Chromatographic removal combined with heat, acid and chaotropic inactivation of four model viruses

The virus removal of protein A affinity chromatography, inactivation capacity, acid pH and a combination of high temperature with a chaotropic agent was determined in this work. The model viruses studied were sendaivirus, human immunodeficency virus (HIV-IIIb), human poliovirus type-II, human herpesvirus I and canine parvovirus. The protein A affinity chromatography showed a maximum reduction factor of 8 logs in the case of viruses larger than 120 nm size, while for small viruses (18-30 nm) the maximum reduction factor was about 5 logs. Non viral inactivation was observed during the monoclonal antibody elution step. Low pH treatment showed a maximum inactivation factor of 7.1 logs for enveloped viruses. However, a weak inactivation factor (3.4 logs) was obtained for DNA nonenveloped viruses. The combination of high temperature with 3 M KSCN showed a high inactivation factor for all of the viruses studied. The total clearance factor was 23.1, 15.1, 13.6, 20.0 and 16.0 logs for sendaivirus, HIV-IIIb, human poliovirus type-II, human herpesvirus I and canine parvovirus, respectively.

Broadly reactive antibodies against a gp120 V3 loop multi-epitope polypeptide neutralize different isolates of human immunodeficiency virus type 1 (HIV-1)

A gene encoding for a novel multi-epitope polypeptide (TAB4) was synthesized and expressed in Escherichia coli. The protein was composed of 15 amino acid fragments derived from the V3 loop of HIV-1 isolates MN, IIIB, RF, JY1, BRVA and LR150, joined by five-amino-acid linkers. Immunogenicity of TAB4 in rabbits was studied, and the antibody response against individual peptides investigated. TAB4 was shown to be immunogenic in Complete Freund's Adjuvant in a dose-dependent manner, and was able to elicit a humoral response against all V3 epitopes included on the protein. Sera from some of the animals were able to neutralize the replication of viral strain MN, and in one case IIIB, with moderate titers. Some sera also neutralized several Cuban clinical strains, isolated in peripheral blood mononuclear cells, after one round of amplification in MT4 cells.

Isolation and virological characterization of HIV-1 in Cuba. Relationship with the clinical status of the patients

The objective of this paper is the isolation and biological characterization of HIV-1 from patients at different clinical status of the disease. Clinical, epidemiological and virological aspects of 54 infected people were studied. Isolate HIV-1 strains were characterized and classified in relation with replication kinetics and cellular tropism as well as syncytium inducing (SI), and non syncytium inducing (NSI) capacity. The biological phenotype of viral isolates was correlated with the clinical status of each patient. HIV was isolated from 92.8% AIDS patients and 46.1% asymptomatic seropositive patients, 12 out of 26 strains of AIDS patients were classified rapid high (RH) and SI, however 2 out of 12 strains of asymptomatic seropositive carriers were considered similar too. The percentage of recovered viral isolates correlates with the patient's clinical status, and the association existing between the isolate biological phenotype and the clinical status of the infection in most of the cases, but not in all was demonstrated.

Envelope V3 region sequences of Cuban HIV-1 isolates

The origin of HIV-1 species, responsible for the AIDS epidemic in Cuba, is a subject that has been intensely debated. This study represents an initial attempt to shed light on this issue, through sequence analysis of the V3 regions of viruses isolated from 15 Cuban subjects. We now report that these viruses fall within three distinct, well-recognized groupings. These findings suggest that viruses of different sources are responsible for the HIV/AIDS epidemic in Cuba.