CD4 + T Lymphocytes—From Their Multiple Immunological Roles to New Sensing Strategies Using Marine Magnetotactic Bacteria—A Systematic Review

Abstract

Highlights CD4+ T cells as central regulators of immune homeostasis, and magnetotactic bacteria in the detection of white blood cells. What are the main findings?1. Current methods are accurate but limited by laborious laboratory infrastructure. 2. MTBs as an innovative alternative for CD4+ detection. What are the implications of the main findings?1. Possibility of developing more flexible and portable sensing platforms. 2. Need for experimentation, standardization and validation for clinical application. Abstract CD4+ T lymphocytes are important regulators of immune homeostasis, and their dysregulation is closely linked to a wide range of diseases. For this reason, their reliable detection remains a major challenge. Despite the fact that current methods are analytically robust, they rely mainly on laboratory infrastructure, limiting their flexibility and wider applicability. The present review analyzes established and emerging approaches for CD4+ T-cell detection, with a focus on their practical limitations regarding portability, flexibility and applicability. To the best of our knowledge, for the first time, the authors are examining the possibility of exploring marine magnetotactic bacteria (MTBs) as active biological elements in immune cell detection due to their intrinsic magnetic properties, biological organization, and surface biofunctionalization potential. Rather than offering an immediate technological solution, the use of MTBs serves as a challenging biological framework that could provide more adaptable and sensitive detection strategies. At the same time, the limitations of this concept are acknowledged, emphasizing the need for further experimental validation, considering that this strategy, although promising, remains an exploratory concept.