Table 4 Preclinical studies of L2-based HPV vaccines

1

HPV-16 L1 VLP

Alum-MPL

RG1 epitope (HPV-16 L2 aa 17–36

Insect cells

In vitro (rabbit)

Passive transfer of sera-protected mice against PsVs of HPV-16/18/45/31/33/52/58/35/39/51/59/68/56/73/26/53/66/34 and LR-HPV-6/43/44

nAbs against HR-HPV- 16/18/45/37/33/52/58/35/39/51/59/68/73/26/69/34/70, LR-HPV-6/11/32/40, and cutaneous HPV-2/27/3/76 in PBNA

2013

[108]

2

HPV-16 L1 VLP

Alum/MPL

RG1 epitope

Sf9 insect cells

In mice (RG1-VLP + HPV-18 L1-VLP)

In rabbits

Cross-protection against vaginal challenge with HR-HPV-58

Cross-neutralization titers (50–1000) against HR-HPV-18/31/33/45/52/58/26/70

2019

[109]

3

HPV-16 L1 VLP

Alum-MPL

HPV-31 L2 (aa.17–38)

Bac-to-Bac baculovirus

In vivo (mice)

Cross-nAbs against HPV-2/5/6/11/16/18/27/31/33/35/39/52/57/58/59/68

2018

[110]

4

HPV-16 L1 VLP

Freund adjuvant

HPV-16 L2 aa108-120

aa 56–81

aa 17–36

BPV-1 L2 aa 1–88

Insect cells

In vitro

In vivo (mice)

Most vaccinated mice could neutralize HPV-16 PsVs

nAbs against HPV-16

nAbs against HPV-16

No nAbs

2013

[111]

5

HPV-16 L1 VLP

Alum-MPL

HPV-58 L2 aa.16–37

Baculovirus

In vivo (rabbits and mice)

nAbs against HPV-2/5/6/11/16/18/27/31/33/35/39/45/52/57/58/59/68

2017

[112]

6

HPV-16 L1 VLP

Alum with BECC470

(Bacterial enzymatic combinatorial chemistry)

HPV-16-L2 17–36 a.a. (RG1 epitope)

Yersinia pestis

In vitro and in vivo

nAbs against HPV-16/18/39

2021

[113]

7

HPV-16 L1 VLP

-

HPV-16 L2

Pichia pastoris

In vitro

Positive reaction against L1-HPV-16 antibody and L2 -HPV-16 antibody

2018

[114]

8

HPV-18 L1 VLP

AS04

HPV-16 L1, HPV-18 L1, and recombinant L2 fragment consisting of HPV-33 and HPV-58

(HPV-33 L2 (aa 17–36) + HPV-58 L2 (aa 56–75))

pAcSG2 baculovirus

In vivo (mouse and rabbit)

Protection against HPV-6/11/16/31/35/39/45/58/59 PsVs or quasivirions

2016

[115]

9

HPV-18 L1 VLP

Alum-MPL

HPV-45 L2

(aa 16–35)

Sf9 insect cells

In vitro

In vivo (rabbits)

nAbs against HPV-18/39/45/68/70

Passive transfer of sera-protected vaginal challenge of mice with PsVs of HPV-18/39/45/68

2015

[116]

10

HPV-16 L1

HPV-5 L1

HPV-1 L1

HPV-16/18 L1

Alum-MPL

HPV-17 L2 RG1

HPV-17 L2 RG1

HPV-4 L2 RG1

HPV-5 L2 aa53-72

Spodoptera frugiperda (Sf9) insect cell

In vitro

PsVs neutralized in L2-based PBNA:

HPV-5/8/20/23/24/36/49/80

HPV-20/24/36/92

HPV-4

No nAb in L2-based PBNA

2017

[82]

11

HPV-16 L1 VLP

-

HPV-16 L2

aa 108–120

aa 65–81

aa 56–81

aa 17–36

Agrobacterium tumefaciens

In vitro

PsVs neutralized in PBNA:

HPV-16/58

HPV-11/16/18

HPV-18

No nAb

2019

[117]

12

MS2 bacteriophage VLP

Incomplete Freund’s adjuvant

HPV-16 L2

aa 17–31

aa 20–29

aa 14–40

aa 14–65

C41 cells (Lucigen)

In vivo (mice)

Protection from vaginal challenge against HPV-5/6/16/31/33/35/39/45/51/53/58

Not tested

Not tested

Not tested

2012

[118]

13

MS2 bacteriophage VLP

Alum hydroxide

HPV-16 L2

aa 17–31

 + 

HPV-31 L2

aa 20–31

 + 

aa 69–86, 108–122 from a consensus L2 sequence

C41 cells

Escherichia coli

In vivo

(mice)

Protection of mice against cervicovaginal infection with HPV-16/18/31/33/45/58 PsVs

2017

[119]

14

MS2 Bacteriophage VLP

With and without alum hydroxide

HPV-16 L2 aa 17–31

E. coli (C41)

In vivo (mice)

Spray-dried VLPs were highly immunogenic and protected mice in the genital challenge with HPV-16 PsVs

2015

[120]

15

MS2 Bacteriophage VLP

PP7

Bacteriophage VLP

Incomplete Freund’s adjuvant (IFA)

L2 aa 17–31 of HPV-16/31

L2 aa 17–31 of HPV-16/18

C41 cells (Lucigen)

In vitro

In vivo (mice)

Neutralized PsVs of HPV-16/18/31/45/58

Protected mice against vaginal challenge with HPV-6 PsVs

2014

[121]

16

MS2 Bacteriophage VLP

Cholera toxin and MPL

1) HPV-31 L2 aa 20–31 + HPV-16 L2 aa 17–31

2) Consensus aa 69–86

C41 E. coli

In vivo (mice)

Mixed VLPs contained both antigens to protect mice from PsVs;

HPV-11/16/35/39/52/53/56/58

2019

[122]

17

MS2 Bacteriophage VLP

Alum

1) HPV-31 L2 aa 20–31 + HPV-16 L2 aa 17–31

2) Consensus aa 69–86

C41 E. coli

In vivo

(mice)

Mixed VLPs protected against genital infection with PsVs of HPV-5/6/51

2021

[123]

18

Qβ bacteriophage VLP

PP7

bacteriophage

VLP

Incomplete Freund’s adjuvant

HPV-16 L2 aa 34–52

aa 49–72

aa 108–120

aa 65–85

Consensus HPV-16 and −18 L2 aa 65–85

HPV-16 L2

aa 17–31

aa 51–65

aa 35–50

C41 E. coli (Lucigen)

In vitro

In vivo

(mice)

Protection against PsVs;

Poor protection against HPV-16

Moderate protection against HPV-16

Strong protection against HPV-16 (in vivo) HPV-6/18/31/45/58 (in vivo)

Strong protection against HPV-16

HPV-16 and −18 (in vivo)

HPV-16/18/31/45/58(in vitro)

Strong protection against HPV-16

Moderate protection against HPV-16

Poor protection against HPV-16

2014

[124]

19

Adeno-associated virus 2 VLP

Montanide ISA 51

HPV-16 and HPV-31 L2 aa 17–36

HEK 293T cells

In vitro and in vivo

nAbs against HPV-16/18/31/45/52/58 PsVs in mice and rabbits

Passive transfer of sera-protected mice against vaginal challenge with HPV-16 PsVs

2012

[125]

20

Adenovirus type 5 VLP

Alum and MPL

HPV-16 L2 aa 12–41

HEK 293T cells

In vitro and in vivo

Protection against vaginal challenge with HPV-16

nAbs against HPV-16/73

2015

[126]

21

Adenovirus type 35 VLP

-

L2 RG1 epitope from HPV-6/11/16/18/31/33/45/52/58

PER C6 cells

In vitro

nAbs against HPV-16/18/31/59

2018

[127]

22

Hepatitis B core (HBc) VLP

Alum

aa 14–122 of HPV-16 L2

Nicotiana benthamiana

In vitro

nAbs against HPV-16

2019

[128]

23

Pyrococcus furiosus thioredoxin (trivalent-PfTrx)

Aluminum hydroxide- MPL

L2 aa 20–38 of HPV-16, HPV-31, and HPV-51

Trichoplusia ni (TN) High Five cells

In vitro (mice and guinea pigs)

In vivo

Cross-nAbs against HPV-16/18/31/33/35/39/45/51//52/58/5968

Cross-protection against vaginal challenge with HPV-16/18/31/33/51

2015

[129]

24

PfTrx–8-mer–OVX313

Alum-MPL

or

glycopyranosyl lipid A

or

Army liposome formulation-alum

L2 aa 20–31 of HPV-6/16/18/31/33/3551/59 fused to PfTrx and OVX313

E. coli BL21 cells

In vitro (mice and guinea pigs)

In vivo

Cross-nAbs in PBNA test against HPV-6/11/16/18/31/33/35/39/45/51/52/56/58/59/68/73

Passive transfer of sera-protected mice against HPV-6/11/16/18/31/33/35/39/45/56/58

2018

[130]

[131]

25

P. furiosus thioredoxin fused to ferritin nanoparticles (Pf FeTrx8mer)

AddaVax

HPV-16 L2 aa 20–38 of HPV-6/16/18/31/33/35/51/59

Baculovirus-infected insect cells

In vitro

In vivo

nAbs titers against HPV-6/11/16/18/31/33/35/39/45/51/52/56/58/59/68/73

Passive transfer of sera-protected mice against HPV-6/11/16/18/33/35/39/45/51/56

2020

[132]

26

Lipidated triple-repeat HPV-16 RG-1 epitope and a hFccRI-specific single-chain antibody fragment (H22scFv)

(LpE3H22)

MF59 and poly I:C

aa 17–36 of HPV-16 L2

E. coli (protein)

293T cells (PsVs)

In vivo

nAbs against HPV-2/5/6/11/16/18/31/33/35/39/45/52/58/59

2016

[133]

27

TLR5 ligand bacterial flagellin (Fla)

-

L2 aa 17–38 of HPV-6/18/31/39/52 added to HPV-16 L2 11–200 or 11–88 fused to flagellin

E. coli

In vitro

In vivo

nAbs against HPV-6/16/18/31/45

Passive transfer of sera-protected rabbit against HPV-6/16/18/31/45/58

2017

[134]

28

L2 concatemer fused to flagellin (A cL2 epitope introduced at the C-terminus of flagellin.) (Fla-5PcL2)

Without adjuvant

or

alum

or

alum-MPL

L2 RG-1 of HPV-18/33/58/59 epitopes and HPV-16 L2 aa 11–88

E. coli

In vitro/in vivo

nAbs against HPV-16/18/31/33/58

Protection of mice against vaginal challenge with HPV-5/39/58

2019

[135]

29

Multimeric protein

Alum

L2 11–88 aa of HPV-6/16/18/31/39 (11–88 × 5)

88 × 8 (HPV-6/16/18/31/39/51/56/73

E. coli BL21

In vivo

Protection of mice against HPV-6/16/26/31/33/35/45/51/56/58/59 challenge

2013

[136]

30

Lactobacillus casei

-

HPV-16 L2 aa 1–224 fused to poly-γ-glutamic acid synthetase A

293T cell line

In vitro and in vivo

Oral administration protected mice against HPV-16/18/45/58

2012

[137]

31

DNA vaccine

-

Fused L1–L2 genes

HEK-293 cell line

In vitro

In vivo

(mice)

The high expression rate of recombinant L1-L2 HPV-16 DNA

Protection against C3 tumor cells

2019

[138]

32

L2-based recombinant vaccine

Self-assembled peptide (OVX313) and thioredoxin

HPV-16 L2

E. coli BL21

In vivo

(mice)

The larger antigen size correlates with enhanced B-cell induction and increased plasma half-life

2017

[74]

33

RG2-VLP

Aluminum hydroxide

RG2

Cottontail rabbit papillomavirus (CRPV) quasivirus

In vivo

(mice)

Robust L2-specific antibody titers and protection against β-type HPV5

Similar HPV16- and HPV18-specific neutralizing Ab responses between RG2-VLP- and Gardasil®9 groups

2022

[139]

34

MS2-L2 VLPs

-

MS2-31L2/16L2 VLPs and MS2-consL2 (69–86)

E. coli

In vivo

(mice)

Constant antibody titer against HPV16 L2 (aa 17–31) and HPV31 L2 (aa 17–31) peptides

2021

[123]

35

RG1-VLP

Aluminum hydroxide or poly[di (carboxylatoethylphenoxy) phosphazene] (PCEP)

HPV16-L1

L2 RG1

293-TTF cells

In vivo

(mice)

Cross-neutralization of pseudovirion types HPV18 and HPV39

Sufficient level of Ab titer after two doses of vaccine with PCEP

2021

[140]

36

HPV16L2-N200 (first 200 aa of L2) HPV16L2-N88 as fused or mixed with Tat-protein transduction domain (PTD) as a CPP

Freund's adjuvant

HPV16-L2

E. coli

In vivo (mice)

Increased titer of anti-HPV16L2 total antibodies and neutralizing antibodies for HPV16 and other HR-HPVs (HPV16, 18, 31, 45, and 58) following vaccination with fused PTD-L2-N200

2016

[141]