Immunophenotyping: Analytical approaches and role in preclinical development of nanomedicines

Study on the mechanism of MDSC-platelets and their role in the breast cancer microenvironment

Myeloid-derived suppressor cells (MDSCs) are key immunosuppressive cells in the tumor microenvironment (TME) that play critical roles in promoting tumor growth and metastasis. Tumor-associated platelets (TAPs) help cancer cells evade the immune system and promote metastasis. In this paper, we describe the interaction between MDSCs and TAPs, including their generation, secretion, activation, and recruitment, as well as the effects of MDSCs and platelets on the generation and changes in the immune, metabolic, and angiogenic breast cancer (BC) microenvironments. In addition, we summarize preclinical and clinical studies, traditional Chinese medicine (TCM) therapeutic approaches, and new technologies related to targeting and preventing MDSCs from interacting with TAPs to modulate the BC TME, discuss the potential mechanisms, and provide perspectives for future development. The therapeutic strategies discussed in this review may have implications in promoting the normalization of the BC TME, reducing primary tumor growth and distant lung metastasis, and improving the efficiency of anti-tumor therapy, thereby improving the overall survival (OS) and progression-free survival (PFS) of patients. However, despite the significant advances in understanding these mechanisms and therapeutic strategies, the complexity and heterogeneity of MDSCs and side effects of antiplatelet agents remain challenging. This requires further investigation in future prospective cohort studies.

Immunophenotyping, Part I: Instrument Calibration and Reagent Qualification for Immunophenotyping Analysis of Human Peripheral Blood Mononuclear Cell Cultures

Nanoparticles are increasingly used in biomedical applications to influence the way the immune system reacts to tumors and infectious disease-causing agents. Nanoparticles not-intended for immunomodulation can also influence immune responses by affecting immune cell subsets' viability and/or activity. While immunophenotyping is commonly used to assess the effects of drugs and nanoparticles on immune cell subsets, no standardized approach exists due to the breadth of available cell models and instrumentation. In this chapter, we describe a protocol for flow cytometer calibration and reagent qualification prior to its use in the immunophenotyping experiment. The strategies described herein can be adapted to other instruments. The subsequent chapter-immunophenotyping part II (Chap. 25 )-provides detailed instructions for applying this methodology to analyze nanoparticle effects on subsets of immune cells present in peripheral blood.

Immunophenotyping, Part II: Analysis of Nanoparticle Effects on the Composition and Activation Status of Human Peripheral Blood Mononuclear Cells

The use of nanoparticles as drug delivery carriers requires analysis of their safety, which among other tests, includes immunotoxicity. Nanoparticles are also increasingly used for applications intended to specifically activate, inhibit, or modify the immune system's responses to improve the treatment of inflammatory and autoimmune disorders, cancer immunotherapy, and vaccines targeting cancer cells and viral and bacterial pathogens. In addition to the safety, the analysis of nanoparticles intended for immune system targeting includes mechanistic immunology investigations. Immunophenotyping provides researchers with a tool to assess the immune cell viability and activation status. These results provide mechanistic insights into nanoparticle efficacy and toxicity and therefore are of interest to the biomedical nanotechnology field. However, no standardized approaches exist due to the breadth of methods and instruments available for this analysis. This chapter provides detailed instructions for applying this methodology to analyze nanoparticle effects on subsets of immune cells present in peripheral blood. While this experimental strategy is specific to the NovoCyte 3005 flow cytometer, it can be adapted to other instruments. Instructions for instrument setup, calibration, and antibody qualification are described in this book's Chapter 24 , Immunophenotyping, part I.

Multicolor flow cytometry-based immunophenotyping for preclinical characterization of nanotechnology-based formulations: an insight into structure activity relationship and nanoparticle biocompatibility profiles

Introduction

Immunophenotyping, which is the identification of immune cell subsets based on antigen expression, is an integral technique used to determine changes of cell composition and activation in various disease states or as a response to different stimuli. As nanoparticles are increasingly utilized for diagnostic and therapeutic applications, it is important to develop methodology that allows for the evaluation of their immunological impact. Therefore, the development of techniques such as immunophenotyping are desirable. Currently, the most common technique used to perform immunophenotyping is multicolor flow cytometry.

Methods

We developed two distinct multicolor flow cytometry immunophenotyping panels which allow for the evaluation of the effects of nanoparticles on the composition and activation status of treated human peripheral blood mononuclear cells. These two panels assess the presence of various lymphoid and myeloid-derived cell populations as well as aspects of their activation statuses-including proliferation, adhesion, co-stimulation/presentation, and early activation-after treatment with controls or nanoparticles. To conduct assay performance qualification and determine the applicability of this method to preclinical characterization of nanoparticles, we used clinical-grade nanoformulations (AmBisome, Doxil and Feraheme) and research-grade PAMAM dendrimers of different sizes (G3, G4 and G5) and surface functionalities (amine-, carboxy- and hydroxy-).

Results and Discussion

We found that formulations possessing intrinsic fluorescent properties (e.g., Doxil and AmBisome) interfere with accurate immunophenotyping; such interference may be partially overcome by dilution. In the absence of interference (e.g., in the case of dendrimers), nanoparticle size and surface functionalities determine their effects on the cells with large amine-terminated dendrimers being the most reactive.

Regulating the microenvironment with nanomaterials: Potential strategies to ameliorate COVID-19

COVID-19, caused by SARS-CoV-2, has resulted in serious economic and health burdens. Current treatments remain inadequate to extinguish the epidemic, and efficient therapeutic approaches for COVID-19 are urgently being sought. Interestingly, accumulating evidence suggests that microenvironmental disorder plays an important role in the progression of COVID-19 in patients. In addition, recent advances in nanomaterial technologies provide promising opportunities for alleviating the altered homeostasis induced by a viral infection, providing new insight into COVID-19 treatment. Most literature reviews focus only on certain aspects of microenvironment alterations and fail to provide a comprehensive overview of the changes in homeostasis in COVID-19 patients. To fill this gap, this review systematically discusses alterations of homeostasis in COVID-19 patients and potential mechanisms. Next, advances in nanotechnology-based strategies for promoting homeostasis restoration are summarized. Finally, we discuss the challenges and prospects of using nanomaterials for COVID-19 management. This review provides a new strategy and insights into treating COVID-19 and other diseases associated with microenvironment disorders.

Allergy in Cancer Care: Antineoplastic Therapy-Induced Hypersensitivity Reactions

As the backbone of oncological treatments, systemic chemotherapy is still one of the main pawns in cancer care, alone or in combination with newer targeted agents. All chemotherapy agents can be associated with a type of adverse event called an infusion reaction, which can be characterized as unpredictable, non-dose related, and unexplained by the cytotoxic profile of the drug. For some of these events, a certain immunological mechanism can be identified by blood or skin testing. In this case, we can speak of true hypersensitivity reactions that occur as a response to an antigen/allergen. The current work summarizes the main antineoplastic therapy agents and their susceptibility to induce hypersensitivity reactions and also includes a review of clinical presentation, diagnostic methods in hypersensitivity reactions, and perspectives to overcome these negative events in the treatment of patients suffering from various types of cancer.