[Role of toll-like receptors (TLRs) and nucleotide-binding oligomerization domain receptors (NLRs) in viral infections]. / Papel de los receptores tipo toll (TLRs) y receptores para dominios de oligomerización para la unión a nucleótidos (NLRs) en las infecciones virales.

The immune system (IS) cells are capable of recognizing a wide variety of microorganisms, through receptors that are expressed and distributed throughout the cell architecture. The interaction between the pathogen-associated molecular patterns or damage-associated molecular patterns (PAMPs or DAMPs) and pattern recognition receptors (PRR), present in host cells, is a critical event that involves intracellular signaling processes that end up in the expression of both, proinflammatory and antiviral mediators. Accordingly, the proper functioning of the different mechanisms of signal transduction from the cell membrane to the cytoplasm will depend on the integrity of these receptors (PRR); and therefore, the IS response triggered against pathogens including viral agents. Hence, in this review we discuss the role of toll-like receptors (TLRs) and nucleotide-binding oligomerization domain receptors (NLRs) in viral infections, using as evidence the studies in humans and mice known to date.

Papel de los receptores tipo toll (TLRs) y receptores para dominios de oligomerización para la unión a nucleótidos (NLRs) en las infecciones virales / Role of toll-like receptors (TLRs) and nucleotide-binding oligomerization domain receptors (NLRs) in viral infections

Las células del sistema inmunitario (SI) son capaces de reconocer una gran variedad de microorganismos, a través de los receptores que se encuentran expresados y distribuidos a lo largo de su arquitectura celular. La interacción entre los patrones moleculares asociados a microorganismos o a daño (PMAM o PMAD) y los receptores reconocedores de patrones (RRP) presentes en las células del hospedero es un evento crítico que implica procesos intracelulares de señalización que finalizan en la expresión de mediadores tanto proinflamatorios como antivirales. Por consiguiente, de la integridad de estos receptores dependerá el buen funcionamiento de los distintos mecanismos de transducción de señal desde las membranas celulares al citoplasma y por ende, de la respuesta que el SI desencadene contra los patógenos entre ellos los agentes virales. De allí que, en esta revisión se discutirá el papel de los receptores tipo toll (TLRs) y receptores para dominios de oligomerización para la unión a nucleótidos (NLRs) en las infecciones virales, tomando como evidencia los estudios en humanos y ratones que a la fecha se conocen.

The immune system (IS) cells are capable of recognizing a wide variety of microorganisms, through receptors that are expressed and distributed throughout the cell architecture. The interaction between the pathogen-associated molecular patterns or damage-associated molecular patterns (PAMPs or DAMPs) and pattern recognition receptors (PRR), present in host cells, is a critical event that involves intracellular signaling processes that end up in the expression of both, proinflammatory and antiviral mediators. Accordingly, the proper functioning of the different mechanisms of signal transduction from the cell membrane to the cytoplasm will depend on the integrity of these receptors (PRR); and therefore, the IS response triggered against pathogens including viral agents. Hence, in this review we discuss the role of toll-like receptors (TLRs) and nucleotide-binding oligomerization domain receptors (NLRs) in viral infections, using as evidence the studies in humans and mice known to date.

Transcription of pattern recognition receptors and abortive agents induced chemokines in the bovine pregnant uterus.

Pattern recognition receptors (PRRs) are important components of the innate immune system whose ligands are specific pathogen associated molecular patterns (PAMPs). Considering the scarcity of studies on transcription of PRRs in the pregnant uterus of cows, and its response to PAMPs and microorganisms that cause abortion in cattle, this study aimed to characterize the transcription of TLR1-10, NOD1, NOD2 and MD2 in bovine uterus throughout gestation and to investigate the sensitivity of different uterine tissues at third trimester of pregnancy to purified TLR ligands or heat-killed Brucella abortus, Salmonella enterica serotype Dublin (S. Dublin), Listeria monocytogenes, and Aspergillus fumigatus, by assessing chemokine transcription. RNA extracted from endometrium, placentome and intercotiledonary region of cows at the first (n=6), second (n=6), and third (n=6) trimesters of pregnancy were subjected to real time RT-PCR. After stimulation of endometrium and intercotiledonary regions with purified TLR ligands or heat-killed microorganisms, gene transcription was assessed by real time RT-PCR. In the placentome, there was no significant variation in TLRs transcription throughout the three trimesters of pregnancy. In the endometrium, there was significant variation in TLR4 and TLR5 transcription during the three stages of gestation; i.e. TLR4 transcription was higher during the third trimester, whereas TLR5 transcription was higher during the last two trimesters. In the intercotiledonary region, there was significant variation in transcription of TLR1/6, TLR7, and TLR8, which were more strongly expressed during the first trimester of pregnancy. At the third trimester of gestation, significant transcription of CXCL6 and CXCL8 was detected mostly in endometrial tissues in response to purified TLR4 and TLR2 ligands. Transcription of these chemokines was induced in the endometrium and intercotiledonary region at the third trimester of pregnancy when stimulated with heat-killed B. abortus or S. Dublin. Therefore, this study demonstrates that some PRRs are expressed in the uterus during pregnancy, which coincides with its ability to respond to stimulation with TLRs ligands as well as heat-killed organisms known to cause abortion in cattle.