Transfer factor: a murine model

Effect of splenic transfer factor on the development of intestinal mucosal barrier in laying hens

BACKGROUND

The aim of this study was to investigate the effects of different doses of chicken spleen transfer factor (TF) on the structure of intestinal epithelial cells in different age groups. One-day-old White Leghorns laying hens were randomly divided into four groups: three groups were administered TF at different dosages (0.10, 0.25 or 1.00 mL) and a fourth group was set as control (administered saline, 1.00 mL). Using hematoxylin and eosin staining, high-throughput sequencing, microbiota analysis, quantitative polymerase reaction and western blotting.

RESULTS

We measured the effects of different doses of TF on the following: intestinal mucosal epithelial tissue morphology, intestinal mucosal epithelial barrier-related gene expression profiles, and intestinal epithelial tight junction gene protein levels. The collected data show that TF can improve the absorption of nutrients by increasing villus height and crypt depth, and regulate intestinal flora disorders. Furthermore, we verified that the expression of the claudin and occludin tight junctions between intestinal epithelial cells was increased with TF. this research is very important for focusing on the structure and gene expression of intestinal tissues.

CONCLUSION

The results provide a scientific rationale for feeding and nutrition programs for green and healthy farming, as well as technical support to improve the production efficiency of the livestock and poultry breeding industry. © 2022 Society of Chemical Industry.

A low-molecular-weight dialysable leukocyte extract selectively enhances development of CD4⁺RORγt⁺ T cells and IL-17 production

A low-molecular-weight (under 10 kDa) dialysable leukocyte extract (called transfer factor, TF) has been shown to be a prospective substance to improve or modulate immune response in autoimmunity, inflammation, infectious diseases or cancers. However, the use of TF has been limited by the absence of any data on the mechanism of its action. Here we show that TF prepared from peripheral blood leukocytes of healthy human donors displays multiple regulatory effects on individual parameters of the immune system. TF decreases proliferation of T and B lymphocytes and partially alters the production of cytokines and nitric oxide by activated macrophages. TF also inhibits production of T helper 1 (Th1) cytokines interleukin 2 (IL-2) and interferon γ, slightly stimulates production of Th2 cytokine IL-10 and considerably enhances the secretion of IL-17 by activated mouse spleen T cells. At the molecular level, TF enhances expression of genes for transcription factor RORγt and for IL-17. The enhanced expression of the RORgt gene corresponds with an increase in the number of RORγt⁺CD4⁺ Th17 cells and with enhanced IL-17 production. In contrast, the expression of the Foxp3 gene and the proportion of CD4⁺CD25⁺Foxp3⁺ regulatory T cells are not significantly changed in the presence of TF. These results suggest that the activation of pro-inflammatory Th17 cells, which have multiple immunoregulatory properties, could be the main mechanism of the immunomodulatory action of a low-molecular-weight leukocyte extract.

Effect of Brucella abortus transfer factor in preventing murine brucellosis

Mice vaccinated with a protein extract of attenuated Brucella abortus strain 19 had increased resistance to infection with virulent B. abortus strain 2308 and had increased antibody responses to strain 2308. However, resistance to infection and antibody responses were not increased when nonvaccinated recipient mice were given transfer factor preparations that were obtained from either vaccinated donor mice or strain 2308-infected donor mice. Vaccination of mice with the strain 19 extract plus treatment with each transfer factor preparation also did not further increase resistance to infection or antibody responses when compared with mice that received the vaccine alone. These results suggest that transfer factor from mice that have either vaccine-induced protective immunity to B. abortus or active B. abortus infections does not enhance antibody responses and resistance to infection with B. abortus.

Protection against lethal Venezuelan equine encephalitis (VEE) virus infection by cell-free supernatant obtained from immune spleen cells

Considerable effort has been directed at unraveling the mechanisms underlying protection and recovery in acute viral infections. Various factors, including antibody, interferon, lymphokines and certain lymphocyte and macrophage cell constituents, have been shown to play a role in host recovery. We have previously studied an adoptive transfer system in experimental VEE virus CNS infection in a mouse model, and shown that both T cells and B cells exert an influence in protecting the host from lethal CNS infection with this virus. Because of the complexity involved in the adoptive transfer of protection, we sought a simpler and more easily defined experimental approach to dissect the various factors responsible for protection in our model. We here report that immune cell-free supernatant, derived from mice immunized with vaccine against VEE virus, exerts as much protection as the whole cell transfer system against lethal VEE virus infection. Such cell-free supernatant allowed us to look more closely at individual host immune factors in their relationship to protection against infection. Studies herein reported demonstrate that the protection conferred by immune cell-free supernatants is not dependent on neutralizing antibody or interferon, but rather appears to be related to the presence of both interleukin-1 and -2 and the activation and potentiation of NK cell activity against VEE virus.

Separate transfer of mouse protection and delayed-type hypersensitivity with Salmonella typhimurium transfer factor

Delayed-type hypersensitivity (DTH) induced with Salmonella typhimurium transfer factor (TF) contributed to an increase in mean survival days of mice challenged with homologous organisms and afforded only a low level of host protection as determined by survival rate, compared with that obtained by active immunization. TF of other enteric bacteria could transfer DTH which is cross-reactive to salmonella antigen but did not afford host protection. Although TF of Listeria monocytogenes did not transfer the cross-reactive DTH, it could confer the significant increase in mean survival days against the lethal challenge with S. typhimurium. Listerial ribosomal vaccine conferred the high level of mouse protection without inducing DTH to salmonella antigen. The resistance generated upon active immunization with listerial ribosomal vaccine could be enhanced by the injection of S. typhimurium TF to the same level as that obtained after immunization with homologous ribosomal vaccine. Among salmonella TF, there could be no cross-reactive immunity between S. typhimurium and S. choleraesuis, although the cross-reactive DTH was observed. The DTH transfer ability of TF was sensitive to Pronase which could not affect the ability to transfer host immunity, but RNase could abolish the ability to transfer host immunity without impairing DTH transfer activity. These results suggest that in mouse typhoid infection, DTH is not associated with host protection as determined by survival rate.

In vitro effect of murine-derived transfer factor on Salmonella-specific rosette formation

The splenic lymphocytes from Salmonella-immune ICR Swiss or C3H/HeJ mice formed greater than 0.2% antigen-specific rosettes with sheep erythrocytes coated with a spent-medium protein antigen of Salmonella typhimurium. These rosette-forming lymphocytes were found to be sensitive to the effects of antithymocyte serum plus complement. Transfer factor prepared from the Salmonella-immune splenic lymphocytes of ICR Swiss mice was active in sensitizing nonimmune ICR Swiss or C3H/HeJ lymphocytes to form greater than or equal to 0.2% rosettes with salmonella antigen-coated sheep erythrocytes. These rosettes were also sensitive to antithymocyte serum and complement. Few rosettes were formed between the transfer factor-treated lymphocytes and sheep erythrocytes coated with a Listeria protein antigen. A nonimmune dialysate preparation was inactive in sensitizing nonimmune lymphocytes, as indicated by a lack of rosette formation. Neither the immune transfer factor nor the nonimmune dialysate had any enhancing or abrogating effect upon rosette formation by splenic lymphocytes from Salmonella-immune mice. The enumeration of antigen-specific rosettes may be a useful means of assaying for transfer factor activity.

Transfer of Salmonella resistance and delayed hypersensitivity with murine-derived transfer factor

Protective host immunity and delayed hypersensitivity were transferred to nonimmune ICR and C3H/HeJ mice with transfer factor prepared from the splenic lymphocytes of ICR Swiss mice immune to Salmonella typhimurium. Only mice injected with the "immune" dialysate exhibited significant footpad swelling (P less than 0.01) to a spent medium antigen of S. typhimurium, but not Listeria monocytogenes. Host survival to a lethal Salmonella challenge infection was seen only in transfer factor-injected mice. Also, these challenged animals had fewer numbers of bacteria present in their spleens (P less than 0.01) than did challenged mice previously injected with either control dialysates or commercial endotoxin. Neither the Salmonella antigens nor endotoxin present in the sterile transfer factor preparation was responsible for the transfer of host protection and delayed hypersensitivity, since none of the control dialysates resulted in any positive responses when injected into either the ICR Swiss or endotoxin-resistant C3H/HeJ mice.

The immunology of mycobacterial infections

Mycobacteria are endowed with substances that profoundly affect the immune system. Leprosy and tuberculosis exemplify broad spectra of useful and detrimental immune responses of mycobacterial infections that range from intense potentiation to severe specific adn nonspecific suppression of humoral and cellular immune elements. The cellular hypersensitivity induced by mycobacteria serves as a classical model for the analysis of specific and nonspecific immune mechanisms. Mycobacterial disease are prevalent worldwide and rank among the most important bacterial diseases. The kaleidoscope of immunologic events induced by injected mycobacteria and during infections will be reviewed from the standpoint of pathogenesis, pathology, in vitro and in vivo effects on cellular and humoral arms of the immune response, diagnosis, classification, potentiation and suppression.