nvestigation. The endogenous e pression of podoplanin on 293T cells as well as certain interaction of podoplanin with CLEC 2 raised the inquiries if podoplanin was incorpo rated into virions selleckchem Nutlin-3a produced in 293T cells, and if incorpo ration of podoplanin was needed for CLEC 2 binding of those virions. Western blot analysis and knock down of podoplanin e pression by shRNA provided affirmative answers to each concerns Podoplanin depletion decreased CLEC 2, but not DC Sign, Nutlin-3a dependent HIV 1 transmis sion by B THP cells, and diminished transmission by platelets by about 50%. The latter obtaining is in agreement with our earlier observation that CLEC 2 unique antiserum decreased HIV 1 transmission by plate lets by about half.
Podoplanin thus joins the record of host things which can be incorporated in to the HIV 1 envelope and affect HIV 1 infection by interacting with their cognate ligands. A prominent e ample for this kind of a factor is ICAM 1 which was discovered to be incorpo rated to the viral membrane, and to facilitate HIV 1 infection by binding to its ligand LFA 1 on T cells. The possible relevance https://en.wikipedia.org/wiki/PKA of podoplanin incorporation for HIV spread in contaminated individuals is critically deter mined by the overlap with the podoplanin e pression pat tern using the cellular tropism of HIV. Evaluation of T cell lines and PBMCs for podoplanin e pression yielded neg ative benefits, at the least when viable cells have been ana lyzed, indicating that HIV particles produced in patients might not harbour podoplanin. The e ception is likely to be viruses released from kidney podocytes which happen to be documented to e press podoplanin and also to be prone to HIV infection.
Even so, the biolog ical relevance of this method is questionable. On this con te t, additionally, it needs to get noted that podoplanin e pression is up regulated in many tumours together with Kaposi sar coma. Podoplanin CLEC 2 dependent platelet stimulation by tumour cells promotes hematogenous Nutlin-3a tumour metastasis, perhaps by inducing development issue secretion by platelets and by selling formation of a platelet cap, which protects the tumour from mechanical forces. As a result, podoplanin may well play a position in the development on the AIDS related Kaposi sarcoma, but is unlikely to modulate HIV spread in individuals.
normally Nev ertheless, HIV 1 created in PBMCs was transmitted to target cells inside a CLEC 2 dependent vogue, sug gesting that major T cells may possibly e press a to date unrec ognized CLEC 2 ligand, and that is integrated into the viral envelope and which facilitates HIV transmission by CLEC 2. Our ongoing research are devoted to the identification of this component. Podoplanin was not detected Nutlin-3a on viable CEM��174 cells and PBMCs, as established by our gat ing strategy and by co staining using the apoptosis and necrosis markers anne in V and 7 AAD, respectively. In contrast, Nutlin-3a we observed productive reactivity of two different podoplanin antibodies with non viable cells, raising the intriguing probability that podoplanin might be e pressed on the cell surface i