[The biological rationale for immunotherapy in cancer]

Combining PD-1 Inhibitor with VEGF/VEGFR2 Inhibitor in Chemotherapy: Report of a Patient with End-Stage Cholangiocarcinoma and Review of Literature

BACKGROUND

Cholangiocarcinoma is the second-largest liver cancer, and develops from the biliary epithelium, where it discretely progresses. Unfortunately, many patients miss the opportunity of performing surgery when diagnosed with cholangiocarcinoma, and due to its chemotherapeutic insensitivity, its control has always been considered difficult.

OBJECTIVE

Here, we present a case of stage 4 cholangiocarcinoma being controlled by the combination of chemotherapy with PD-1 and VEGF/VEGFR2 inhibitors.

CASE PRESENTATION

The patient is a 58-year-old male who was diagnosed with a progressed cholangiocarcinoma 2 years ago. From the beginning, metastases were discovered in multiple places, and the patient was unsuccessfully treated with 3 chemotherapy regimens. Therefore, a new therapeutic method was considered, and that involved the testing of a new combination of chemotherapy with PD-1 and VEGF/VEGFR2 inhibitors.

RESULTS

After 6 courses of treatment with this combination, the patient's lesions became smaller and stable.

CONCLUSION

Our case highlights the possibility of combining chemotherapy with PD-1 and VEGF/ VEGFR2 inhibitors for the treatment of cholangiocarcinoma patients. This combination may herald new hope for patients who run out of regimens.

Lectin Affinity Chromatography: An Efficient Method to Purify Horse IgG3

Affinity chromatography is a separation method based on a specific binding interaction between an immobilized ligand and its binding partner. An important class of ligands for the effective separation and purification of biotechnologically important substances is lectins, a group of naturally occurring molecules widely found in plants that display a range of specificities to bind different sugars. As sugars are often added to proteins through the process of glycosylation, ∼1/3 of all genetically encoded proteins are glycosylated, numerous cognate pairs of lectins with glycosylation groups have been discovered. Their specific binding interactions have not only allowed the development of numerous methodological strategies involving immobilized lectins to isolate molecules of interests but also for understanding the intermolecular interactions and alterations in glycosylation during a diverse set of biological phenomena, including tumor cell metastasis, intracellular communication, and inflammation. In this chapter, we describe a basic procedure for the separation of horse antibody classes by affinity chromatography based on differences in their glycosylation patterns. This procedure has been utilized for the purification of horse IgG3 (hoIgG3) from other six Ig from equine sera in a single step by using an Artocarpus integrifolia Jacalin column. This class of antibody comprises the therapeutic fraction generated in equine for passive antibody therapy and can serve as a biomarker for patient hypersensitivity. During the course of developing the protocol, the affinity interaction constant between the huIgE-hypersensitive immunoglobulin and the purified hoIgG3 was also determined.

Management of cancer patients during COVID-19 pandemic at developing countries

Cancer patient care requires a multi-disciplinary approach and multiple medical and ethical considerations. Clinical care during a pandemic health crisis requires prioritising the use of resources for patients with a greater chance of survival, especially in developing countries. The coronavirus disease 2019 crisis has generated new challenges given that cancer patients are normally not prioritised for admission in critical care units. Nevertheless, the development of new cancer drugs and novel adjuvant/neoadjuvant protocols has dramatically improved the prognosis of cancer patients, resulting in a more complex decision-making when prioritising intensive care in pandemic times. In this context, it is essential to establish an effective and transparent communication between the oncology team, critical care, and emergency units to make the best decisions, considering the principles of justice and charity. Concurrently, cancer treatment protocols must be adapted to prioritise according to oncologic response and prognosis. Communication technologies are powerful tools to optimise cancer care during pandemics, and we must adapt quickly to this new scenario of clinical care and teaching. In this new challenging pandemic scenario, multi-disciplinary work and effective communication between clinics, technology, science, and ethics is the key to optimising clinical care of cancer patients.

Purification of equine IgG3 by lectin affinity and an interaction analysis via microscale thermophoresis

The availability of purified antibodies is a prerequisite for many applications and the appropriate choice(s) for antibody-purification is crucial. Numerous methods have been developed for the purification of antibodies from different sources with affinity chromatography-based methods being the most extensively utilized. These methods are based on high specificity, easy reversibility and biological interactions between two molecules (e.g., between receptor and ligand or antibody and antigen). However, no simple techniques have yet been described to characterize and purify subclasses of immunoglobulins (Ig) from some animals of biotechnology importance such as equines, which are frequently used to produce biotherapeutic antibodies. The sera of these animals present a large number of Ig classes that have a greater complexity than other animals. The implementation of an effective protocol to purify the desired antibody class/subclasses requires meticulous planning to achieve yields at a high purity. The IgG3 subclass of equine-Ig has recently been used as antigen in a new diagnostic test for allergic responses to horse sera-based therapies. Here, we defined a simple method using Jacalin lectin immobilized on Sepharose beads to prepare highly pure equine IgG3 antibodies with a determination of the affinity constants for Jacalin lectin and horse IgG3.