艾滋病疫苗与中和抗体

清华大学 张林琦 2014年10月20日

Current situation

有病无苗

有苗不优

优苗不种

Lu L, and Zhang L., Nature 2008

Rapid rise in sexual transmission of HIV

Shang H and Zhang L., Nature 2012

Risk factors in different regions

三个关键方面

以毒攻毒的哲学理念

Practice of variolation originated in China and widely used by 1500’s to control smallpox Lady Mary Wortley Montagu introduced

Variolation to England in 1700’s.

Edward Jenner (1749 – 1823)

Edward Jenner, FRS, (17 May 1749 – 26 January 1823) was an English country doctor who studied nature and his natural surroundings from childhood and practiced medicine in Berkeley, Gloucestershire, England. He is famous as the first doctor to introduce and study the smallpox vaccine

疫苗接种后人体的正常反应

Smallpox eradication in 1980

100nm

Edward Jenner (1749-1823)

Edward Jenner (1749-1823)

Prevention of poliovirus infection

• Most countries use OPV because of its ability to

induce local immunity and also it is much

cheaper to produce than IPV.

• The normal response rate to OPV is close to

100%.

• OPV is used for the WHO poliovirus eradication

campaign.

• Because of the slight risk of paralytic

poliomyelitis, some Scandinavian countries have

reverted to using IPV. Because of the lack of

local immunity, small community outbreaks of

poliovirus infections have been reported.

• Poliovirus was targeted for eradication by the

WHO and Gates Foundation. To this end, an

extensive monitoring network had been set up.

• Poliovirus has been eradicated from most

regions of the world except the Indian

subcontinent and sub-Saharan Africa. It is

possible that the WHO target may be achieved.

泰国RV144是唯一具保护性的临床试验

Challenges ahead: Improve vaccine efficacy and longevity of protection

Mucosal prime with a replicating vaccinia-based vaccine

Prime with MVTTSIVgpe and

boost with Ad5SIVgpe

Challenge with pathogenic SIVmac239 ( 5 x 105 intrarectal challenge)

4 8 12 24

Protection from SIV infection /SAIDS

30 150wk

Protective effects of the MVTTioin+Adim regimen in Chinese monkeys

艾滋疫苗研发的主要障碍

• 自然感染状态下，保护性免疫反应不详

• 重复感染现象已被证实

• 传统的疫苗策略至今没有一个成功

• 变异与逃逸能力

• 对抗体的不敏感性

• 没有理想的动物模型

First Nobel prize and serum treatment

One of the first bottles (1895) of diphtheria antitoxin produced at the Hygienic Laboratory, which became the NIH in 1930

From Dr. Bailin Tu,

白喉抗毒素

Monoclonal antibody (mAb)

Georges Jean Franz Köhler (1946-1995) César Milstein (1927-2002) Niels Kaj Jerne, (1911 – 1994)

1984

Original publication in Nature

Nature 256, 495-497 (7 August 1975) Continuous cultures of fused cells secreting antibody of predefined specificity G. KÖ HLER & C. MILSTEIN MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Abstract THE manufacture of predefined specific antibodies by means of permanent tissue

culture cell lines is of general interest. There are at present a considerable number of permanent cultures of myeloma cells and screening procedures have been used to reveal antibody activity in some of them. This, however, is not a satisfactory source of monoclonal antibodies of predefined specificity. We describe here the derivation of a number of tissue culture cell lines which secrete anti-sheep red blood cell (SRBC) antibodies. The cell lines are made by fusion of a mouse myeloma and mouse spleen cells from an immunised donor. To understand the expression and interactions of the Ig chains from the parental lines, fusion experiments between two known mouse myeloma lines were carried out.

Hybridoma and mAb

Hybridoma Fusions

Immunized Animal

Isolate B-cells contain desired antibody

Myeloma cells imparts immortality

Screen clones and expand cell line

Antibody producing clone

Wilson P, NRI, 2012

New technologies for isolating mAbs from animals and

humans

Protective Immunity ? Protective antibody response?

保护性免疫反应？

保护性抗体反应？

Key roles of neutralizing antibodies

Corti and Lanzavecchia, Annnu. Rev. Immunol. 2013

Immune response against HIV-1

Johnston and Fauci, NEJM, 2007

Virus and antibody interaction

Letvin and Walker, Nat. Medicine 2003

New technology in isolating mAbs

Antigen-specific B cells

Single B cells based mAb isolation

1.单个抗原特异性浆细胞分选 2.单个抗原特异性记忆B淋巴细胞分选 3.分选并培养记忆B淋巴细胞

+ VH L

VL L

Ig VH

Ig VL

抗体基因序列分析

+ VH L IgG1 CH PCMV BGH

Poly A

VL L CK or CL PCMV BGH Poly A

线性抗体重链基因

线性抗体轻链基因

RT/PCR

分选

单个细胞

细胞转染

抗体结合和中和实验

B细胞培养

PCRb IgH

PCRb IgK PCRb IgL

R002 R026 R041 R001 M R002 R026 R041 R001 M R002 R026 R041 R001 M R002 R026 R041 R001 M

HIV-1 Spike and Its Recognition by Neutralizing Antibodies。 The 20A °cryoelectron tomogram of the HIV-1 BaL isolate viral spike (Liu et al., 2008) is shown in gray, fitted with three copies of the HIV-1 gp120 core in the CD4-bound conformation (Pancera et al., 2010a), with modeled glycans and with modeled sites of Env vulnerability colored red (CD4-binding site), green (glycan N160 in V1/V2), blue (glycan N332 at the base of V3), and cyan (MPER of gp41). Effective mAbs are shown that recognize each site (see main text for fuller descriptions and references). Movie S1 available online shows the viral spike and recognizing antibodies.

Kwong and Mascola, Immunity 2012

Reverse vaccinology approach

反向疫苗学

1

2

Specificity o

f selection

pro

cess

VRC01 selected longest fragment

VRC01 selected shortest fragment

VRC01 selected fragments core

Consensus sequences of yeast clones positively selected by VRC01 are shown aligned with the original full-length HIV-1 subtype B sequence used to construct the random fragment yeast library

The full-length HIV-1 CNE11 sequence

Wang H. and Zhang L., unpublished

Selected fragments contain epitope

Selected fragments contain epitopes

Structure of antibody VRC01 in complex with HIV-1 gp120

Structure of the V1/V2 domain of HIV-1 gp120 in complex with PG9

McLellan JS et al, Nature, 2011 Zhou T et al, Nature, 2010

Structure rearrangement of RSV F

McLellan et al., Science 2013

Crystal structure of mAb D25 with RSV F

McLellan et al., Science 2013

Engineered RSV F to preserve antigenic site

McLellan et al., Science 2013

Immunogenicity of engineered RSV F trimers

McLellan et al., Science 2013

Challenges and Opportunities

Dynamic understanding of protective antibody response throughout the course of infection.

Correlate studies on antigenic domains with protective antibody response.

Identify the antigenic domains recognized by broadly neutralizing antibodies for rational design and optimization of vaccines.

Challenges and opportunities ahead

Acknowledgements

National Science and Technology Major Project MOST and MOH

Bill and Melinda Gates Foundation

Jassen Investigator Award

Acknowledgements