Cross-neutralizing Anti-hemagglutinin Antibodies Isolated from Patients Infected with Avian Influenza A(H5N1) Virus

Objective To recover broad-neutralizing monoclonal antibodies(Bn Abs)from avian influenza A(H5N1)virus infection cases and investigate their genetic and functional features.Methods We screened the Abs repertoires of expanded B cells circulating in the peripheral blood of H5N1 patients.The genetic basis,biological functions,and epitopes of the obtained Bn Abs were assessed and modeled.Results Two Bn Abs,2-12 D5,and 3-37 G7.1,were respectively obtained from two human H5N1 cases on days 12 and 21 after disease onset.Both Abs demonstrated cross-neutralizing and Ab-dependent cellular cytotoxicity(ADCC)activity.Albeit derived from distinct Ab lineages,i.e.,V^H1-69-D2-15-JH^4(2-12D5)and V^H1-2-D3-9-JH^5(3-32 G7.1),the Bn Abs were directed toward CR6261-like epitopes in the HA stem,and HA2 I45 in the hydrophobic pocket was the critical residue for their binding.Signature motifs for binding with the HA stem,namely,IFY in VH1-69-encoded Abs and LXYFXW in D3-9-encoded Abs,were also observed in 2-12D5 and 3-32 G7.1,respectively.Conclusions Cross-reactive B cells of different germline origins could be activated and re-circulated by avian influenza virus.The HA stem epitopes targeted by the Bn Abs,and the two Ab-encoding genes usage implied the VH1-69 and D3-9 are the ideal candidates triggered by influenza virus for vaccine development.

Effects of autoantibodies against AT1-receptor and angiotensin Ⅱ on refractory hypertension

Objective The study will explore effects of the autoantibodies against AT1 receptor and angiotensin Ⅱ on the refractory hypertension. Methods Seventy-seven patients (46 men and 31 women) with essential hypertension were divided into groups of refractory hypertension (RH) and hypertension (HT) according to the 1999 WHO-ISH Guidelines for the Management of Hypertension. Forty normotensives (22 men) were recruited as controls. The mean age was 54. 3±13 years old in RH group, 53. 5±9 years old in HT group and 51. 2±11. 9 years old in normotensives (NT) group. The mean blood pressure was 154. 2±9. 4/98. 4± 8. 2 mmHg in RH group and 130. 1±7. 6/80. 5±6. 7 mmHg in HT group after combination drug therapy of hypertension for 4 weeks. Blood pressure in NT group was 120. 8±11. 7/76. 4 ± 7. 2 mmHg. The epitope of the 2nd extracellular loops of AT1 receptor was synthesized and used as antigens to screen the autoantibodies by ELISA. Plasma angiotensin (Ang) II were examined by a radioimmunoassay. Results The autoantibodies against AT1 receptor were positive in 18 (46. 15 %) patients with RH, in 4 (10. 5 % ) hypertension and in 3 (7. 5 % ) normotensives, P < 0. 01. Ang Ⅱwas 57. 01±52. 63 pmol/L in patients with RH. Both the autoantibodies positive and the Ang Ⅱ increasing were 4 (10. 3 % ) cases, both normal were 7 (17. 9 % ) cases, the autoantibodies positive or Ang II increasing was all of 14 (35. 9 % ) cases (x2 = 0. 09, P>0. 05) . There was no relationship between the autoantibodies against AT1 receptor and the angiotensin Ⅱ in refractory hypertension. Conclusion The autoantibodies against AT1 receptor and Ang Ⅱ might be two independent factors in developing of refractory hypertension. The findings suggest that AT1 receptor an-tagnist used in the treatment of refractory hypertension might have an important value.

Paraneoplastic Anti-Tif1-gamma Autoantibody-positive Dermatomyositis as Clinical Presentation of Hepatocellular Carcinoma Recurrence

Hepatocellular carcinoma(HCC)is rarely associated with autoimmune paraneoplastic syndromes.We report a case of anti-transcriptional intermediary factor-1 gamma(TIF1-γ)-positive dermatomyositis(DM)as clinical presentation of HCC recurrence in a 72-year-old male patient admitted to our hospital due to fatigue,myalgia,and typical skin rash.His medical history was notable for hepatitis C-related cirrhosis,successful treatment with direct-acting antiviral agents,and previously efficacious treatment of HCC.Laboratory testing showed significant rhabdomyolysis with antiTIF1-γantibodies at high titer,and DM was diagnosed.After a careful diagnostic workup,HCC recurrence was diagnosed.After first-line corticosteroid treatment,azathioprine and intravenous immunoglobulin treatments were administered;unfortunately,he mounted only partial response.Owing to the compromised performance status,no HCC treatment was feasible,and,according to international guidelines,he received only best supportive care.Here,we discuss the diagnostic,prognostic,and pathogenic roles of anti-TIF1-γantibodies associated with paraneoplastic DM and the scant literature data on its occurrence in HCC patients.Considering the TIF1 gene family’s established role in oncogenesis,we also review the role of TIF1-γas a tumor-related neoantigen,leading to the development of clinically overt antiTIF1-γantibodies-positive DM.

A non-human primate derived anti-P-selectin glycoprotein ligand-1 antibody curtails acute pancreatitis by alleviating the inflammatory responses

Acute pancreatitis(AP)is a devastating disease characterized by an inflammatory disorder of the pancreas.P-selectin glycoprotein ligand-1(PSGL-1)plays a crucial role in the initial steps of the adhesive at process to inflammatory sites,blockade of PSGL-1 might confer potent anti-inflammatory effects.In this study,we generated two non-human primate derived monoclonal antibodies capable of efficiently targeting human PSGL-1,RH001-6 and RH001-22,which were screened from immunized rhesus macaques.We found that RH001-6,can effectively block the binding of P-selectin to PSGL-1,and abolish the adhesion of leukocytes to endothelial cells in vitro.In vivo,we verified that RH001-6 relieved inflammatory responses and pancreatic injury in both caerulein and L-arginine induced AP models.We also evaluated the safety profile after RH001-6 treatment in mice,and verified that RH001-6 did not cause any significant pathological damages in vivo.Taken together,we developed a novel non-human primate derived PSGL-1 blocking antibody with high-specificity,named RH001-6,which can interrupt the binding of PSGL-1 and P-selectin and attenuate inflammatory responses during AP.Therefore,RH001-6 is highly potential to be further developed into therapeutics against acute inflammatory diseases,such as AP.

Combination of specific monoclonal antibodies allow identification of soluble aggregates of by sandwich ELISA

Aggregate amyloid beta protein1-42 (Aβ1-42) can typically be found in the early stage of Alzheimer’s disease (AD). Aβ1-42 self-assembles and is highly toxic to neurons. Thus, recognizing aggregated Aβ1-42 is very important for elucidation of Aβ1-42 structure and for the diagnosis of AD. In this study, the specificity of the 79-3 monoclonal antibody against soluble aggre- gate Aβ1-42 was measured by sandwich Enzyme-Linked Immuno Sorbent Assay (ELISA). Eight monoclonal antibodies against both soluble aggregates and amorphous aggregates were used as primary antibodies. Soluble aggregates and amorphous aggregates were used as antigen. As secondary antibody, HRP was labeled with the 79-3 monoclonal antibody. The reactivity of the 79-3 monoclonal antibody against soluble aggregates was confirmed in all combinations, but little reactivity against amorphous aggregates was found. Furthermore, we performed the above sandwich ELISA using the 37-11 antibody, which is reactive against large oval aggregates (LOA) that occur in micro aggregates, instead of the 79-3 antibody. The 77-3 antibody is 1 of the 8 monoclonal antibodies against soluble aggregates;amorphous aggregates also reacted with the 37-11 antibody. These results indicated that soluble aggregates are specifically recognized by a combination of different antibodies. The combined use of these antibodies can be applied to the diagnosis of AD and to defining the structure of the Aβ1-42.

Identification of a New Member of the Ep-CAM (17-1A) Tumor-Associated Antigen Family

The tumor-associated antigen Ep-CAM (17-1A antigen), defined by the murine monoclonal antibody (mAb) 17-1A, has been identified as a 42-kD glycoprotein. The mAb 17-1A has been used for immunotherapy of colorectal cancer. We obtained mAb 19F4 using a synthetic peptide containing antigen determinants of 17-1A antigen. The mAb 19F4 can bind the corresponding dominants of the 17-1A antigen in ELISA. Western-blot analysis demonstrated that mAb 19F4 recognized a 50-kD protein from cell lysates of MCF-7 (breast cancer cell line). Both mAb 19F4 and 17-1A detected a 42-kD protein in the cell lysates of HT-29 (colorectal cancer cell line). The results suggest that new members of the tumor-associated antigen family 17-1A may exist.