ProposedProposed Animal Study to Evaluate Animal Study to Evaluate Simian Foamy Virus (SFV) Transmission Simian Foamy Virus (SFV) Transmission

by Bloodby Blood

Arifa S. Khan, Ph.D.Arifa S. Khan, Ph.D.

DVP, DVP, OVRROVRR, CBER, FDA, CBER, FDA

BPAC, December 13, 2001BPAC, December 13, 2001

Overall Summary of Planned Overall Summary of Planned StudyStudy

• Whole blood from an SFV-infected rhesus macaque will be injected into SFV-negative monkeys.

• Blood recipients will be monitored for SFV infection by virological, serological, molecular and clinical analysis.

• The inoculated animals will be followed for 1 year to evaluate SFV infection by blood.

Donor CriteriaDonor Criteria

• Adult, rhesus macaque from which SFV has been well-characterized (biologically and molecularly).

- Exist in-house from previous studies- Exist in-house from previous studies

• High viral load in plasma and/or PBMCs.

- TaqMan PCR for SFV- TaqMan PCR for SFV

• Good replication efficiency.

- - in vitroin vitro analysis in different human cell lines analysis in different human cell lines

Selection of SFV Negative Animals as Selection of SFV Negative Animals as Blood RecipientsBlood Recipients

• Juvenile, rhesus macaques will be obtained from a known “retrovirus-free” colony and the absence of SRV, STLV and SIV confirmed by independent analysis.

• SFV negative animals will be identified by serology and confirmed by PCR and culture.

• Animals will be individually-housed at the time of initial serology and maintained as such throughout study.

Experimental Details of Monkey Study to Experimental Details of Monkey Study to

Evaluate SFV Transmission by BloodEvaluate SFV Transmission by Blood Animals [SFV -ve Rhesus macaques]

6 = transfused with SFV+ blood

2 = transfused with SFV- blood (controls)

Inoculum: blood volume for intravenous transfusion will be determined according to body weight

Blood Preservative: CPD-adenine (currently used in human blood transfusions)

Plasma and PBMCs will be prepared and stored from every blood collection

Experimentally negative animals will be challenged with a laboratory stock of SFV

Monitoring of SFV Infection in Blood Monitoring of SFV Infection in Blood RecipientsRecipients

• Serology Serology - neutralizing antibody titer- neutralizing antibody titer

- Western blot- Western blot

• VirologyVirology - SFV detection in monkey PBMCs by PCR and- SFV detection in monkey PBMCs by PCR and

virus identification by sequencingvirus identification by sequencing

- virus isolation by co-culture of monkey PBMCs - virus isolation by co-culture of monkey PBMCs

with with Mus dunniMus dunni cells cells

Additional Evaluation of Monkeys Additional Evaluation of Monkeys Transfused with SFVTransfused with SFV++ Blood Blood

• Clinical monitoring

- Hematology- Hematology

- Serum chemistry- Serum chemistry

- physical exam- physical exam• Toxicology• Histology• Immunophenotyping

• The results of the proposed study will The results of the proposed study will provide a scientific basis for evaluating provide a scientific basis for evaluating potential risk of SFV transmission by blood potential risk of SFV transmission by blood transfusion and help formulate criteria for transfusion and help formulate criteria for acceptance or exclusion of potential blood acceptance or exclusion of potential blood donors who are at risk for SFV infection.donors who are at risk for SFV infection.

STUDY OUTCOMESTUDY OUTCOME