[Heat-shock protein enhances immunogenicity of E7 oncoprotein of human papillomavirus included in chimeric construction (E7 HPV-HSP70)].

AIM: To study the effect of chimeric E7 protein of human papillomavirus type 18 on activation of adaptive immunity in absence of adjuvant. MATERIALS AND METHODS: Chimeric protein was genetically engineered and represents the protein molecule consisting of full-size E7 oncoprotein and heat-shock protein 70 (HSP70) of Mycobacterium tuberculosis in one polypeptide chain. Antibody titers as well as isotypes and subisotypes of immunoglobulins were measured by ELISA in sera of immunized animals. RESULTS: It was shown that studied construction E7 (HPV-18)-HSP70 significantly increases titers of antibodies to E7 protein of HPV type 18 and have cross-reactive antigenic activity with E7 protein of HPV type 16. Immunization with chimeric protein resulted in increase of IgG1 and IgG2b levels and decrease of IgG2a and IgM levels. CONCLUSION: . Oncoprotein E7 included in chimeric construction with HSP70 could be used for further studies on development of therapeutic vaccine for treatment of cervical cancer and precancerous lesions. Skew of immune response to Th2 type after intraperitoneal administration of the studied construction points to necessity for control of immunity during such studies.

[Recombinant heat-shock protein (rHSP70) boosts activation of innate and adaptive immunity during simultaneous administration with bacterial antigens in experiment].

Experimental study of adjuvant effect of recombinant mycobacterial heat-shock protein rHSP70 on immune response to antigens of opportunistic microorganisms was performed. Therapeutic poly-component vaccine Immunovac-VP-4, containing ligands for binding with Toll-like receptors (TLRs) 2, 4 and 9, was used as a source of bacterial antigens. Obtained data showed that administration of rHSP70 mixed with bacterial antigens of opportunistic microorganisms leads to maturation of mice dendritic cells obtained from bone marrow precursors, increased expression of TLRs 2, 4, 9 on their surface and production of cytokines IL-1beta, IL-6, IL-10, TNFalpha, as well as to activation of innate immunity in experiments in vivo resulting to increased resistance of mice to experimental Salmonella infection. Simultaneous administration of rHSP70 with bacterial antigens increased titers of antibodies to vaccine's antigenic components in direct hemagglutination reaction. Thus, adjuvant effect of rHSP70 was confirmed on the used model as well as increase of stimulation of innate and adaptive immunity was shown.

[Effect of recombinant heat-shock protein (rHSP70) of Mycobacterium tuberculosis on immunogenicity of Haemophilus influenzae type B capsular polysaccharide].

AIM: To study effect of recombinant heat-shock protein (rHSP70) of Mycobacterium tuberculosis on immunogenicity of Haemophilus influenzae type b capsular polysaccharide (CPSHib). MATERIALS AND METHODS: Capsular polysaccharide was obtained by precipitation with cetavlon, antibody titers and Toll-like receptors (TLRs) were detected by enzyme immunoassay and flow cytometry respectively. RESULTS: rHSP70 modified immune response to chemically conjugated and unconjugated CPSHib. rHSP70 enhanced expression of TLRs 2, 4, 9 on mice splenocytes; increased levels of CD3+, CD8+, NK, CD3/NK (NKT) lymphocytes. Levels of CD4+, CD25+ (markers of early activation of T-helpers) as well as MHC class II molecules were increased that could be appraised as a shift from T-independent to T-dependent immune response. Difference in antibody titers after 2- or 3-dose immunization of mice with 5 mcg/dose of CPSHib in mixture or conjugated with rHSP70 was not revealed. Level of antibodies to rHSP70 in serum samples of mice immunized with CPSHib conjugated with rHSP70 was 6.55 - 8.4 times higher compared to unimmunized animals. Antibodies, which have common antigenic epitopes to human organs and tissues, were not detected. CONCLUSION: rHSP70 modifies immune response to CPSHib.