Lactic acid (LA) accumulation in tumor microenvironments (TME) has been implicated in immune suppression and tumor progress. Diverse roles of LA have been elucidated, including microenvironmental pH regulation, signal transduction, post-translational modification, and metabolic remodeling. This review summarizes LA functions within TME, focusing on the effects on tumor cells, immune cells, and stromal cells. Reducing LA levels is a potential strategy to attack cancer, which inevitably affects the physiological functions of normal tissues. Alternatively, transporting LA into the mitochondria as an energy source for immune cells is intriguing. We underscore the significance of LA in both tumor biology and immunology, proposing the burning of LA as a potential therapeutic approach to enhance antitumor immune responses.
Humans ; Tumor Microenvironment/immunology* ; Neoplasms/therapy* ; Lactic Acid/immunology* ; Mitochondria/metabolism* ; Animals ; Signal Transduction

The Warburg effect, originally discovered by Otto Warburg, refers to the metabolic reprogramming of tumor cells from aerobic oxidation to glycolysis, enabling rapid energy production to support their growth and metastasis. This process is accompanied by the massive production and accumulation of lactate both intracellularly and extracellularly. The resulting acidic microenvironment impairs the normal physiological functions of immune cells and promotes tumor progression. An increasing number of studies indicate that lactate, a key metabolite in the tumor microenvironment (TME), acts as a pivotal immunosuppressive signaling molecule that modulates immune cell function. This review aims to comprehensively examine lactate's role as an immunosuppressive molecule in TME. It focuses on mechanisms such as membrane receptor binding, functional reshaping of immune cells via lactate shuttle transport, epigenetic regulation of gene expression through histone lactylation, and modulation of protein structure and function through nonhistone lactylation, emphasizing lactate's importance in immune regulation within the TME. Ultimately, this review offers novel insights into immunosuppressive therapies aimed at targeting lactate function.
Humans ; Neoplasms/metabolism* ; Tumor Microenvironment/immunology* ; Lactic Acid/immunology* ; Warburg Effect, Oncologic ; Animals ; Glycolysis ; Epigenesis, Genetic

Animals ; Antigens, Neoplasm ; chemistry ; immunology ; Cancer Vaccines ; chemistry ; therapeutic use ; Cell Line, Tumor ; CpG Islands ; Cytotoxicity, Immunologic ; Dendritic Cells ; immunology ; metabolism ; Humans ; In Vitro Techniques ; Lactic Acid ; chemistry ; Leukemia ; immunology ; therapy ; Lymphocytes ; cytology ; immunology ; Nanoparticles ; chemistry ; Peptides ; chemistry ; immunology ; therapeutic use ; Polyglycolic Acid ; chemistry ; Polylactic Acid-Polyglycolic Acid Copolymer ; WT1 Proteins ; chemistry ; immunology

OBJECTIVE: To examine the biocompatibility of polylactic/glycolic acid (PLGA) and Schwann cells. METHOD: Schwann cells were harvested from rat brachial and sciatic nerves. Schwann cells were cultured with PLGA, observed by phase-contrast microscopy and electron microscopy. RESULT: Schwann cells could attach and proliferate on the surface of the PLGA. CONCLUSION The PLGA has good cellular biocompatibility. It can be used as biomaterial for tissue engineering.
Animals ; Biocompatible Materials ; Cells, Cultured ; Lactic Acid ; Nerve Regeneration ; Polyesters ; Polyglycolic Acid ; Polymers ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; cytology ; immunology

OBJECTIVETo prepare (99m)Tc-labeled Anti-VEGF mAb 5-FU loaded polylactic acid nanoparticles ((99m)Tc-Ab-5-FU-NPs) and investigate its biodistribution in human gastric carcinoma xenografts.

METHODS(99m)Tc-Ab-5-FU-NPs were prepared by labeling Ab-5-FU-NPs with (99m)Tc using improved Schwarz method. After isolation of (99m)Tc-Ab-5-FU-NPs using SephadexG250 column, the labeling ratio and radiochemical purity were determined using chromatography. The immunocompetence of (99m)Tc- Ab-5-FU-NPs was detected by ELISA and immunohistochemistry. (99m)Tc-Ab-5-FU-NPs were then injected via the tail vein into SCID mice bearing human gastric carcinoma, and (99m)Tc labeled mice-derived monoclonal IgG loaded polylactic acid nanoparticles were used as the control, followed by radioimmunoscintigraphic imaging at 2 and 6 h. The radioactive count and radioactive ratio of the tumor and non-tumor tissue (T/NT) in the animal models were calculated using ROI technique. After imaging at 24 h, SCID mice were sacrificed and the radioactive distribution, the %ID/g, as well as the T/NT radioactive ratio were examined, respectively. The concentrations of 5-FU in the tumor and blood were also detected using HPLC method.

RESULTSThe labeling ratio of (99m)Tc-Ab-5-FU-NPs was 90%-95%. (99m)Tc-Ab-5-FU-NPs were detected in the tumor tissues by radioimmunoimaging 2 h after the injection. ID%/g in the tumor tissues at 2 and 6 h were both significantly higher than that of the control group. Both the ID%/g in tumor tissues and radioactive ratio of tumor and blood at 6 h were higher than those at 2 h, and the concentration of 5-FU in experimental group increased continuously with time and was significantly higher than that in control group.

CONCLUSIONS(99m)Tc-Ab-5-FU-NPs prepared in this study can meet the demands of radioimmunoimaging, and the anti-VEGF monoclonal antibody possesses reliable immune targeting ability. Six hours after injection, (99m)Tc-Ab-5-FU-NPs can specifically accumulate in the tumor tissues in human gastric carcinoma xenografts at high concentration.

Animals ; Antibodies, Monoclonal ; chemistry ; immunology ; Cell Line, Tumor ; Cell Transformation, Neoplastic ; Female ; Fluorouracil ; blood ; chemistry ; pharmacokinetics ; Humans ; Lactic Acid ; chemistry ; Male ; Mice ; Mice, SCID ; Nanoparticles ; Polyesters ; Polymers ; chemistry ; Radioimmunotherapy ; Stomach Neoplasms ; blood ; metabolism ; pathology ; radiotherapy ; Technetium ; chemistry ; Vascular Endothelial Growth Factor A ; immunology

In order to prove the feasibility of preparation of the drug-incorporated stent by immersing stent wires in the monoclonal antibody (mAb) solution, fluorescence stain and image analysis were used to evaluate the L-PLA-coated stent. Absorption was measured using a radioisotope technique after preparing the mAb-incorporated stent, and the absorption curve was determined from the absorption data. In an in vitro perfusion circuit, the antibody was eluted from the stent matrices, and the related influence factors were evaluated based on the release data.
Absorption ; Alloys ; chemistry ; Antibodies, Monoclonal ; chemistry ; immunology ; Drug-Eluting Stents ; Graft Occlusion, Vascular ; immunology ; prevention & control ; Humans ; Lactic Acid ; chemistry ; Platelet Aggregation Inhibitors ; chemistry ; immunology ; Platelet Glycoprotein GPIIb-IIIa Complex ; immunology ; Polymers ; analysis ; chemistry ; Time Factors

AIMTo investigate the level of immune response and the immune mechanism of the single-dose hepatitis B surface antigen (HBsAg)-poly (d, l)-lactide-co-glicolide acid (PLGA) microspheres in BALB/c mice.

METHODSThree kind of HBsAg-PLGA microspheres, HBsAg-PLGA50/50-COOH microspheres, HBsAg-PLGA75/25 microspheres and HBsAg-PLGA50/50 microspheres, were prepared by double emulsion microencapsulation technique used three kinds of PLGA with different L/G ratio. The single-dose of HBsAg-PLGA microspheres was subcutaneously injected into BALB/c mice at the dose of 7.5 microg HBsAg per mouse. The conventional aluminum-adjuvant vaccine was subcutaneously injected at 0, 1 and 2 month as positive control. In certain time interval, the induced immune level of total antibody was detected by enzyme linked immunosorbent assay (ELISA). For subclass of IgG antibody and cytokines studies, the dose of HBsAg was 2.5 microg per mouse.

RESULTSThe HBsAg-PLGA microspheres could successfully induce a humoral immune response in BALB/c mice. Compared with the conventional aluminum-adjuvant vaccine, the antibody response of the HBsAg-PLGA50/50-COOH microspheres was significantly lower than the group received three injections of aluminum-adjuvant vaccine (P < 0.01) except for a higher priming response during the early 6 weeks. The results were ascribed to the relatively rapid degradation charactics of PLGA50/50-COOH polymer. The immune response for the HBsAg-PLGA50/50 microspheres and HBsAg-PLGA75/25 microspheres were comparable to the group administered with aluminum-adjuvant vaccine (P > 0.05) which was due to the sustained degradation of PLGA50/50 and PLGA75/25 polymer.

CONCLUSIONThe HBsAg-PLGA microsphere is a promising candidate for the controlled delivery of a vaccine which does not require multiple injections.

Animals ; Delayed-Action Preparations ; Dose-Response Relationship, Immunologic ; Drug Carriers ; Female ; Hepatitis B Antibodies ; blood ; Hepatitis B Surface Antigens ; administration & dosage ; chemistry ; immunology ; Hepatitis B Vaccines ; administration & dosage ; immunology ; Immunization ; Immunoglobulin G ; blood ; Interferon-gamma ; metabolism ; Interleukin-2 ; metabolism ; Interleukin-5 ; metabolism ; Lactic Acid ; Mice ; Mice, Inbred BALB C ; Microspheres ; Polyglycolic Acid ; Polymers ; Random Allocation ; Rats ; Rats, Wistar

This study aimed at immobilizing the antibodies on the surfaces of the solid host membranes in order to improve the property of the biomaterial. The von Willebrand factor (vWf) antibodies were immobilized on the surface of Bombyx mori silk fibroin and PLA (Poly Lactic Acid) membrane by NH3 plasma treatment followed by covalent cross-linking reaction. The immobilization efficiency was evaluated by two methods including the antibody surplus and enzyme-linked immunosorbent assay (ELISA). The in vitro antithrombogenicity representing the activity of immobilized vWf antibody was determined by the method of Activated Partial Thromboplastin Time (APTT), Prothrombin Time (PT) and Thrombin Time (TT) test. The results demonstrate that the vWf antibodies are immobilized on silk fibroin and PLA membranes in an efficient way with the efficiency of antibody surplus up to 23.88% and ELISA reaction is positive. APTT and TT exceeded the upper limits distinctly, but the value of PT did not change noticeably. The in vitro antithrombogenicity represented the is activity-retaining form of antibodies. These results extend the application of antibody immobilization technique and provide a new idea about the design of biomaterials relating to the coagulation factors.
Antibodies ; chemistry ; Lactic Acid ; chemistry ; Polyesters ; Polymers ; chemistry ; von Willebrand Factor ; immunology

OBJECTIVETo investigate how antibodies influence the fermentation of Lactobacillus GG and how Lactobacillus GG influences the biological properties of antibodies during the fermentation and storage periods.

METHODSAnti-caries immune colostrum powder (IP) and control colostrum powder (CP), skimmed milk powder (SP) at concentrations of 1%, 2.5%, 5% and 10% (w/v) were added to MRS and 50 mM Hepes buffer system was used in the milk, the growth curves of Lactobacillus GG including viable cells, lactic acid concentratrion and pH, and also the titer of specific antibodies were determined during the fermentation and storage periods.

RESULTSIn MRS, SP could improve the growth of Lactobacillus GG in all periods of fermentation, especially at the concentrations of 5% and 10%. CP at the concentrations of 1% and 2.5% had a good initial velocity at the beginning and CP (1%, 2.5%, 5%, 10%) in all the groups could reach a high viable cell concentration at the end of fermentation, which suggested that there were some growth factors for Lactobacillus GG in CP overcoming the inhibition of unspecific antibodies. IP at 1%, 2.5%, 5% and 10% could inhibit the growth of Lactobacillus GG in all the fermentation periods, the critical concentration point was between 2.5%-5%, and there was a competition between growth factors and the inhibition of specific antibodies. In pasteurized milk, the influence of Hepes could help the fermentation start quickly and reach the log phase earlier than in the control group; however, when combined with 5% IP, the growth of Lactobacillus GG was strongly inhibited during all the fermentation periods. The fermentation of Lactobacillus GG had no significant effect on the titer change of anti-caries antibodies during the fermentation and storage periods.

CONCLUSIONSP and CP is beneficial to the growth of Lactobacillus GG in MRS, whereas there is a competition between growth factors and the inhibition of specific antibodies to the growth of Lactobacillus GG, the critical concentration of IP is 2.5%-5%. Hepes could influence the titer of antibodies through buffering Ph, thus influence the fermentation of Lactobacillus GG. The fermentation of Lactobacillus GG with IP or CP could be used for the development of functionally fermented immune milk in the future.

Animals ; Antibodies, Bacterial ; immunology ; Antibody Specificity ; Cattle ; Colostrum ; immunology ; Fermentation ; Lactic Acid ; analysis ; Lactobacillus ; growth & development ; immunology ; Milk ; immunology ; microbiology ; Probiotics