Production Group

• Vaccine Production by Rodjana Chunhabundit

• Interleukin-2 by Prasit Faipenkhong

• Waste Water Treatment for IL-2 Production Plant b

y Wang Dong Mei

• Plant Location and Quality Control

by Waraporn Pornlab

• Design of New Protease Inhibitors and Ritonavir S

ynthesis by Sathaporn Prutipanlai

Production Group

• Purification Strategies by Thida Chanyachukul• Production Plant Design by Udomsak Kongmung• Pollution Control Strategies by Kanatip Ratanachoo• Production Cost Analysis by Siranee Sreesai

Rodjana Chunhabundit

Toxicology Program, Faculty of Science

Mahidol University

Outlines

• Introduction

- Requirement and strategies for HIV vaccines

• Contents

- Implementation of candidate HIV vaccine

- Production techniques

- Clinical trials of candidate HIV vaccines

• Conclusion

The Need for HIV Vaccine

• The high infection rate

• The high cost of palliative care and drug therapies

• Poor toleration of drugs and the emergence of drug resistance

• Persistent of virus in the host

To stop the global HIV/AIDS pandemic

Requirements for an HIV vaccine

The successful vaccine must induce

– Neutralizing antibody

– Lymphokines

– Cell mediated immunity (CMI)

CTLs

– Long-lasting memory T and B cells

Current Strategies for an HIV Vaccine

• Inactivated or killed vaccines

• Live attenuated vaccines

• Subunit vaccines– Recombinant envelope protein– Peptide vaccine

• Live vector-based vaccines

• DNA vaccines (DNA plasmids)

Inactivated or Killed Vaccines

• Whole viruses killed or inactivated by some chemicals.

• Antigens are presented in a fashion similar to

the way they are presented by real pathogen.

• Incomplete activation of HIV viruses can lead

to inadvertent infection of vaccines.

Preparation of the inactivated whole-virus vaccine derived from a proviral DNA clone of SIV

I. Preparation of the infectious SIV• Transfecting a proviral DNA clone of SIV from so

oty mangbeys into CEM x174 cells

• Collect supernatants from expanded cultured,

clarify and concentrate 100 fold by ultrafiltration

• Purify concentrated virus by ultracentrifugation

through a 20% glycerol

• Resuspened pelleted, partially purified virus in ph

osphate-buffer saline and store at -70oC until

inactivation

Preparation of the Inactivated Whole-virus Vaccine Derived from a Proviral DNA Clone of SIV

II. Inactivation of virus

• Add the solution of psoralen (trioxsalen) to

conc. virus at room temp.

• Expose the suspension of virus to UV light (365 nm)

for 15 min.

• Repeat psoralen/UV light treatment for 3 times.

• Dilute inactivated virus in buffer, aliquot and store in

liq. Nitrogen.

• Confirm inactivation by inoculating CEMx174 cells in

culture.

Live Attenuated Vaccines• Nonpathogenic organisms that have been engineered

to carry and express antigenic determinants from

pathogenic agents or pathogenic organisms in which

the virulent genes have been modified or deleted.

• Antigenic determinant exist in a conformation that is very

similar form of the antigen in the disease-causing

organisms sustained stimulus to the HIR and CIR.

• An attenuated strain of HIV,mutant lacks a large of

nef gene long-term non-progressors.

• Live attenuated viruses may revert to pathogenic strain or cDN

A from vaccine strain may enhance the cellular oncogene.

Strategy for Deleting Part of the Cholera Toxin A1 Peptide DNA Sequence

Limitations of Traditional Vaccines

• Require animal cell culture which is expensive

• The yield and rate of production are often quite low,

thereby making vaccine production costly

• Extensive safety precautions are necessary

• Insufficiency killing or attenuation can introduce

virulent organisms into vaccine spreading dis.

• Attenuated strains may revert

• Not all diseases (e.g., AIDS) are preventable through

the use of traditional vaccines

Subunit Vaccines

• Components of a pathogenic organism.

• Using of recombinant DNA technology.

• Advantages: stable, safe, defined chemically and free from contaminate proteins and nucleic acids.

• Disadvantages: costly, altered conformation fo antigenic determinants.

• Immunization with gp 120 or recombinant vaccinia virus coding for the HIV gp 160 induce T-cell mediated IR.

• Neutralizing epitopes are presented on both gp 120 and gp 41 proteins.

• Immunization in chimpanzees with purified gp 120 has failed to protect against infection with HIV-1.

Evidence Supporting gp 160 is the one of the candidate HIV vaccine

Development of the Full-length Envelope Glycoprotein

• Approach by cloning and expression of env. glycoproteins in bacterial, mammalian and insect cell systems.

• A gp 160 expression system based on coinfection of Vero cells with two recombinant vaccinia viruses which are the vector for genes required in synthesis of env. glycoproteins.

Large-scale Production of a Vaccine Recombinant Derived HIV-1 gp 160

• Construction of Plasmids

- gp 160 gene flanked by bacteriophage T7 promotor and terminate sequence.

- T7 RNA polymerase gene under the vaccinia promotor

• Construction of Vaccinia Virus Recombinants

- Infecting CV-1 cells with vaccinia virus and transfecting them with precipitate plasmid DNA.

- Harvest the cells and isolate recombinant virus.

Production of Recombinant Virus Stocks

Vero cells + recombinant viruses

37o C, 2-3 days

shaken and centrifuged

supernatant cells

stored at 4o C washed and trypsinized

pooled and aliquoted, frozen at -80o C

Large-scale Cultivation of Vero Cells

Vero cell inoculum

Roller bottles

6 liter fermenter

40 liter vessel

Cells adhere on microcarriers

gp 160 Production

5 x 109 cells/liter

medium settled recomb. virus

microcarrier + medium

40 hrs

detached cells pump out with the medium

adhering cells are washed and rapid stirring

70 m sieve

centrifugation

pellet store at -80o C

Peptide Vaccines

• Target epitopes most immunogenic

• Peptide sequences strongly binding with

neutralizing antibody

• amino acid 735 to 752 of gp160, RP-35 of gp120,

core protein p17

• highly specific, inexpensive and safe

• tertiary structure different from neutral protein

Preparation of the Hybrid T1-SP10 Peptide

• Synthesize peptide by using of peptide synthesizer

• Deprotect and cleave peptides from the supporting

resin with hydrogen fluoride in 10% anisole

• Solubilized in 15-25 % (v/v) glacial acetic acid and

lyophilized

• Reconstitued in PBS and dialyzed or HPLC purified

• Determine molecular mass by mass spectrometry

Live Vector-Based Vaccine

• Live virus vectors containing HIV gene

• Sustained expression of large amount of HIV Ag

neutralizing Ab and CTLs responses

• Vaccinia virus is a strong candidate as a vector vaccine becaus

e– It can express inserted gene independently of host regulator

y or enzymatic functions– broad host range, stable, benign virus

• Gene coding for specific antigen must be introduced

into viral genome by in vivo homologous recombination

Method for the Integration into Vaccinia Virus of a Gene Whose Protein Product

DNA Vaccines

• In vivo delivery of antigen-encoding plasmid DNAs, not protein immunogens

• Correctly folded and glycosylated antigens in vivo

effective HIR and CIR against live virus challenge

• Cloned gene encoding antigen in a plasmid is coated o

n a gold particles

• ‘Gene gun’ is used to accelerate DNA-coated gold parti

cles into target tissue

Clinical Trials of HIV Vaccines

Phase I trial

- evaluate safety and immunogenic response

- sample size and the length of follow-up are

grater than other vaccines

- population for phase I trial should be individuals

at no risk of HIV infection

Phase II trial

- determine optimal dosage schedules based on

safety and immunogenicity data

- larger number of volunteers

- high and low-risk populations

Phase III trial

- placebo-controlled, randomized and

double-blind studies

- number of volunteers is determined by

incidence of infection rate and statistical

parameters of protection

- be performed only in the most promising

candidate vaccines

- target populations, including

Homosexual men, intravenous drug users,

prostitutes, prisoners, newborn of seropositive mother,

and seual transmitted disease patients

Phase of Clinical Trials of a Candidate AIDS Vaccine

Phase Type of Duration Purpose

subjects

1 Low risk Up to 1 yr Mainly safety, some

immunogenicity

2 Low & high Up to 2 yr Safety, immunogenicity

risk

3 All target Up to 4 yr Efficacy, safety,

populations dosage

AIDS Vaccines Currently in Clinical Trials

• Subunit Vaccines

- Recombinant envelope protein: gp 160, gp 120

- Peptide: V3 peptide, T-B peptide

• Live vector-based vaccines

- Vaccinia envelope

- Canarypox envelope

• DNA vaccines

Conclusion

The preventive HIV vaccine

- elicit specific CTLs and neutralizing

antibody for all strains of HIV

- easy administration

- safe

- low cost