People are expected to have been previously vaccinated with a Vaccinia‐based vaccine, as until 1980 smallpox vaccination was a standard protocol in China. It is unclear whether people with smallpox vaccine still have antibody against vaccinia virus (VACV) and cross‐antibody against monkeypox virus (MPXV). Herein, we assessed the binding antibodies with antigen of VACV‐A33 and MPXV‐A35 in the general population and HIV‐1 infected patients. Firstly, we detected VACV antibody with A33 protein to evaluate the efficiency of smallpox vaccination. The result show that 29% (23 of 79) of hospital staff (age ≥ 42 years) and 63% (60 of 95) of HIV‐positive patients (age ≥ 42 years) from Guangzhou Eighth People's Hospital were able to bind A33. However, among the subjects below 42 years of age, 1.5% (3/198) of the hospital volunteer samples and 1% (1/104) of the samples from HIV patients were positive for antibodies against A33 antigen. Then, we assessed the specific cross‐reactive antibodies against MPXV A35 protein. 24% (19 of 79) hospital staff (age〉 = 42 years) and 44% (42 of 95) of HIV‐positive patients (age〉 = 42 years) were positive. 98% (194/198) of the hospital staff and 99% (103/104) of the HIV patients had no A35‐binding antibodies. Further, we found significant sex differences for the reactivity to A35 antigen were observed in HIV population, but no significant sex differences in hospital staff. Further, we analyzed the positivity rate of anti‐A35 antibody of men who have sex with men (MSM) and non‐MSM in HIV patients (age〉 = 42years). We found that 47% of no‐MSM population and 40% of MSM population were positive for A35 antigen, with no significant difference. Lastly, we found only 59 samples were positive for anti‐A33 IgG and anti‐A35 IgG in all participants. Together, we demonstrated A33 and A35 antigens binding antibodies were detected in HIV patients and general population who were older than 42 years, and cohort studies only provided data of serological detection to support early response to monkeypox outbreak.

2021-07-01·Nature protocols1区 · 生物学

Inverse electron demand Diels–Alder click chemistry for pretargeted PET imaging and radioimmunotherapy

1区 · 生物学

Article

作者: Sarrett, Samantha M ; Carnazza, Kathryn E ; Keinänen, Outi ; Dayts, Eric J ; Dewaele-Le Roi, Guillaume ; Rodriguez, Cindy ; Zeglis, Brian M

Radiolabeled antibodies have shown promise as tools for both the nuclear imaging and endoradiotherapy of cancer, but the protracted circulation time of radioimmunoconjugates can lead to high radiation doses to healthy tissues. To circumvent this issue, we have developed an approach to positron emission tomography (PET) imaging and radioimmunotherapy (RIT) predicated on radiolabeling the antibody after it has reached its target within the body. This in vivo pretargeting strategy is based on the rapid and bio-orthogonal inverse electron demand Diels-Alder reaction between tetrazine (Tz) and trans-cyclooctene (TCO). Pretargeted PET imaging and RIT using TCO-modified antibodies in conjunction with Tz-bearing radioligands produce high activity concentrations in target tissues as well as reduced radiation doses to healthy organs compared to directly labeled radioimmunoconjugates. Herein, we describe how to prepare a TCO-modified antibody (humanized A33-TCO) as well as how to synthesize two Tz-bearing radioligands: one labeled with the positron-emitting radiometal copper-64 ([⁶⁴Cu]Cu-SarAr-Tz) and one labeled with the β-emitting radiolanthanide lutetium-177 ([¹⁷⁷Lu]Lu-DOTA-PEG₇-Tz). We also provide a detailed description of pretargeted PET and pretargeted RIT experiments in a murine model of human colorectal carcinoma. Proper training in both radiation safety and the handling of laboratory mice is required for the successful execution of this protocol.

2020-01-01·mAbs2区 · 医学

A novel human monoclonal antibody specific to the A33 glycoprotein recognizes colorectal cancer and inhibits metastasis

2区 · 医学

Article

作者: Plüss, Louis ; Neri, Dario ; Murer, Patrizia

Colorectal cancer represents the second most common cause of cancer-related death. The human A33 transmembrane glycoprotein is a validated tumor-associated antigen, expressed in 95% of primary and metastatic colorectal cancers. Using phage display technology, we generated a human monoclonal antibody (termed A2) specific to human A33 and we compared its epitope and performance to those of previously described clinical-stage anti-human A33 antibodies. All antibodies recognized a similar immunodominant epitope, located in the V-domain of A33, as revealed by SPOT analysis. The A2 antibody homogenously stained samples of poorly, moderately, and well differentiated colon adenocarcinomas. All antibodies also exhibited an intense staining of healthy human colon sections. The A2 antibody, reformatted in murine IgG2a format, preferentially localized to A33-transfected CT26 murine colon adenocarcinomas in immunocompetent mice with a homogenous distribution within the tumor mass, while other antibodies exhibited a patchy uptake in neoplastic lesions. A2 efficiently induced killing of A33-expressing cells through antibody-dependent cell-mediated cytotoxicity in vitro and was able to inhibit the growth of A33-positive murine CT26 and C51 lung metastases in vivo. Anti-A33 antibodies may thus represent useful vehicles for the selective delivery of bioactive payloads to colorectal cancer, or may be used in IgG format in a setting of minimal residual disease.

100 项与 A33-radionuclides 相关的药物交易

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