Microbial heat shock protein 70 stimulatory properties have different TLR requirements.
Members of the HSP70 family have acquired special significance in immunity. Among other receptors, toll like receptor (TLR)-2 and TLR-4 have been suggested to be involved in HSP70-mediated signalling. We have previously shown that recombinant HSP70 from Trypanosoma cruzi and from Plasmodium falciparum function as adjuvants. In the present study, we have extended the study with other microbial HSPs (mHSPs) and considered of interest to assess the influence of TLR-2 and TLR-4 in mHSP-promoted responses. To test this, we evaluated the adjuvant effect of various mHSP molecules in TLR-2(-/-), TLR-4(-/-) and MyD88(-/-) mice. We show that all the mHSPs tested are strong adjuvants and induced IL-12 production by bone marrow macrophages. However, even within the same family, mHSPs induced different types of immune responses. Furthermore, the mHSPs tested, possess different requirements for signaling through TLRs. Interestingly, Tc70 was found to induce in vivo and in vitro responses in both TLR-2(-/-) and TLR-4(-/-) mice. Possible implications of our findings are taken up in the discussion section.
Qazi
Khaleda Rahman
KR
Department of Immunology, Stockholm University, S-10691 Stockholm, Sweden.
Oehlmann
Wulf
W
Singh
Mahavir
M
López
Manuel Carlos
MC
Fernández
Carmen
C
D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology / Q000494:pharmacology*; D007892:Leishmania braziliensis; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009169:Mycobacterium tuberculosis; D053594:Myeloid Differentiation Factor 88 / Q000172:deficiency / Q000276:immunology; D010047:Ovalbumin / Q000276:immunology / Q000494:pharmacology; D015398:Signal Transduction / Q000276:immunology; D051195:Toll-Like Receptor 2 / Q000172:deficiency / Q000276:immunology*; D051197:Toll-Like Receptor 4 / Q000172:deficiency / Q000276:immunology*; D014349:Trypanosoma cruzi
D000276:Adjuvants, Immunologic; D018840:HSP70 Heat-Shock Proteins; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D010047:Ovalbumin