The Major Histocompatibility Complex
The major histocompatibility complex encodes MHC molecules that present peptide antigens to T cells, playing a central role in immune recognition, transplant rejection, and disease association.
Biology
Emerging Viral Pathogens
Emerging viral pathogens are newly identified or re-emerging viruses that pose increasing threats to human health, often originating from animal reservoirs through zoonotic spillover.
BiologyInfluenza Viruses
Influenza viruses are negative-sense RNA viruses that cause seasonal epidemics and occasional pandemics through continuous antigenic drift and shift.
Biology
The Cytoskeleton: Structure and Dynamics
The cytoskeleton is a dynamic network of protein filaments that provides structural support, enables cell movement, facilitates intracellular transport, and drives cell division.
BiologyMitochondria and Cellular Energetics
Mitochondria are double-membrane organelles that generate ATP through oxidative phosphorylation and serve as central hubs for metabolism, calcium homeostasis, and apoptosis regulation.
Biology
Epigenetic Regulation of Gene Expression
Epigenetic regulation is defined as heritable changes in gene expression that do not alter the DNA sequence, mediated by DNA methylation, histone modifications, and non-coding RNAs.
BiologyMutation and Genetic Variation
Mutations are permanent changes in DNA sequence that generate genetic variation, driving evolution and causing disease when they disrupt gene function.
BiologyB Cell Development and Antibody Production
B cells develop in the bone marrow and produce antibodies that neutralize pathogens, with each B cell generating a unique immunoglobulin through genetic recombination and somatic hypermutation.
BiologyT Cell Development and Activation
T cells develop in the thymus through a rigorous selection process and are activated by antigen presentation to orchestrate cell-mediated immune responses.
BiologyHIV and Retroviruses
Retroviruses are RNA viruses that reverse-transcribe their genome into DNA and integrate into the host chromosome, with HIV being the most clinically important member.
BiologyViral Diagnostics and Detection
Viral diagnostics encompasses a range of techniques for detecting and identifying viruses in clinical samples, including molecular, serological, and culture-based methods.
BiologyCell Membrane Structure and Transport
The cell membrane is a selective permeability barrier composed of a phospholipid bilayer with embedded proteins, controlling the passage of molecules via passive and active transport mechanisms.
Biology