In vitro selective elimination of HIV-infected cells from peripheral blood in AIDS patients by the immunotoxin DAB389CD4.
OBJECTIVE
To study the antiviral efficacy of the recombinant immunotoxin DAB389CD4 against wild-type strains of HIV and to analyse its potential toxicity in non-infected peripheral blood mononuclear cells (PBMC).


METHODS
PBMC from HIV-seropositive patients were cultured in the presence of DAB389CD4. After 30 days in culture, viral load was assessed by quantification of RNA levels in supernatants and HIV-specific polymerase chain reaction (PCR) was performed for measuring proviral DNA as an indicator of remaining virus in cells. To study the toxicity of DAB389CD4, PBMC from healthy donors were isolated and cell viability and lymphocyte proliferation were assessed after immunotoxin treatment.


RESULTS
DAB389CD4 presented a strong antiviral activity in five of the six primary isolates decreasing p24 production in cultures to undetectable levels and eliminating selectively HIV-infected cells as measured by HIV DNA-specific PCR. One viral isolate was resistant to DAB389CD4 treatment. The immunotoxin was active against both syncytial and non-syncytial HIV strains. DAB389CD4 was not toxic in non-infected PBMC as measured by different techniques: trypan blue exclusion, methyl thiazol tetrazolium oxidation, lymphocyte proliferation, and CD4 cell count.


CONCLUSIONS
DAB389CD4 showed a strong antiviral and specific activity against primary HIV isolates by killing selectively HIV-infected cells without affecting non-infected cells. This antiviral effect produced the eradication of HIV in cultures and indicated the potential use of this drug as a new therapeutic tool in combination with antiretroviral drugs. This immunotoxin would be especially interesting in the context of the marginal populations of HIV-infected cells remaining after successful antiviral treatment.
Martín-Serrano
J
J
Servicio de Microbiología, Centro de Investigación, Hospital 12 de Octubre, Madrid, Spain.
Folgueira
L
L
Laín de Lera
T
T
Pedraza
M A
MA
Lemichez
E
E
Sánchez-Palomino
S
S
Noriega
A R
AR
Boquet
P
P
Alcamí
J
J
D019380:Anti-HIV Agents / Q000494:pharmacology*; D015704:CD4 Antigens / Q000235:genetics / Q000494:pharmacology* / Q000633:toxicity; D002470:Cell Survival; D002478:Cells, Cultured; D004167:Diphtheria Toxin / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D006678:HIV / Q000502:physiology*; D016655:HIV Core Protein p24 / Q000096:biosynthesis; D006801:Humans; D000922:Immunotoxins / Q000494:pharmacology* / Q000633:toxicity; D007963:Leukocytes, Mononuclear / Q000821:virology*; D010641:Phenotype; D011533:Proviruses; D012367:RNA, Viral / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000494:pharmacology / Q000633:toxicity; D014779:Virus Replication
D019380:Anti-HIV Agents; D015704:CD4 Antigens; C114227:DAB389CD4; D004167:Diphtheria Toxin; D016655:HIV Core Protein p24; D000922:Immunotoxins; D012367:RNA, Viral; D011993:Recombinant Fusion Proteins