In-Vitro Bioservices

Revisiting Complement, An Old Friend… (Part 3)

After summarizing how the complement system can have both anti-tumor and pro-tumor effects, we conclude our blog series on Reis et al. by discussing the clinical aspects of complement as a target and biomarker.  As discussed in the previous blogs, the imbalance in activation of complement leads to overproduction of complement proteins that causes a switch from immunosurveillance to tumorigenesis.  Thus, therapeutics may be developed that target complement proteins and fragments to restore balance and an effective immune environment. Using complement to enhance monoclonal antibody-based (mAb) therapies Engineering antibodies to enhance Fc region-mediated effector functions have been well [...]

Revisiting Complement, An Old Friend… (Part 2)

Complement in promotion of tumorigenesis. The imbalance and dysfunction of complement activity and activation can lead to various mechanisms that promote tumorigenesis. These mechanisms can have affects on the immune cells to provide a more favorable tumor growth environment, including: 1) recruitment of MDSCs, 2) suppression of effector T cell function, and 3) sustained release of pro-inflammatory factors for favorable tumor growth. In addition, loss of complement regulation has affects on non-immune cells that sustain tumor growth and metastasis, including: 1) angiogenesis, 2) abnormal tumor cell proliferation, and 3) cell invasion and metastasis. Please see our blogs for more [...]

Revisiting Complement, An Old Friend… (Part 1)

The complement system of the innate immune system has been widely regarded as an early deterrent to infections and a means to clear pathogens by activating a group of proteins that leads to cell lysis, phagocytosis, and inflammation.  In addition, the power of complement has been implicated as a mechanism by which therapeutic antibodies, such as Rituxan, promoted their anti-tumor effects.  Along those lines, many biotechnology and pharmaceutical companies have tried to harness that power in targeted monoclonal antibody (mAb) cancer therapies.  However, more recent findings have indicated that, like everything about the immune system, balance is key and dysregulation [...]

Serious Monkey Business: A Short Take on Cynomolgus Monkeys in Research

What are cynomolgus monkeys? Cynomolgus monkeys (Macaca fascicularis), also known as the long-tailed or crab-eating macaque, are non-human primates (NHP) commonly used in biomedical research.  There are 10 subspecies of these macaques and they are found predominantly in southeast Asia.  The cynomolgus monkeys are typically 15-22 inches long, and the females weigh between 7-13 pounds, while males can weigh between 11-20 pounds. Why use cynomolgus monkeys and how are they used in biomedical research? Cynomolgus monkeys are frequently used in biomedical research because researchers believe these monkeys are the ideal models due to the 90-93% genetic similarity to and recent [...]

It’s All About the Mice: How the Mouse is Used in Research

What are inbred mice, why use them, and how are they generated? Inbred mice?  Knockout mice?  Transgenic mice?  Congenic mice?  Why so many?!  Inbred mice are mice that are genetically identical within a generation and across generations.  The use of these animals permits reproducibility and consistency across experiments in order to make definitive observations and interpretations that cannot be attributed to genetic variation.  For example, humans are an outbred species and each individual responds differently to the same influenza virus.  This is due to the genetic variation in humans in which some of us carry certain alleles for genes that [...]

By |2018-05-30T01:26:10+00:00February 7th, 2017|Blog, C57BL/6, CD45.1, CD45.2, In-Vitro Bioservices|0 Comments

Hurry up and Wait? The recent fuss about CAR-Ts

What are CAR-T cells? CAR (chimeric antigen receptor) T cells (CAR-T) are genetically engineered T cells that express receptors which recognize cancer antigens and attack the cells that express them. Therefore, they are a new cell-based immunotherapy for oncology indications. The results for leukemia and lymphoma patients receiving CD19-specific CAR-T cells have been extremely promising so far. CAR-T currently come in two main flavors: autologous or allogeneic. In order to prevent an allogeneic response against foreign T cells, CAR T cells are generated from the patient’s own T cells. T cells are taken from the patient and genetically engineered to [...]

ADCC: The Antibody Awakens…the Immune System (Part 2)

What is ADCC and why would you need it? This is Part 2 of our series, “ADCC: The Antibody Awakens…the Immune System”. Miss Part 1? Catch up here. Potential Applications & Implications for ADCC assays As alluded to in Part 1, one of the most important applications for ADCC assays is to identify candidate therapeutic antibodies that can mediate ADCC activity. Originally thought to prevent downstream signaling of the target receptor by blocking its oligomerization or engagement to ligands, most therapeutic antibodies are now suggested to work through multiple mechanisms, including ADCC. Thus, many companies screen their therapeutic antibody candidates [...]

ADCC: The Antibody Awakens…the Immune System (Part 1)

What is ADCC and why would you need it? What is Antibody-Dependent Cell-Mediated Cytotoxicity? Antibody-dependent cell-mediated cytotoxicity (ADCC) is the lysis of target cells mediated by antibodies that recruit effector cells to the target. This is achieved when the antigen recognition domain of the antibody binds antigen on the target, and the Fc domain of the antibody binds Fc receptors on effector cells. This engagement of Fc receptors results in activation of the effector cells and the subsequent release of cytolytic molecules towards the target to promote lysis. What are the molecules and effector cell types involved in ADCC? Several [...]

The Power of Complements… (Part 2)

What is CDC and why would you need it? This is Part 2 of our series, “The Power of Complements…”. Miss Part 1? Catch up here. Potential applications & implications for CDC assays As alluded to in Part 1, one of the most important applications for CDC assays is to determine if a potential therapeutic antibody can mediate CDC activity. Originally thought to only prevent downstream signaling of the target receptor by blocking its oligomerization or engagement to ligands, most therapeutic antibodies are now suggested to work through multiple mechanisms, including CDC activity. Thus, many companies screen their therapeutic antibody [...]

The Power of Complements… (Part 1)

What is CDC and why would you need it? What is Complement-Dependent Cytotoxicity? Complement-Dependent Cytotoxicity (CDC) is a form of cytotoxicity mediated by the host organism’s complement system. Components of the complement system become activated by three main mechanisms and all pathways lead to the formation of the membrane attack complex (MAC) on a target cell or organism. This MAC creates an opening in the plasma membrane of the cell or organism to drive death by osmotic lysis. What is the complement system and what are its associated pathways? A host organism’s complement system consists of over 30 proteins, including [...]