The interaction of Pseudomonas aeruginosa clinical isolates and human monoclonal antibodies

Popular Abstract

The invaders vs. the protectors: who wins the battle?

Pseudomonas aeruginosa or in short PsA is a type of microorganism, also known as “bacteria” or “germ” or “bug”. It is very tiny and invisible to our naked eyes. This germ is found everywhere in places like soil, and water. PsA can get into the human body through wounds and other injuries and make people sick. To prevent humans from getting infections, the human body has a defense mechanism called the “immune system”. As these bacterial invaders enter the body, the immune system is triggered and activated. Specific immune cells called “B cells” start producing “antibodies”- the protectors- to fight against PsA that causes infections. This is when the battle begins!

Many diseases like skin, eyes, urinary tract, and even lung infections are often caused by PsA. They are also called pathogens because they can cause these infectious diseases. Moreover, they have many different weapons called virulence factors that can contribute to successful invasion. When the immune system is weak, drugs that are effective in killing these bacteria are prescribed by doctors to help treat the infection, and these drugs are called “antibiotics”. As many people use antibiotics in the wrong ways without proper prescription because of the lack of antibiotic control guidelines, many bacteria have become resistant to antibiotics, meaning that they can no longer kill bacteria or treat the infection. This phenomenon is an antimicrobial resistance (AMR),

and over time they became stronger and more resistant to more than one antibiotic, known as multidrug-resistant (MDR) strains. These problems have caused many public health concerns for the past decades. PsA is one of the critical strains in the priority list of bacterial pathogens of WHO in 2017 and remains in the high group in 2024, in which new antibiotics and alternative treatments are urgently needed.

To overcome this challenging battle, our protectors need to be stronger than these invaders, but is it possible? And how do we tackle this issue? Recently, the research on laboratory-made antibodies called monoclonal antibodies (mAbs) has been in the spotlight and they could potentially become alternative treatments in many ways. MAb binds specific antigens (weapons of the pathogen) and prevents them from functioning, thus disrupting the infection. With the advancement of technology nowadays, scientists can design different mAbs into a single mAb that poses high efficiency against certain pathogens. When bacteria are bound by antibodies, many immune system-related processes could be activated. For example, antibodies can flag bacteria with an “eat me” signal, and special immune cells such as phagocytes can swallow the bacteria and kill them. This process is called “phagocytosis”.

In this study, I investigated the efficacy of two mAbs namely Ab005G1 and Ab006G1 against four different PsA from patients using many laboratory techniques but a method based on the phagocytosis process was the main focus. I found both mAbs can promote phagocytosis in one of the four tested PsA strains. This interesting result provided an insight into how bacteria and mAbs interact and brought a possibility of a new mAb candidate that could be further developed for bacterial treatment in the future.

Master’s Degree Thesis Project in Molecular Biology, 30 credits, Spring 2024
Department of Biology, Faculty of Science, Lund University
Supervisors: Pontus Nordenfelt and Berit Olofsson
Infection Medicine (BMC), Department of Clinical Sciences, Faculty of Medicine, Lund University

• author: Sovann, Saren
• supervisor: Pontus Nordenfelt
• organization: Degree Projects in Molecular Biology
• course: MOBM02 20232
• year: 2024
• type: H2 - Master's Degree (Two Years)
• subject: Biology and Life Sciences
• language: English
• id: 9176405
• date added to LUP: 2024-10-10 14:21:42
• date last changed: 2024-10-10 14:21:42