Ribonuclease is partly responsible for the HIV-1 inhibitory effect activated by HLA alloantigen recognition.
OBJECTIVE
This study was performed to determine whether ribonucleases (RNases) contribute to the soluble HIV-1 inhibitory activity that results from the recognition of HLA alloantigens.


METHODS
Supernatants from mixed lymphocyte reactions of peripheral blood mononuclear cells from healthy HLA-discordant individuals exhibited HIV-1 inhibitory activity (alloantigen-stimulated factors; ASF). These supernatants were tested for their sensitivity to heating (90 degrees C for 3 min), and for the presence of three RNases belonging to the RNase A superfamily: eosinophil-derived neurotoxin (EDN); RNase A; and angiogenin. Polyclonal antibodies specific for these RNases were used for Western blot analysis of the ASF, as well as for blocking the HIV-1 inhibitory activity of ASF. In addition, an RNase inhibitor (RI) was used to determine whether the anti-viral activity of ASF was due to RNase activity.


RESULTS
HIV-1 inhibitory activity of ASF was: (i). resistant to heat treatment; (ii). blocked by 58% with an antibody specific for EDN, but not with antibodies against RNase A or angiogenin; and (iii) blocked by 65-100% with an RI. Moreover, Western blot analysis with an anti-EDN antibody detected EDN in the ASF.


CONCLUSIONS
These findings indicate that the majority of the soluble HIV-1 inhibitory activity contained in the supernatants of mixed lymphocyte reactions is due to EDN or a closely related RNase.
Rugeles
Maria T
MT
Universidad de Antioquia, Medellin, Colombia, the Experimental Immunology Branch, NCI, NIH, Bethesda, USA.
Trubey
Charles M
CM
Bedoya
Victoria I
VI
Pinto
Ligia A
LA
Oppenheim
Joost J
JJ
Rybak
Susanna M
SM
Shearer
Gene M
GM
D000998:Antiviral Agents; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1; D006649:Histocompatibility Antigens / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D012260:Ribonucleases / Q000378:metabolism*
D000998:Antiviral Agents; D006649:Histocompatibility Antigens; D012260:Ribonucleases