/metabolism , Adult , B7-1 Antigen/metabolism , B7-2 Antigen/metabolism , CD58 Antigens/metabolism , Carcinoma, Squamous Cell/pathology , Female , HLA-DQ Antigens/metabolism , HLA-DR Antigens/metabolism , Humans , Intercellular Adhesion Molecule-1/metabolism , Middle Aged , Monocytes/cytology , Up-Regulation , Uterine Cervical Neoplasms/pathology , Uterine Cervical Dysplasia/pathology
18.
Clin Med Oncol ; 2: 257-65, 2008.
Article in English | MEDLINE | ID: mdl-21892287

ABSTRACT

Cancer vaccines have always been in the scope of gene therapy research. One of the most successful approaches has been working with genetically modified tumor cells. However, to become a clinical reality, tumor cells must suffer a long and risky process from the extraction from the patient to the reimplantation as a vaccine. In this work, we explain our group's approach to reduce the cell number required to achieve an immune response against a melanoma murine model, employing bead-selected B16 tumor cells expressing GM-CSF and B7.2.

19.
Article in Korean | WPRIM (Western Pacific) | ID: wpr-196282

ABSTRACT

OBJECTIVE: To determine phenotypic and functional characteristics of memory B cells in patients with systemic lupus erythematosus (SLE). METHODS: The percentage of memory B cell subsets in peripheral blood mononuclear cells (PBMC) from normal control (n=11), inactive (n=15) and active (n=10) SLE patients was determined by Fluorescence Activated Cell Sorter (FACS). In addition, the activation status of memory B cells was measured by the surface expression of CD86 (B7-2). The production of antibodies to chromatin and dsDNA (IgG and IgM type) by isolated memory B cell subsets was examined by enzyme-linked immunosorbent assay (ELISA). RESULTS: In this study, we analyzed 2 subtypes of memory B cells: FSC (Forward Side Scatter)(low) and FSC(high) memory B cell. The percentage of both subtypes from active and inactive SLE patients was significantly reduced compared to that of normal controls (p<0.01). In addition, the expression of activation markers, CD86 on FSC(high) memory B cells from active SLE patients was higher than those of inactive SLE patients and normal controls (p=0.014). Upon stimulation with CpG and IL-15 in vitro for 8 days, isolated FSC(high) memory B cells from active SLE patients revealed augmented production of autoantibodies to chromatin and dsDNA. CONCLUSION: Our results suggest that abnormally activated FSC(high) memory B cells from active SLE patients might be involved in spontaneous production of autoantibodies and induce transition from inactive to active phase of the patients.


Subject(s)
Humans , Antibodies , Autoantibodies , B-Lymphocyte Subsets , B-Lymphocytes , Chromatin , Enzyme-Linked Immunosorbent Assay , Fluorescence , Immunoglobulin M , Interleukin-15 , Lupus Erythematosus, Systemic , Memory
20.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-564753

ABSTRACT

Objective To study the effects of IFN-?on expression of B7 molecules in human lung adenocarcinoma cell line cultured in vitro.Methods Human lung adenocarcinoma SPC-A-1 cells were incubated in the medium with IFN-?respectively.Cell proliferation effect was measured by MTT assay;apoptosis was detected with flow cytometry assay;expression of B7-1 and B7-2 mRNA was determined by RT-PCR.Results Compared with those of control group,MTT shows that IFN-?could reduce the SPC-A-1 cell proliferation.FCM shows the apoptosis rate in the IFN-? group was significantly higher,but there is no different changes in each concentration group.Compared with the control group,expression of B7-1 and B7-2 significantly increased in the IFN-?group,and the expression was not correlated with the concentration of IFN-?in each control group.Conclusion IFN-?can inhibit cell proliferation and induce apoptosis in SPC-A-1 cell line.IFN-?markedly enhance the expression of B7-1 and B7-2 in SPC-A-1 line.The apoptosis may be mediated by up-expression of gene B7-1 and B7-2.

SELECTION OF CITATIONS
SEARCH DETAIL