Many specific therapeutic antibody drugs have been developed for different indications. In drug development, it has been found that the antibody isotype framework can not only affect the physical and chemical properties of therapeutic antibodies, but also influence the activity and therapeutic effect. As a result, IgG isotype selection should be considered carefully in antibody drug development strategies. Because of the unique biological characteristics, IgG4 isotype has been used in some therapeutic antibodies for which effector functions are not desired. In order to provide new ideas for the development of antibody drugs, the research and application progress of IgG4 isotype in therapeutic antibody drug development has been reviewed.
Drug Design ; Humans ; Immunoglobulin G ; chemistry ; pharmacology

Snake antivenomimmunoglobulins are considered to be the most efficient drugs in snake envenomings. Most snake antivenomimmunoglobulins all over the world are still prepared by fragmentation of polyclonal antibodies isolated from hyper-immunized horse serum till now. In this review, we retrospect the history of snake antivenomimmunoglobulins, analysis the present situation and pay the close attention on the key technological links in the process of research and manufacturing, such as properties of IgG and its fragments, selection and preparation of immunogen, optimization of immunization schedule and protein isolation and purification, which can be available for the reference in the research and development of snake antivenom.
Animals ; Antivenins ; pharmacology ; Humans ; Immunoglobulin G ; pharmacology ; Snake Bites ; drug therapy ; Snakes

OBJECTIVETo investigate which of the two immunoglobulin (Ig)-like domains, the immunoglobulin variable region homologous domain IgV (hB7.2 IgV) and the immunoglobulin constant region homologous domain IgC (hB7.2 IgC) on the human B7.2 molecule contains receptor binding sites, and to evaluate whether the B7.2 protein expressed in bacteria has biological activity in vitro.

METHODSThree fragments of hB7.2 IgV,hB7.2 IgC and the complete extracellular region of human B7.2 containing both the IgV and IgC domains,hB7.2 Ig (V+C), were amplified by PCR and subcloned into pGEM-Teasy. Three recombinants,pGEX-4T-3-hB7.2 IgV,pGEX-4T-3-hB7.2 IgC and pGEX-4T-3-hB7.2 Ig (V+C), were generated by cloning the fragments into a prokaryote expression plasmid (pGEX-4T-3) and transformed into the host strain E. coli DH5alpha. The relevant target fusion proteins consisting of GST and hB7.2 IgV,hB7.2 IgC and hB7.2 Ig (V+C), were identified by SDS-PAGE and Western blotting. With the presence of the first signal imitated by anti-CD3 antibody, T cell activation was observed by exposing purified T lymphocytes to each soluble form of the three bacterially-produced human B7.2 fusion proteins by [(3)H]-TdR incorporation.

RESULTSThree recombinant fusion proteins of human B7.2, GST-hB7.2 IgV, GST-hB7.2 IgC and GST-hB7.2 Ig (V+C) were produced and detected in inclusion body form from engineered bacteria. With the first signal present,T lymphocytes proliferated when co-stimulated by bacterially-produced either GST-hB7.2 Ig (V+C) or GST-hB7.2 IgV fusion proteins, but not by GST-hB7.2 IgC.

CONCLUSIONSFunctional human B7.2 fusion protein can be produced in bacteria. The IgV-like domain of human B7.2 is sufficient for B7.2 to interact with its counter-receptors and co-stimulate T lymphocytes.

Antigens, CD ; pharmacology ; B7-2 Antigen ; Escherichia coli ; genetics ; Humans ; Immunoglobulin Constant Regions ; pharmacology ; Immunoglobulin Variable Region ; pharmacology ; Lymphocyte Activation ; Membrane Glycoproteins ; pharmacology ; Plasmids ; Recombinant Fusion Proteins ; pharmacology ; T-Lymphocytes ; immunology

OBJECTIVETo examine the effect of aqueous extracts of Scutellaria baicalensis Georgi and Radix paeoniae Alba on periodontitis mice and compare the results of the two herbs for the treatment of the periodontitis mice.

METHODSSixty-four SPF 12-week-old male Kunming mice were selected and randomly divided into four groups:Control group(C); Experimental periodontitis group (P):the peridontitis models in Kunming mice were prepared by wrapping silk ligature and inoculating with putative periodontopathic bacteria; Scutellaria baicalensis Georgi treatment group (SG): periodontitis was induced by the same method described above, the mice were gavaged with Scutellaria baicalensis Georgi; Radix paeoniae Alba treatment group (RG): periodontitis was induced by the same method described above, the mice were gavaged with Radix paeoniae Alba.Four mice were sacrificed at each time point of the end of 4, 6, 8 and 10 weeks in each group. The histopathological changes of periodontal tissue were observed under microscope with HE staining. The level of serum IgG1 and IgG2a was measured by enzyme-linked immunosorbent assay (ELISA) .

RESULTSA serious inflammatory response, alveolar progressive absorption and a large number of osteoclasts were observed in the experimental periodontitis group.However, in SG and RG, the inflammation of the periodontal tissue was decreased and tissue repair was significant. The level of serum IgG2a in SG (6 week:0.934 ± 0.006, 8 week:0.743 ± 0.009, 10 week: 0.674 ± 0.008) and RG (6 week: 1.023 ± 0.032, 8 week: 0.851 ± 0.032, 10 week:0.790 ± 0.009) was significantly decreased after the mice were gavaged with the two herbs(P < 0.01). The level of serum IgG2a in SG was significantly lower than that of RG (P < 0.01). The level of serum IgG1 in SG (6 week: 0.314 ± 0.006, 8 week: 0.344 ± 0.004, 10 week: 0.367 ± 0.006) and RG (6 week: 0.287 ± 0.005, 8 week: 0.303 ± 0.058, 10 week: 0.336 ± 0.006) were significantly increased (P < 0.01). The level of serum IgG1 in SG was significantly higher than that of RG (P < 0.01).

CONCLUSIONSBoth the aqueous extracts of Scutellaria baicalensis Georgi and Radix paeoniae Alba showed therapeutic effect on periodontitis in mice.Scutellaria baicalensis Georgi was more effective than Radix paeoniae Alba.

Aconitum ; Animals ; Immunoglobulin G ; metabolism ; Male ; Mice ; Paeonia ; Periodontitis ; metabolism ; Plant Extracts ; pharmacology ; Scutellaria baicalensis ; Water

Urticaria is an immune-mediated allergic disease. This study explored the effect of Jingfang Mixture on spleen T lymphocyte subsets of urticaria mice. A total of 50 Kunming mice were randomized into normal group(C), model group(V), and low-(JF-L, 0.5 g·kg~(-1)), medium-(JF-M, 1 g·kg~(-1)) and high-dose(JF-H, 2 g·kg~(-1)) Jingfang Mixture groups, with 10 mice in each group. The mixture of ovalbumin and aluminum hydroxide(0.1 mg + 0.1 mL) was used(intraperitoneal injection) to induce urticaria in mice. The administration began 6 days after the first immunization, and the second immunization was carried out 10 days after the first immunization. The pruritus index was detected within 30 min after the second immunization. The administration lasted 21 days. After 21 days, the serum was taken to detect the total IgE level. Based on hematoxylin and eosin(HE) staining, the pathological changes of skin tissue were observed, and Western blot was used to detect the levels of p-Janus kinase 2(JAK2)/JAK2 and p-signal transducer and activator of transcription 3(STAT3)/STAT3 in skin tissue. The spleen was taken to detect the spleen index, and flow cytometry was employed to determine the expression of lymphocyte subsets. The results showed that group V had obvious pathological changes in skin tissue compared with group C. Moreover, group V showed more scratches, higher spleen index, and higher level of total serum IgE than group C. In addition, higher levels of p-JAK2 and p-STAT3, lower proportions of CD4~+T, Th1, and Treg, higher proportions of CD8~+T, Th2, and Th17, and lower ratios of CD4~+/CD8~+, Th1/Th2, and Terg/Th17 were observed in group V than in group C. Compared with group V, each administration group showed alleviation of the pathological morphology of skin tissue, obvious epidermal thickening, relatively intact collagen fiber structure of dermal reticular layer, alleviated edema, and relief of vasodilation and peripheral inflammatory cell infiltration. Moreover, less scratching, lower spleen index, lower p-JAK2/JAK2 and p-STAT3/STAT3 were observed in the administration groups than in group V. JF-M group and JF-H group demonstrated lower levels of total IgE, larger proportions of CD4~+T, Th1, and Treg, smaller proportions of CD8~+ T, Th2, and Th17, and higher ratios of CD4~+/CD8~+, Th1/Th2, and Terg/Th17. In conclusion, Jingfang Mixture may improve the symptoms of urticaria mice by regulating the balance of spleen T lymphocyte subsets through JAK2-STAT3 signaling pathway.
Mice ; Animals ; Janus Kinase 2/pharmacology* ; Spleen ; T-Lymphocyte Subsets/metabolism* ; Signal Transduction ; Urticaria ; Immunoglobulin E

Immunoglobulin G4-related sialadenitis (IgG4-RS) is an immune-mediated fibro-inflammatory disease and the pathogenesis is still not fully understood. The aim of this study was to explore the role and mechanism of interleukin-13 (IL-13) in the cellular senescence during the progress of IgG4-RS. We found that the expression of IL-13 and IL-13 receptor α1 (IL-13Rα1) as well as the number of senescent cells were significantly higher in the submandibular glands (SMGs) of IgG4-RS patients. IL-13 directly induced senescence as shown by the elevated activity of senescence-associated β-galactosidase (SA-β-gal), the decreased cell proliferation, and the upregulation of senescence markers (p53 and p16) and senescence-associated secretory phenotype (SASP) factors (IL-1β and IL-6) in SMG-C6 cells. Mechanistically, IL-13 increased the level of phosphorylated signal transducer and activator of transcription 6 (p-STAT6) and mitochondrial-reactive oxygen species (mtROS), while decreased the mitochondrial membrane potential, ATP level, and the expression and activity of superoxide dismutase 2 (SOD2). Notably, the IL-13-induced cellular senescence and mitochondrial dysfunction could be inhibited by pretreatment with either STAT6 inhibitor AS1517499 or mitochondria-targeted ROS scavenger MitoTEMPO. Moreover, IL-13 increased the interaction between p-STAT6 and cAMP-response element binding protein (CREB)-binding protein (CBP) and decreased the transcriptional activity of CREB on SOD2. Taken together, our findings revealed a critical role of IL-13 in the induction of salivary gland epithelial cell senescence through the elevated mitochondrial oxidative stress in a STAT6-CREB-SOD2-dependent pathway in IgG4-RS.
Cellular Senescence/genetics* ; Humans ; Immunoglobulin G/metabolism* ; Interleukin-13/pharmacology* ; Mitochondria/metabolism* ; Sialadenitis/metabolism*

The experiment was conducted to prepare chitosan nanoparticles (CNP), to entrap VRMIL-2 with CNP, the eukaryotic VR1020 expression plasmid containing murine IL-2 gene (mlL-2), and to investigate the expression in vivo and the regulatory effect of mIL-2 on immune-response and immuno-protection in mice inoculated muscularly with CNP entrapped VMIL-2 at 21 days old. The results showed that IgG, IgM and IgA contents increased to different degrees in the sera from the inoculated mice, which were remarkably higher than those of the controls inoculated VR1020 packed with CNP (P<0.05); so were the IL-2, IL-4 and IL-6 contents in the sera of the immunized mice. The number of white blood cells and lymphocytes significantly increased respectively in the vaccinated mice, compared with those of controls. These mice were orally challenged with virulent E. coli 35 days post-inoculation, and all the immune responses were significantly higher than those of the control except the number of neutrophils. The mice inoculated with VRMIL-2 survived healthily, while the mice of control group were ill with the evident lesions. Although there are no remarkable differences between the cellular and humoral immune indexes of mice inoculated with CNP-VRMIL-2 and nude VRMIL-2 (P>0.05), the dosage of CNP-VRMIL-2 is only one fifth of the VRMIL-2. These indicated that entrapment of mIL-2 gene with chitosan nanoparticles could remarkably enhance the expression of mIL-2 in vivo, and significantly raise the levels of cellular and humoral immune, and increase the resistance of mice against E. coli infection. The results suggested that chitosan nanoparticles and IL-2 gene could be used as an effective immunoenhancer to increase the immunity of animals against infection.
Adjuvants, Immunologic ; pharmacology ; Animals ; Chitosan ; pharmacology ; Escherichia coli Infections ; immunology ; prevention & control ; Female ; Immunoglobulin G ; blood ; Interleukin-2 ; biosynthesis ; genetics ; pharmacology ; Mice ; Nanostructures

OBJECTIVEUsing monoclonal antibody (mAb) Fab' fragment to develop mAb immunoconjugates for cancer.

METHODSFab' fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithiothreitol (DT), while Fab' fragment of mAb 3D6 was obtained by digestion of the antibody with ficin and subsequently reduced by beta-mercaptoethanol. The conjugation between Fab' fragment and pingyangmycin (PYM), an antitumor antibiotic, was mediated by dextran T-40. Immunoreactivity of Fab'-PYM conjugates with cancer cells was determined by ELISA, and the cytotoxicity of those conjugates to cancer cells was determined by clonogenic assay. Antitumor effects of the Fab'-PYM conjugates were evaluated by subcutaneously transplanted tumors in mice.

RESULTSThe molecular weight of Fab' fragment was approximately 53 kD, while the average molecular weight of Fab'-PYM conjugate was 170 kD. The Fab'-PYM conjugates showed immunoreactivity with antigen-relevant cancer cells and selective cytotoxicity against target cells. Administered intravenously, Fab'-PYM conjugates were more effective against the growth of tumors in mice than free PYM and PYM conjugated with intact mAb.

CONCLUSIONFab'-PYM conjugate may be capable of targeting cancer cells and effectively inhibiting tumor growth, suggesting its therapeutic potential in cancer treatment.

Animals ; Antibiotics, Antineoplastic ; pharmacology ; Antibodies, Monoclonal ; pharmacology ; Bleomycin ; analogs & derivatives ; pharmacology ; Carcinoma, Hepatocellular ; pathology ; Colonic Neoplasms ; pathology ; Female ; HT29 Cells ; Humans ; Immunoglobulin Fab Fragments ; pharmacology ; Immunotoxins ; pharmacology ; KB Cells ; Liver Neoplasms ; pathology ; Mice ; Tumor Cells, Cultured ; drug effects

OBJECTIVETo prepare the tumor antigen peptide complex (HSP70-1d) of HSP70 and idiotype (Id) from SmIg ScFv fragment in patients with Chronic B cell leukemia (B-CLL), and to study the anti-tumor effect of cytotoxic T lymphocyte (CTL) induced by HSP70-Id complex-modified dendritic cell (DC) in vitro and explore their immune mechanism.

METHODSPurified HSP70 was combined into peptide complex (HSP70-Id) with the prepared Id-ScFv from B-CLL cells in vitro by using biochemical technique. The plastic-adherent monocytes from human peripheral blood were cultured and induced into DC with rhGM-CSF and rhIL-4 using cell culture and separation technique. The cultured DC were harvested and pulsed by HSP70-Id complex. DC morphology was observed under converted phase microscope and its phenotype was characterized by FCM on 8th day as well as their secreting cytokines were measured. Host lymphocytes were stimulated by DC loaded with HSP70-Id complex and co-cultured in the medium containing IL-2. The activation and proliferation of lymphocytes were examined by MTr test, which was also used to assay cytotoxicity of CTL elicited by modified DC to Daudi, K562 and HepG2 tumor cells, and FCM analyzed the changes of T lymphocyte subsets.

RESULTSMature DCs were obtained successfully, showing typical morphology and phenotypic properties, the expression ratio of cellular surface molecules, CD1a was 20% - 30%, CD83 was more than 72% , both CD86 and HLA-DR over-expressed obviously in the complex-loaded DC group secreting cytokines of Thl type, IL-12 and TNF-alpha. The culturing lymphocytes that were activated by modified DC could more effectively and specifically kill Daudi (71. 24%), but not K562 and HepG2 tumor cells. Results of FCM assay demonstrated that percentage of CD4+ and CD8+ T lymphocytes cocultured with complex-modified DC increased notably to 56.51% and 70.21%, respectively. CD4+ T/ CD8+ T proportion was changed from 1.49 to 0.81. The dose of peptide would be reduced to 1/50 if specific CTL induced by complex-modified DC instead of directly by peptide complex.

CONCLUSIONDCs modified by HSP70-Id complex exhibit powerful biological activities, and could induce CTL to specific cytotoxicity against carcinoma cells. It might be produced by cooperation of CD4+ T, CD8+ T lymphocytes and DC. The results also suggested that DC modified by HSP70-Id complex can present antigen and induce CTL with high efficacy and specificity.

Cell Line, Tumor ; Cells, Cultured ; Cytotoxicity, Immunologic ; Dendritic Cells ; cytology ; drug effects ; immunology ; Flow Cytometry ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; HSP70 Heat-Shock Proteins ; pharmacology ; Humans ; Immunoglobulin Idiotypes ; pharmacology ; Immunoglobulin Variable Region ; pharmacology ; Interleukin-4 ; genetics ; pharmacology ; K562 Cells ; Lymphocyte Activation ; Monocytes ; cytology ; drug effects ; immunology ; Recombinant Proteins ; pharmacology ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo induce anti-B-cell acute lymphoblastic leukemia (B-ALL) cytotoxic T lymphocyte response against immunoglobulin heavy chain frame-derived nonapeptide.

METHODSThe peptide, QLVQSGAEV, containing IgHV1 frame region 3rd-11th amino acids (IgHV1(3-11)), was synthesized. IgHV1(3-11)-T2 binding tests were performed. HLA-A * 0201-positive normal peripheral blood mononuclear cells (PBMNC) were stimulated by IgHV1(3-11)-loaded antigen presenting cells three times at weekly intervals. HLA-A * 0201/IgHV1(3-11) tetramers were used to detect the proliferation of IgHV1(3-11)-specific CD8(+) T cells in the culture. Seven IgHV gene families of B-ALL patients were respectively amplified by PCR and the PCR products were sequenced to select IgHV1 and IgHV3 family monoallelic functional rearrangements. Among them, HLA-A * 0201 positive individuals were subsequently identified. Cytotoxicity of IgHV1(3-11)-specific CD8(+) T cells against HLA-A * 0201-positive IgHV1/IgHV3 family B-ALL cells was measured by MTT assay.

RESULTSThe synthesized IgHV1(3-11) up-regulated HLA-A * 0201 expression on T2 cell surface by 1.63-folds. The percentage of IgHV1(3-11)-specific CD8(+) T cells in HLA-A * 0201-positive normal PBMNC was increased from 1.64% after second stimulation to 82.57% after third stimulation. At effector: target ratio of 20:1, the killing rate of IgHV1(3-11)-specific CD8(+) T cells against IgHV1 family B-ALL cells was 18.24%, being 1.8-folds as that against IgHV3 family B-ALL cells (P = 0.01).

CONCLUSIONCytolytic T lymphocytes generated in vitro against immunoglobulin heavy chain frame-derived nonapeptides can kill B-ALL cells expressing these peptides.

Cells, Cultured ; Humans ; Immunoglobulin Heavy Chains ; immunology ; pharmacology ; Leukemia, B-Cell ; immunology ; pathology ; T-Lymphocytes, Cytotoxic ; drug effects ; immunology