A work co-led by the Translational Research in HIV laboratory of the research group on http://www.vhir.org/portal1/grup-equip.asp?t=malalties-infeccioses&s=recerca&contentid=186953 Infectious Diseases of the VHIR and the http://www.irsicaixa.es/ca/retrovirologia-i-estudis-clinics-grec Retrovirology and Clinical Studies group of IrsiCaixa shows that the dendritic cells of the cervix play a significant role in the acquisition and dissemination of HIV in women. The study, published in the journal https://www.frontiersin.org/articles/10.3389/fimmu.2019.00825/full?&utm_source=Email_to_authors_&utm_medium=Email&utm_content=T1_11.5e1_author&utm_campaign=Email_publication&field=&journalName=Frontiers_in_Immunology&id=447514 Frontiers in Immunology, also proposes a way to stop this route of propagation of HIV by blocking Siglec-1, a key protein for the capture of viruses by these cells.The study highlights the importance of the cells that reside in the mucosa of the female genital tract that favor the transmission of viruses and facilitating their rapid expansion in the most initial stages, once the woman has been exposed to the virus. "We have always focused a lot on CD4 + lymphocytes, which are the cells that become infected with the HIV virus, and now we have verified that other cell types, such as the cells antigen presenters and specifically dendritic cervical cells may play an important role in HIV infection, "says Jon Cantero, a researcher at VHIR, and the first author of the article, along with Daniel Perez-Zsolt of IrsiCaixa.Some dendritic cells have a molecule called Siglec-1 that facilitates entry and storage of the virus into the cell and its subsequent transmission to CD4 + T lymphocytes, which are the main target of the virus. This mechanism of infection is called trans-infection, where the dendritic cell only acts as a transmitter of the infection, without it being infected. The virus uses this input path to spread when the dendritic cell establishes contact with other CD4 T lymphocytes to activate them, as part of the immunological response.The researchers were able to determine that this protein, Siglec-1, is expressed in antigen-presenting cells of the female genital tract of any healthy woman. They have also observed that when there is inflammation, there are more cells that express this molecule, which means that the presence of other sexually transmitted infections could facilitate this pathway of transmission and spread of the virus. The researchers propose blocking Siglec-1 in a microbicidal strategy to prevent this propagation mechanism and prevent the spread of the virus from the genital tract of women to the rest of the body.This work has been possible thanks to the complementarity of the two research groups. On the one hand, the VHIR group's research focuses on the role of immune cells residing in the female genital tract in the presence of sexually transmitted infections, especially HIV. On the other hand, the Irsicaixa group is more focused on describing the mechanisms used by the virus to enter dendritic cells and promote viral dissemination. Through this collaboration, we have been able to determine the main mechanism by which the cells presenting antigens of the cervical mucosa could amplify HIV by propagating the infection without these cells being infected, but only by transmitters "These studies have been carried out thanks to the sample circuit that we have established in collaboration with gynecologists and pathologists, as well as the voluntary participation of women to whom uterus must be extracted for various reasons" explains Meritxell Genescà, principal investigator of the VHIR Infectious Diseases Research Group, and who co-led the study together with researcher Nuria Izquierdo-Useros from IrsiCaixa.