Related Experiment Video
Updated: Aug 10, 2026
Rapid Quantification of Mitogen-induced Blastogenesis in T Lymphocytes for Identifying Immunomodulatory Drugs
Published on: December 27, 2016
Effect of recombinant human interferon-alpha in vitro and in vivo on mitogen-induced lymphocyte blastogenesis in cats
1Scott-Ritchey Research Program, College of Veterinary Medicine, Auburn University, AL 36849.
Insights
Recombinant human interferon-alpha (rHuIFN-alpha) affects feline lymphocyte blastogenesis differently based on dose. High doses suppress responses, while lower doses enhance them, suggesting dose-dependent immunomodulatory effects in cats.
Area of Science:
- Immunology
- Virology
- Pharmacology
Background:
- Interferons (IFNs) are crucial cytokines in antiviral and immune responses.
- Recombinant human interferon-alpha (rHuIFN-alpha) has therapeutic applications.
- The immunomodulatory effects of rHuIFN-alpha on feline lymphocytes require detailed investigation.
Purpose of the Study:
- To evaluate the in vitro and in vivo effects of rHuIFN-alpha on mitogen-induced lymphocyte blastogenesis in cats.
- To determine the dose-dependent immunomodulatory actions of rHuIFN-alpha on feline immune cells.
Main Methods:
- Feline peripheral blood lymphocytes (PBL) were incubated with varying doses of rHuIFN-alpha in vitro.
- Lymphocyte blastogenesis was assessed by [methyl-3H] thymidine incorporation in response to concanavalin A (Con A) and pokeweed mitogen (PWM).
- Cats were inoculated intramuscularly with different doses of rHuIFN-alpha, and lymphocyte responses were measured before and after treatment.
Main Results:
- In vitro, high doses of rHuIFN-alpha (10(4)-10(3) U) significantly suppressed Con A and PWM-induced blastogenesis.
- In vitro, lower doses of rHuIFN-alpha resulted in decreased DNA synthesis in the absence of mitogens, independent of cytotoxicity.
- In vivo, a high dose (10(6) U/kg) of rHuIFN-alpha suppressed Con A responses, while moderate (10(4) U/kg) and low (10(2) U/kg) doses enhanced Con A-induced blastogenesis.
Conclusions:
- Very high parenteral doses of rHuIFN-alpha may suppress certain T-cell responses in cats.
- Lower doses of rHuIFN-alpha can exhibit immunoenhancing effects on feline lymphocyte blastogenesis.
- These findings highlight the dose-dependent immunomodulatory potential of rHuIFN-alpha in a feline model.
Abstract:
The effect of recombinant human interferon-alpha (rHuIFN-alpha) in vitro and in vivo on mitogen-induced lymphocyte blastogenesis was evaluated in specific-pathogen-free cats. Pre-incubation of isolated feline peripheral blood lymphocytes (PBL) in vitro with either 10(4) or 10(3) International Units (U) of rHuIFN-alpha for 24 h significantly suppressed (P less than 0.001 and 0.01, respectively) blastogenic responses to the phytomitogens concanavalin A (Con A) and pokeweed mitogen (PWM). Lower doses of IFN (range, 10-10(-3) U/ml) neither suppressed nor enhanced mitogenesis. In the absence of phytomitogens, incubation of PBL with 10(4) - 10(2) U (P less than 0.001) or 10 U (P less than 0.05) of rHuIFN-alpha/ml resulted in a significant decrease in incorporation of [methyl-3H] thymidine into newly synthesized cellular DNA. Cultures of PBL exposed continuously for 4 days to rHuIFN-alpha doses of 10(4) U/ml or less did not demonstrate specific reductions in cell viability, indicating that the observed antiproliferative actions of IFN apparently were independent of any direct cytotoxic effects. To investigate the dose-response effects of rHuIFN-alpha in vivo on lymphocyte blastogenesis, individual groups of cats were evaluated on 3 consecutive days before and then 24 h after each cat was inoculated intramuscularly with either a high dose (10(6) U/kg), moderate dose (10(4) U/kg), or a relatively low dose (10(2) U/kg) of rHuIFN-alpha. Cats inoculated with 10(6) U of rHuIFN-alpha/kg had significantly reduced (P = 0.037) blastogenic responses to Con a at 24 h postinoculation compared to preinoculation values; mean PWM responses were also decreased, but this effect was not statistically significant. In contrast, inoculation of cats with either 10(4) or 10(2) U of rHuIFN-alpha/kg significantly enhanced (P = 0.05 or 0.008, respectively) Con A-induced blastogenesis and had no discernible effect on PWM responses. These findings suggest that very high doses of rHuIFN-alpha given parenterally may be associated with suppression of certain T-cell responses in cats; conversely, much lower doses may be immunoenhancing.
