Specialized Services

Contacts: Drs.Rebeca Geffin (RGeffin@med.miami.edu) and Walter Scott (Scott@med.miami.edu)

The virology component of the University of Miami D-CFAR has expertise in the following assays and procedures.  In some cases we can offer to carry out virology procedures on a fee-for-service basis (fees to be determined).  For other, more specialized procedures, we are interested in establishing collaborative efforts.

Virus quantitation. Preparation of HIV-1 stocks from clinical specimens, and evaluating these virus stocks by measuring HIV-1 capsid antigen (HIV-1 p24 Ag), HIV-1 infectious titer by limiting dilution titration in activated PBMC.  These procedures are useful for cell culture studies where virus input must be quantitated.

HIV-1 subtype determination by polymerase chain reaction (PCR) assay.  This may be of interest in clinical studies of patients infected with a HIV virus that may not be clade B and therefore may give aberrant results in standard determinations of viral load by molecular methods. 

Assays to determine HIV-1 coreceptor usage by a clinical isolate. This can be accomplished by various assays but we use PCR amplification, sequencing and determination of overall charge of the HIV envelope V3 loop, which is predictive of coreceptor usage. We will advise if phenotypic confirmation is needed.

HIV-1 fitness assay. Drug resistance mutations, antibody and CTL escape mutations, and changes in coreceptor specificity may all alter the ability of HIV-1 to replicate and also may affect HIV-1 pathogenesis.  To some extent these effects are reflected in the rate of HIV-1 replication in cell culture.  We feel that the exploration of these assays in connection with specific clinical studies to be a potential area for collaboration. We are currently developing an assay that can measure the ability of a test isolate to compete with a standard isolate for growth in peripheral blood mononuclear cells. This competition assay is more sensitive than conventional measurements of viral growth kinetics.

HIV-1 immune serum neutralization assay. Humoral antibody response is an important factor in driving the evolution of virus envelope protein.  Specific questions about host response to the HIV-1 infection and HIV-1 adaptation to the host humoral response can be assayed by cell culture assays that measure the ability of patient's serum to neutralize HIV-1 infectivity.  We would welcome inquiries about potential collaborations in this area.

Contact: Dr. Helena Schmidtmayerova (HSchmidtmayerova@med.miami.edu)

Virus infectivity assays. We will concentrate the virus from clinical samples, such as plasma and cervical lavage, determine viral infectious units (i.u.) using reporter cell lines.

Preparation of in vitro infected cells. We can prepare primary lymphocytes and macrophage cultures infected in vitro with primary HIV-1 R5, X4, or R5/X4 strains. This service may be useful for studies directed to the identification of HIV-related changes in the expression of host proteins and immune markers (gene array, functional genomic, proteomic).

Pre-clinical in vitro studies of HIV-1 inhibitors.  Evaluating the in vitro efficiency of HIV-1 inhibitors in cultures of primary lymphocyte and macrophages.