Induction of specific immunosuppression of cardiac allograft rejection withmonoclonal antibodies to CD44, LFA-1 and ICAM-1

Objective:To evaluate the immunosuppressive effect of monoclonal antibodies (McAb) against cell surface adhesion molecules on transplant rejection. Methods: C57BL/6 (H-2b) mouse cardiac grafts were transplanted into BALB/c(H- 2d) mice. This model was used to investigate the possibility of immunosuppressive induction with CD44 McAb, leukocyte function associated antigen (LFA-1) and intercellular adhesion molecule (ICAM-1). Results: Treatment of the allograft recipients with CD44 McAb alone, or both LFA-1 and ICAM-1 or combination of these 3 McAb significantly prolonged the cardiac allografts survival as compared with PBS controls (P<0.01). The combination of anti-CD44 and ICAM-1 and LFA-1 McAb was shown to produce more significant prolongation of grafts survival than anti-CD44 McAb alone or both anti-ICAM- 1 and LFA-1 McAb (P < 0.01). Histological examination of the grafts treated with the McAb displayed greatly reduced mononuclear cell infiltration. The proliferation of spleen cells from recipient BALB/c with McAb treatment was significantly inhibited in response to the stimulators of C57BL/6 spleen cells, but increased upon the stimulation of C3H/He (H-2k) spleen cells, as demonstrated by mixed lymphocyte reaction. Similarly, the cytotoxic activity against donor H-2-compatible (H-2b) target cells, EL-4 cells, was significantly suppressed. The spleen cells from allografted recipient BALB/c mice with McAb treatment induced specific tolerance for C57BL/6 cardiac grafts in allografted recipients, whereas those from allografted BALB/c mice without McAb treatment induced acute rejection. Conclusion: These results indicate that antiadhesion therapy using a combination of McAb to adhesion molecules can induce specific immunosuppression of transplant rejection.

Evaluation of teplizumab's efficacy and safety in treatment of type 1 diabetes mellitus:A systematic review and meta-analysis

BACKGROUND Islets of Langerhans beta cells diminish in autoimmune type 1 diabetes mellitus(T1DM).Teplizumab,a humanized anti-CD3 monoclonal antibody,may help T1DM.Its long-term implications on clinical T1DM development,safety,and efficacy are unknown.AIM To assess the effectiveness and safety of teplizumab as a therapeutic intervention for individuals with T1DM.METHODS A systematic search was conducted using four electronic databases(PubMed,Embase,Scopus,and Cochrane Library)to select publications published in peerreviewed journals written in English.The odds ratio(OR)and risk ratio(RR)were calculated,along with their 95%CI.We assessed heterogeneity using Cochrane Q and I2 statistics and the appropriate P value.RESULTS There were 8 randomized controlled trials(RCTs)in the current meta-analysis with a total of 1908 T1DM patients from diverse age cohorts,with 1361 patients receiving Teplizumab and 547 patients receiving a placebo.Teplizumab was found to have a substantial link with a decrease in insulin consumption,with an OR of 4.13(95%CI:1.72 to 9.90).Teplizumab is associated with an improved Cpeptide response(OR 2.49;95%CI:1.62 to 3.81)and a significant change in Glycated haemoglobin A1c(HbA1c)levels in people with type 1 diabetes[OR 1.75(95%CI:1.03 to 2.98)],and it has a RR of 0.71(95%CI:0.53 to 0.95).CONCLUSION In type 1 diabetics,teplizumab decreased insulin consumption,improved C-peptide response,and significantly changed HbA1c levels with negligible side effects.Teplizumab appears to improve glycaemic control and diabetes management with good safety and efficacy.

Expression of Anti-CD4 Human/Murine Chimeric Antibody and Their Killer Tumor Activity

From the mouse hybridoma cell line secreting an anti-CD4 monoclonal antibody (McAb), total RNA was prepared. The VH and VL genes were amplified by RT-PCR with family specific primer pairs. The PCR products were cloned into pGEM-T vectors, then tranfected into JM109. The VH and VL genes were snalyzed by automatic DNA sequencer. According to Kabat classification, the VH and VL genes belong to the mouse ig heavy subgroup Ⅱ(A) and x chain subgroupⅢ, respectively. The VH and VL genes were subcloned into pr1-Expr and Pk Expr respectively, then transfected into XL2-Blue. The VH- Pr1 and VL- pk were trans feeted by electroporation into mouse myeloma cell X63Ag8. 653. The transfectoma cells were selected by G418 screening, and then supernatant of cultured transfectoma were analyzed by ELISA and immunofluorescence techniques.We have acquired transfectoma cells secreting anti-CD4 chimeric antibodies.These chimeric antibodies are able to kill tumor cells specifically in vitro.

Characterization of two monoclonal antibodies, 38F10 and 44D11, against the major envelope fusion protein of Helicoverpa armigera nucleopolyhedrovirus

The envelope fusion protein F of baculoviruses is a class I viral fusion protein which play a significant role during virus entry into insect cells. F is initially synthesized as a precursor(F_0) and then cleaved into a disulfide-linked F_1 and F_2 subunits during the process of protein maturation and secretion. To facilitate further investigation into the structure and function of F protein during virus infection, monoclonal antibodies(mAbs) against the F_2 subunit of Helicoverpa armigera nucleopolyhedrovirus(HearNPV)(Ha F) were generated. Two kinds of mAbs were obtained according to their different recognition epitopes: one kind of mAbs, as represented by 38F10,recognizes amino acid(aa) 85 to 123 of F_2 and the other kind, represented by 44D11, recognizes aa148 to 173 of F_2. Western blot and immunofluorescence assay confirmed that both of the mAbs recognized the F protein expressed in HearNPV infected cells, however, only 44D11 could neutralize HearNPV infection. The results further showed that 44D11 may not interact with a receptor binding epitope, rather it was demonstrated to inhibit syncytium formation in cells expressing the Ha F protein. The results imply that the monoclonal antibody 44D11 recognizes a region within HaF_2 that may be involved in the F-mediated membrane fusion process.

Treatment strategies for nodal and gastrointestinal follicular lymphoma:Current status and future development

In recent years,therapies for follicular lymphoma (FL) have steadily improved.A series of phase Ⅲ trials comparing the effect of rituximab with chemotherapy vs chemotherapy alone in treating FL have indicated significant improvements in progression-free survival (PFS) and overall survival.Recent studies have found that prolonged response durations and PFS were obtained with maintenance therapy using rituximab or interferon after completion of first line therapy.For patients with relapsed or refractory FL,phase Ⅱ studies have assessed the effectiveness of combination therapies using a Toll-like receptor-9 agonist (1018ISS),oblimersen sodium (a Bcl-2 antisense oligonucleotide),bendamustine,and rituximab,as well as veltuzumab,a new humanized anti-CD20 antibody,and epratuzumab.In addition,the effectiveness of yttrium-90 ibritumomab tiuxetan and iodine-131 tositumomab as radioimmunotherapies has been reported.Furthermore,three phase Ⅲ studies on an idiotype vaccine are near completion.Unfortunately,these vaccines,which appeared highly effective in phase Ⅰ and Ⅱ trials,do not appear to result in prolonged PFS.This report will summarize the current knowledge on therapies for treatment of FL,and will conclude with a brief discussion of feasiblefuture options for effective treatments.Lastly,we added descriptions of the management of gastrointestinal FL,which is considered to be controversial because it is rare.

A multi-center,open-label,randomized,parallel-controlled phase II study comparing pharmacokinetic,pharmacodynamics and safety of ripertamab(SCT400)to rituximab(Mab Thera?)in patients with CD20-positive B-cell non-Hodgkin lymphoma

Objective:This multi-center,open-label,randomized,parallel-controlled phaseⅡstudy aimed to compare the pharmacokinetics(PK),pharmacodynamics(PD)and safety profile of ripertamab(SCT400),a recombinant antiCD20 monoclonal antibody,to rituximab(MabThera^(■))in patients with CD20-positive B-cell non-Hodgkin lymphoma(NHL).Methods:Patients with CD20-positive B-cell NHL who achieved complete remission or unconfirmed complete remission after standard treatment were randomly assigned at a 1:1 ratio to receive a single dose of ripertamab(375mg/m^(2))or rituximab(MabThera^(■),375 mg/m^(2)).PK was evaluated using area under the concentration-time curve(AUC)from time 0 to d 85(AUC_(0-85d)),AUC from time 0 to week 1(AUC0-1 w),AUC from time 0 to week 2(AUC_(0-2 w)),AUC from time 0 to week 3(AUC_(0-3 w)),AUC from time 0 to week 8(AUC_(0-8 w)),maximum serum concentration(C_(max)),terminal half-life(T_(1/2)),time to maximum serum concentration(T_(max))and clearance(CL).Bioequivalence was confirmed if the 90%confidence interval(90%CI)of the geometric mean ratio of ripertamab/rituximab was within the pre-defined bioequivalence range of 80.0%-125.0%.PD,immunogenicity,and safety were also evaluated.Results:From December 30,2014 to November 24,2015,a total of 84 patients were randomized(ripertamab,n=42;rituximab,n=42)and the PK analysis was performed on 76 patients(ripertamab,n=38;rituximab,n=38).The geometric mean ratios of ripertamab/rituximab for AUC_(0-85d),ATC_(0-inf),and Cmaxwere 96.1%(90%CI:87.6%-105.5%),95.9%(90%CI:86.5%-106.4%)and 97.4%(90%CI:91.6%-103.6%),respectively.All PK parameters met the pre-defined bioequivalence range of 80.0%-125.0%.For PD and safety evaluation,there was no statistical difference in peripheral CD 19-positive B-cell counts and CD20-positive B-cell counts at each visit,and no difference in the incidence of anti-drug antibodies was observed between the two groups.The incidences of treatment-emergent adverse events and treatment-related adverse events were also comparable between the two groups.Conclusions:In this study,the PK,PD,immunogenicity,and safety profile of ripertamab(SCT400)were similar to rituximab(MabThera^(■))in Chinese patients with CD20-positive B-cell NHL.

Advances in the treatment of IgA nephropathy with biological agents

Immunoglobulin A nephropathy(IgAN)is the most common primary glomerular disease,and the“four-hit”theory represents its currently accepted pathogenic mechanism.Mucosal immunity triggered by infections in the respiratory tract,intestines,or other areas leads to antigen presentation,T cell stimulation,B cell maturation,and the production of IgA-producing plasma cells.The proteins B-lymphocyte stimulator(BLyS)and a proliferation-inducing ligand(APRIL)are involved in this process,and alternative complement and lectin pathway activation are also part of the pathogenic mechanism.Kidney Disease Improving Global Outcomes guidelines indicate that a specific effective treatment for IgAN is lacking,with renin-angiotensin-aldosterone system inhibitors being the primary therapy.Recent research shows that biological agents can significantly reduce proteinuria,stabilize the estimated glomerular filtration rate,and reverse some pathological changes,such as endocapillary proliferation and crescent formation.There are four main categories of biological agents used to treat IgA nephropathy,specifically anti-CD20 monoclonal antibodies,anti-BLyS or APRIL monoclonal antibodies,monoclonal antibodies targeting both BLyS and APRIL(telitacicept and atacicept),and monoclonal antibodies inhibiting complement system activation(narsoplimab and eculizumab).However,further research on the dosages,treatment duration,long-term efficacy,and safety of these biological agents is required.

Clinical significance of the loss of CD20 antigen on tumor cells in patients with relapsed or refractory follicular lymphoma

Aim:Anti-CD20 monoclonal antibody is a cornerstone therapy for follicular lymphoma.Following anti-CD20 therapy,a potential decrease in CD20 antigen,and therefore a loss of the tumor target might be expected.However,the incidence and clinical significance of CD20 loss on tumor cells in patients with relapsed or refractory follicular lymphoma are unknown.This study aims to investigate the incidence and outcome of patients with relapsed or refractory follicular lymphoma patients harboring the loss of the tumor target,CD20.Methods:All consecutive adult patients with relapsed or refractory follicular lymphoma referred to the Early Drug Department at Gustave Roussy were included.The main objectives were to assess the incidence and prognosis of the loss in expression of CD20 antigen on the surface of tumor cells on patient outcome.Results:Over the study period 2013-2018,131 patients were screened for clinical trials with B-cell malignancies in the early drug department of Gustave Roussy in France.Forty-four patients presented with relapsed or refractory follicular lymphoma and 32 had tumor biopsies at the time of relapse that were retained for analysis.The median(range)age was 67.5 years(55.3-75.3)and the median number of prior anti-cancer systemic therapies was 3(2-4).At the time of relapse,CD20 expression was positive in 84%of tumors(n=27)and negative in 16%of tumors(n=5).At a median follow-up of 18.3(0.6-83.3)months,CD20 negativity was associated with a poorer prognosis with a median overall survival of 8.9 months(95%CI:2.4-19.1)in comparison to CD20 positive patients(28.3 months,95%CI:25.1-75.3 months,P=0.019).Conclusion:The loss of the tumor target antigen,CD20,occurred in 16%of patients with relapse or refractory follicular lymphoma.Due to confounding factors in patients who received anti-CD20 immunotherapy,it was not possible to formally establish the prognostic significance of CD20 negativity.However,we suggest that a check for CD20 antigen positivity nevertheless be performed to adapt subsequent therapies for patients with relapsed or refractory follicular lymphoma.