3-Hydroxyphthaloyl β-Lactoglobulin. IV. Antiviral Activity in the Mouse Model of Genital Herpesvirus Infection

The spread of sexually transmitted infections caused by herpes simplex virus type 2 (HSV-2) has continued unabated despite educational efforts generated in response to the human immunodeficiency virus (HIV) epidemic. Given the absence of effective vaccines, this indicates the need to develop prophylactic measures such as topical antiviral agents. Chemical modification of bovine β-lactoglobulin (β-LG), the major protein of whey, by hydroxyphthalic anhydride (3HP) led to the generation of a potent HIV-1 inhibitor designated 3HP-β-LG. This agent was shown to also have antiviral activity against HSV-2 and HSV-1 in vitro. Recent studies indicate that 3HP-β-LG binds to HSV-1 virions, which, at least in part, involves the viral glycoprotein gE. Here we show that 3HP-β-LG inhibits HSV-2 infection in the mouse model of genital HSV-2 infection. Simultaneous exposure to HSV-2 and 3HP-β-LG caused a significant decrease in the proportion of infected animals (27% virus shedding, 5% lesion development and 0% fatality for 3HP-β-LG as compared to 80% shedding, 60% lesion development and 53% fatality in micetreated with PBS). The proportion of animals with HSV-2 infection after treatment with β-LG was similar to that in the PBS-treated group. Pretreatment with 3HP-β-LG formulated in a gel, which prolongs the presence of the agent in the vagina, also significantly reduced the proportion of HSV-2-infected mice (5% virus shedding, 5% lesion development and 0% fatality for 3HP-β-LG as compared to 70% shedding, 60% lesion development and 40% fatality in vehicle-treated mice). These differences were significant ( P≤0.0005, 0.002 and 0.008 for shedding, lesion development and fatality, respectively). Virus titres in the minority of mice that developed infection were similar to those in untreated mice. HSV-2 infection was not inhibited by treatment of an ongoing infection, indicating that 3HP-β-LG interferes with the initial infection. These data suggest that 3HP-β-LG may be an efficacious agent for preventing vaginal transmission of genital herpesvirus infections.

Short communication: Variation of total immunoglobulin G and β-lactoglobulin concentrations in colostrum and milk from Canadian Holsteins classified as high, average, or low immune responders

The objective of this study was to evaluate IgG and β-lactoglobulin (β-LG) concentrations in colostrum and milk of Canadian Holsteins (n=108) classified as high (H), average (A), or low (L) for antibody-mediated (AMIR) or cell-mediated immune responses (CMIR) based on estimated breeding values. It was hypothesized that H-AMIR and H-CMIR cows produce colostrum (first milking) and milk (d 5 postcalving) with higher concentrations of IgG and β-LG. Data for IgG and β-LG in colostrum and milk were analyzed independently using mixed linear models. Least squares means were compared using Tukey's test. Cows classified as H-AMIR had higher IgG and β-LG concentrations in colostrum compared with A- and L-AMIR cows; 84% of H-AMIR, 69% of A-AMIR, and 68% of L-AMIR cows had over 5,000 mg/dL IgG in colostrum. No differences in IgG and β-LG concentrations in colostrum were noted among cows ranked on CMIR or in milk of cows ranked on AMIR. β-Lactoglobulin and IgG concentrations were positively correlated in colostrum. Breeding cows for H-AMIR status may reduce failure of passive transfer of IgG in their calves; β-LG may play a role in bovine immune defenses. Colostrum from H-AMIR cows may serve as a more economical feedstock source for manufacturing natural health products.

Maleic anhydride-modified chicken ovalbumin as an effective and inexpensive anti-HIV microbicide candidate for prevention of HIV sexual transmission

Background

Previous studies have shown that 3-hydroxyphthalic anhydride (HP)-modified bovine milk protein, β-lactoglobulin (β-LG), is a promising microbicide candidate. However, concerns regarding the potential risk of prion contamination in bovine products and carcinogenic potential of phthalate derivatives were raised. Here we sought to replace bovine protein with an animal protein of non-bovine origin and substitute HP with another anhydride for the development of anti-HIV microbicide for preventing HIV sexual transmission.

Results

Maleic anhydride (ML), succinic anhydride (SU) and HP at different conditions and variable pH values were used for modification of proteins. All the anhydrate-modified globulin-like proteins showed potent anti-HIV activity, which is correlated with the percentage of modified lysine and arginine residues in the modified protein. We selected maleic anhydride-modified ovalbumin (ML-OVA) for further study because OVA is easier to obtain than β-LG, and ML is safer than HP. Furthermore, ML-OVA exhibited broad antiviral activities against HIV-1, HIV-2, SHIV and SIV. This modified protein has no or low in vitro cytotoxicity to human T cells and vaginal epithelial cells. It is resistant to trypsin hydrolysis, possibly because the lysine and arginine residues in OVA are modified by ML. Mechanism studies suggest that ML-OVA inhibits HIV-1 entry by targeting gp120 on HIV-1 virions and also the CD4 receptor on the host cells.

Conclusion

ML-OVA is a potent HIV fusion/entry inhibitor with the potential to be developed as an effective, safe and inexpensive anti-HIV microbicide.

3-hydroxyphthalic anhydride-modified chicken ovalbumin exhibits potent and broad anti-HIV-1 activity: a potential microbicide for preventing sexual transmission of HIV-1

Heterosexual transmission is the primary route by which women acquire human immunodeficiency virus (HIV)/AIDS. Thus, development of woman-controlled topical microbicides for prevention of sexual transmission of HIV is urgently needed. Here we report that 3-hydroxyphthalic anhydride-modified chicken ovalbumin (HP-OVA) exhibits potent antiviral activity against a broad spectrum of human immunodeficiency virus type 1 (HIV-1) isolates with different genotypes and biotypes. Its antiviral activity is correlated with the percentages of the chemically modified and unmodified lysines and arginines in OVA. HP-OVA inhibits HIV-1 fusion and entry through multiple mechanisms of action, including (i) blocking gp120 binding to CD4 and (ii) interfering with gp41 six-helix bundle formation. Because of the widespread availability and established safety profile of OVA, HP-OVA has good potential to be developed as an effective, safe, and affordable microbicide for prevention of HIV sexual transmission.

Effect of a cellulose acetate phthalate topical cream on vaginal transmission of simian immunodeficiency virus in rhesus monkeys

Human immunodeficiency virus type 1 (HIV-1) infection continues to spread in developing countries, mostly through heterosexual transmission. The development of a safe and cost-effective topical microbicide, effective against a range of STDs including HIV-1, would greatly impact the ongoing epidemic. When formulated in a vehicle, a micronized form of cellulose acetate phthalate (CAP), which is an inactive pharmaceutical excipient, has been shown to inactivate HIV-1, herpes simplex virus types 1 and 2, cytomegalovirus, Neisseria gonorrhoeae, Trichomonas vaginalis, Haemophilus ducreyi, and Chlamydia trachomatis in vitro. Formulated CAP was also shown to be effective against herpes simplex virus type 2 in vivo. Here we show that a formulation of CAP protected four of six rhesus monkeys from vaginal infection with simian immunodeficiency virus. Thus, CAP may be a candidate for use as a topical microbicide for preventing HIV-1 infection in humans.

Effect of 3-hydroxyphthaloyl-beta-lactoglobulin on vaginal transmission of simian immunodeficiency virus in rhesus monkeys

Heterosexual transmission of human immunodeficiency virus type 1 (HIV-1) is the major cause of the ongoing AIDS epidemic. Application of chemical barrier methods is expected to contribute to the worldwide control of this epidemic. Bovine beta-lactoglobulin modified by 3-hydroxyphthalic anhydride (3-hydroxyphthalovyl-beta-lactoglobulin [3HP-beta-LG]) was shown to inhibit HIV-1, HIV-2, simian immunodeficiency virus (SIV), herpes simplex virus type 1 and 2, and Chlamydia trachomatis infection in vitro. Here, we show that 3HP-beta-LG not formulated into any vehicle protected three of six rhesus monkeys against vaginal infection by SIV. Incorporation of the compound into an appropriate vehicle is expected to increase the degree of protection. 3HP-beta-LG may be effective as a vaginal inhibitor of HIV-1 infection in humans.

Design of a "microbicide" for prevention of sexually transmitted diseases using "inactive" pharmaceutical excipients

The human immunodeficiency virus (HIV-1) pandemic has been driven primarily by the sexual transmission of the virus, and facilitated by prior infections with other sexually transmitted disease (STD) pathogens. Although treatment of these STDs has been proposed as a means to decrease the rate of HIV-1 sexual transmission, preventive measures effective against both HIV-1 and other STD pathogens are expected to have a larger impact. These measures include topically applied mechanical and chemical (i.e. microbicidal) barriers. Microbicides of preference should have a broad specificity against diverse STD pathogens and a well established safety record, considering their repeated use over decades. Here, we report that cellulose acetate phthalate (CAP), an "inactive" pharmaceutical excipient, commonly used in the production of enteric tablets and capsules: (1) has antiviral activity against HIV-1 and several herpesviruses (HSV); and (2) when appropriately formulated, in micronized form, inactivates HIV-1, HSV-1, HSV-2, cytomegalovirus, Neisseria gonorrhoeae, Trichomonas vaginalis, Haemophilus ducreyi and Chlamydia trachomatis but does not affect Lactobacilli, components of the natural vaginal flora contributing to resistance against STDs. Thus, the CAP formulations meet the criteria for preferred microbicides and warrant further evaluation in vivo in humans.

3-Hydroxyphthaloyl beta-lactoglobulin. III. Antiviral activity against herpesviruses

The spread of sexually transmitted diseases, including human immunodeficiency virus type 1 (HIV-1) and herpesvirus infections, has continued unabated despite educational efforts spearheaded as a response to the HIV-1 epidemic. This suggests the need for prophylactic measures, including the application of topical antiviral agents. Chemical modification of bovine beta-lactoglobulin (beta-LG), the major protein of whey, by hydroxyphthalic anhydride (3HP) led to the generation of a potent HIV-1 inhibitor (designated 3HP-beta-LG) shown to also have activity against herpes simplex virus types 1 and 2 (HSV-1, HSV-2). This report provides more detailed results concerning the anti-herpesvirus activity of 3HP-beta-LG, indicating that this compound: (i) inhibited infection by human cytomegalovirus (HCMV), which is known to be sexually transmitted; (ii) inactivated the infectivity of both HSV-1 and HSV-2; (iii) inhibited cell-to-cell transmission of HSV-1 and HSV-2; and (iv) bound to HSV-1, HSV-2 and HCMV virus particles and partially inhibited the binding of anti-glycoprotein E (gE) and anti-gC monoclonal antibodies to HSV-1 and HSV-2. The binding of 3HP-beta-LG to the herpesviruses under study was inhibited by aggregated human IgG, suggesting that the respective viral Fc receptor is one of the target sites for 3HP-beta-LG. In agreement with results on inhibition of HIV-1 infection, 3HP-beta-LG appears to be the acid anhydride-modified protein of choice as an antiviral agent against herpesviruses.