a Related Biological Terms

A specialized type of cell, bearing cell surface Class II MHC (major histocompatibility complex) molecules, involved in processing and presentation of antigen to inducer, or helper , T cells. Examples: macrophage, dendritic cells.

The altering of a microorganism's surface antigens through genetic rearrangement, to elude detection by the Host's immune system.

Any chemical or biological agent that harms the growth of microorganisms. Antimicrobial agents can be any chemical or biological agent that harms the growth of microorganisms. Antimicrobial agent is a general term mainly concerned with antibiotics, antibacterials, antifungals, antivirals, and antiprotozoans. Antimicrobial agents are drugs, chemicals, or other substances capable of acting in two modes: kill (microbiocidal) or slow the growth of microbes (microbiostatic). The production and use of the antibiotic penicillin in the early 1940s became the basis for modern antimicrobial therapy. Streptomycin was discovered in 1944, and since then, many other antibiotics and other types of antimicrobials have been found and put into use. A significant discovery following the introduction of these agents into medicine was the finding that their basic structure could be modified chemically to improve their characteristics. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against.

A mutant expressing some agent that antagonizes a normal gene product.

A substance used to reduce fever.

Antisense RNAs are a type of non-coding RNA (ncRNA) that regulate gene expression through different mechanisms. For example, the binding of a single-stranded antisense RNA to its complementary messenger RNA (mRNA) may inhibit translation or lead to its degradation. Antisense RNA or natural regulatory RNA molecules are commonly small molecules and were first discovered in bacteria in 1967. Nevertheless, natural antisense RNAs have been identified in many organisms. Antisense RNA mechanisms and synthetic oligonucleotides are being leveraged as therapeutics for various diseases, including cancer. RNA targeting therapeutics such as antisense oligonucleotides (ASO) reduce protein expression by targeting mRNA for degradation, inhibiting translation, or preventing mRNA maturation. To silence mRNA through the induction of RNAi in the cytoplasm, different RNA oligonucleotides may be used, such as microRNA and short interfering RNA (siRNA).

A protein that, when bound at its normal attachment sites in DNA, lets RNA Polymerase read through normal terminator sequences (eg the N- and Q- gene products of phage lambda).

The opening to the anal canal.

The largest artery; it leaves the heart.

endonuclease that initiates excision repair at apurinic and apyrimidinic sites on DNA.